Sugarcane: Physiology, Biochemistry, and Functional Biology (Moore/Sugarcane) || Sugarcane: The Crop, the Plant, and Domestication

Chapter 1

Sugarcane: The Crop, the Plant,and Domestication

Paul H. Moore, Andrew H. Paterson, and Thomas Tew

SUMMARY

Sugarcane, a significant component of the econ-omy of many countries in the tropics and sub-tropics, is a large, tropical grass that stores sucrosein its stem and serves as an important food andbioenergy crop. It has long been recognized as oneof the world’s most efficient crops in convertingsolar energy into chemical energy harvestable assucrose and biomass. Current taxonomy dividessugarcane into six species, two of which are wildand always recognized (Saccharum spontaneum L.and Saccharum robustum Brandes and Jewiet exGrassl). The other species are cultivated and clas-sified variously. Of the four domesticated speciesof sugarcane, S. officinarum L. was the first namedand is the primary species for production ofsugar. Recent genomic data for evaluating geneticdiversity within Saccharum suggest relationshipsamong accessions that may ultimately producea definitive classification for the group. Culti-vated sugarcanes of today are complex interspe-cific hybrids primarily between Saccharum offici-narum, known as the noble cane, and Saccharumspontaneum, with contributions from S. robustum,S. sinense, S. barberi, and related grass genera suchas Miscanthus, Narenga, and Erianthus. Under-standing the source and range of diversity of sug-arcane species and cultivars can enable breedersin the development of new varieties improved forhigh productivity with low inputs and wide adap-tation to varied environments.

INTRODUCTION

Sugarcane is an important food and bioenergysource and a significant component of the econ-omy of many countries in the tropics and sub-tropics. The economic value of sugarcane isbased primarily on three attributes: it is highlyproductive; it efficiently uses agricultural inputs(water, fertilizers, pesticides, labor); and it canbe locally processed into added-value products–sugar, molasses, ethanol, and energy–all amenableto storage and transport. Collectively, these cropattributes contribute to making sugarcane a pri-mary trade commodity of those countries where itis grown.

Sugarcanes are generally large, perennial, trop-ical or subtropical grasses that evolved underconditions of high sunlight, high temperatures,and large quantities of water. Sugarcane is thusadapted to a climatic zone around the worldbetween 35o north and south of the equator (Blume1985). Because sugarcane can be used as a tradecommodity, it is produced by nearly 100 coun-tries over an area of 23.8 million hectares (FAO-STAT 2009), which is approximately 1.5% of thetotal world cropland area (Table 1.1). The landarea devoted to sugarcane is small compared tothat for the three major cereal crops, which col-lectively occupy 34.6% of the world’s cropland.On the basis of the relatively small area undercultivation, sugarcane can be considered a special-ity crop, but of all food crops, sugarcane has the

Sugarcane: Physiology, Biochemistry, and Functional Biology, First Edition. Edited by Paul H. Moore and Frederik C. Botha.

C© 2014 John Wiley & Sons, Inc. Published 2014 by John Wiley & Sons, Inc.

1

2 Sugarcane: Physiology, Biochemistry, and Functional Biology

Table 1.1 Crop production and daily caloric consumption of the world’s most cultivated food crops.

Productiona Rank by tonnage Consumptiona Rank by calories Areaa Fraction ofCrop (Mt) produced (kcal/capita/day) consumed (Mha) cropland (%)

Sugarcane 1661 1 152 3 23.8 1.5Maize 819 2 139 4 158.6 10.2Wheat 685 3 530 2 225.6 14.4Rice 685 4 533 1 158.3 10.0Potatoes 330 5 59 7 18.7 1.2Cassava 234 6 43 9 18.9 1.2Sugar beet 227 7 76 6 4.3 0.3Soybeans 223 8 105 5 99.5 6.4Oil palm kernel 210 9 50 8 14.9 1.0Tomatoes 153 10 9.2 12 4.4 0.3Barley 152 11 6.5 13 54.0 3.5Sweet potatoes 102 12 22 10 8.2 0.5Watermelons 98 13 — — 3.4 0.2Bananas 97 14 19 11 4.9 0.3

Total 2798 b1562 51.1

aFAO 2009.bWorld’s total cropland. Data uploaded by Viridiplantae from FAOstat (24 January 2009).Mt, megatonnes (metric tons × 106); Mha, megahectare (ha × 106).

highest level of production (1661 megatonnes) fol-lowed by the cereals (maize, wheat, and rice), theroot or tuber crops (potatoes and cassava), and theoil crops (soybeans and palm kernel) (Table 1.1).The high level of production recorded for sug-arcane could be misleading because the reportedproductivity is the total harvested biomass andonly a fraction of this (approximately 25+percent)is dry matter, whereas the dry matter percentof grain and tuber crops is much higher. Nev-ertheless, the sugarcane crop provides the thirdhighest quantity of human consumed plant calo-ries (152 kcal/capita/day) following rice (533 kcal)and wheat (530 kcal). These production statisticsemphasize the very much higher productivity ofsugarcane compared to other food crops and raisequestions about the physiological bases for howthis productivity is achieved and how it might besustained or improved.

SINGULAR PROPERTIES OF THE GENUSSACCHARUM AND ITS MEMBERS

Taxonomy

Sugarcane is the common name given to a group ofcultivated, sucrose-storing, large tropical grassesthat have been classified variously depending on

the criteria employed and the taxonomic conven-tion of the time. The original classification of cul-tivated sugarcane as Saccharum officinarum L. byLinnaeus in 1753 established the genus Saccha-rum L. for sugarcane. However, the genus Saccha-rum was subsequently expanded to include manyaccessions that, with the exception of inflorescenceand floral morphologies, have little in commonwith sugarcane. For example, a search of the Inte-grated Taxonomic Information System (ITIS)database (http://www.itis.gov) lists 23 species ofSaccharum, seven of which are no longer acceptedand five of which are currently listed as a speciesof wild or domesticated sugarcane. The moreextensive Kew GrassBase database (http://www.kew.org/data/grasses-db.html) lists 37 speciesof Saccharum, only four of which are currentlyaccepted as species of sugarcane. Current sugar-cane literature recognizes six species of Saccha-rum, two of which are wild and always recognized(Saccharum spontaneum L. and Saccharum robus-tum Brandes and Jewiet ex Grassl). The otherspecies are cultivated. This review is restricted toonly those Saccharum species generally recognizedas sugarcane.

Sugarcane species are members of the sub-tribe Saccharinae, tribe Andropogoneae, of thegrass family, Poaceae or Gramineae. The grass

Sugarcane: The Crop, the Plant, and Domestication 3

family is large, including approximately 10,000species classified into 600 to 700 genera. Thetribe Andropogoneae contains 85 genera and960 species (Clayton & Renvoize 1986 as citedby Spangler et al. 1999), many of which havehigh economic value, including the C4 cropsSaccharum officinarum L. (sugarcane), Sorghumbicolor (L.) Moench (sorghum), and Zea maysL. (maize). Miscanthus Anderss. is an additionalC4 grass that shows considerable potential as agermplasm source for cold tolerance (Clifton-Brown & Lewandowski 2000), as a biomass cropfor renewable energy production, and as raw mate-rial for the cellulose and paper industries (Bullardet al. 1995; Dohleman et al. 2009).

Classical taxonomy based on cytologicaland morphological characters has been usedto describe probable evolutionary relationshipswithin Saccharinae, and recently molecular datahave allowed for more definitive relationships.Spangler et al. (1999) used chloroplast DNAmarkers to show broad relationships among theAndropogoneae and probable polyphyletic originsof Sorghum, Miscanthus, and Saccharum (Fig. 1.1).Hodkinson et al. (2002) used DNA sequences of anuclear ribosomal gene and two plastid sequencesto confirm the polyphyletic origin of Miscanthusand Saccharum and to distinguish between them.The other members of the subtribe Saccharinaecould not be completely resolved with such lim-ited data.

The present compilation of Saccharum speciesdoes not have a stable history. The first editionof Species Plantarum (Linnaeus 1753) listed twospecies of Saccharum: S. officinarum and S. spi-catum. Subsequent taxonomic treatments up tothe time of revision by Jeswiet in 1927 listed upto 22 species of Saccharum (discussed in Irvine1999 and presented as Table 8 in Daniels & Roach1987). Jeswiet (1927) reassigned many of thoseadded species to different genera and went onto describe four natural groups consisting of S.spontaneum L., S. sinense (Roxb) Jesw., S. barberiJesw., and S. officinarum L. to be included in Sac-charum L. Subsequently, two forms of Saccharumdiscovered in New Guinea (S. robustum Brandes& Jeswiet ex Grassl. [Grassl 1946] and S. eduleHassk. [Whalen 1991]) were added to the genus tobring the number of widely recognized species of

Mbp/1C=2n=Sorghum bicolorP

anso

rghu

mP

aras

orgh

um

Sac

char

inae

Eus

orgh

umH

eter

osor

ghum

Sorghum halepense

Sorghum propinquum

Sorghum nitidum

Vacoparis macrospermum

Vacoparis laxiflorum

Sarga angustum

Sarga intrans

Sarga leiocladum

Sarga plumosum

Sarga purpureo-sericeum

Sarga timorense

Sarga trichocladum

Sarga versicolor

Cleistachne

Miscanthus sinensis

Miscanthus x. giganteus

Miscanthus sacchariflorus

M. sacchariflorus ‘Robustus’

Microstegium nudum

Saccharum spontaneum

Saccharum cultivars

Zea mays 20

Saccharum officinarum

Saccharum robustum 60-170

70-140

100-130

36-128

38

76

57

38

10, 20

?

10

10

10

10

10

40

40

40

20

20

20 736

?

690

4307

1014

1220

1813

1117

2254

3748

2048

622

?

1592, 3268

2824-3786

3916-4576

2234-2867

4183

2300

30

Fig. 1.1. Phylogenetic relationship of selected members ofthe Saccharinae clade. Phylogenetic interpretation from Span-gler et al. (1999). Genome size estimates from Arumuganathan& Earle (1991), Bennett & Leitch (2003), and Price et al.(2005).

sugarcane to six. Two of them (S. spontaneum andS. robustum) are wild and always recognized; theremaining four (S. barberi, S. edule, S. officinarum,and S. sinense) are cultivated forms and have beenaccorded the status of species, but because theydo not survive in the wild, there is an increasingtrend to consider these as cultigens (Irvine 1999;Grivet et al. 2004, 2006).

The identification and delineation of thosespecies grouped as sugarcane have been compli-cated by hybridizations, both natural and man-made, among themselves and with related species.Many members of the interbreeding group havedifferent genome structures that produce inter-mediate forms, and some of those intermediateforms have totally new genome structure due to


different types of chromosome transmission. Widehybridization has resulted in a mixture of sug-arcane euploids and aneuploids. Layered on topof this genetic complexity are the selection pres-sures applied by nature and man to drive dif-ferent population structures. Cultivars of sugar-cane are hybrids of different species of the genusSaccharum and may include germplasm from thenine related genera, Imperata, Eriochrysis, Eccol-ipus, Spodiopogon, Miscanthidium, Erianthus sect.Ripidium, Miscanthus, Sclerostachya, and Narenga,which are included in the subtribe Saccharinae(Clayton 1972, 1973).

Mukherjee (1954) revised the genus Saccha-rum based on phytogeographical data, morphol-ogy, cytology, and breeding evidence to combinethe genus with three other Saccharinae gen-era (Erianthus sect. Ripidium, Sclerostachya, andNarenga) into an informal taxonomic group hecalled the “Saccharum complex.” Later, Danielset al. (1975) added the genus Miscanthus to theSaccharum complex because it was consideredthat Miscanthus also contributed to the originof Saccharum. Although the Saccharum complexconcept has proven useful in guiding sugarcanebreeders toward utilizing the species within itas part of the gene pool available for sugarcaneimprovement, recent molecular data raise seriousdoubts about some of the earlier proposed originsand genetic relationships of the Saccharum species(Irvine 1999; Grivet et al. 2004, 2006).

The morphological differences among themembers of the Saccharum complex are mostlyrelated to floral characters but also include somevegetative structure characters such as the num-ber of rows of nodal root primordia, axillary buddevelopment, and presence or absence of a leafdewlap (Table 1.2). A significant difference amongmembers of the Saccharum complex is the levelof sucrose accumulation in the stems of Saccha-rum spp., ranging from very low levels in the wildSaccharum species S. spontaneum and S. robus-tum to high levels in the domesticated species S.officinarum, S. sinense, and S. barberi (Table 1.3).Sugarcane species designation has been based onchromosome numbers, floral characters, sugar andfiber content, and stalk diameter. However, thefree intercrossing among the species, the stronginfluence of environment on the quantitative phe-notypic characters, and the wide overlap of mea-sured values do not always allow for clear speciesdifferentiation. More recently, molecular cytoge-netics and genomics have revealed evolutionaryrelationships among the Saccharum species thatare more definitive.

Of the four cultivated groups of Saccharum, S.officinarum L. (2n = 80) was the first named andis the primary group for production of sugar. S.officinarum accessions have thick stalks with lowfiber and high sucrose contents (Table 1.2). Sac-charum barberi Jeswiet (2n = 82–124) in India andSaccharum sinense Roxb. (2n = 88) in China have

Table 1.2 Morphological differences at the generic level between members of the Saccharum complex as described byMukherjee (1954) and revised by Daniels et al. (1975).

Character Saccharum Erianthus Sclerostachya Narenga Miscanthus

Root eyes 2 or more rows Only 1 row ifpresent

Absent Absent 1 or 2 rows ifpresent

Bud Well developed,reproductive

Scaly, except in 2species

Absent Scaly, notreproductive

Well developed,reproductive

Dewlap Present Absent Present Present PresentSpikelet pair Sessile and

pedicellateSessile and

pedicellateBoth pedicellate Sessile and

pedicellateSessile and

pedicellateCallus hairs ≥ 2–3 times length

of spikelet∼ same as spikelet ∼ 0.5 length of

spikelet≤ length of spikelet 0.5–2 times length

of spikelet

Source: Modified from Amalraj & Balasundaram [2006].Note: Mukherjee revised the genus Saccharum and noted three species (Erianthus, Sclerostachya, and Narenga) that are closelyrelated and interbreeding with sugarcane. He grouped these three species with Saccharum, referring to the group as theSaccharum complex (1954), to indicate a large breeding pool involved in the origin of sugarcane (1957). Daniels et al. (1975)added Miscanthus to the Saccharum complex postulating it also contributed to the origin of sugarcane.


Table 1.3 Principal characteristics of six species of Saccharum and Erianthus with the number of accessions in two of theworld collections.

Germplasm No.accessions

Species (chromosomenumber)

Commonname

Sucrosecontent(% f.wt)

Fibercontent(% f. wt)

Stemdiameter(cm.) Adaptability USa Indiab

S. officinarum Noble High Low Thick Tropical 748 764(2n = 80) (1825) (5–15) 2.8 ±

0.30S. sinense Chinese Medium High Medium Tropical 61 29

(2n = 110–120) (12–15) (10–15) (1.4–2.2) and subtropicalS. barberi Indian Medium High Medium Tropical 57 43

(2n = 81–124) (13–17) (10–15) (1.7–2.1) and subtropicalS. spontaneum Wild Very low Very high Slender Tropical/through 635 598

(2n = 40–128) (1–4) (25–40) (05–0.9) temperateS. robustum Wild Low Very high Medium Tropical 128 145

(2n = 60–194, usually 80) (3–7) (20–35) (1.1–1.7) wetlandsS. edule Edible Low Low Medium Tropical 22 16

(2n = 60, 80, up to 122) (3–8) ? (1.1–1.8)Erianthusc Related Very low Very high Slender Subtropical and 282

(2n = 20, 30, 40, 60) temperate

Note: Sucrose, fiber, and stem diameter values are either the range or the mean ± SD measured by the Sugarcane BreedingInstitute, Coimbatore, India, reported in the germplasm catalogs: Sugarcane Genetic Resources I. Saccharum spontaneum L.(1983); II. Saccharum barberi, Jeswiet; Saccharum sinense, Roxb. amend Jeswiet; Saccharum robustum, Brandes et Jeswiet exGrassl; Saccharum edule, Hassk (1985); III. Saccharum officinarum L. (1991).aSaccharum germplasm inventory maintained by the USDA, ARS, Miami, Florida; data from http://www.ars-grin.gov NationalPlant Germplasm System (GRIN) of the USDA/ARS web site 3-30-2010.bGermplasm inventory maintained by the Sugarcane Breeding Institute, Coimbatore, India; data from http://sugarcane-breeding.tn.nic.in/genresources.htm 3-30-2010 and the germplasm catalogs “Sugarcane Genetic Resources Vols. I, II, III.”cErianthus germplasm, classified in GRIN as Saccharum spp. (arundinaceum, bengalense, gigantium, brevibarbe, etc.) is main-tained at several germplasm repositories.

been cultivated since prehistoric times, but areseldom, if ever, cultivated today; they exist pri-marily in germplasm or garden collections. Thesetwo species are sometimes grouped together as asingle species, or as historical cultigens, havingthin to medium stalks, low to moderate sucrosecontent, and higher fiber and greater tolerance tostress than does S. officinarum. The fourth domes-ticated species, Saccharum edule Hassk. (2n =60 or 80 sometimes up to 122), has an abortedand edible inflorescence and is cultivated fromNew Guinea to Fiji as a vegetable. Based onits geographical distribution and vegetative mor-phology, S. edule was proposed to be an inter-generic hybrid between either S. officinarum or S.robustum and a related genus, or to be a mutantof either of these Saccharum species (Daniels &Roach 1987; Roach & Daniels 1987). However,molecular data now indicate that S. edule may bea series of mutant clones selected from S. robus-

tum populations and preserved by humans (Grivetet al. 2006).

Among the wild species, S. spontaneum (2n =40–128, with chromosome numbers frequently asmultiples of eight) is highly variable in morphol-ogy, cytology, and geographic distribution broadlythroughout tropical and subtropical regions fromAfrica to the Middle East, China, and Malaysia,through the Pacific to New Guinea. S. sponta-neum accessions exhibit phenotypic, cytological,and cytoplasmic and nuclear DNA sequences thatare quite different from those of the other Sac-charum species. It is a perennial grass, from shortbushy types with no stalk, to large-stemmed clonesover 5 m in height, but typically with pencil-thinstalks and very low sucrose content (Table 1.2). Itis free tillering with robust rhizomes and has con-tributed toward the development of modern cul-tivars by conferring resistance to most major dis-eases, providing vigor and hardiness for increased


abiotic stress tolerance (such as cold and drought),increasing tillering, and improving ratoonability(Panje 1971).

The other wild species of Saccharum, S. robus-tum, (two cytotypes predominate as 2n = 60 or80, but with some accessions having chromosomenumbers as high as 194) has its center of diversityin New Guinea in the same region as the domes-ticated S. officinarum (2n = 80). S. robustum hasthick stalks and low sucrose content. It is dis-tinguished from S. spontaneum, but similar to S.officinarum, by its lack of rhizomes, thickness andheight of stalks, and larger inflorescences.

Recent genomic data for evaluating geneticdiversity within Saccharum suggest relationshipsamong accessions that may ultimately produce adefinitive classification for the genus. The firstmolecular evidence came from restriction frag-ment patterns of nuclear ribosomal DNA that wereused to separate accessions of S. spontaneum, whichshowed the widest within-species variation, fromaccessions of S. robustum, S. officinarum, S. barberi,and S. sinense (Glaszmann et al. 1990). Restrictionfragment length polymorphism (RFLP) analysesof the mitochondrial genome showed an identicalpattern among 18 S. officinarum clones and 15 of 17S. robustum clones (D’Hont et al. 1993). RFLP pat-terns were similar among S. officinarum, S. barberi,S. sinense, and S. edule, all of which were distinc-tively different from S. spontaneum. Restrictionpatterns of the chloroplast genome suggested that,except for S. spontaneum, the Saccharum species allhave the same chloroplast restriction sites (Sobralet al. 1994). RFLP analyses of nuclear genomicDNA confirmed observations about the cytoplas-mic genomes that suggested distinctively greaterdiversity within S. spontaneum than within thefour other species (Burnquist et al. 1992; Lu et al.1994a, b; Nair et al. 1999). More recent genomicin situ hybridization (GISH) analysis supportsthe hypothesis that S. barberi and S. sinense werederived from interspecific hybridization betweenS. officinarum and S. spontaneum (D’Hont et al.2002). These authors concluded that genetic sim-ilarities between S. barberi and S. sinense acces-sions do not support the taxonomic separationof these two groups into separate species. The

species S. barberi is not listed in the Kew databaseGrassBase (http://www.kew.org/data/grasses-db.html) but is included as S. sinense.

Genome structure of modern cultivars

Modern cultivars are highly polyploid and ane-uploid with around 120 chromosomes. They arederived from interspecific hybridization betweenS. officinarum and S. spontaneum. As a conse-quence of the different basic chromosome num-bers of S. officinarum (x = 10) and S. spontaneum(x = 8), two distinct chromosome organizationscoexist in modern cultivars. (See the section titled“Breeding through nobilization to produce nobi-lized cultivars” for details on chromosome inher-itance in these wide species hybrids.) GISH oftotal genomic DNA suggests that 10 to 20% ofmodern cultivars chromosomes are inherited intheir entirety from S. spontaneum; 70 to 80% areinherited entirely from S. officinarum; and around10% are the result of recombination between chro-mosomes from the two ancestral species (D’Hontet al. 1996; Cuadrado et al. 2004; Piperidis, G.et al. 2010).

Cultivated sugarcane is rare among majorcrops in being an interspecific aneuploid. Theoccurrence of chromosomal segment exchangesbetween S. officinarum and S. spontaneum chro-mosomes is supported by both fluorescence insitu hybridization (FISH) (D’Hont et al. 1996)and by genetic mapping (Grivet et al. 1996; Hoa-rau et al. 2001) and disproves the prior assump-tion (Price 1963, 1965; Berding & Roach 1987)that no recombination occurs between the chro-mosomes of the two species. Collectively, thesedata were used to propose a schematic representa-tion (Fig. 1.2) of the genomic organization of mod-ern sugarcane cultivars genomes (D’Hont 2005).Sugarcane’s polyploid nature and interspecific ori-gin contribute substantially to high levels of het-erozygosity detected among modern cultivars (Luet al. 1994b; Jannoo et al. 1999a; D’Hont et al.1996; Lima et al. 2002). On the other hand, therecent origin of modern sugarcane cultivars froma small germplasm base results in strong linkagedisequilibrium with some haplotypes conserved in


S. spontaneum

S. officinarum recombinants

Fig. 1.2. Schematic of the genome of a typical modern sug-arcane cultivar. Each bar represents a chromosome; openboxes represent regions originating from S. officinarum andshaded boxes regions originating from S. spontaneum. Chro-mosomes aligned in the same row are hom(oe)ologous andrepresent a homology group (HG). Chromosomes assembledvertically correspond to monoploid genomes (MG) of S. offic-inarum and S. spontaneum. The key characteristics of thisgenome are the high level of ploidy, the aneuploidy, the bis-pecific origin of the chromosomes, the existence of structuraldifferences between chromosomes of the two origins, and thepresence of interspecific chromosome recombinants. Modi-fied from D’Hont (2005). Reproduced with permission fromGenetics Society of America.

segments extending for at least 10 cM (Jannoo et al.1999b), far greater than in most other crops.

SECONDARY AND TERTIARY GENEPOOLS, GERMPLASM RESOURCES

Related genera

Saccharum, Erianthus sect. Ripidium, Sclerostachya(2n = 30), Narenga (2n = 30), and Miscanthus(2n = 38 and 40) were added into the “Saccha-rum complex” as a closely related interbreeding

group (Mukherjee 1957; Daniels et al. 1975). Eri-anthus sect. Ripidium includes chromosome num-bers of 2n = 20, 30, 40, and 60 with a basic chro-mosome set of x = 10, the same basic numberas favored for Saccharum (Whalen 1991). Thisgroup of related genera has a number of traitsdesired by sugarcane breeders for improving cul-tivar performance, including a wide environmen-tal distribution due to their tolerance of cold anddrought, vigor, good ratooning, and disease resis-tance (Berding & Roach 1987).

Sugarcane breeders have long tried to introgressagronomic characteristics of Miscanthus and Eri-anthus arundinaceus into sugarcane hybrids. How-ever, it has been difficult to produce fertileprogeny and to identify true hybrids involvingE. arundinaceus on the basis of morphologicalcharacters (Grassl 1965). Molecular diagnostictools including species-specific DNA markers andGISH have been used in attempts to identify Sac-charum x Erianthus hybrids at the seedling stageand to follow the introgressed genes into later gen-erations (D’Hont et al. 1995; Alix et al. 1998, 1999;Piperidis et al. 2000). GISH allowed analysis of thechromosome complement of intergeneric hybridsinvolving Erianthus and Miscanthus (D’Hont et al.1995) and revealed that chromosome eliminationoccurs in Saccharum x E. arundinaceus hybrids(D’Hont et al. 1995; Piperidis et al. 2000).

GISH revealed a high contrast between thechromosomes of the two genera in Saccharum xE. arundinaceus hybrids as compared to those ofS. officinarum x S. spontaneum hybrids. BecauseGISH is based on the presence of species-specificrepeated sequences that evolved quickly duringspeciation, the greater contrast between Saccha-rum and Erianthus could reflect a greater geneticdistance between these two genera than mightbe expected based on morphological character-istics. This difference in chromosome structuremay explain the occurrence of chromosome elimi-nation and the difficulties encountered by breedersattempting to exploit Erianthus. Several Erianthusand Miscanthus specific repeated sequences werecloned. Their distribution on the chromosomeswas analyzed by FISH and revealed two subtelom-eric families (Alix et al. 1998), one centromeric


family, and one family apparently dispersed alongthe genome (Alix et al. 1999).

More recently, AFLP markers clearly identi-fied hybrids between S. officinarum or sugarcanecultivars and Erianthus rockii (Aitken et al. 2006).Both crosses produced progeny all showing n + ninheritance. All of the progeny from the S. offic-inarum cross were hybrids but only 10% of theprogeny from the sugarcane cultivars were hybridsof E. rockii. The remaining 90% were identifiedas selfs.

Germplasm resources

Sugarcane breeders have long realized that a large,diverse germplasm collection is essential for sus-tained crop improvement. At least 31 separatecollecting expeditions across the complete naturaldistribution of Saccharum species were made from1892 through 1985 to collect genotypes focusingon those that were resistant to pests and diseases,were highly productive, or had high sugar con-tent (Berding & Roach 1987). Clones from thesecollections have been deposited in the two worldcollections, one maintained in India and one in theUnited States. These collections serve as geneticreservoirs to be used in breeding new cultivarsfor specific agronomic needs and to broaden thegenetic base of commercially grown cultivars. Thereported number of accessions for each species inthe World Collection of Sugarcane and RelatedGrasses located at the India and U.S. sites is listedin Table 1.3.

Passport and descriptor information

Passport data, including taxonomic designationand information about where an accession was col-lected, and phenotypic descriptor data are avail-able from the Germplasm Resources Informa-tion Network (GRIN) database maintained bythe National Plant Germplasm System (NPGS)of the USDA at http://www.ars-grin.gov/cgi-bin/npgs/html/crop.pl?101. The 102 descriptorsare classified into eight categories, with the largestcategories being morphology (69 descriptors) anddisease reactions (19). These data are useful forclassification of accessions, but they are subject to

environmental influences and most have a signifi-cant genotype × environment interaction.

Phenotypic evaluation

Phenotypic evaluation of germplasm in the collec-tions is a lengthy and costly process of examiningaccessions for traits of significance; however, itadds tremendous value to the collections.

Clones of S. sinense, S. barberi, and S. robus-tum were evaluated for agronomic and qualitycharacters and to estimate the genetic diversitywithin and between the populations. Thirty clonesof each species were evaluated in two environ-ments for eight phenotypic characteristics. Sig-nificant differences were found among the threespecies as well as for clones within species. Thegenetic repeatability for every character, exceptstalk number, was high, indicating that this infor-mation would be useful for breeders interested inusing the material in commercial crosses (Brownet al. 2002). Additional phenotypic evaluationis in progress to characterize this germplasmfor quality-related characteristics (sucrose, starch,etc.) and to estimate its tolerance to environmentalstresses (freezing temperatures, diseases, etc.).

Core collections

The potential usefulness of establishing core col-lections of Saccharum species has been analyzed inboth the India and United States world collections.With the exceptions of S. spontaneum and S. offic-inarum, the numbers of accessions of species thathave been characterized are so few that Tai andMiller (2001) considered the entire United Statescollection of those limited species to function ascores. Workers in India analyzed their collectionsof both S. spontaneum and S. officinarum, whileworkers in the United States limited their analysisto their collection of S. spontaneum. In the UnitedStates, Tai and Miller (2001) evaluated 11 meth-ods using 11 quantitative traits to estimate thenumber of randomly selected accessions neededfor a representative core to be approximately 75.Although the authors did not suggest any one coreas the best, they did list members of the core basedon cluster analysis within each geographic region


based on retained principal components for mor-phological traits and random selection of entrieswithin each cluster. Workers in India analyzed aset of 21 qualitative and 10 quantitative descrip-tors on 617 accessions of S. spontaneum and foundmost characters would be represented in a core sizeof about 60 randomly sampled accessions (Amal-raj et al. 2006). In a separate study, workers inIndia analyzed a set of 27 qualitative morpho-logical descriptors for computing the Shannon-Weaver diversity index and a list of 10 quantita-tive descriptors for principal component analysisof 690 accessions of S. officinarum to find a coreoptimum of about 164 accessions (Balakrishnanet al. 2000). Reports from both world collectionsemphasized the smaller diversity in S. officinarumthan in S. spontaneum. Although the potential forestablishing core collections of Saccharum has beenshown in both world collections, both collectionscontinue to be preserved in their entirety.

EVOLUTION AND IMPROVEMENT OFSUGARCANES

The origin of sugarcane

Sugarcane prehistory apparently occurred across avast area of Southeast Asia, including the MalayanArchipelago, New Guinea, India, and some of theisland groups of Melanesia. The preponderanceof evidence indicates that domestication of sugar-cane probably occurred in New Guinea with theselection of S. officinarum from the wild species S.robustum (Brandes 1956; Daniels & Roach 1987;Grivet et al. 2006). Hypotheses about possiblecontributions to sugarcane of genera other thanSaccharum, specifically Erianthus, Sclerostachya,Narenga, and Miscanthus (Barber 1920; Jeswiet1930; Parthasarathy 1948; Brandes 1956; Mukher-jee 1957), were based on cytology and breedingevidence, morphology, and overlapping geograph-ical distribution. These hypotheses were reviewedin Daniels & Roach (1987), who produced thesynopsis supporting the scenario developed byBrandes (1956), which has been supplemented bymolecular data (Grivet et al. 2004, 2006) and ispresented as Figure 1.3.

Cultivated sugarcanes of today are complexinterspecific hybrids primarily between Saccha-rum officinarum, known as the noble cane, andSaccharum spontaneum with contributions from S.robustum, S. sinense, and S. barberi. Early author-ities hypothesized additional contributions fromrelated grasses of the Saccharum complex (Bran-des 1956; Daniels & Roach 1987; Roach & Daniels1987; Sreenivasan et al. 1987), but such proposalsare not supported by the limited molecular evi-dence available (Irvine 1999; Grivet et al. 2004;Grivet et al. 2006). Based on vegetative charactersand native distribution, the species S. officinarum,with high sucrose content, is believed to have beenderived from S. robustum in New Guinea (Bran-des 1956, 1958). It has been postulated (Brandes1956) and widely accepted from various evidence(Daniels & Roach 1987; Roach & Daniels 1987)that S. officinarum spread during prehistoric timesfrom New Guinea to Indonesia, the Malay Penin-sula, China, India, Micronesia, and Polynesia, andby 500 AD, from Indonesia to southern Arabiaand east Africa. As detailed below, S. barberi andS. sinense were likely derived from interspecifichybridization between S. officinarum and S. spon-taneum (Grivet et al. 2004, 2006) and possibleintrogression from other species (Brown et al.2007). The distribution of S. officinarum fromPolynesia to Hawaii probably took place withnative migrations around 500–1000 AD.

Origins of S. barberi and S. sinense

Sugarcanes indigenous to North India and Chinaand cultivated from prehistoric times are referredto as S. barberi (2n = 81–124) and S. sinense(2n = 110–120), respectively. S. sinense cultivatedin China and Pansahi India was used for chewing aswell as for sugar production, whereas the thinner,harder stalks of S. barberi cultivated in northernIndia may have been primarily for crushing. Thetwo cultivated sugarcanes were probably the resultof natural hybrids of S. officinarum and S. sponta-neum with other genera about 1000 BCE. S. bar-beri subsequently spread from India to the MiddleEast, the Mediterranean, and to the New Worldbeginning with the second voyage of Columbus in1493. Today, S. sinense and S. barberi exist only in


M. (less sect. Diandra) = E. Asia & Pacific(x = 19, 2n = 38, 57, 76, 95, 114)M. sect. Diandra = Himalayas to S. China (x = ?, 2n = 40)Miscanthidium Stapf = Africa(x = 7, 2n = 28,30)

E.. (less sect. Ripidium) = new world (x = 2n = 30, 34 -38, 60)

E.. (sect. Ripidium) = old world (x = 10, 2n = 20, 30, 40, 60)

S. spontaneum(x = 8, 2n = 40 - 128)

?

S. sinense(2n = 116 to 120)

S. barberi(2n = 81 to 124)

Modern hybrid cultivars (2n = 100 to 130)

Several Million Years Several Thousand Years

Cultivated

Wild

=

Miscanthus

S. officinarum = noble (x = 10, 2n = 80)S. edule = vegetable(x = 10, 2n = 60 to 122)

Erianthus

S. robustum = fiber for fencing(x = 10, 2n = 60 or 80 + up to ca 200)

Ancient hybrids

Fig. 1.3. Hypothetical pathway for sugarcane evolution and domestication based on molecular data indicating only membersof the Saccharum clade contributed directly to sugarcane cultivars through allopatric speciation of S. spontaneum west ofSulawesi and S. robustum east of Sulawesi (Grivet et al. 2006). Miscanthus and Erianthus, previously proposed as contributingto sugarcane, are recognized as sharing common ancestors. Following Saccharum speciation, S. robustum in New Guineacontributed to cultivars of S. officinarum for sugar, S. edule for vegetables, and S. robustum for fencing and construction.S. officinarum was moved by humans from the tropics to more temperate India and China where it hybridized to native S.spontaneum, giving rise to S. barberi and S. sinense as locally adapted sugarcane cultigens. Chromosome numbers are froma compilation by Daniels and Roach (1987). Strongest evidence for the evolution and domestication are indicated with solidlines; weaker evidence is indicated with dashed lines. Modified after Grivet et al. (2006) and D’Hont et al. (2008).

collections (Stevenson 1965; Blume 1985; Heinzet al. 1994).

Leading hypotheses on the origins of S. bar-beri and S. sinense (reviewed by Daniels & Daniels1975; Paton et al. 1978; Daniels & Roach 1987;Roach & Daniels 1987; D’Hont et al. 2002; Grivetet al. 2004, 2006) are that (1) S. barberi andS. sinense arose from hybridization of S. offici-narum with S. spontaneum in India and China,(2) S. barberi was developed from S. sinense inIndia, and (3) S. barberi and S. sinense arosethrough introgression between S. officinarum, S.spontaneum, or other genera such as Erianthus

and Miscanthus (Brown et al. 2007). Artschwa-ger and Brandes (1958) and Whalen (1991) con-sidered S. barberi to be a horticultural vari-ant of S. sinense, as does the Kew databaseGrassBase (http://www.kew.org/data/grasses-db.html) even though it lists 37 species in thegenus Saccharum.

The hypotheses about the origins of S. sinenseand S. barberi were tested by GISH performedusing total genomic DNA from S. spontaneum andS. officinarum as probes on chromosome prepara-tions of genotypes representative of S. barberi andS. sinense. In all clones analyzed, GISH clearly


identified two distinct populations of chromo-somes or chromosome fragments, thus revealingthe interspecific origin of S. barberi and S. sinense(D’Hont et al. 2002). GISH showed no genomicregions lacking color, nor was there a third colorpattern that would have been the case if a thirdspecies were involved, especially if it belonged toanother genus. For example, GISH performed onintergeneric hybrids between S. officinarum x Eri-anthus or S. officinarum x Miscanthus showed thattotal genomic DNA of one genus gave a very weakhybridization signal on the other genus (D’Hontet al. 1995; Piperidis et al. 2000; and unpublishedresults of these workers). These results are corrob-orated by the absence of Erianthus or Miscanthusgenus specific sequences in S. barberi and S. sinenseon Southern hybridization patterns (Alix et al.1998, 1999). These results, together with cyto-plasmic (D’Hont et al. 1993) and nuclear molec-ular marker analyses (Glaszmann et al. 1990; Luet al. 1994a), are in agreement with the hypoth-esis that S. barberi and S. sinense originated fromhybridizations between S. officinarum (female) andS. spontaneum (male).

The proportion of chromosomes from the twospecies was variable in the clones studied with61% S. officinarum: 39% S. spontaneum for 2n =82 clones, 68%: 32% for a clone with 2n = 91,and 66%: 33% for a clone with 2n = 116. From0 to 4 chromosomes per cell appeared to resultfrom interspecific intrachromosomal exchanges(D’Hont et al. 2002). Considering the frequencyof such exchanges in modern cultivars, this indi-cates that a very small number of meiotic eventsmust have occurred since interspecific hybridiza-tion. Further RFLP analyses indicated that the S.barberi and S. sinense clones are clustered into a fewgroups, each derived from a single interspecifichybrid that has subsequently undergone somaticmutations. These groups correspond quite wellwith those already defined based on morphologicalcharacters and chromosome numbers (reviewedby Daniels et al. 1991). However, the calculatedgenetic similarities do not support the existenceof two distinct taxa. The “North Indian” and“Chinese” sugarcanes thus represent a set of hor-ticultural groups rather than established species(D’Hont et al. 2002).

Cultivated noble canes for sugarproduction

As mentioned above, sugarcane culture spreadfrom India to the Middle East, Mediterranean,and to the New World in 1493, well before Lin-naeus established classification in 1753 and beforethe discovery of “noble” canes in the islands ofthe South Seas. The first of the noble canesleft Tahiti with Bougainville in 1768, eventu-ally arriving in the Caribbean in 1789 (Deerr1921, 1949; Machado et al. 1987). The sugar-cane that spread across the Mediterranean tothe New World was the Indian cultivar known‘Creole’ in French, ‘Criola’ in Spanish, or‘Crioula’ in Portuguese.

‘Creole’ was quickly replaced in cultivation bythe noble cultivar ‘Otaheite’ when Bligh broughtit to Jamaica from Tahiti in 1793 (Machado et al.1987). From there it was distributed throughoutthe Caribbean and the Americas. Original noblecanes collected from the Pacific Islands quicklyreplaced the less productive Indian varieties andwere the only source of cultivars for plantations forthe world’s sugar production for over a hundredyears. Before sugarcane breeding programs werestarted in 1888, the most important noble culti-vars were the ‘Otaheite’ (‘Bourbon’, ‘Lahaina’) ofTahiti, ‘Cheribon’ (‘Louisiana Purple’) of Java,and ‘Caledonia’ of New Hebrides. ‘Bourbon’ wasextremely susceptible to root rot, mosaic, andgumming disease; ‘Cheribon’ to sereh, mosaic, androot rot; and Caledonia to mosaic (Edgerton 1958;Stevenson 1965). These initial cultivars werereplaced by new hybrids selected from emergingsugarcane breeding programs (Fig. 1.4). Today,clones of S. officinarum are in breeding collectionsand/or cultivated as garden canes for chewing.

The first sugarcane breeding programs beganin Java and Barbados in 1888, following the obser-vations independently in Java (1858) and Barba-dos (1859) that sugarcane was capable of pro-ducing viable seed (Stevenson 1965; Kennedy& Rao 2000). Varieties produced by the Proef-station Oost Java, identified as POJ varieties,became foundational for germplasm developmentin other countries, which soon established theirown breeding stations to produce locally adapted

Co 312S. hyb: 2n=118

Co 281S. hyb: 2n=120

Co 244S. hyb: 2n=120

POJ 2364S. hyb: 2n=148

Co 221S. hyb: 2n=1??

Co 213S. hyb: 2n=118

Co 285S. hyb: 2n=112

Black CheribonS. off: 2n=80

ChunneeS. barb: 2n=91-92

POJ 213S. hyb: 2n=124-128

Kaludai BoothanS. off: 2n=80

Unknown IndiaS. spont: 2n=64

Banjermasin HitamS. off: 2n=80

LoethersS. hyb: 2n=99

M2S. hyb: 2n=??

Rose BambooS. off: 2n=80

UnknownS. off: 2n=80

KansarS. barb: 2n=92

POJ 100S. hyb: 2n=89

Unknown JavaS. off: 2n=80

Unknown JavaS. spont 2n=112

KassoerS. hyb 2n=136

Ashy MauritiusS. off: 2n=80

Unknown IndiaS. pont: 2n=64

Co 206S. hyb: 2n=112

Striped MauritiusS. off: 2n=80

Unknown IndiaS. off: 2n=80

Green SportS. off: 2n=80

Unknown IndiaS. spont: 2n=64

HYBRIDIZATIONSpecies

AccessionsModern Cultivars

Early Cultivars

D 74S. hyb: 2n=80

EK 28S. off hyb: 2n=80

POJ 2878S. hyb: 2n=120

Co 290S. hyb: 2n=118

VellaiS. Off: 2n=80 Co 205

S. hyb: 2n=112

Unknown IndiaS. spont 2n=64

Fig. 1.4. Sugarcane hybrid foundations. Accessions of Saccharum species and the early crosses among them serve as thefoundation for all modern cultivars of sugarcane. The early selections from crosses by Proefstation Oost Java are named as aseries of POJ cultivars and those conducted in Coimbatore, India, are named as a series of Co cultivars. The accessions of S.officinarum (2n = 80), S. spontaneum (2n = 64–112), and S. Barberi (2n = 92) were named where discovered and served asthe original sugarcane cultivars. Early generation crosses among S. officinarum produced a new series of S. officinarum hybrids(S. off hyb: 2n = 80), or when a different species was crossed to S. officinarum the lines produced are Saccharum hybrids (S.hyb: 2n = 112-148). Courtesy of Genetics Society of America.


varieties. Notable among the early sugarcanebreeding efforts for producing varieties with wideadaptation was Coimbatore, India (1912), thatdeveloped Co and NCo varieties (Fig. 1.3). Inthe sugarcane breeding history that follows, wedescribe these changes in four stages: (1) breed-ing among noble canes (S. officinarum) to producenoble cultivars; (2) breeding through nobilization,i.e., interspecific hybridization with backcross-ing to noble cultivars to produce nobilized cul-tivars; (3) breeding of nobilized canes to producehybrid cultivars; and (4) breeding to broaden thegenetic base.

Interbreeding of S. officinarum toproduce noble cultivars

Progenies of open-pollinated noble canes wereselected for sugar production. Each selectedseedling was assigned a call sign followed witha seedling number. ‘Otaheite’ (‘Lahaina’, ‘Bour-bon’) produced the EK seedlings in Java, ‘H109’ inHawaii, and ‘B716’ in Barbados. In Queensland,Australia, ‘Q813’ came from Badila, the famouschewing cane that originated in New Guinea.These selected noble cultivars were important forsugar production in the early 1900s. The origi-nal noble canes and selected noble progenies werefound susceptible to disease and insects and lim-ited to particular tropical environments. Breederssoon realized that the genetic base of the noblecanes needed to be broadened to improve theiradaptabilities and disease and insect resistance(Stevenson 1965).

Breeding through nobilization to producehybrid cultivars

Nobilization is the pollination of noble cane S.officinarum with its wild relative S. spontaneumfollowed by repeated backcrosses to noble canes.The wild relatives were considered “nobilized”through the breeding process and the selectedhybrid progenies are referred to as “nobilizedcanes” (Bremer 1961). A key event of early nobi-lization breeding was the production of the nobi-lized cultivar ‘POJ2878’ in 1921 (Fig. 1.3), whichbecame the most universal breeding cane ever

developed, found in the pedigrees of almost allof the dominant cane varieties grown around theworld.

The first step of the nobilization processinvolved “doubling” of the S. officinarum gameticchromosome number to the somatic chromosomenumber in the fertilized egg with the additionof the gametic chromosome number of the wildclones of S. spontaneum used as males. The mech-anism to explain maternal transmission of diploidchromosome numbers seems to involve the fusionof daughter nuclei after the second meiotic divi-sion in the innermost megaspore dyad cell ofS. officinarum (Narayanaswami 1940). However,doubling also occurs in crosses involving thespecies S. sinense as shown by Price (1957) andeven modern cultivars (Piperidis, N. et al. 2010).Subsequent steps in nobilization involved back-crossing the F1 to another noble cane, where therecould be a second doubling of maternal chromo-somes, and then crossing the F2 once again to anoble cane, at which time normal n + n transmis-sion seems to be the norm.

More than 90% of the accessions classified asS. officinarum have 2n = 80, x = 10 chromosomeswhereas the most frequent chromosome numberin S. spontaneum is 2n = 64, x = 8 (Panje &Babu 1960; Irvine 1999). Using these two chromo-some complements as an example, one can envi-sion nobilization in the simplified crossing schemewhere NN = noble, 2n = 80; SS = spontaneum,2n = 64 (Table 1.4).

Progeny of F1 and BC1 have the nonreducedsomatic complement (2n) of the female parentsplus the gametic number (n) of the male. Mostcultivated nobilized canes (BC2s, BC3s, etc.) have100–130 chromosomes with about 5–10% from S.spontaneum (Fig. 1.1). Clones with chromosomenumbers outside of this range are rarely suited forcommercial production.

Following efforts to achieve interspecificcrosses between S. officinarum and S. spontaneum,early sugarcane breeders realized that resultantF1 progeny were distinctively more robust thaneither parent. When S. officinarum clones wereused as the female parent, progeny tended to belarger stalked, higher in sucrose levels, and gen-erally more vigorous than when S. spontaneum


Table 1.4 Nobilization crossing scheme showing the numbers and origin of chromosomes in each progeny generation (F1,BC1, and BC2) and the percentage of progeny chromosomes that are of S. spontaneum origin.

ProgenyFemale X Male → chromosomes (2n) (% Spontaneum)

NN(80) X SS(64) → F1 (80+32=112) S = 29% (100 × 32/112)NN(80) X F1(112) → BC1 (80 + 56 = 136) S = 12% (100 × 16/136)NN(80) X B1(136) → BC2 (40 + 68 = 108) S = 7% (100 × 8/108)

NN = noble, S. officinarum 2n = 80; SS = wild, S. spontaneum, 2n = 64.

clones were used as the female parent. Reciprocaldifferences in vigor were eventually explained bythe cytological phenomenon of a high frequencyof “2n + n” progeny in S. officinarum (female) ×S. spontaneum (male) crosses (Bremer 1923).

In Coimbatore, India, nobilization of S. barberiand S. spontaneum with S. officinarum producedthe famous early nobilized trispecies hybrids of“Co” seedlings (Fig. 1.4) that gained wide accep-tance in subtropical regions in India, South Africa,Australia, Louisiana, Argentina, and Brazil. The“Co” cultivars also were used on the poorer soilsand under marginal growth conditions in thetropics.

The brief period (1920–1930) of nobilizationbreeding was followed by a longer period (fromthen up to today) of crossing among nobilized linesto produce hybrid cultivars and introgression ofspecific traits into the hybrid cultivars (Stevenson1965; Simmonds 1976; Ethirajan 1987).

Breeding of nobilized canes to producehybrid cultivars

Crosses among nobilized canes in the 1930sproduced many important hybrid cultivars forsugar production in the next three decades (Fig.1.4). Breeding of ‘POJ2878’ with other nobi-lized POJ canes produced cultivars ‘POJ3016’ and‘POJ3067’. Together they occupied more than85% of the cane area of Java in 1960. Cross-ing of ‘Co312’ and ‘POJ2878’ produced Hawaii’smost important cultivar, ‘H32–8560’, which wasresponsible for 65% of the cane area of Hawaii in1945. ‘POJ2878’ x ‘Co290’ produced ‘Co419’ forthe tropical area of India. The cross of ‘Co421’x ‘Co312’ was made in Coimbatore in 1938 toproduce progeny of the cross that was grown in

Natal, South Africa, in the same year. One of theprogeny selected in 1939, ‘NCo310’, became themost important cultivar of the world in the 1950sand 1960s (Anonymous 1945; Nuss & Brett 1995).Even as late as the 1980s, ‘NCo310’ still rankedfirst in growing area in Japan, Texas (US), andUruguay; second in Malawi and Gabon; third inMexico; and fourth in Ecuador (Tew 1987).

Commercial cultivars and hybrids fromadvanced stages of selection have been the mainbreeding materials for the development of cur-rent cultivars since the 1950s. The names of thecurrent cultivars, rank in percent of area occu-pied, immediate parents, and breeding stations ofthe world are listed in the Sugar Cane VarietyNotes (Machado 2001), the Sugarcane Varieties(Machado 2002), and the World Sugarcane Vari-ety Census–Year 2000 (Tew 2003).

Breeding to broaden the genetic base

Modern cultivars are essentially derivatives of nomore than 15–20 nobilized cultivars that in turntrace back to the initial nobilized genetic basedeveloped in Java and India (Roach 1989). Geneticdiversity in today’s advanced breeding popula-tions is expected to be somewhat narrower thanthat in the initial germplasm following more than100 years of directional selection (Walker 1987).Attempts to increase this narrow base, called thebase broadening program (BB-program), werestarted in Barbados in 1965 using clones differentfrom those initially used in Java and India. TheBB-program started with nobilization crosses fol-lowed by hybridization of nobilized canes. TheBB-program has produced many semicommercialtype clones that have been incorporated into thegene pool of advanced breeding populations since


the late 1980s (Kennedy & Rao 2000). Other coun-tries have tried BB-programs over the past 50 yearsby crossing wild canes with their commercial cul-tivars. However, none of these efforts was as longterm or as broad based as the BB-program of Bar-bados and Louisiana.

Our inability to trace or follow the incorporatedgermplasm into the germplasm of the advancedbreeding population through visual selection isperhaps the main reason for failure of base broad-ening programs. Large favorable genetic variationexists among clones of Saccharum species (Tai &Miller 2002). What is missing is a breeding tool toassist breeders in incorporating useful genes fromany source into the gene pool of the advancedcultivars. Recent developments in biotechnologyare beginning to yield information and technolo-gies that undoubtedly will help the breeders tobroaden the gene pool of their advanced breedingpopulations and produce higher yielding cultivarsin the future.

REFERENCES

Aitken, K., Li, J., Wang, L., et al. (2006) Characterizationof intergeneric hybrids of Erianthus rockii and Saccharumusing molecular markers. Genetic Resources and Crop Evolo-lution, 54, 1395–1405.

Alix, K., Baurens, F.C., Paulet, F., et al. (1998) Isolation andcharacterization of a satellite DNA family in the Saccharumcomplex. Genome, 41, 854–864.

Alix, K., Paulet, F., Glaszmann, J.C., et al. (1999) Inter-Alulike species-specific sequences in the Saccharum complex.Theoretical and Applied Genetics, 6, 962–968.

Anonymous. (1945) A newly released cane: some notes onNCo310. South Africa Sugar Journal, 30, 91.

Amalraj, V.A. & Balasundaram, N. (2006) On the taxonomyof the members of ‘Saccharum complex’. Genetic Resourcesand Crop Evololution, 53, 35–41.

Amalraj, V.A., Balakrishnan, R., Jebadhas, A.W., et al.(2006) Constituting a core collection of Saccharum sponta-neum L. and comparison of three stratified random sam-pling procedures. Genetic Resources and Crop Evololution,53, 1563–1572.

Artschwager, E. & Brandes, E.W. (1958) Sugarcane (Saccha-rum officinarum L.) Agriculture Handbook No 122. UnitedStates Department of Agriculture, Washington, DC.

Arumuganathan, K. & Earle, E. (1991) Nuclear DNA contentof some important plant species. Plant Molecular BiologyReporter, 9, 208–218.

Balakrishnan, R., Nair, N.V., & Sreenivasan, T.V. (2000) Amethod for establishing a core collection of Saccharum offic-

inarum L. germplasm based on quantitative-morphologicaldata. Genetic Resources and Crop Evololution, 47, 1–9.

Barber, C.A. (1920) The origin of sugarcane. InternationalSugar Journal, 22, 249–251.

Bennett, M.D. & Leitch, I.J. (2003) Angiosperm DNAC-values Database (release 8.0, Dec. 2012). Available at:http://data.kew.org/cvalues/ (accessed 4 July 2013).

Berding, N. & Roach, B.T. (1987) Germplasm collection,maintenance, and use. In: Sugarcane Improvement throughBreeding (ed. D.J Heinz), pp. 143–210. Elsevier, Amster-dam.

Blume, H. (1985) Geography of Sugar Cane: Environmental,Structural and Economical Aspects of Cane Sugar Production.Verlag Dr. Albert Bartens, Berlin.

Brandes, E.W. (1956) Origin, dispersal and use in breedingof the Melanesian garden sugarcanes and their derivatives,Saccharum officinarum L. Proceedings of the InternationalSociety of Sugar Cane Technologists, 9, 709–750.

Brandes, E.W. (1958) Origin, classification and character-istics. In: Sugarcane (Saccharum officinarum L.) (eds E.Artschwager & E.W. Brandes), pp. 1–35. U.S. Depart-ment of Agriculture Handbook 122, Washington, DC.

Bremer, G. (1923) A cytological investigation of some speciesand species-hybrids of the genus Saccharum. Genetica, 5,273–326.

Bremer, G. (1961) Problems in breeding and cytology of sugarcane. Euphytica, 10, 59–78.

Brown, J.S., Schnell, R.J., Power, E.J., et al. (2007) Anal-ysis of clonal germplasm from five Saccharum species: S.barberi, S. robustum, S. officinarum, S. sinense and S. spon-taneum. A study of inter- and intra species relationshipsusing microsatellite markers. Genetic Resources and CropEvololution, 54, 627–648.

Brown, J.S., Schnell, R.J., Tai, P.Y.P., et al. (2002) Pheno-typic evaluation of Saccharum barberi, S. robustum, and S.sinense Germplasm from the Miami, Florida, USA worldcollection. Sugar Cane International, 20, 3–16.

Bullard, M.J., Heath, M.C., & Nixon, P.M. (1995) Shootgrowth, radiation interception and dry matter productionand partitioning during the establishment phase of Miscn-thus sinensis “Giganteus” grown at two densities in the UK.Annals of Applied Biology, 126, 94–102.

Burnquist, W.L., Sorrells, M.E., & Tanksley, S.(1992) Characterization of genetic variability in Saccharumgermplasm by means of restriction fragment length poly-morphism (RFLP) analysis. Proceedings of the InternationalSociety of Sugar Cane Technologists, 21, 355–365.

Clayton, W.D. (1972) The awned genera of Andropogoneae.Studies in the Gramneae: 31. Kew Bulletin, 27(3), 457–454.

Clayton, W.D. (1973) The awnless genera of Andropogoneae.Studies in the Gramneae: 33. Kew Bulletin, 28(1), 49–58.

Clayton, W.D. & Renvoize, S.A. (1986) Genera Graminum–Grasses of the world. Kew Bulletin, Additional Series, 13,1–389.

Clifton-Brown, J.C. & Lewandowski, I. (2000) Over-wintering problems of new established Miscanthus plan-tations can be overcome by identifying genotypes withimproved rhizome cold tolerance. New Phytologist, 148,287–294.


Cuadrado, A., Acevedo, R., Moreno Dias de la Espina,S., et al. (2004) Genome remodelling in three modern S.officinarum x S. spontaneum sugarcane cultivars. Journal ofExperimental Botany, 55, 847–854.

D’Hont, A. (2005) Unravelling the genome structure of poly-ploids using FISH and GISH; examples of sugarcane andbanana. Cytogenetics and Genome Research, 109(1–3), 27–33.

D’Hont, A., Grivet, L., Feldmann, P., et al. (1996) Charac-terisation of the double genome structure of modern sugar-cane cultivars (Saccharun spp.) by molecular cytogenetics.Molecular and General Genetics, 250, 405–413.

D’Hont, A., Lu, Y.H., Feldmann, P., et al. (1993) Cytoplas-mic diversity in sugarcane revealed by heterologous probes.Sugar Cane, 1, 12–15.

D’Hont, A., Lu, Y.H., Paulet, F., et al. (2002) Oligoclonalinterspecific origin of ‘North Indian’ and ‘Chinese’ sugar-canes. Chromosome Research, 10, 253–262.

D’Hont, A., Rao, P.S., Feldmann, P., et al. (1995) Iden-tification and characterization of sugarcane intergenerichybrids, Saccharum officinarum x Erianthus arundinaceus,with molecular markers and DNA in situ hybridisation.Theoretical and Applied Genetics, 91, 320–326.

D’Hont, A., Souza G.M., Menossi M., et al. (2008) Sugar-cane: A major source of sweetness, alcohol, and bio-energy.In: Genomics of Tropical Crop Plants (eds P.H. Moore &R. Ming), pp. 483–513. Springer, New York.

Daniels, J. & Daniels, C. (1975) Geographical, historical andcultural aspect of the origin of the Indian and Chinesesugarcanes S. barberi and S. sinense. International Soci-ety of Sugar Cane Technologists Breeding Newsletter, 36,4–23.

Daniels, J. & Roach, B.T. (1987) Taxonomy and evolutionin sugarcane. In: Sugarcane Improvement through Breeding(ed. D.J Heinz), pp. 7–84. Elsevier, Amsterdam.

Daniels, J., Roach, B., Daniels, C. et al. (1991) The taxonomicstatus of Saccharum barberi Jesweit and S. sinense Roxb.Sugar Cane, 3, 11–16.

Daniels, J., Smith, P., Paton, N., et al. (1975) The origin ofthe genus Saccharum. International Society of Sugar CaneTechnologists Breeding Newsletter, 36, 24–39.

Deerr, N. (1921) Cane sugar, 2nd edn. Norma Roger, London.Deerr, N. (1949) The History of Sugar, Vol. 1. Chapman &

Hall, London.Dohleman, F.G., Heaton, E.A., Leakey, A.D.B., et al.

(2009) Does greater leaf-level photosynthesis explain thelarger solar energy conversion efficiency of Miscanthus rel-ative to switchgrass? Plant, Cell & Environment, 32, 1525–1537.

Edgerton, C.W. (1958) Sugarcane and Its Diseases, pp.43–61.Louisiana State University, Baton Rouge.

Ethirajan, A.S. (1987) Sugarcane hybridization techniques.In: Copersucar International Sugarcane Breeding Workshop,pp. 129–148. Copersucar, Brazil.

Food and Agricultural Organization of the United Nations2009. FAO. http://faostat.fao.org/default.aspx (accessed4 July 2013).

Glaszmann, J.C., Lu, Y.H., & Lanaud, C. (1990) Variationof nuclear ribosomal DNA in sugarcane. Journal of Genetics& Breeding, 44, 191–198.

Grassl, C.O. (1946) Saccharum robustum and other wild rela-tives of “noble” sugar canes. Journal of the Arnold Arbore-tum, 27, 234–252.

Grassl, C.O. (1965) Introgression between Saccharum andMiscanthus in New Guinea and the Pacific area. Proceedingsof the International Society of Sugar Cane Technologists, 12,995–1003.

Grivet, L., Daniels, C., Glaszmann, J.C., et al. (2004) Areview of recent molecular genetics evidence for sugarcaneevolution and domestication. Ethanobotany Journal, 2, 9–17.

Grivet, L., D’Hont, A., Roques, D., et al. (1996) RFLPmapping in cultivated sugarcane (Saccharum spp.): genomeorganization in a highly polyploid and aneuploid interspe-cific hybrid. Genetics, 142, 987–1000.

Grivet, L., Glaszmann, J.C., & D’Hont, A. (2006) Molecularevidences for sugarcane evolution and domestication. In:Darwin’s Harvest. New Approaches to the Origins, Evolution,and Conservation of Crop (eds T. Motley, N. Zerega, & H.Cross), pp. 49–66. Columbia University Press, New York.

Heinz, D.J, Osgood, R.V., & Moore, P.H. (1994) Sugarcane.In: Encyclopedia of Agricultural Science (ed. C. Arntzen),Vol. 4, pp. 225–238. Academic Press, New York.

Hoarau, J.Y., Offmann, B., D’Hont, A., et al. (2001)Genetic dissection of a modern cultivar (Saccharum spp.).I. Genome mapping with AFLP. Theoretical and AppliedGenetics, 103, 84–97.

Hodkinson, T.R., Chase, M.C., Lledo, M.D., et al. (2002)Phylogenetics of Miscanthus, Saccharum and related gen-era (Saccharinae, Andropogoneae, Poaceae) based on DNAsequences from ITS nuclear ribosomal DNA and plastidtrnL intron and trnL-F intergenic spacers. Journal of PlantResearch, 115, 381–392.

Irvine, J.E. (1999) Saccharum species as horticultural classes.Theoretical and Applied Genetics, 98, 186–194.

Jannoo, N., Grivet, L., Dookun, A., et al. (1999a) Linkagedisequilibrium among modern sugarcane cultivars. Theo-retical and Applied Genetics, 99, 1053–1060.

Jannoo, N., Grivet, L., Seguin, M., et al. (1999b) Molecularinvestigation of the genetic base of sugarcane cultivars.Theoretical and Applied Genetics, 99, 171–184.

Jeswiet, J. (1927) World material of Saccharum. Proceedingsof the International Society of Sugar Cane Technologists, 2,137–139.

Jeswiet, J. (1930) The development of selection and breedingof the sugar cane in Java. Proceedings of the InternationalSociety of Sugar Cane Technologists, 3, 44–57.

Kennedy, A.J. & Rao, P.S. (2000). Handbook 2000, pp. 1–10.West Indies Central Sugar Cane Breeding Station, Groves,St. George, Barbados.

Lima, M.L.A., Garcia, A.A.F., Oliveira, K.M., et al. (2002)Analysis of genetic similarity detected by AFLP and coef-ficient of parentage among genotypes of sugar cane (Sac-charum spp.). Theoretical and Applied Genetics, 104, 30–38.

Linnaeus, C. (1753) Species Plantarum. Laurentius Salvius,Sweden.

Lu, Y.H., D’Hont, A., Walker, D.I.T., et al. (1994a) Rela-tionships among ancestral species of sugarcane revealedwith RFLP using single copy maize nuclear probes.Euphytica, 78, 7–8.


Lu, Y.H., D’Hont, A., Paulet, F., et al. (1994b) Molec-ular diversity and genome structure in modern sugarcanevarieties. Euphytica, 78, 217–226.

Machado, G.R. (2001) Sugarcane Variety Notes “An Interna-tional Directory” (ed. G. Rossi), 7th rev. G. Rossi Consul-tants, Campus Luiz de Queiroz, University of Sao Paulo,Piracicaba, SP, Brazil. 132 pp.

Machado, G.R. (2002) Sugarcane varieties. Sugar Journal,65(5), 6–7.

Machado, G.R., da Silva, W.M., & Irvine, J.E. (1987)Sugarcane breeding in Brazil: the Copersucar program. In:Copersucar International Sugarcane Breeding Workshop, pp.217–232. Copersucar, Brazil.

Mukherjee, S.K. (1954) Revision of the genus SaccharumLinn. Bulletin Botanical Society of Bengal 89, 143–148.

Mukherjee, S.K. (1957) Origin and distribution of Saccharum.Botanical Gazette, 119, 55–61.

Nair, N.V., Nair, S., Sreenivasan, T.V., et al. (1999) Anal-ysis of genetic diversity and phylogeny in Saccharum andrelated genera using RAPD markers. Genetic Resources andCrop Evololution, 46, 73–79.

Narayanaswamy, S. (1940) Megasporogenesis and origin oftripolidy in Saccharum. Indian Journal of Agricultural Sci-ences, 10, 534–551.

Nuss, K.J. & Brett, P.G.C. (1995) The release of cultivarNCo310 in 1945 and its impact on the sugar industry. Pro-ceedings of the South Africa Sugar Technologist Association,69, 3–8.

Panje, R.R. (1971) The role of Saccharum spontaneum in sug-arcane breeding. Proceedings of the International Society ofSugar Cane Technologists, 14, 217–223.

Panje, R.R. & Babu, C.N. (1960) Studies in Saccharumspontaneum. Distribution and geographical association ofchromosome numbers. Cytologia, 25, 152–172.

Parthasarathy, N. (1948) Origin of noble canes (Saccharumofficinarum). Nature, 161, 608.

Paton N., Daniels, J., & Smith, P. (1978) A study of S.sinense Roxb. and S. barberi Jesw. International Society ofSugar Cane Technologists Breeding Newsletter, 41, 33–50.

Piperidis, G., Christopher, M.J., Carroll, B.J., et al. (2000)Molecular contribution to selection of intergeneric hybridsbetween sugarcane and the wild species Erianthus arundi-naceus. Genome, 43, 1033–1037.

Piperidis, G., Piperidis, N., & D’Hont, A. (2010) Molec-ular cytogenetic investigation of chromosome composi-tion and transmission in sugarcane. Molecular Genetics andGenomics, 284, 65–73.

Piperidis, N., Chen, J.W., Deng, H.H, et al. (2010) GISHcharacterization of Erianthus arundinaceus chromosomesin three generations of sugarcane intergeneric hybrids.Genome, 53, 331–336.

Price, H.J., Dillon, S.L., Hodnett, G., et al. (2005)Genome evolution in the genus Sorghum (Poaceae). Annalsof Botany, 95, 219–227.

Price, S. (1957) Cytological studies in Saccharum and alliedgenera II. Chromosome numbers in interspecific hybrids.Botanical Gazette, 118, 146–159.

Price, S. (1963) Cytogenetics of modern sugar canes. EconomicBotany, 17, 97–105.

Price, S. (1965) Interspecific hybridization in sugarcanebreeding. Proceedings of the International Society of SugarCane Technologists, 12, 1021–1026.

Roach, B.T. (1989) Origin and improvement of the geneticbase of sugarcane. Proceedings of the Australian Society ofSugar Cane Technologists, 11, 34–47.

Roach, B.T. & Daniels, J. (1987) The Saccharum complex andthe genus Saccharum. In: Copersucar International Sugar-cane Breeding Workshop (eds Anonymous), pp. 1–33. Cop-ersucar, Brazil.

Simmonds, N.W. (1976) Sugarcanes. In: Evolution of cropplants (ed. N.W. Simmonds), pp. 104–198. Longmans,London.

Sobral, B.W.S., Braga, D.P.V., LaHood, E.S., et al. (1994)Phylogenetic analysis of chloroplast restriction enzyme sitemutations in the Saccharinae Griseb. Subtribe of the Andro-pogoneae Dumort. Tribe. Theoretical and Applied Genetics,87, 843–853.

Spangler, R., Zaitchik, B., Russo, E., et al. (1999)Andropogoneae evolution and generic limits in Sorghum(Poaceae) using ndhF sequences. Systematic Botany, 24,267–281.

Sreenivasan, T.V., Ahloowalia, B.S., & Heinz, D.J (1987)Cytogenetics. In: Sugarcane Improvement through Breeding(ed. D. J Heinz), pp. 211–253. Elsevier, Amsterdam.

Stevenson, G.C. (1965) Genetics and Breeding of Sugar Cane.Longman, London.

Tai, P.Y.P, & Miller, J.D. (2001) A core collection for Saccha-rum spontaneum L. from the World Collection of Sugarcane.Crop Science, 41, 879–885.

Tai, P.Y.P. & Miller, J.D. (2002) Germplasm diversity amongfour sugarcane species for sugar composition. Crop Science,42, 958–964.

Tew, T.L. (1987) New varieties. In: Sugarcane Improvementthrough Breeding (ed. D.J Heinz), pp. 559–594. Elsevier,Amsterdam.

Tew, T.L. (2003) World sugarcane variety census–Year 2000.Sugar Cane International, March/April 2003, 12–18.

Walker, D.I.T. (1987) Manipulating the genetic base ofsugarcane. In: Copersucar International Sugarcane Breed-ing Workshop, pp. 321–334. Copersucar, Brazil.

Whalen, M.D. (1991) Taxonomy of Saccharum (Poaceae).Baileya, 23, 109–125.

Documents

Sugarcane: Physiology, Biochemistry, and Functional Biology (Moore/Sugarcane) || Sugarcane: The Crop, the Plant, and Domestication