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Citrus rootstock identification by tissue coloring tests
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Authors Makhdum, Nazir Ahmad, 1902-
Publisher The University of Arizona.
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Link to Item http://hdl.handle.net/10150/348333
CITRUS ROOTSTOCK IDENTIFICATION BY TISSUE COLORING TESTS
byNazir Ahmad Makhdum
A Thesis submitted to the faculty of the
Department of Horticulture
in partial fulfillment of the requirements for the degree of
Master of Science
in the Graduate College University of Arizona
1 9 U 8
Director of Thesis p DateApproved
' Appreciation /is •: extended ■ to the Department of/;/ /. Horticulture, of the; University of Arizona for guidance- durihg the peripd of studys for use of equipment and . laboratory facilitiess and for the encouragement that, made this study possible^ Especial Credit is given' to. Dro Deon Ko Pultz and’Dr/ Leland: Burkhart'''under '.:: '
■ whose supervision the study was 'eonduefe'ds particularly ; for'/their part in planning the experiment and reviewing
the manuscript,,: \ >
TlBEB OF CONTEITS
I H T R O D U C T 3COM O o o o O O O O O O O O O O O p O O O O O O O C O O C O ^ O O O - O - O O O ■
REsiiZSlilf OF LITFHJLTUHFo<>p o o o o o <?•<o o o o c o o o o o o <>e o o q p o <* '
Al® - <> o o o o o* o o © © p o o p q o 6 o p q o o o o o © 3
BBSULTS Am) DISCUSSION o»**oooofa***oo»a.4ooob*4* 11 , <; \ v ', : y;: :/. / .. :: '' \: :
S O M M S R X O F RMjSUXjIS-- o o o o o o o o o <> o o o o o o o- C O O 6- O' O O O O P O d o l 5
XfXXi>I^AX01i& O O O' O' o o cob 0 0.0 o o o o b O 0 o b o b o o o b o o o 0 o 28
APPEHDIGES g • . . ■ ■ . ' , •,, '" A* Reagenis8, Preparation Methods booQo0 * 0 0 = o = 2h
-iy in-- S° 'Identifiestioh o£ Rootstoeks for OraEiges • ■ ■athw thdn Gheztiical Tests =<, = <, 25 ' •
LIST OF TABLES
lo. ■ : Golor' d®Tel©pro#a s iflib iinezi-'i’eagerii: - ' , 'r©ported:by.yaPious ■wor'kerSflooooooooooooooooooc.-oo X2'
2'o Qplor dewlopmetos iritb' isrooniTO/moIybda.t,® ; ;s v'.' . • ; reagent'. as; reported' by Marlon# worker#»o«o««-<,.» ' . 133» Color developments of Titanous: ©bloride reagent ■
' ;■• as:reported;by :yarious:wforker%<>,o 09 »<>v«,,?.6o<>d0o o «■.<,«» - Ikiio Color developments;of Ferric chloride reagent
■ as reported by::#ariotts;iworker®o<>’o0ooooC,0o(>.<).<j:0'o''oo'<) ,, 15$o : Color ■■resetions of straight bark■ (stbbo )■ azid- of.■ : - 'straight leaf (stdo) samples' mtti the
Ilmen. reagent o o»p;.oo o o o o »o o o oo,<> o o o a o o <> o oo o ooo 10
6q Color reactions'df different root,stocks idth . ■Almen reagent aecording to Ridgway Standards ■ (7)»«» 21
Jo -' . ' Color reactions; of thes eifnis rootstocks tissues - ■.'with ammonimuE mblybdate reagent 00»»e»■».»,»o * , 2 2 :,
06 . Color.reactions of the citrus rootstocks tissues' by (a) titanous chloride' and:: (b) ferrie . ehlorid®.0:o ot ■ 23’
:'' V'' IMTRODUGTIOM "V.* ;: - : - \ ; .:
Goramercisi eltras propagation Is practiced in the United States by budding .the scion,': on a compatible rootstock? 'lost; oOBainonly v ' meed .:'roQtat()e%sJ at tW preBeht: # ■■■■'■.■
'. 'Souy: orange (Gitims' aaramtinm) M'mn. / ' - b - :' : ;• ; : •/SosH^orahge is a hardy .deep-rooted stock9 considered resistant
to .various fungus.diseases especially to brownrot guamdsis (2) , bat 11 npmg:. It,•was Considered; .a compatible’ rootstock for- oranges and ' , :grfeefri3a.W w lit' redent'jyear^ Washington navel and Valenciaoi^hges diiiits :'ipp‘%ave; witown,in certain areas .a vims disease called <piclcV decline5 which has caused a rapid decline or sudden death of the affected trees. So far it; has affected only sweet orange oh : ■ Sour-orange root (2) . = •• • 2o " Rough lemon (Citrus llmon);, (Linno ) Burmann , ■ ; ■; . ■ ;■ Roughlernon: rootstock produces large '.vigorous- trees. It is -mited .to', lighter • soils $.: being; used' id soils "where drganie matter is. low; and topography rolling, ;The. fmit^ ;ho?feyer'j, :is low in. both.,; sugar' and acid and often has a coprse texture and rather a thick rind.(2) It also bends'-to f avor development of gi anulation in the fruit s more ; especially in valenclas (2) = Both the tree and the' fruit on this, stock-
1, Figures;in parentheses, refer to Literature■ Gited^
: are more; susceptilDle to coldp s a l t - i n g u r y o 3o Sweet orange (Citrus sinensis),'(Linn0) Osbeek
;Sweet orange, is adapted to a. wide range-of soils, but does best on soils that are light to medium loam in texture and is suitable for . . soil rich in organic matter and of level topographyo la heary-soils v this1 rootstook Is; mseeptible' to brownrot gummosls '.(2)<, • It; is> howevers most widely' used stock for all. eoipiereial Tarieties of eitras and is particularly suited to lemonso ' 1 , - ' ,
: ' Uo Grapefruit (Citrus paz’adiisil'.flacfo :; ' : . This has been used as a rootstock usually for lemonss and ;. occasionally foz" oranges3 but trees budded on it have proved less pro
ductive than on'sweet or sour-orange stocks (2)0 : Consequently it-is increaeingly getting into disfavor among citrus growers<, , '■ . The importance of identification' of .unknown rootstocks in ,oM
''eitras groves, cannot -be overemphasisedo. ■ In the first place this would offer US an excellent'opportunity to. study the interrelation between stock and sei©hs were it possible to eydlvb a definite "knowhow" for ' the identification1'of these .bto©ks0 Secondly5, it would help growers to fortify themselves against■economic loss by obtaining frees on" disease^ .
•. resistant .rootstocks for .replacing the ones that may die ' of "quick decline8 Thirdlyg it would .afford the eitras growers more reliable basis for
3
■ bevibw op. litebAtuh® • . ■. ■ ;
■ "V ' Hendrieksori (k) published a method-which 'ds based on the fact ' thaf all eitras z oots contain.:glueosides: and that these glucosides : - contain phenolSo He. treated aqmous extracts of these roots, with ' ferric ehloride and observed different:shades of color with sour orange> grapefruit and rough lemono Sweet orange gave inconsistant .results» ■ llrfs: worker considers his method . ‘’reliable only for rough .lemon*'« ■
Halma and Hans (U) report a; series of tests which were conducted on poivdered. bark water^eKtracts of these' stocks0 Briefly stated their methods were as follows 8 ■ -■
aB Al^en testa . .. '■: M d ' 2 drop sof ■ ICOH to 10 cco of the water extract of. the baz-k •speeimen.:under study; followed by 8 drops of saturated copper sulfate .solution : Shake well. Then add 8 drops of Almen reagent '. . Boilthe resulting. heavy creamy yellow precipitate for about two minutes. . ■this would; result in the following color developments s v:
• 1, Sour orange .......... brown ' ’ '2. ' Equgh lemon .......... colorless,;• . . '
. ...it'^aphfruit ......... 4 .- light pink' h. Sweet orange ........ 'pink
2. Methdd'Of preparatidn of this: as well as all other reagents are v’ ' detailed on page 2h. . ' • -
wTfoe. sweet orange solutions show a. narrow range of pink while the sour orange and .grapefruit solutions flue'tuate in some eases over a . eoi^aratively wide range within their coloz- grbup»"
bo Ammonium molybdate tests , ■■ ■ ■ ! . •Ten drops of this reagent added to 5 6c= "of the liquid extract
and hoiled will give the following colorationo ..1P: Sour orange d o o o o o qio o 6 "iarying shades of green,20 Rough lemon 00-00000000 Deep blue color ’
•3o Grapefruit o = ooop.oo.oV’.Light blue or bluish gray ho Sweet orang© o!oooooooo.;Varying shades of green color
Co Titanous chlorid© testa ; - ■ ' ; 1 . ■ ’Two drops bf this reagent {20 S-soltatioh)'-.addeditol'5ceo<, -Sf th©-
extract will,yield the following colorationo . ' I,, -Sour ©range o o«o»o 9 o Greenish color
'2o Rough lemon oooooooo.oo #ery light pink ’ . . .3o Gfhpeiruit o:o ol o»»«i «1 Warm; gray ' - ' ■ - '
. .. Sireet orange =»Q»o»»»« Greenish color 'do Ferric chloride test: , - - . ■ : ' . . . , '•'Two drops of a.saturated solution of' this'reagent added to
5 ecp of the bark extract will develop coloration as f ollows s. '' .lo Sour-orange oooooooodo Dark clear brown :
" 2o Rough lemon tooooioooo-Glearystraw color > . . . .: ; 3 0--Gfapefruit . o ooo o’o oooo o-f. V ' n ' n ' \
. . ; Sweet prang© .ooo.ooo;oio Brownish turbid - ;
Iriih regard. to thelast three test5, the author's, remark that ■ .'Hthese methods- mil be fdiind, helpfuls although they are not ,as reliable '.as: the .Almeh reagent .method91 o • ; .. ' ; ;\
.vJhAti'#:'';itasters .(5) reports ph"A Me^iew of Laboratory Tests, for the ■ ; Determination of Citrus has further' developed the methods .tried by Halma and Haaso He has endeavered to be more precise in procedures observations, and conclusiohso the details worked out by him are as follows and;his color comparisons were made with Ridgway standards ,(7)0
' ■a.a .iliaen tests ..; .: - f :To 10 cco of the bark extract add 2 drops of KOH. solution followed
by 8 drops of a saturated solution of copper sulfate, Shake thoroughly.-and then add'8 drops of the Almen reagentc Boil the solution for 10 or15 .mimiteso " The resulting color is noted 8 '.to 3. hours later when it has ■.developed mazimm intensity ahd ihe precipitate *lch had formed during ...the reaction has settled to the bdtt#i of: the .test tubet . v. . ; ' :
■ 1<, Sour orange />000<,00.000 Cinnamon coloration - ' .V. g'd, Rough-lemon-oo00000 =,,00.'Pale'vinaeeous coloration 3»'Grapefruit ». „ „ o. 0 Vinacequs lilac coloration
: Ro 'Sweet: orange; =o.o o:o"o Lighf rosolahe purple "t f'/
To 3 to b, drops of armonium molybdate reagent add 5 cco' of the bark
extract and boil the soldtlbn. f or 2Q to 30 seconds., Within 3 to 5 ■ -minutes the reaction gives .'its: most .'typical: color 9 The • tests are then set aside .for' 2k hours to allow the; sblutions. to; clears thus making it possihie to -study the-results and match .'tfee cOldfSo • '. • ^
lo Sour., orange" 00-, o Light sulfate green to eendre ^een2@ Bough lemon ooooofoooo Eeti 'l blue : . : . ■
:; Jo Sweet orange. »»o o«s 0 = 0 Light sulfate .green . :Bo Sweet orange 006oo0ooo Cendre green-
Oo .Siianou's chlbri.d.e tests' ■ / . ' .. :Two drops of fifanous ehlorid® solution are added to 5 ce0' of
the hark extract and then shakeno The reaction is completed within an houro . . . - " " - ...
'• : , Qhservations - X ■ . . ' . -: 1<,VSduf orange :oo<,o06of.oo Olive' green ■: : : ; • -2o Rough lemon: oooooooooo Light hrown1 pink tint 3o Grapefruit .0 0 00 o o o ?o 00 lellow to light brown .
Bo Sweet orange oooCo = »-o» Vivid green ' • do Ferric chldride tests'; X ■ ' - X ' ■ ,' Add 2 drops of the ferric chloride solution to 5 e’Co of the hark
eatractoX Shake at once and observe" during the first 15 minuteso The " immediate., result, is indicative of its degree of turbidity and colors. with .the reaction reaching, its peak at the end of this intervals
1 '. Observations X ' : -X.-1& Sour orange '=00«oXf-Wo. Brown' to dark/browhg but, very clear
. 2o -Rough lemon ooq0000ooo Pale to straw yellows. cloudy So- Grapefruit *-•<,<, Gream-to buff yellowj, cloudy ■-- Bo. Sweet orange 'o'dXoX boXX Brmras turbid . . - - 1
Varieties of rootstocks.; Under study, by -MroX Lc Go . Masters were
th®:foll@«ihgg" '■ ; ' ' \ \"Sour orange Staxidards African Brazilian^ Pazjagaay3 - Seville
; and Bitters'weei 'Rough lemon ■ Rough lemon9 Eureka lemon and LisbonGrapefruit ; All at&ilabltiv varieties were ttsedo Regarding . .
'. ' -‘this rootstockn the author of the article remarks:'f.\ : % that ’’Grapefruit was found to be inconsistent in its
; ; reactienMo" ;■; > 'f : : :Sweet orange Keethani Madam ¥iimsP, Bessie^ Orovills3 Indian
.. prphard and Homossasa
The author of this: work concludes his findings with remarks', to the following effects : eolors 'used for the above charts (l»e«. ,mthregard to,: the Almen test and Immomum molybdate test) were selected, in most casess from average color 'reactions of several varieties of each specie sH s and seems'to , draw the pointed attention of his readers by observing thatVMfhese (colors) •ean be considered only approximate 'because of the variation in bark samples and the differences .in the eye»
mtEEIALS AMD METHODS.
Both ti&rk and leaf t-issues were s tudiedi fhe bark used was of- kindsg vi8aS. a) bark from trees of the rootstock varieties mbieh
for eenvenienee. m^"-be termed as straight-barks and b) bark from a budded tree obtained from below the bud=union0 The leaves under test were only from the straight trees and not from the trees budded on topo Bark .and leaf samples as above described were taken from each of . the four species under test and dried in an oven for at least. 21$. hours
at about-?0 . Co' ThdLp temperature is considered optimum by most
' engymes and volatilise -certain produetso If the: than-the above: marky 'the drying prpeedure may
become too prolonged thus entailing loss- of time: and delaying .the proeeg TOnee@ssarily? The dried material .was run through a mechanical grinder and-powdered to a i$.0=mesh , sieve-siseo - - -" -All the, reagents-'were, prepared on- the- lines of the previous workersdetails of ifiich are given-on page 2&s Appendix Ac : Samples under study were taken a® follows s
.- 1«-ao Bark- -straights. -Trees growing on ,the University Campus ba Leaves straights Trees ” 48 » «©o' Bark below bud-unions Obtained from Tempe Citrus Farm
1, Sour orange with - grapefruit top „ Plot &/19: -; - -:'2<y Sour ©range with Eureka- lemon top = =»»=. Plot Q , 3o. Sour,orange 88' . 88 - 18' 88C o o . Plot
' Uo. Sour orange with WasMng-ton navel top .0 6 0 o Plot F/U ■ 5o Sour orange with • ® " ■ ■ M • « Plot F/j?
■ . ; . , . ■ ■ ; > 0- Bark straights Trees gromng on the University Campus
1 ... ■
. Go. Bark from below bud«=union with grapefruit tops Obtained
3 e" Grapefruit; : a. Bark 'Straights": Marsh. - trees #owlmg, "on the 'Uzdyersi^ Campus
w w e s - ' . , . ; .!•. , - Co. Bark from below bud-uhions " Hot available from Tempe or elsewhere
■. a<> Bark, straights . .Biller and Washington, .navel trees oh the Univer-
■ ....- : 1' • ei-'Bark from' below bud-unlon's ' Obtained froin Tempe Citrus Farm ■ .
'; 'lo"Sweet 'orange; with Eureka lemon.on top= o.ooo.o. Plot D/122o Sweet orange ” M ■ ” w 81 »,,oo-oc Plot D/13
. . ■■■■• ■ . . . :
: A sample of o75 grams of the ground dried, bark was weighed, placed
in .a; beaker .and 20 0% .of 'distilled, irater; /added 'to ito ' The; S u s p e n s i o n ; wad allowed to Stand f or at -least half an hour g: and $ the eontentswere agitated' occasionally during the interval» The. suspension was filtered .; into a flaskg and the residue washed with an additional 10cCo of dis=%lled 'water o' .'. The water extract so obtained was then' tr eat ed with the
10
reagents on the same lines as followed.by the previous -workers»(For details please refer t© (jj.s55= The color reactions ©f the .tlssTie.s nnder study are given in'the tables los<» 5 to os pagesy. .18 to
11
/: _ ; . : ; ismLTs jti® pischssecs;:, ■ ■ ,; . ■
Almen reagents Color developments with this reagent are givenin tables 5 and- 6S page 18 to. 21o The edlors have been described in -'table 5». in terms of plates outlined in the Haerg and Paul (6) s and those in table 6 in terms of ‘‘Color Standardsand lomenclatur®”'' by.'Bidgwaj (?)o 4 reference to these books will show that the main ground-color development in ease of each-of the .rootstock under - study;is more or less constant throughout| although "With respect to rang® in shade within that color2 they continue to vary slightly from test to test0 In case of sour orange2 for instances the, min ground-color is5 what in common parlance may be described ass “brown"' or. “dark brownffl| for rough lemon it . is “brownish pink"g for grapefruits, “smoke, transparent®- or "almost eolorless®s and, for -sweet orange2:"pink or ."deep pink*? . A slight variation in shade within the limit of the main■color range noticeable in each'test is obviously .due to certain laboratory treatment differences that were unavoidable»
In addition to working on bark testsg the writer of . this thesis has included the reactions of leaf tissues in his studieso. - 'For it has been observed frequently that' suckers usually develop from the stock . below the bud=?uni©n<,: and should these sucker leaves offer some clue to the root that produced them, an additional facility will naturally become available to s ' student of rootstock identifieation0 Moreover, leaves provide as compared to-harkg "a relatively-uniform tissue that is easily sampled3 dried and grounds . Also removal of a leaf .-sample
is Btoeh less damagi.fig to the tree than, the bark sample85 (3)c, • •: ‘ : A , series .of leaf sasples tests ran on lines sisiilar to thoseof bark yielded color reactions asaally in: agreement with the bark.,
; except for the following differential .pointss.'a0 Leaf reactions irere asnslly a shade deeper in color than
' those of: the bark». ' "' bo Leaf extract coloration faded away more rapidly than in ; : ease of barkoV ’ Leaf "reaction iss:; therefore less stable«,
: For the sake of making a ready comparison between the findings •• -of the previoiis workers and the writer of this th@sis3 th® following •
tabl@" showing the average reactions'as given by the Almen reagent is :
" ■ ■ : : : :Table 1» .Color developments with Almem. reagent as reported by
: ■ various workers v : . ' " : . - y v - ■ .: . .- : ' /The writer .of
• Rootstock Halma and Haa#: Co L, Masters this " thesis ■
lb’Sour orang® ■ Brown /. Cinnamon' / . ,' Brown. ' /' 2o Rough lemon Colorless, Bale ’Finaeeous "Brownish pink:3o Grapefruit. ' Light "pink Finaceous lilac Smoke- transparent or
/ ; ;'"5 . ' .. colorless . :ho Sweet orange’ .-Hnk . ' . •>.: Light rosolsn® ’ Pink dr deep pink
. " v : ■ ,;-V/ ’ '' ’'f;-':,;"- 'purple } _ , ^ ...'
; . A '@tu% of the above :will show that regarding sour orange reactions Raima and Baas:, and the writer, of this the sis are in complete agreement j, but Masi@rs:"repofts: & different ‘color reaetiono, As regards sweet orange allv three workers are in close agreements although here Masters 'uses ■- a rathsr. different'phraseologyp but in essence h® arrives practically
this thesis .was aware of this fact from.the rery start ands in acquire confidence in bis, oim findings^ he has devoted much tiss attention to the solution of this: discrepancy, vAth the results by the previous workerso Accordingly , the test was repeated tim;
as zar a the light of his own
fences. in
yariety«=>differenee s of tions in soils climate and
possibles any chance ©£ error or di®.gs the writer . is inclined to concluds
findings under review are possibly due used by each workers edmbined with
Ammonium molybdat® reagents Findings of the previous workers as as those of the writer of this thesis
a chart for a comparative study. (For details reference may to table no. 7 on
Table 2. Color developments with Ammonium molybdats as reported by.
1. Sour orange2. Rough lemon 3o Grapefruit i*. Swe et dr sag®
Varying shades of green
Beep blueLight blue or bluish ay '
of
Writerthis
0 o ho
,® to ' Gendinlight Methyl blueLight sulfate . green- ■ Gendre green
green blue to "
greenish blue . .Light sulfate to
Table no. TV page' 22 shows 1 eolor reactions of leaf tissue
bit mope intensifi@d'c
SeioB effect on rootstock?• fable no. Ts "page 22s • als© sBows that with gimmozilm molybdate rea
; on.the source of- th© tissa@s ioeo-j, whether It
a straight stock or fro® a budded..stocko .There iss of .course That isi, sour orange with WasMtigtoB nairel top
yielded sulfate green color-instead of a cendre.green color were' no top on toisystoek. / '' .v . ’ . ; . ; . / '...
fit anon s chloride ■ and Ferric •chloride ’ re-Both of the above
conclusive reactiOBSj
;3 oddly enough failed to as would ■ appear from the • following
o' : Color various
■’ of' ■ Titanous chloride: as reported by
stock Ealma'& HaasThe writer of
0„:Greenish color ■ Olive' eeng clear Olive greens
. '' ' • " Or cloudyLight bpomj pink . ■ 89 19fellow to light Light olive<, *'brown . .
. 2. Rough lemon W» light pink3. Grapefruit %o ••8%?eet orange: No definite pink or brown of any shad® ever developed'tests conducted by the writer of this thesiSo- Different shades of olive
Greenish color Vivid green greens
'green did appes? '.an4 charact -:aiidaas sy,eha almost valueless» . ■ ' v'' ■; ' . ' : . ■
Table k® Color developments of Ferrib chloride reagent as y®~■ ’ : ' ported by , various-/workers ;. .
.v,' . "v; - ' , v... " ” ■Halma & Haas . Co Lo Masters this thesis
Dark clear to dark broun Dark browij, turbid' b r o w : . but very clear : :V: ;' : ' :
Clear straw, Pale to stra*.: yaib* t : V*V;:v 111 ',|if: 'yellow lowa cloudy . - . . >
88 ' 5 Clear to buff yel- ; , n M « ./I/ - lows eloudy i .''' ■ (but light shade)
lo Smet orange. BroTEnish, turbid 'Brofea. turbid Dark brouma turbid •
lemon3o uranefrait
This reagent as well did not prove to be of much practical -use -as ■ the' color reactions showed' variations every time ' the test was re= 'pbated and indibated no marked^ "fixed -feature of. any importaaeeo -
l6
. SDMMBI OF BESTOfS . ■ ' ' •,; ■
10 Tissue coloring tests with cheiEieal reagents for the purpose of identification were ■ e'ottdncted on the fomr commercially important ■ Arisom Oitrap .rootstocks ■wia«> Sour oranges Rough lemon5 Sweet orange , and Grapefruit^;y' ; .
2o Chemical reagents tried were four,, viso^ Mmen reagents Ammoniuia molybdatej, Titanous chlorider'and‘Ferric chloride For the color tests, the first, two reagents- have proved ’rery efficacious and the last two of a doubtful Utility, at least, under. "Arissona conditions
3o Almen reagent, yields a'brbmi.color with Sour orangey pink, with sweet orangepinkish brown,or light pink, with rough lemony and, is transparent or colorless with.grapefruito . ■, - - .
U» The ammonium molybdate test, helps to. segregate rottgh lemon from sour orange - or sweet' ©range with which it is likely to be confused in the■ Almen. reagent test. Rough lemon gives a methyl blue,or. occasionally a' greenish blue' coloration with ammonium molybdate, while sweet - orange - and sour orange yield a eendre green color and grapefruit, gives a light sulfate green to sulfate.green, ‘ - :
$6 Grapefruit invariably yields a characteristic smoke transparent or almost colorless reaction with the Almen reagent and can seldom be
confused with other rootstockso ’ - '': leaf tissues of the rootstocks under study .v© approximately',
the same colors as the. bark tissuesj the former, however, usually show & deeper shade within the same color than the latter<s; The colorations
■ - shmm- by the,leaf tissues seem to fade more, readily arid, appear to‘ .be less stable than bark eolorso - - . ; ■: : 7» fhe color'development for obserTation purposes’ is. at its .best "within the first Sit hours of the reaction* ‘ .After this period
■ " the color starts fading and the sample is no longer reliable^■ • 8d- In order to get satisfactory resultss it has been found.
necessary to soak, the dried, leaf tissue for one-half, how arid the bark tissue for, two to three hours before filterihgo , Ihe suspension zaust. be agitated oeeasionally during the soaking periodo . -
% TO’ obtain proper colordevelopments it-is necessary that th@ . tube .containing: extract" arid reagent be boiled-over the flame for at
' least one minute in the ease "Of anmonium molybdate and for two minutes ' in the' case of the Mmen reagento :: ■ . ,." V 10o The chemical color tests above described m y be further corrobor? afed by studying;the eharac'teristic leaf features and bu^union develops.
hments as outlined on page-1 of this thesiso . : .. Ho fo avoid, all chance of possible error arising out of azr'
: abnormal'color behavior due possibly to th© peculiar soibB^sioek effect■ and" other’"faetbrSs it seems also desirable that first of alls color ■developments for the locally known rootstocks .should be prepared and then the identity of the unknown stoeks be determined by making the neeessary/eomparisons of" one against the otherG , :
18
Table" $o ■Color: reactions of straight bark fsiv b«) and of straigWb leaf%/": -- • ■ ■■ •
NO o .
test
lo ,
M '
■ ■ Bo:
' ;7»'
;;a,
W ;
: w13oV
m
iSo
’ ; ‘:Souy: orangeSto' bo: . gto lo
plat® yang©
a :; S^:\;5r < v « ;
$ k ' E /3 ~ k 55 " B/W5
' 55 E /W
:5k: " :: .>
5k P/5-6 55 '.C/3»k
W ■ SaW'iadd"fatill- a.st/;.e|itlpn/. 1930.
S S S t e lsto bo ■ sto
S M E £ B5k :. v w
5k V W ,
5k; - ".1/3=4
5k - i / W5k .P/2-3
53 ;;., B/1^2: 5k-:/'e/W 5k . 3/k-5 '5k \ S /^ 353 i/1 -2 3k . P/2-3
1/1-2 5k 3k / G/3-k
gk";::; 1/3-4
5k . E /34
# 1-2 ^ k
5Sv :#i=z-\ . 5k
5 3 /:/:i/l-2 ’ , 5k
53 # - 2
5k, ; P /2 4
S ' ; 4/34 5k F /2-3
5k ' . 3 /3 4
5k 1 /3 4
S / 4/14/: #/: #3^2: ; S S a/ 2 4 5k t : 1/1-2
53- " P /3 4 S: " G/34 5k :";#4 5k # 4
S 3/k453 ' , B/14 5k 3 /W
53/ 4 / 1 4 S 5 k , 1 4 4
sto. bo ' , sto lo Plate .range:-' . plate-rang®--:■ .plate: .mage-
/5k ::’ 'F/142/ ’ 53 'J 53’ ' W
: .5kv/^Z:r/55:/:4/^, A :.V2^ 0 : ^ 2 4
S ' ; / # i 4 ’ . :-55 ■■■■ f / W ; -53h: 4 / 1-2
; s: 4
: 5k: ,,P /3 4 ; "55"'/ # - 2
/ S;/'# ^ 2/^0 /;-
5k . :p/k-5 5k P /2 4
:.; / (continued on the next page)
Jo . Tbf 4late; aaT rang© bf. '.koloi'S 'are quoted from the 9,Dlctionary of Colors®
. ir-T" -;-4-
. ■ -/-tv
19 :
Noo
&
I80
:21o.
f2:o- /:
•:25a:: :
: Was. :
30.jloV
32..:
- S o#'; st». "bo ;# # # 2 :.' • . sbo lo ■ st< 11 sibo.
’ruit :: iET'lo
Swsgtor.ange ,1 S o ic
; pl^;yeag^;
A '5k P /^ K
#
'55 6/3=k,'
:5g', ' # ^ 2;
; r # ' :
55:; c / w ;ev2-3 . » : j /s-s
514
»• :
/ #o. .%: 2
Slafe:.;p^#; ;5lai© plate^^gai a f e ^ g g ;': S - : W i=2: .;':5k ; i / i -2 "vSkv' .F /a ^ : il*'; : i/i^ 5
s y ^ s : :'f 53 j ' 5 k F/l-2 5 k 1 / 3 = 4
5k V l-2. 53 " , ' i / l “2:
. 53 2&/W:'
. ' 5 t : B/l=2
: 5k - B/l-2
5 & ;: #1^2 ■■'
.5 k :% ^ 2 ::
5k ' #1^2
5k p/3^k 54 F / #
55 B /l-2 '5 5 : '# - Z i
-■55;'Eyi»2'': '55 q/3-k
S ;W3-k.; -. '-;2 ■>s ' G /W l
5k2;.F/34:5k ;/lV % 4:
55 : P/2-3 ; 55 # - 3
:W .; 1 W 3 . ,
55 2 F/l=2
''55 F/2-3142<1,:/:.21 53 F /> k
;55 I v t / ^ i' : ■ .;' • .
. ??. ' •F/ 1^ ‘
i: 53:,:;: 1/1-2' :i53:: # 1-2
- ^#1-2
'Z 5 3 : ;% 2 ^
i; :5k; •; .0/3=4.: ■ •'■■;5k;':lf i/P5|;
5k ; s /1-2 /5kv ■ 1 ■ ;2 ■
5k . 1 /1 -2 ;;;5k.
5k ' i / i - 2 ;;5k
5k i /1 - 2 ■:;> 5k ;
5 k ' : 4 / 1 - 2 2 5 k22... : ' ;2'>':.2
q / w# 2 % :& 'I'l/sw. :5k
:5k 2; i / M
: :5 k 2 -% W
.■5k. I''2/1-2 ;;:5k ;:2#3% : 3k 'C .l/W :
5k 2 # 2 - 3
5 k ; # 1 -2 :
5k : 3 /2 -3
:5k..::l / H
.5k 2 D/3-k
5k :.D/3-k:
35 # k -5
55 # k - 5
;55 :# 2 § r :
55 #1-2 /
55: ' # W '
55
:55;:2#3-ky5 5 ,: .F /W ;
•53 ''
: # : 2# k 25k > v;F /^ 3 .,‘' . .. ..
^5k%2:#W55#-2'#3#' 5k \#2-3 J M ' ; #1-2
:::532;: B/#2;:; 5i':: # 1-2:
S'/ B/i-a; -53 #1-2 251.. i /1 - 2
.5k ; 1 /1 -2 [ 5k2 , ' . '2/ 5 k ;2:B/i-2 {/5k;
5 k ; .1/ 1-2 :'5k
5k A /i-2 l;5k
5k # 1-2 5&: -
: : # m
F/k#W k "
,% -3 :
S:,'#i-2 j;5k / ^ W k
5k : . 1/2-3
:.:5k:;; i / M
' s : i:#2S;
,5k : ;i/2-3
5k ■ i/2 ^ 3"2 2, r2:2:22
(eoBtinued on the next page).
'■26
: >
Table 5 .(conto■ ; -'S' 3
: ‘: V .
' ■ ■ ■; Sour orange A, c -' ■ % - ; 'Grapefg fe'' | „Sbo 3/ • sto bo . r sto,: lo;": ; ■' ■;. st .bo.f ' , vy"; st0. bo ■: ■?'sbo! la .;o£ ; : -''■'■;,. ■ ' ■ '■ \T .. .3 ; : ' : ‘ V >■■ . : ■ : ■.■.;„,.!' 'plaW rWg® plat© range plate range plat® range,' plate range plate,range
'-'S'.'---;;3i i o 55 F/1-2iii 3 53 -5^i 9/1=235. 5k F/3-k 55 C/3-k 5k F/2-3 53 F/l< 53 A/l-2 . 5k V %-2
36o , 53 E/i»2 55 c/3»k , 5k F/k 5 53 \ F/i-g , 53 4/1-2 5k" Vi-2:' 3?o' ■ ■ 5k '. F/2-3.; ■; 55 :G/3-k; ’ c ■■w \ 'E/2-3: ' ' ; 53' ' : 5i'j i/i»238* 5k E/1-2 55 c/i-2 5k E/3-k 55 F/3-k 53 4/1-2 5k B/l-2
rJ39fi ■ -: 5k' ;|/2-3v.: 55 '#3#; > ■:'5k F/l=2 • 59- - I / M .M / # ^ 2/':-5k/i B/l-2, 'kQ. . : 5k: -E/3=k : ' 59\ 1^2:, Jk" : :F#»2'''53 ' v E / W / 51': \#]^ 2: B/l-2: klo ; 'P:;' E/3-k95 ;#2-3 5k>;-: 95- ^-2 : :'5k ■ 4/1=2k2. 5k E/3-k 55 Vk-5 5k F/2-3 ‘ 55 E/3-k 53 ''4/1-2 ' 5k' 4/1-2
/k3o, : . ;.3k 1/3-k 55 E / W 9k '59 53/,:.b/i 2 ' v 9k,/ 4/1=2kko 5k E/3-k 55 E/k-5 , 5k E/2-3 55 2/1-2 ' 53 4/1-2 5k 4/1-2
■ 1 ' .
I21-•
I
'■ Sweet orange " ./ ■ 8to ■bo , ' ' /g'tv' loi' range-; plate :"rang(
m
F/3-k : , ,5k /: 1/20.
E/k^ \ 5k- :3/2-3:
5k:
5 k '
-'Sk:/
: 5k
=2;
a2 / W :3 2-3'
H3:''5k';: V W :
■/
i: :
GoIok reactions reagent ac
different rootstocks tith i,lmen b© Eidgway Standards.
(Specimen Noo 1 to 12' obtained from University Citrus Farm at Temp®) Plot Eootstock Tfti-th , Color Description Plate
Noo . Uo 0 nature of top ' iiuith Ridgway St^ds=:'' Ho<.Remarks
1»' ' W h Sour orange (E=L<, top) Livid brown .38 Bark below the, bud-uniono - •
2o F/3 • ■ M / , (Wol»top) Veinonia purple 38 1 a
3o c/1 . n " (Valencia top) n 88, 38 . ii
ho D/16 ' « (EoLotop) ' Light brownish drab
k$ : : -11
. 5o . F A re '■« (HoNotop) Vetnonia purple 38 11
60 ,G/3 ' re ,9 (Valencia top) Brownish drab 16 11
7 0 G/5:' IS " 88 . 88: . , , : ; :
Deep brownish , drab
k$ «
80 F/5 « (¥c No top) M ffl h$ . ' re,.
9o D/12 , Street orange (EoLo top) Dephne red 38 18
10= , D/13 ' 81 81 0* 88 it ' : 38 ; 11
lie. ; ' D/17 88 ■ 81 ; 81 ' ' - M : n : 38 « , ■ ;
12= w Rough lemon (OoFotop) .. Russet vihaceous; 39 IS
•0 Local Spur orange Dark livid brown 39 Straight bark used
lll-o si ; Sweet orange : ; Livid brown 39 38 88 #
15o er Grapefruit ,: : i:..,/ , : . : Smpke: gray,;'; ' ' M6 83 U
.160 Rough lemon ' ‘ . ■ Light russet ' vinaeeous '■ • 39 83 ' n '
1?=' : Spur orange : ■ ■ Dephne red • • - 38 Straight-leaves '18 = ir ■ Sweet orange . . • Roeellin purple 38 # M #
1% n Grapefruit . ^. Pale aeru drab h6 38 US M
.20= H . Bough lemon " :. Dephhe' red , . , ': 38 M' W ' ".R:.
22
.. Table Jo’ ' Color Reactions of the Citrus Rootstocks tissues, idth. :
Serialv-loolo ; '
(According to: lidgway'StahdardsDescription of the - rootstock r-
Sour drasge (SoLoto] cendr® green
■ Remarks
Bark , obtained from '' ’' Tempe' citrus farm
[WoKotpp) :t; vv ;sulfate green ' . ; .. . : • i #
: : ■ II ' (Valencia top) .' .cendre;/gr#en. .\ - . . :
:;ti.o , ■ : % ;■ « (EJ = top) 1$ " ' # , . \ 'n ( « htop) : / » ■/::' ' ' • *\ ; . '■ 33
; 6i; ' :(Valencia top)- '
- # 1 ' :'.iit:,:" ' "M r-'-t ' ■
8 0 * . tw=iiiotop) r ' ; ; \. * n
•'■9® ;v''-' , 'Sweeiy^dhafhge; (E.oLotop) ,.y - •, ; 1 ” ; ; 88
1 0 0 . W, • 111,; ■ • 'y' # ' - y. *y : ' - /' ..■*/ #
lit/:’ 80 '# 'V. . , ,■•; • . ■ : . ‘ 19
12=; Rougi1' lenion l'OoFotdp) /.''r . ' #
13,: ■ Sour' prMge ,z 'light cendre1 green Straight bar^ bb» to cendr® green ; tained loyally
1W . .: , ;-Rdugh; lemon,:';'I, t: deep •.greenish ■ blue •-' - - '. X-''' - '%
is. , , light,-sulfate green , , 15 ■' • ' to/ sulfate; green •/. • , '
16. ^ ' Sweet/drange 1 cendre;; green.; , ■ • « ■ . • '■
11= ; Sour orange leaves / .1) . : .cendre p ’-een'; . Straight leaves obtained locally
l8» ; Rough lemon leaves : ; . deep, bluish green ■: ■' K : .
19= ' -. .Grapefruit leavfes ; sulfate' green, to . . ■'I,. . . ’ .
.20o,", ’Sweet.'orahge leavesaeep cenar'e green
’ 'cehdre green to ■.deep cendre green
.Color reactions Qf-.thp by (a) titanous chloride
eiteus rootstocks tissues feWid iCM'oride,.
• .go,' 'Titanous- chloride reagent-' v?:
; lo.: Sour- orange =■=' 2 o ’ Rough lemon =??; 3° Grapefruit ==■“ -
' : vRo' Sireet orarig©”- ho Rerric' chloride •
Barkli' Sbtar dranee ==-•
/: ■ .t'o Rough: .lenjon’’ === ■ 'J?:; a|>©Truit- ’ - V
ho Sweet .orange1 •
olive;:greens cloudy- 83 • Si • .. ffl •
light olive -greeny . cldudyu;dliye greeny cloudy
dark'’hrbwh-'81
?!
v . : .Remarks'. - ■ ■ •• Tests ifere repeated mary times to arrive at some eon= elusive findings s-‘hut no definite reaction was; avail” able, except.'very: slight " -difference in color shade=
Remarks
Thev above remarks' hold,
List and, method of preparation reagents used in the eitras . cation by Vthe Tissue Coloring. Test
lo Almen-, r.eagenti Weigh out, 110 'grains of'.,pure mercury in a beaker L10 cco ofred fuming nitrip. aeid,;CoFo: (spogr’c. '1<>60)o -i. - slight
shaking ■ will start at once, the chemical action accompanied by clouds of thick red fxmeso Place the beaker in a hood or use any other effective deirie:<a to keep the fumes from poisoning the atmosphere«In about am hour or sog the chemical action Will be eomplet® and the . fumes will cease* • Dilute the resulting liquid by adding to it; 220 cc* of di stilled water * ’ The Aimen reagent is .now. ready for use*
mixture of of distilled
Dissolve 100 Co* of ammonium
Pour, slowly' with.« 9 ec.o. of nitric acid 0oPo
grams of molybdie .acid in a.:■ (•■ sp'ogro 0*90) and 271 cc* eonsfant ■ shaking, into, a 60QL spo gro;, l»i$2} and'. 11^8 cco ol
distilled waterc
3o Tltanous.. chlorides This is used as a 20% solution in distilled water .and is obtainable in the ready mad® form .from chemical inanufaet=
■ _ ' ; . Appendiss: ■(B) ■ Identification of Rootstocks for qranges by methods• "..'■ ■:■■'.-■. 'v' .\y, . other than chemical tests. -v ■ ' ■ ■ , \ "
. , ' ;■; •,; ■ .'■ . According to v Wa„ Pa Bitters. (l) g the ahove-; described chemical .. ■: ^^‘bhlor'f @sts ;0f rbotstoek identification are reliable for sweet' orange' ’ .. 'f. : ; stock and sour .orange stocky, the reliability , of the method diminishest . for other types of stocks* Variables iW the age-of 1'the treea thickness. of the 'barkg the nearness of the samples to the todtiunions the scion'' 1 ' •' ■ varietyj, :' the1 freedom or the presence of disea.ses t-t® presence of surface -
contaminants^ et cetera,are all factors which may affect hhC- tasts and / -ren&r-Bd©titification:iit3hertaih,'t v ■ ' >1;: : / yy '
y ; . y In' tie# of the ShWe factsit would not be overemphasizing the i; ■ . value and usefulness of getting' at some morphological' or, physical .': features of these- rootstocks which could be utilised as a means toy . - verify and td: corroborate the findings arrived' at by the aforementioned
•' ycoloh tests o::; Jortunatelys 'hpwevers; foliage: characters - and the types ■; of bud=unions of; the eommonly used rootstocks have features ’ of their■ . •_ own. and an intelligent use. of these'milS' no doubt, greatly help solve
. the problem of'rootstock identification^ : BSlow are - given some of the
more important characteristics of the^e stocks that may be of. practical - -
; rFoliage:-.characters§ ; . P.-' ; v: -" ryi; "vy ':V;" ::yV-;-. y y./ y. /■ -r •' / ;v:v:-;ia;-'S#ety:braiige leavess:': They -are medium in size, pointed at the top
' and1 rathbrWbiitided at the base*. The. petiole is usually wingeds narrow t.y and does, not overlap the; leaf blade®. •. Moreoversythese'.leaves have "- . ■
petioles that a m only about one-third in size as compared to that of. th@ s'our orange leafs and for this.-reason'there shouM be no eon- ■ fusion between the two0 - ' Crashed leairesv of: this stodk ©mit no marked ,aroma either = ... ^
go. Sour, orange leaves8. Her© leaves are usually larger than those of the sweet:orangeo Petioles are also.relatively longer and more .broadly 'mngedc: The tip- of th©.,leaf is often pointed' and the base is , usually wedge^shapedo When erusheds the leaves yield'a peculiar pungent sort of aromao- ''.3o Grapefruit leaves s. They are larger in size than either sweet or : sour oranges .are .slightly oval, in shape s rather blunt at the tip and; rounded rather than wedge-shaped at- .'the base© The petiole usually ' . terminates with broad wings which more frequently touch or overlap the leaf-base© V . ■.
ho Bough lemon leaves: -These have rather an oval form terminating in a blunt tip© They are relatively of' light shade gzaeen color and are characterized by absence of any wings at -the leaf-base©. When .held up . . to light? the leaves reveal placements of conspicuous oil glands©
Bud-Unlon Features8 ' - ■ ;v- •
M study of the scion-stock combination at the point of the bud-
union fl’equently offers an added help in the rootstock identification© . This stu^- willj, of course r, be more dependable in eases where stocks - are budded high and planted high- in the orehardo If placed i@w5.,ideati- ' fication of the bud-union may cause - considerable , confusion as . "tffee roots would start close to the -soil surface and consequently may not reveal
the normal differences in the shape of the bud-=-union that wouM b®-, . nofieeable otherwiseo ■'■■■ , Y '■ ,v .
According to their form of .combinations .and'w©ntual 'developiQients the seion=stoek nnlons may be classified into .three - types as - follows g ,:
, (a) Smooth bud-union : 'hi's union results usually from a sweet'orange top on a'Sweef-prhhge,or rough lemon rootstocks In this ease, girth both of the stock and the scion is about equalo Bark of - the stoefc is smooths contours of the, bhion,' if anyg- are also .smooth .and -the color "of'the1: bar k' -iEl)©ye arid i^lbW'the 'tirdbn is. usually identic ale ' .
(b) jjnder'groirbh of. the stocks This would:<hold true when -gweet . drange.-Is budded On a; sour - orai e" stoeko In such a cases the under= groxrth of the stock is. usually quite nofieeables but Variations associated with different strains' within 'the same rootstock are., likely,
to oecfixV • There are. howevers "no distinquishable features in the bark- eharaetefistides of the Stock and the seion0 : ■
,. (c) Overgrowth of the stocki This, type of bud-unioh is frequently ’ met with where • grapefruit 1 s. used as. a stock -with sweet' oran%@ budded ■; at the tbpi - here- the stock., portion. displays an overgrowth relative to the; scion . portion giving. to>-the. foriaef. a sort of bulging.: eff ect o This . enlarged' base -feature in grapefruit;stock renders it readily distiaquish- able frm- sweet: orange or. rough lemon stoclcst:; - -
29
mmTUHEGiTi
lu, ’ BitterSy;Wo-Po .- Foliage [and bud "aaaion .characters of rootstocks ■' ; [fo - brangeso ; Galifornia Oitrdgraph 33(9ls378=379o
2o Carylj, Ro Eo Citrus culture in Califoruiao Calif <> AgriCo Exto . 'Serriee Cir= #lll'.s page lh~l$» »Jano l9U0s B,ev0 Feb0 19k6o
3 & Furr.3 .<3= ::R V and Beebes. P* Co. Identification of hybrid and meellar ; •. ’ . ’ citrus seedlings by a modification of the 'rootstock color •;
Eroco of Imo, SdCo for Horto Scio 19W«B®. Halmaj.Fo Po and Haass ■ Ao Ho 'Co identification of certain species
of citrus by colorimetric tests© Plant Pfagrsi'oloQr • Us26>-268* -v" ' / . , 1929. : ' ■;' • •" . ■ ' '."• ■So MasterSs> ho . C» " ' A review of laboratory tests for the determination
of eitrah rootstock varieties© Citrus leaves 28(3) s.21= 24s .' '.Marchp.; 19U8©.
s 'Ao and PaulP Mo Bo A dictionary of color» ; MeGrair Hill.Book Go00 Inco Hew fork» First Editions 1930=
7o- Ridgways Ro '. Color standards and color nomenclatur®© . Washington^Do Co 1912© ;
