New  elite Potato clones with heat tolerance, late blight and virus resistance to address 

climate change

Manuel  Gastelo, Luis Diaz, Juan Landeo,  Merideth Bonierbale 

APA 2013 – 9th Triennial Conference June 30 – July 04, 2013  Naivasha ‐ Kenia

IntroductionPotato production in developing countries is expanding to warmerenvironments in search of income opportunities and food security,climate change is also already affecting weather patterns in traditionalpotato growing areas

The International Potato Center has developed a new populationdenominated LBHT (late blight resistance plus heat tolerance), withthe objective to obtain clones with:

Resistance to late blight

Heat tolerance

Mid‐early maturity (90 days).

Resistance to PVY, PVX

Drought tolerance

Good quality and agronomic traits

Causes of Climate ChangeIndustrial activity: from the early nineteenth century by the use of fossil fuels (CO2) 

Methane gas (CH4): from intensive livestock production .

Nitrous oxide (N2O): used in aerosolsincandescent lamps .

With this combination of factors and events thatcontribute to climate change, what happened incenturies before, now occurs in decades.

Effects of Climate Change

Greenhouse effect - Global warming

Drought

Effects of Climate Change on Potato

The rising temperatures and theappearance of new pests and diseasesaffecting the production of potato cropin the world.

The temperature rise from globalwarming is an ongoing process and withnegative effects both for the productionof traditional potato varieties as for newareas. So CIP decided to look for newvarieties adapted to heat.

Materials and MethodsPopulation LBHT: was developed usingRecurrent phenotypic selection, with fourseason cycle Season  II

1,000 ‐ 3,000Screening  under field conditions :  10 hill‐plot: San Ramon ( Jul – Oct)

Season IV50 ‐100

Screening under field conditions:  LB, HeatSan Ramon, Oxapampa, Majes, La Molina

Season I20,000 sedlings planted under

Greenhouse  for  screening by heatSan Ramon,  Summer (December –

April)

Season III100‐ 200

Screening under field  conditions: LB, Heat San Ramon, Oxapampa, Majes, La 

Molina

Selected clones (Parents)Stability,  VarietiesVirus  resistant test, drought Clean virus for export

San Ramon.‐ a warm rain forestenvironment at 800 m

Average temperatures in experimentsduring tuberization under field conditions,were 21ºC at night and 27ºC at day

Day

Night Night

# Locality Altitude masl Latitude Growing seasons Agroecological

zone Selection for

1 San Ramon 800 11° 08´ S Dry and Warm  Mid elevation tropics Heat

2 La Molina 240 12° 05´ S Spring ‐ SummerLowland tropics Heat

3 Oxapampa 1850 10°37´ S Spring ‐ Summer Mid elevation tropics Late blight

4 Majes 1294 16° 28´ S Spring ‐ Summer Mid elevation tropics Heat, Drought

Research sites in Peru and the potato growing seasons

Oxapampa  LB 1850 mals San Ramon  Heat 800 mals

La Molina Heat Spring Season 240mals

Majes Heat Spring – Summer Season1294 mals

Screening for virus resistence

All selected clones were screened for resistance to PVX and PVY bymechanical inoculation and grafftig in the greenhouse and index byELISA

For drought tolerance comparative fields with normal andrestricted irrigation were performed, for seletcion of clones wasused drought tolerance index DTI

Screening for Drought tolerance

Selection of clones with resistance to late blight were using scale ofsusceptibility development by Yuen and Forbes in 2009

Screening and Selection for Late Blight under field conditions

Yield Stability Analysis

2012 – 2013 : 61 advanced clones were assessesd for tuber yield in SRA, LAM ,MAJ under high temperatures

All trials were conducted in a simple lattice design 8x8 with 20 plants per plot

Two varieties were used as controls : Desiree, heat tolerant and Amarilis,heat sensitive

Traits measured : Plant vigor, maturity, Marketable tuber number, Marketableand Total tuber yield

The experiments were harvested at 90 days after planting

Stability analyiis was performed with AMMI stability model

The results of the AMMI model were interpreted on the basis of two AMMIgraphs for principal components and tuber yield

San Ramon La Molina Majes San Ramon La Molina MajesReplications 1 31.245* 27.161 26.757 57.682** 10.911 57.228*Genotypes 63 65.067** 138.491** 167.078** 68.459** 127.172** 184.397**Block/Replications 14 3.346 21.752 13.096 4.384 30.391* 13.842Error 49 2.793 14.402 9.882 3.009 12.745 10.785C.V. % 9.8 14.5 16.8 9.5 12 16.5

Total tuber yield  tha‐1Means Square

Source of variation df Marketable tuber yield tha‐1

ANOVA for Marketable and Total tuber yield (tha‐1) in three environments 2012‐2013

Results

Source of variation  df Means Square

Marketable tuber yield Total tuber yieldReplications/Environments  3 28.39*  41.90*Block/Replications/Environments 42 12.73  16.20*Treatments  191 153.63  177.78Environments  2 2997.12**  5007.20**Genotypes  63 200.92**  200.30**Genotypes x Environments  126 84.86**  89.90**PCA1  64  118.01**  134.53** PCA2  62 51.92**  45.88**Pooled error  147 9.03  8.80C.V. % 15.20 14.31

Combined ANOVA  for AMMI  model for Marketable and Total tuber yield (tha‐1) 

AMMI  Yield Stability Analysis

Stable Clones      Low tuber yield

Stable Clones      High tuber yield

  Unstable Clones      Low tuber yield

 Unstable Clones      High tuber yield

Tuber yield of 40 elite clones under San Ramon conditions in 2012

0

1

2

3

4

5

6

Clones

Scale

Resistance to Late Blight based on Scale of susceptibility in 40 elite clonesover five seasons years in Oxapampa, 2009‐2013

Total tuber yield tha‐1 

under  LB AUPDCFemale Male San Ramon La Molina Majes Oxapampa Oxapampa LB* PVX PVY Heat Drought

30 398098.203 393371.58 392639.31 21.29 41.83 11.48 24.03 199 0.75 ER T T

31 398098.204 393371.58 392639.31 16.81 29.98 16.65 24.93 94 0.47 ER T

32 398098.205 393371.58 392639.31 18.66 26.67 13.26 11.30 259 0.56 ER T

33 398098.231 393371.58 392639.31 20.37 21.37 13.28 21.85 18 0.19 ER T51 398201.510 393242.5 392633.64 24.54 35.05 30.65 19.41 529 0.80 ER ER T

55 398208.219 393371.58 392633.64 24.26 34.26 27.93 14.85 607 2.15 ER ER T T

56 398208.29 393371.58 392633.64 26.85 44.57 31.69 11.48 905 2.53 ER ER T

58 398208.505 393371.58 392633.64 21.29 38.19 24.87 48.63 59 0.44 ER ER T

60 398208.670 393371.58 392633.64 25.37 36.58 18.46 32.52 59 0.48 ER ER T36 398098.98 393371.58 392639.31 16.20 16.50 13.80 12.59 166 0.35 ER T

3 398017.53 391002.6 392639.31 26.50 36.70 19.20 15.37 488 0.93 ER T

62 Amarilis 11.94 25.00 11.33 13.37 1155 3.33 NT

63 Desiree 15.74 24.71 10.16 S T64 Granola 11.02 13.09 2.48 S T

Yungay 3.15 2079 6.00 NT

Kory 9.41 488 1.79 NT

#

Total tuber yield   tha‐1 High Temperatures Resistance Tolerance Pedigree

Clone

Eleven clones with early tuberization (90 days), heat tolerance, resistance to lateblight and extreme resistance to PVY suitable for mid‐elevation tropics and climatechange

In summary good progress has been achieved in this population and40 outstanding clones have been selected for their heat tolerance,resistance to late blight and high tuber yields and 90 days fromplanting to harvest.

In the screening for drought tolerance 10 clones were identified thatmaintain their yields under water deficit conditions and thatshowed higher values of drought tolerance index.

28 clones were stables and 12 were unstables but all with high tuberyield and were selected as elite clones.

Conclusions

Eleven clones with resistance to late blight, heat tolerance, earlytuberization, and extreme resistance to PVY suitable for mid‐elevation tropics and climate change; are available for varietydevelopment and further use in breeding.

29 mid‐maturing clones with heat tolerant, late blight resistantand early maturity but without extreme resistance to PVY can berecommended for highland conditions.

Harvest San Ramon 2012

Thank you