BREEDING VEGETABLES FOR DISEASE RESISTANCE:
ISSUES AND STRATEGIES
Dr. JAG PAUL SHARMAProfessor & head
Division of vegetable science &floricultureSKUAST-JAMMU
Appraisal Sheet
35-40%1,00,00010,000100030,00020,00016003 million tons2 million 1.40 lakh ton0.7 kg/ha3.7 kg/ha10.5%
World wide crop losses due to diseasesCrop pests:- Microbial pathogensInsect-pestsNematodesWeedsPesticidial formulations in use world wideCommonly used formulationsEstimated annual consumptionsPersons adversely affected per annumIndia's pesticide consumption (annually)Per capita consumption of pesticides in IndiaPer capita consumption of pesticide in EuropePre-harvest losses in vegetables
StatusFact
Issues in disease resistant breeding
• Yield losses due to diseases• Quality deterioration both due to diseases and
pesticides• Unpredictable fluctuations in vegetable production• Pesticide contamination of soil, water and atmosphere• Export problems• Development of chemical resistance in pathogens• Human health problems• Development of Organic Farming
YIELD LOSSES DUE TO SOME MAJOR DISEASES IN INDIA
503140-1008518-2520-305020-50235020-40
Yellow vein mosaic virusLate blightLeaf curl virusPotato mosaic virusCassava mosaic virusBlack rotStem rotWilt and root rotWilt and root rotRustPowdery mildew
OkraPotatoTomatoPotatoCassavaCauliflowerCauliflowerGarden peaChilliSoybeanGarden pea
Yield loss (%)DiseaseDiseases
Sources: Dasgupta et.al. (2003), Grover and Gowthaman(2003) and others
QUALITY DETERIORATION
• Yellow vein mosaic infection in okra• Black rot in cauliflower, broccoli and
cabbage• Bacterial spot and Alternaria blight in
tomato• Phomopsis blight in brinjal• Anthracnose infection in chilli• Rust in vegetable pea
Pestcide residue problem
• Water Pollution: Threats to aquatic flora and fauna• Adverse effects on pollinators and silk worm• Soil pollution: Threats to soil productivity
Organic matter decomposition Nitrogen transformation Phosphate and trace element availability Soil enzyme activity
• Quality deterioration: Contamination incidence( Based on analysis of 13000 samples)
Vegetables : 53.7% Fruits : 42% Spices : 71%
• Human health problems• Export problems
Problem of pathogen resistance to pesticides
• World wide 504 insect-pests, mites and spiders have developed pesticide resistance including 31found in India
• Three pathogens of apple show pesticide rersistanceVenturia inaequalis (Apple scab)– Dodline(Cyprex), Benzimidazole (Benlate), Thiophanate methyl(Topsin M)Erwinia amylovora (fire blight) – Streptomycin (Agrimycin-17)Psuedomonas syringae (blister spot) – Streptomycin• Some level of pesticide resistance observed in
Late blight of potato pathogen– Phytopthrora infestansBlack rot of cole crops pathogen – Xanthomonas campestris
Objectives in vegetable breeding for disease resistance
Leaf curl, Early blight, Bacterial wilt, Alternaria blight, Root knot nematodeLate blight, Various potato virusesPurple blotch, Stemphyllium blightRoot rot, Sclerotinia blight, Phomopsis blightAnthracnose, Leaf blight, Leaf curl, Bacterial wiltBlack rot, Downy mildew, Pith rotAnthracnose, Leaf spot, Downy mildewDowny mildew, Mosaic virusesPowdery mildew, Downy mildew, AnthracnoseYellow vein mosaic virus, leaf curlRoot & stem rot, collar rot, powdery mildew
Tomato
PotatoOnionBrinjalCapsicum sppCole cropsBottle gourdCucumberWater melonOkraPea
DiseasesVegetables
Research priorities for multiple resistant F1 hybrids
• Tomato : TLCV+ Early blight + Bacterial wilt + RKN• Brinjal : Phomopsis + Bacterial wilt + Fruit-shoot borer• Chilli : Leaf curl + Thrips + Mites + Anthracnose• Capsicum: Phytopthora + Thrips + Mites• Okra : Yellow vein mosaic virus + Fruit borer• Onion : Stemphyllium blight + Purple blotch + Thrips• Cucumber : Downy mildew + Mosaic viruses• Muskmelon : Powdery mildew (PM) + Downy mildew +
Anthracnose + Fusarium• Watermelon : PM + Downy mildew + Anthracnose• Cabbage & Cauliflower: Black rot + Diamond back moth
Breeding Strategies
• Short term strategies : 1 – 3 yearsI ) IntroductionII ) Selection• Medium term strategies: > 3 – 6 years
I) Intervarietal hybridization (related gene pool)II) Acquired resistance (LAR / SAR)• Long term strategies : > 6 years
I) Backcrossing methodII) Transgenic technology
Disease resistant introductions in vegetables
TaiwanUSAUSATaiwanUSAUKBangladeshUSAUSATaiwan TaiwanUSAUSAUSA
Club root & black resistanceMultiple disease resistanceMultiple disease resistanceMultiple disease resistanceMultiple disease resistancePink rot resistanceYVMV resistanceMultiple disease resistanceMultiple disease resistanceTMV & BW resistanceFusarium wilt resistanceFusarium wilt resistanceWilt resistanceFusarium wilt & Gummy stem blight resistance
EC 168041-42EC 175800-06323333345978320526378476-773056163330956399828-38321890-928383809378523-24333659-69217073-74
CabbageCauliflowerChilliChinese cabbageCucumberGarlicOkraMuskmelonTomato
Watermelon
CountryResistant characterAccessionCrop
Varieties developed through simple selection
Copenhagen market
Kt-Sel-1Local materialDenmark introductionSingapore introductionHong Kong marketPhilippinesBati
Golden acrePride of India Early green Superlal Pusa ChetkiArka NishantAgrifound ParvatiPusa BarsatiArka Jeet
Cabbage
BrocolliCarrotRadish
GarlicCowpeaMuskmelon
PedigreeVarietyCrop
Varieties through intervarietal hybridization
Hissar LalitPusa Bhairav, Pusa AnupamPant SamratPant C-1, Pant C-3Punjab LalPusa ShubhraArka AjitPhule greenJBS 2
Varieties
Root knot nematodePhomopsis blightBacterial wiltVarious chilli virusesViruses, fruit rot, die backBlack rot, curd blightPowdery mildew, rustDowny mildewYVMV
Resistant to
TomatoBrinjal
Chilli
CauliflowerPeaBitter gourdOkra
Crop
Cases of induced resistance in vegetables
Scab pathogenFusarium (avirulent form)
Fungal elicitors
Non-pathogens of beans2,6-dichloroisonicotinic acid
PhytophthoraSalicylic acid
Prior inoculation
AnthracnoseSame wilt fungus
Anthracnose fungus
Anthracnose fungusScab, rust & blister blight
Same fungusAlternaria blight
CucumberLAR
MuskmelonSARGreen beanLARSAR
TomatoSAR
Resistance againstCrop /AR
Recurrent parent X Non-recurrent parentF1 x Recurrent parent ( BC1) Backcrossmethod BCI x Recurrent parent ( BC2 ) F1 / BC2 generationF2 population (single selection plant practised) F3 Progenies PedigreemethodF4 progenies F5 progenies F6 progenies
Yield trialsFigure Backcross- pedigree method. Adopted from Kalloo(1988)
Late maturity Early maturityLarge fruit Small fruit(Punjab Tropic) PT X HS-102
Selection PT x F1 x HS-102 Selection For forEarly PT x BC1 BC'1 x HS-102 larger fruit Maturity sizePT x BC2 BC'2 x HS-102BC3 X BC'3 F1
BC3 F2 BC'3 Selection for early maturity and larger fruit size in tomato Figure Double backcross method
Recurrent parent A X Non-recurrent parentF1 x Recurrent parent ABC1 x Recurrent parent BBC2 x Recurrent parent BBC3 x Recurrent parent CBC4 x Recurrent parent CBC4 generationSelfingAdvancing to F2 generation, single plant selection is practised.Figure Multi-recurrent parent backcrossing
Donor parent X Recurrent parent (Alfalfa selection (Alfalfa California common)
resistant to wilt) F1 hybrid
SelfingF2 generation
Screening for wilt X Califorma Commonresistant plant
BC1 F2 generation X California CommonScreen for wilt
resistanceBC2F1 wilt resistant X California common line possessing
Leafspot and mildew resistanceBC3 F1 with mildew X California Common
and leaf spot resistanceIntercrossing of BC4 F1 plants having multiple resistance
against wilt, mildew and leaf spot resistantIntercrossing of BC4 F2 population
having multiple resistanceProgeny testing
Selection of 50 most resistant progenies they are intercrossed to produce California Common composite with multiple disease resistance.
Figure Use of backcrossing in improvement of cross-pollinated crops
A X B A X C A X D
F1 X B F1 X C F1 X D
BC1 X B BC1 X C BC1 X D
BC2 X B BC2 X C BC2 X DBC3 BC3 BC3XF1 X
F1
F2
Selection of plants possessing desirable featuresfrom donor parents B, C and D and intercrossing
Development of transgressive varietiesFig . Convergent breeding procedure involving backcrossing system
Distant hybridization in disease resistance breeding
Late blight, Early blight, Fusarium wilt, Bacterial wilt, Leaf curlCurly top virus, TMV, Verticellium wilt, RKN
Stemphyllium blight, Purple blotch, pink rot, Smut
Damping off, Leaf spot, Sclerotinia rot, Leaf curl, Mosaic virus, Pseudomonas wilt
Phomopsis blight, Little leaf, Fusarium wilt
TomatoLycopersicon pimpinellifoliumL. PeruvianumOnionAllium fistulosumChilliCapsicum frutescensBrinjalSolanum incanum
Diseases against which showing resistanceCrop/species
Steps in transgenic technology
• Identification of disease resistant genetic stock
• Isolation of target gene (s)• Multiplication of the target gene• Integration of the target (transgene ) into the
host genome• Confirmation of genetic integration• Regeneration of the transgenic cell• Field evaluation of transgenic plants
Anti-fungal compounds for which genes have been cloned
• Pathogenesis related proteins (PR1 to PR5)• Ribosome binding proteins• Small cystein-rich proteins• Lipid transfer proteins• Storage albumins• Polygalacturonase inhibitor proteins• Anti-viral proteins• Non-plant anti-fungal proteins
Virus resistant transgenics in various vegetable crops
Tomato mosaic virus, yellow mosaic virus, cucumber mosaic virusZucchini yellow mosaic virusZucchini yellow mosaic, watermelon mosaic-2, Cucumber mosaic virusZucchini yellow mosaic, watermelon mosaic-2Tomato spotted wilt virusPotato leaf roll, Potato virus X and virus YLettuce mosaic virus, Tomato spotted wilt virusBean pod mottle virus
Tomato
MuskmelonCantaloupeCucumberSquashPepperPotatoLettuceBean
VirusesVegetable
ConclusionEvolution of resistance in host plant and pathogenicity in pathogen are the counteracting processes and have evolved in response to their struggle for existence. However, Human interventions have provided protection to several susceptible crop varieties by transferring disease resistance to them with sole objective of ensuring food and nutritional security to 6.5 billion people of the world. Thus, development of resistant varieties in cultivated plants is an unending human war against microbial pathogens.
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