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Screening of IR50 x Rathu Heenati F 7 RILs and identification of SSR markers linked to Brown Planthopper ( Nilaparvata lugens Stål ) resistance in Rice ( Oryza sativa L . ). Student : Sanju Kumari 07-607-020. Chairman : Dr. N. Senthil Associate Professor. Rice.
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Screening of IR50 x Rathu Heenati F7 RILs and identification of SSR markers linked to Brown Planthopper (NilaparvatalugensStål) resistance in Rice (Oryza sativa L.) Student : Sanju Kumari 07-607-020 Chairman : Dr. N. Senthil Associate Professor
Rice • Stable food for more than half of the world’s population • Rice production in India – 99.37 million tonnes(2008-2009) • Production loss by biotic factor – 52% • Production loss by insect pests – 21% (Yarasiet al.,2008)
International Conference on Rice Planthoppers • 1970 – BPH became a threat in Indonesia, Thailand, India, Solomon Islands and the Philippines. • 1977 - IRRI organized the first BPH international conference • 2005 - Outbreaks of BPH in Vietnam, China, Korea and Japan • Biggest damage in china – 7.5 million ha area affected - loss of 2.8 million tonn of paddy
Theme - Planthoppers – New threats to the sustainability of intensive rice production systems in Asia
Brown planthopper • Four BPH biotypes have been reported so far. • Biotypes 1 and 2 - widely distributed in Southeast Asia • Biotype 3 - laboratory biotype produced in Philippines • Biotype 4 – occurs in the Indian subcontinent (Huang et al., 2001)
BPH resistant varieties released • IR26, IR 1561-228-3 : Bph 1 gene • IR36, IR38 : bph 2 gene • IR50, IR60 : Bph 3 gene
BPH resistant genes • Mudgo, TKM6 - Bph1 • ASD 7, IR1154-243 - bph2 • RathuHeenati - Bph3 • Babawee - bph4 (Lakshminarayana and Khush, 1977). • bph5 - ARC10550 (Khushet al., 1985), • Bph6 - Swarnalatha and bph7 - T12 (Kabir and Khush, 1988), bph8 in Chin Saba (Nemotoet al., 1989) • Bph9 - Kharamana, Balamwee and Pokkali (Ikeda, 1985) • Bph10 - introgression line of O. australiensis (Jena and Khush, 1990).
Bph3,bph4 -resistant to all four biotype • Bph5,Bph6.Bph7 - resistant to biotype 4 -susceptible to biotypes 1,2,3 • Bph8,Bph9,Bph10(t) - resistant to biotypes1,2,3
RathuHeenati • Sri Lankan indicarice cultivar RathuHeenati displayed a resistance to all 4 BPH biotypes • Bph3 locusis mapped on the chomosome 6 between two flanking SSR markers RM589 and RM588 within 0.9 and 1.4 cM,respectively. (Jairinet al.,2007) • QTL on chromosome 4 is a major resistance gene in RathuHeenati • BPH resistance gene was located between two SSR markers RM8213 and RM5953 on the short arm of chromosome 4 with map distance of 3.6cM and 3.2cM, tentatively designated as Bph17. (Sun et al.,2005)
Gomathi (2002) identified two SSR marker RM168 and RM186 associated with BPH resistance in F3 population of RathuHeenati • Jennifer (2008) identified the marker RM3180 on the chromosome 3 is linked for BPH resistance in F4 population of IR50 and RathuHeenati
Location of the gene • Bph1, bph2, Bph9 and Bph10 - chromosome 12 • Bph13, Bph15 and bph12 - chromosome 4 • Bph3 and bph4 - chromosome 6 • Bph6 - chromosome 11 • bph11 and Bph13, Bph14 and Bph19 - chromosome 3 (Jena et al., 2003; Sharma et al., 2003) • Bph18(t) - chromosome 12 (Jena et al.,2006)
Objectives Phenotypic screening of F7 families of IR50/RathuHeenati for the inheritance of BPH resistance. Identification of polymorphic SSR markers between IR50 and RathuHeenati parents in rice chromosome 3 Selective genotyping of the F7 families using identified polymorphic SSR markers Identification of SSR markersassociated with BPH resistance in rice chromosome 3
Materials and Methods • Plant Materials and insects 268 F7 RILs of IR50 and RathuHeenati Biotype 4 of insects • RILs population and method used for development single seed descent method • Evaluation of insect resistance Mass rearing of the BPH Standard Seedbox Screening Test
Molecular marker analysis Isolation of genomic DNA by Modified CTAB protocol (Ausubel et al.,1994). Quality check of DNA by Agarose gel electrophoresis Quantification of DNA by Nanodrop Spectrophotometer • SSR genotyping of parents and F7 RILs
SSR genotyping of parents and F7 RILs • PCR amplification of genomic DNA was done using forward and reverse microsatellite primers • Resolution of polymorphism through agarose gel electrophoresis and denaturing Polyacrylamide gel electrophoresis. (PAGE) • Staining and developing the gel • Analysis of banding pattern
Parental polymorphism 53 SSR Primers • Phenotypic screening of F7 RILs of IR50/RathuHeenati • Time-period of the phenotyping screening :
Result • Phenotyping the IR50 x RathuHeenati F7 RIL population for BPH resistance
cont…… • Selective genotyping of the resistant and susceptible F7 RILs • Identification of SSR markers linked to BPH resistance • Co-segregation Analysis
Future prospects • The selected resistant F7 RILs can be used for development of resistant varieties. • Possibilities of Fine mapping of BPH resistant gene of the reported region on chromosome 3 with more markers. • Marker assisted breeding • Map based cloning for isolation of BPH resistant gene • Marker assisted gene pyramiding