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Subject: Biotechnology × Author: Hegde, Shrinidhi S. × End date: 2016 × Start date: 2014 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Marker Assisted Introgression of Pi1 and Pi2 Genes for Blast Resistance in Intan Variety of Rice
    (University of Agricultural Science, Dharwad, 2016-03) Hegde, Shrinidhi S.; Prashanthi S. K.
    The most devastating diseases that constrain rice production is rice blast, caused by Magnaporthe oryzae, ranking first in threat to high productivity. The use of resistant cultivars is the most effective and economical way to control rice blast disease. “Intan” is a medium slender indica variety, popular with farmers and consumers across Karnataka because of its high yield and excellent popping quality. However, this variety is highly susceptible to blast disease. The present study was aimed to improve Intan variety for blast resistance. Near isogenic lines (NILs) in BPT5204 background carrying blast resistant genes Pi1 and Pi2 were used as donor parent to introgress these genes into Intan variety using marker assisted backcrossing (MABC). Molecular markers genic/linked, flanking and unlinked to Pi1 and Pi2 gene were used for foreground, recombinant and background selection respectively in marker assisted selection (MAS). Genic/linked markers RM224 (0.0 cM), RM1233 (0.0 cM) for Pi1 gene and AP5930 (0.0 cM), AP5659-5 (0.10cM) for Pi2 gene were polymorphic and were used for confirmation of hybrids. Flanking markers RM144 (3.0 cM), RM206 (18.2 cM) and AP5413 (1.2 cM), RM6836 (1.5 cM) were polymorphic between the parents for Pi1 and Pi2 gene respectively. Among 63 genome wide markers, 26 markers were polymorphic between Intan and BPT5204 NIL possessing Pi2 gene. F1 plants were generated by independent cross for both the genes and hybridity was confirmed. One plant out of seven plants for Pi1 gene and ten plants out of thirty two plants for Pi2 gene were confirmed to be heterozygous. Wx marker linked to Wx gene responsible for amylase content was also used for hybrid confirmation. Further, these F1 plants were challenge inoculated with Magnaporthe oryzae isolates and F1s showed resistant reaction, confirming the hybridity. Confirmed F1 plants were backcrossed to generate BC1F1 plants.