Marker assisted transfer of anthracnose resistance gene Co-5 to elite French bean (Phaseolus vulgaris L.) background.

Anthracnose caused by Colletotrichum lindemuthianum is one of the most prevalent and severe disease of beans. Anthracnose resistance to most of the prevalent races in the state is provided by Co-5 gene. Therefore, deployment of this gene is more relevant as the lines developed under this study harboring Co-5 gene have potential to impart resistance against prevalent races. Hybridisation between a resistant genotype, TU having bean anthracnose resistance gene Co-5 and elite cultivar Arka Komal was done and further advanced to generate F1, BC1F1, BC2F1 and BC2F2 plants. Co-5 gene linked SCAR marker SAB3 was used for screening of hybridity of F1, BC1F1, BC2F1 and BC2F2 plants/pods. The results of the foreground selection in these plants revealed that out of a population of 50 BC2F2 plants, 36 plants portrayed Co-5 gene. Further foreground selection with SAB3 SCAR marker, revealed lack of segregation in 12 progenies. Screening of these progenies by detached pod and germinated seed dip methods using race 3 of C. lindemuthianum, validated Co-5 resistance in all 12 BC2F3 progenies. All 12 Co-5 gene-positive BC2F4 progenies were evaluated for 17 agronomic traits including 8 qualitative and 9 quantitative traits. Evaluation identified AKTU 19 and AKTU 33 lines that possessed better elite background. These progenies can further be advanced to isolate variety/(ies) directly or as prebred donor of anthracnose resistance gene Co-5 in the future breeding programmes. [ABSTRACT FROM AUTHOR]