Genetic Variability and Diversity for Yield and Yield Attributing Traits in M₃ and M₄ Generations of Butter Bean (Phaseolus lunatus L.)

Butter beans (Phaselous lunatus L) belong to the family Leguminaceae, is one of the oldest cool season food legume crops. A throughout knowledge of existing genetic variation among yield and its yield component traits is essential for developing high yielding varieties in butter bean. Realizing the importance of genetic diversity and variability in key economic characters, the present investigation had been planned to assess the genetic diversity and variability in for yield improvement in butter bean breeding programme.

Investigation was carried at Horticultural Research Station, Tamil Nadu Agricultural University, Kodaikanal, Tamil Nadu during 2019-2021. A total of 2734 M₂ mutant lines were evaluated as individual progenies in the previous study. Stringent selection was made based on yield, earliness and plant habit and a total of 35 mutant lines were identified and forwarded to M₃ and a total of 12 mutant lines for M₄ generations in present study. The data on elevan quantitative were analyzed using Mahalanobis D² statistic.

The present study has assessed the genetic variation among studied traits of butter bean mutants for yield and its component traits. Thus, a total of five mutant lines namely BBMG-7-9-7, BBMG-9-10-6, BBMG-18-9-6, BBMG-25-13-3, BBMG-35-7-2 were identified to be forward to the M₅ generation as promising mutant lines for developing high yielding varieties and to test its homogeneity and stability.