Tolerance to post-emergence herbicide Imazethapyr in chickpea

The present research work aimed at identification of sources of tolerance to herbicide Imazethapyr for their possible utilization in development of herbicide tolerant 'chickpea. Sixty five genotypes (55 desi and 10 kabuli) screened included accessions from ICRISAT core collection, advanced breeding lines and cultivars. The herbicide tolerance score ranged from 1.9 to 5.0. Nine tolerant to moderately tolerant and three susceptible genotypes were further evaluated under control and sprayed condition. Genotype x environment interactions were observed fol.' days to 50% flowering, NDVI, days to maturity, seed yield, biomass, harvest index, 100-seed weight and branched chain amino acids (BCAA) viz, valine, leucine and isoleucine content. Highly significant reduction in seed yield was observed in all the genotypes except ICCV 10, ICCL 82104 and ICC 1710 as revealed by pairwise comparison of means using Tukey's test. The spraying of herbicide reduced the total biomass production. Analysis of BCAA content in sample revealed non-significant differences for percent valine content in ICCIL 04001, ICCV 00305, ICCV 96003 and ICCL 82104, for isoleucine content in all the genotypes except, ICCV 3 and ICCV 96003 and for leucine content in case of ICCV 03407, ICCIL 04001, ICCV 10, ICCV 96003, ICC 1710, ICCV 00108 and ICCL 82104. The genotypes tolerant to post -emergence herbicide Imazethapyr identified based on non-significant reduction in the yield attributes and BCAA content in the sample were ICC 82104, ICCV 10, ICCV 96003, ICC 00305 and ICC 1710. These genotypes can be used to study the genetics of herbicide tolerance in chickpea and in breeding programs for developing lines with tolerance to post -emergence herbicide Imazethapyr.