Unveiling genotype x environment interactions towards identification of stable sources of resistance in chickpea-collar rot pathosystem exploiting GGE biplot technique

The pervasive soil-borne pathogen Sclerotium rolfsii (Sacc.) is responsible for collar rot (CR) of chickpea identified as one of the major production constraints for its cultivation worldwide. Presence of wider host range and absence of stable resistance sources against the pathogen makes it more difficult to manage, and seeks urgency towards identification of new sources of resistance. Environment play vital role towards host-pathogen dynamics also impact disease management. This study was focused on deciphering genotype x environment interactions with the objective of delineating and validating durable resistant genotypes against CR, identifying a suitable testing location. Initially, from 81 genotypes, 25 promising genotypes were selected based on their disease reaction (< 20%) against CR and evaluated further across three locations in two consecutive years. The test result from GGE biplot analysis suggested higher proportion of variation in CR reaction due to genotype than environment. It also confirmed the presence of inconsistent genotypic response, thus supporting the need for multi-location, multi-year trials. In the present study, selected locations grouped into two environment clusters suggesting the existence of cross over interaction with delineation of genotypes based on specific adaptation. Integration of GGE biplot as well as REML/BLUP analysis identified 'FLIP07-314C-S2' as the ideal genotype whereas, FLIP10-81C as well as FLIP10-6C as desirable genotypes considering their static response against CR. Moreover, FLIP07-314C-S2 was detected as the winning genotype in cluster I and XIIth77-S2 as best performing genotype in cluster II. Genotypes detected in the present study could be recommended for their future deployment in chickpea resistance breeding programme.

Automated summary

The study aimed to investigate genotype x environment interactions to identify durable resistant genotypes against collar rot in chickpea. 25 promising genotypes were selected based on disease reaction and evaluated across three locations in two consecutive years. The results indicated that genotype had a higher influence on disease reaction than environment, supporting the necessity for multi-location, multi-year trials.