Exploring GGE biplot, stability index, correlation, and clustering analysis for growth and seed yield-related traits in celery (Apium graveolens L.)

The effect of genotype by environment interaction is one of the limiting factors for successfully identifying superior genotypes in plant breeding programs. The study aimed to identify celery genotypes with high and stable yields across different environments by assessing G×E interactions, stability indices, and associations between agronomic parameters. Twenty celery genotypes were sown in randomized complete block design field trials at three locations in Punjab, India, viz., Amritsar, Ludhiana, and Gurdaspur during 2018-19, 2019-20, and 2020-21. Phenotypic data for thirteen agronomic parameters were collected for the GE interaction study. The investigation mainly focused on the significance of GGE biplots in explaining G×E interactions based on seed yield-related traits. Results revealed significant differences in genotypes, locations, years, and interactions in the studied traits. The WAASB (Weighted Average of Absolute Scores) stability index estimation was highlighted to identify superior genotypes with maximum seed yield and high stability. The investigation specified the suitability of MTSI (multi-trait stability index), which considers multiple traits through genotype-ideotype distance, for assessing stability. Seed yield showed a positive and significant correlation with primary branches and umbels per plant that would be effective in simultaneous selection for multiple traits. Based on MTSI, three genotypes, PAU1, PAU9, and PAU10, were identified as stable and high-yielding across all three tested sites. The investigation suggests that efforts should focus on identifying location-specific genotypes using multi-location and multi-year data for varietal releases rather than emphasizing the overall performance of genotypes.