Phenotypic, stability and adaptation analysis of vegetable pea (Pisum sativum var hortense L.) genotypes for high-temperature stress tolerance

• Climate change drives breeders to develop climate-resilient, high-yielding cultivars for multiple cropping. • Twenty-two pea genotypes were tested under High Temp stress (25–34 °C) across five environments. • High Temp stress affects plant height, pod number, length and weight, seed-weight, reducing pod yield by 96.79 %. • Pod formation, seed conversion, and pod weight & length were key traits for yield under stress. • VRPE-955, VRPE-29, VRPE-30, Kashi Purvi and VRPE-944 showed high yield under stress. Climate change has driven pea breeders to develop climate-resilient, high-yielding cultivars suitable for a wide range of conditions. Farmers prefer short-duration cultivars that can be planted early or late, maximising returns and supporting multiple cropping. The present study evaluated 22 vegetable pea genotypes under high-temperature stress (25–34 °C) in five environments, exposing plants to stress during the vegetative and reproductive stages. Compared to normal conditions, stressed conditions (TS1: T Max 34 °C, T Min 21 °C at vegetative stage; T Max 32 °C, T Min 15 °C at flowering) resulted in 39.4 % reductions in pod length, 70.7 % in plant height, 85.8 % in total pod formation, and 96.8 % in pod yield/hectare. Based upon five tolerance indices viz ., HSI, TOL, MP, PYR and YSI, the genotypes VRPE-955, Kashi Udai, VRPE-29, VRPE-30, Kashi Purvi and VRPE-944 exhibited high pod yield under stress conditions. Trait association analysis revealed that total pod formation/plant, ovule-to-seed conversion, 10-pod weight, and pod length are critical selection traits. PCA revealed that associations between traits varied across environments, with above-mentioned traits showing maximum loading on PC1. Stability analysis using AMMI and GGE biplots revealed that VRPE-100, VRPE-30, VRPE-953, VRPE-955, and VRPE-29 are well-adapted to high temperatures. Multi-trait stability indices showed that VRPE-953, VRPE-944, and VRPE-18 were the most stable, making them suitable for multi-cropping in variable conditions.