Stability analysis for pod yield and component traits and validation of powdery mildew resistance in garden pea

Abstract

The experimental material comprised of 48 genotypes was evaluated in Randomized Complete Block Design with three replications at five diverse locations by creating seven environments during 2016-17 and 2017-18 viz., Bajaura (E1), Dhaulakuan (E2), Una (E3), Palampur (E4) and Natural Farming at Palampur (E5) during winter 2016-17, Kukumseri (E6) during summer 2017 and Palampur (E7) during winter 2017-18. The advance breeding lines SP-3 (83.35g) followed by SP-6 (79.45g) and SP-22 (76.90g) significantly produced more pod yield than check Pb-89 with an increase of 20.2%, 14.6% and 10.9%, respectively over the environments which was mainly attributed to their desirable performance for important pod characteristics. They also showed comparable performance for total soluble solids, ascorbic acid and protein content besides having long, lush green pods. Joint regression analysis revealed that G × E (linear) was signiand#64257;cant for days to first picking, plant height, harvest duration pods/plant, pod yield/plant, average pod weight and protein content, whereas non-linear component was signiand#64257;cant for all the traits. Of the 48 genotypes, only seven genotypes including the high yielding lines SP-6 and SP-22 showed stability for pod yield based on Eberhart and Russell model. Both these genotypes also showed stability across environments for majority of the economic traits. G+GE biplot model extrude that Dhaulakuan was the most representative and discriminating environment for pod yield i.e. suitable for selecting generally adapted genotypes. Which won where polygon view also showed that SP-3, SP-6 and SP-22 were in general stable across the environments for pod yield and other desirable traits. Screening for powdery mildew resistance under field and in-vitro conditions revealed that 10 genotypes viz., SP7, SN-1, SN-6-1, SN-7-1, SN-2, SN-5-2, SN-6-2, SN-21 and SP-28-1 along with Palam Sumool were found resistant for powdery mioldew disease. In addition, 27 lines including SP-3, SP-6 and SP-22 were moderately resistant whereas check Azad-P1 was highly susceptible. It can be concluded that high yielding lines viz., SP-3, SP-6 and SP-22 showed stability for majority of the desirable traits across the environments along with moderate resistance to powdery mildew disease both under field and in-vitro conditions and thus, can be exploited for commercial cultivation.