Evaluation of grain yield stability of irrigated barley (Hordeum vulgare L.) promising lines in temperate agro-climatic conditions of Iran-using GGE biplot analysis

The genotype and environment interaction is one of the main challenges in the breeding of different crop plants and causes different genotypes to perform differently under different environments. Assessment of genotypes and environment interaction for quantitative traits such as grain yield is very important for development of new improved cultivars.

Nineteen barley promising lines together with a commercial barley cultivar (cv. Behrokh as check) were evaluated across eight agricultural research stations in Karaj, Varamin, Neishabour, Mashhad, Birjand, Yazd, Isfahan and Shiraz (Zarghan) in 2020-21 and 2021-22 cropping seasons. Combined analysis of variance was performed for grain yield, andGGE bi-plot graphic analysis used fore the assessment of grain yield stability of barley promising lines.

The results of combined analysis of variance showed that the effects of location, genotype, year × location and genotype × year × location interaction effect were significant on grain yield. Mean comparison, using LSD test, showed that promising lines; No. 3, No. 4, No. 11, No. 12 and No. 13 with grain yield of 6673, 6663, 6412, 6340 and 6249 kg.ha-1, respectively, were high yielding compared with cv. Behrokh as well as others. The grain yield stability analysis facilitated to identify promising lines with with high grain yield and yield stability. In the first year lines; No. 3, No. 4 and No. 11, in the second year lines; No. 4 and No. 12 and in the two years lines; No. 3 and No. 4 were close to the ideal genotype.

Barley promising lines; No. 3 and No.4 were identified as high yielding with high yield stability. These promising lines are adapted to temperate agro-climatic condition in Iran and can be used in irrigated barley breeding programs. Of the eight test locations, Karaj was the most discriminative and representative environment. Therefore, this location can be recommended as a suitable test location for the selection of superior genotypes adapted temperate agro-climate conditions in Iran.