Stability analysis and genotype × environment interaction for grain yield of rice (Oryza sativa L.) promising breeding lines

Improvement of rice characteristics of Iranian traditional and high-yielding cultivars is very important in rice breeding programmes for sustainable rice production in Iran. Therefore, a total of seven advanced promising breeding lines of rice were tested for their adaptability and genotype × environment interaction in 2014 to 2016 and four locations at Amol, Babol, Behshahr and Tonekabon, Iran. Results of analysis of variance showed significant differences among these promising breeding lines and their parents as well as check cultivars for important characteristics such as grain yield, plant height, panicle number per plant, grain per panicle most of environments. It's found that promising breeding line G1 (AN74), originated from Alikazemi × Nemat, was significantly early maturity as compared with other lines, and was similar to Tarom-Mahalli, a local variety. Combined analysis of variance indicated that year, year × location, genotypes × location and year × location × genotype interaction effects were significant on grain yield. According to the adaptability analysis for grain yield, we found that two promising breeding lines; AN74 (G1) with bi=0.62 and an average yield of 6500 Kg/ha showed specific adaptation in central Mazandaran, while genotype TS84 (G7) with bi=0.89 and average yield of 8089 kg.ha-1 with higher yield and yield stability in most of the environments. Analysis of genotype × environment interaction through AMMI method showed that two first components of interaction (IPCA1 and IPCA2) were significant explained 36.8 and 26.1 percent of the variation in grain yield, respectively. The promising breeding line AN74, of Ali-Kazemi background, with an average of 97 days to 50 percent flowering, plant height of ~85 cm and intermediate amylose content (20~24 %) was identified as a suitable promising breeding line for centeral areas of Mazandaran. Another suitable promising breeding line with Tarom background, TS84, was well adapted to rice growing areas in Mazandaran. Therefore, these two promising breeding lines; AN74 and TS84 can be considered for further verifications on farmers’ fields for being released as new rice cultivars.