Analysis of grain yield stability of new rice (Oryza sativa L.) genotypes originated from Iranian local cultivars

Genotype × environment interaction (GEI) effect is very important for plant breeders. Identifying the GEI effect would help breeders for better evaluation of different genotypes and select the superior genotypes based on both high grain yield and its stability. In this study, thirteen advanced rice genotypes orignated fromthe Iranian local rice varieties including two local rice cultivars (Hashemi and Saleh) as checks were evaluated in randomized complete block design with three replications at three locations (Rasht, Abkenar and Chaparsar) in two rice growing seasons (2014-2015). Analysis of variance indicated significant differences among rice genotypes for grain yield in three locations. GGE biplot analysis revealed that the first principal component (PC1) explained 77% of the total variation while PC2 explained 20%. Thus, the two components together accounted for 97% of the G GE variation for the grain yield in all environments. Two distinct mega-environments were also identified. The first mega-environment included; Rasht and Abkenar in which genotypes RI18430-47, RI18430-56, RI18430-87, RI18430-12 and RI18430-72 were the winners. The second mega-environment included; Chaparsar in which genotype RI18430-77 was the winner. RI18430-12 and RI18430-47 genotypes were selected as superior genotypes for their higher grain yield and its stability, intermediate amylose content, early maturity, suitable plant height, high head rice recovery and lower breakage. These two genotypes have been obtained from crossing between Saleh (improved cultivar) as a female parent and Hashemi (local) as male parent. Considering phenotypic characteritics, RI18430-12 was similar to the local rice variety with long grains and short black awns. The cooking quality of this line was as good as as local rice cultivars such as Hashemi and Domsiah. However, RI18430-47 genotype was similar to Saleh cultivar with bold and long grains. RI18430-47 has short awns and its grain quality with intermediate amylose content is better than Saleh cultivar, but lower than Hasehmi. Plant height of these two selected rice genotypes are short, and could be classified in early to medium maturity groups.