Use of AMMI and other stability statistics in the simultaneous selection of rice genotypes for yield and stability under direct-seeded conditions

Rice (Oryza sativa L.) is one of the most important cereal crops in the world. India is one of the largest rice-producing countries. Although more than 900 rice varieties have been released in India, many of them are no longer cultivated within a few years of release due to inconsistent performance in diverse environments; only a few varieties with stable performance continue to be under cultivation after 15 to 20 yr of their release. Development and adaptability of rice cultivars in a wide range of target environments are the eventual goals of plant breeders. An attempt has been made to estimate the level of genotype-environment interaction (GEI) and eliminate as much as possible the unexplainable and extraneous variability contained in the data. Therefore, several statistical techniques have been used to describe GEI and measure genotype stability. Field experiments were conducted with 12 genotypes under direct-seeded conditions (irrigated and rainfed) for three consecutive years (2009 to 2012) in a randomized complete block design with three replicates. The GEI was analyzed using additive main effects and multiplicative interaction (AMMI). Results of AMMI analysis indicated that the first three AMMI (AMMI1 to AMMI3) were highly significant (P < 0.05). The partitioning of TSS (total sum of squares) exhibited that the genotype effect was a predominant source of variation followed by GEI and environment, which suggests the possible existence of different environment groups. The AMMI stability value discriminated genotypes 11 and 12 as stable genotypes based on the yield stability index (YSI) and sustainability index (SI).