Stability and phenotypic adaptability by AMMI analysis in cowpea beans (Vigna unguiculata (L.) Walp.)

ABSTRACT Cowpea beans (Vigna unguiculata (L.) Walp), is the most important legume in the Colombian Caribbean and is cultivated mainly by family-economy farmers under variable environmental conditions. This demands the identification of cultivars with greater adaptation and stability, since genotype - environment interaction (GEI) hinders the process of selection and recommendation of cultivars that, because of their genetic potential, exceed the current yield (600 kg ha-1). The objective of this study was to evaluate the adaptability and stability of 10 cowpea bean genotypes of semi-prostrate habit in eight environments of the Colombian Caribbean, during the years 2017B and 2018A; using the randomized complete block design with four repetitions. The analysis was performed using the additive main effects and multiplicative interaction (AMMI) model. The results showed highly significant differences at the level of environments, genotypes and GEI. The first three axes of the interaction were significant, selecting the first two for accumulating 81.84% of the sum of squares of the genotype by environment interaction. Genotype 2 showed the greatest adaptability and stability, but its performance was slightly lower than the average; genotypes 6 and 10 presented the highest grain yields, but were influenced by the environments, with the best response in favorable environments. The best environments corresponded to VN8A and SA7B.摘要 豇豆（Vigna unguiculata (L.) Walp）是哥伦比亚加勒比地区最重要的豆科作物，主要由家庭经营农户在多变的环境条件下种植。鉴于基因型-环境互作（Genotype-Environment Interaction，GEI）会阻碍筛选与推广那些凭借遗传潜力突破当前产量（600 千克·公顷⁻¹）的品种，因此亟需鉴定适应性与稳定性更优的品种。本研究于2017B与2018A年度，在哥伦比亚加勒比地区的8个试验环境中，采用设置4次重复的随机完全区组设计，对10个半匍匐生长型豇豆基因型的适应性与稳定性进行评价。分析过程采用加性主效应和乘积互作（Additive Main Effects and Multiplicative Interaction，AMMI）模型完成。结果表明，试验环境、基因型及GEI均存在极显著差异。互作的前三个主轴均显著，选取前两个主轴可累积基因型×环境互作平方和的81.84%。基因型2的适应性与稳定性最优，但产量表现略低于总体平均水平；基因型6与10的籽粒产量最高，但易受环境影响，在有利环境中可获得最佳响应。表现最优的试验环境为VN8A与SA7B。