Relative Discriminatory Ability of GGE Biplot and YS; in the Analysis of Genotype x Environment Interaction in Okra(Abelmoschus esculentus)

摘要

The variation of response of genotypes to environments has made multi-environment study a necessity in plant breeding. Twelve Okra genotypes were tested over three environments (locations) Ibadan, Abeokuta and Ayetoro to study the effects of Genotypeby Environment Interaction (GEI) on seed yield. Seed yield data were subjected to Yield stability index (YS;) and Genotype plus GenotypexEnvironment Interaction (GGE) biplot in order to select desirable genotypes for yield and stability and to compare the relative discriminatory ability of the two techniques. The GGE biplot and YS; techniques jointly identified NHGB/09/009A as the genotype that best combined high yield and stability; and FUNAAB-11-4 and FUNAAB-11-6 as having good potential in this regard. The YS; in addition, also selected FUNAAB-11-8, FUNAAB-11-3 and LD-88. The three genotypes solely selected by YS( did not consistently produce above average yield across the three locations indicating that YS; was less reliable in the selection of genotypes for high yield and stability. Also, the mean yield of the selections by the two techniques were statistically similar indicating that the selection of high yielding but unstable genotypes would not be of any practical advantage in a selection programme. The GGE biplot identified two mega-environments viz Ibadan and Ayetoro where FUNAAB-11-8 was outstanding and Abeokuta where FUNAAB-11-3 was the best. It identified Ayetoro as the best location for the selection of superior genotypes. Okra genotypes NHGB/09/009A, FUNAAB-11-4 and FUNAAB-11-6 would therefore be desirable for cultivation across the three environments.