BIPLOT ANALYSIS OF SEED YIELD OF FABA BEAN GENOTYPES AT DIFFERENT PLANTING DATES

The magnitude of interaction indicates the influence of planting date on adaptability and stability, which is a desired character only when it is connected with yield above average (Yan and Hunt, 2003). [...]the genotype x planting date interactions were studied on seed yield by biplot method. Since the second principal component (PC2) score play a significant role (19.7%) in explaining the genotype x environment (planting date) interactions (GEI), the first principal component (PC1) score were plotted against PC2 score, to further explore adaptation (Figure 1 B.). The TT Biplot indicated that the ideal genotype must have a high PC1 value (high mean productivity) and a PC2 value next to zero (more stable). [...]based on the graphic interpretation, the genotypes with the highest PC1 values were G1, G3 and G2, respectively. According to this polygon view of biplot, the autochthonous landrace from north of Iran (G1) were as a genotype with high mean productivity, but their stability in four planting date is low.