Yield and carbon isotope discrimination in near-isogenic lines of durum wheat differing in glume length

The objective of this study was to assess the effect of the genes for long glume (P and P2) on carbon-isotope discrimination (x) and grain yield (GY) using near-isogenic lines of a durum wheat cultivar, LD 222 in Japan and Turkey. The location had major effects on variation of x and GY, but the effects of glume length on x and GY were little in overall environments. It was suggested that the gene P2 had more adaptive effects than the P gene. The curvilinear relationship between x and GY is probably based on the difference between the locations with relatively little genetic variation.