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 P-2) on carbon-isotope discrimination (Delta) and grain yield (GY) using near-isogenic lines of a durum wheat cultivar, LD222 in Japan an d Turkey. The location had major effects on variation of Delta and GY, but the effects of glume length on Delta and GY were little in overall environm ents. It was suggested that the gene P-2 had more adaptive effects than the P gene. The curvilinear relationship between Delta and GY is probably base d on the difference between the locations with relatively little genetic va riation.