Gpc-B1 mediated grain protein enhancement in wheat is compatible with high grain weight at moderated yield thresholds

A set of 94 BC2F7 lines (BC RILs), selected for presence of Gpc-B1 gene from the cross Glupro/3*PBW568 were evaluated for morpho-physiological characters including yield and its components, grain protein content, grain zinc and iron concentration for two seasons. Gpc-B1 mediated grain protein enhancement as influenced by combination of other agronomic traits was studied through inter-trait correlations. Grain protein content was positively correlated with plant height (r=0.552**, 0.676**) and 1000-grain weight (r=0.257**, 0.287**) in both years. Lines with high yield conferring combinations of yield components showed lower grain protein content. The results showed that there were no constraints for combining grain weight with Gpc-B1 mediated proteins enhancement provided yield moderation can be exercised. Grain protein contents showed significant and positive correlation with grain zinc (0.557**, 0.764**) and iron concentration (0.542**, 0.595**) indicating that Gpc-B1 mediated enhancement in protein content and not just presence of Gpc-B1 was necessary. Zinc and iron concentration were also positively associated with each other (0.567**, 0.648**).