GRAIN PROTEIN CONTENT AND YIELD IN CHROMOSOME 7B RECOMBINANT SUBSTITUTION LINES

Increasing wheat grain concentration is desirable in or-der to meet requirements of bread-making industry and wheat markets, but protein concentration tends to be negatively correlated with yield. High protein line F26-70, created at NARDI Fundulea, was identified as a prom-ising parent in breeding, having acceptable yield. We studied the effect of chromosome 7B from F26-70 on pro-tein content, yield, and yield components, by testing 45 recombinant substitution lines derived from the cross Favorit//Favorit/F26-70 (7B) in 2006 and 2007, in field trials, with and without nitrogen fertilization. Genes located on chromosome 7B of line F26-70 had significant effect on grain protein concentration and protein content per kernel of recombinant substitution lines, but not on grain yield, weight of 1,000 grains and number of grains per square meter. In the conditions of our trials, protein content was negatively associated with grain yield only in a dry year without nitrogen fertilization. Association of high protein content with earliness was significant in three out of four conditions. The interaction between RSLs and nitrogen fertilization was not significant, sug-gesting that the high protein gene(s) on chromosome 7B might be useful at a wide range of nitrogen availability. Our results preliminarily suggest potential usefulness of 7B chromosome genes of F26-70 in breeding for increased grain protein concentration, without significantly reduc-ing grain yield. Further studies to estimate the effects of F26-70 7B chromosome in a modern genetic background and in more high yielding environments are necessary to confirm the real breeding value of this chromosome. Key words: wheat, chromosome 7B, grain yield, grain protein concentration