Effects of Nitrogen and Wx Gene Deletion on Starch Biosynthesis in Wheat

Purpose The effects of nitrogen fertilizer level and grain filling stage on the grain starch content of near isogenic Wx wheat lines were determined by different nitrogen application levels.Method Eight Wx near-isogenic wheat lines in Ningmai 14 were researched at no basal fertilizer, and 5 nitrogen levels including 0, 150, 300, 450 and 600 kg/hm2 were fertilized at three-leaf period. The amylose, amylopectin and total starch contents of wheat grain were determined at 7, 14, 21, 28 and 35 days after anthesis.Results The grain amylose, amylopectin and total starch contents were significantly affected by the Wx genotypes and grain filling period, while the nitrogen levels did not cause significant changes in content and composition of starch. Starch synthesis was speed up 10 d after anthesis till the end of filling period.Conclusion The amylose synthesis ability of three Wx genes was Wx-B1 Wx-D1 Wx-A1, and the comprehensive effect of Wx-A1 and Wx-D1 was the equivalent of Wx-B1.