Accumulation Regularity of Starch Components in Wheat Varieties

Three wheat varieties(Ningmai 9,Sumai 6 and Chongqing bread wheat)were used in 1999～2000 to analyze dynamics of starch components and ratio of amylose contents to amylopectin contents of wheat grain.The fastest accumulation for amylose in three wheat varieties appeared during 17～27 d after anthesis,but for amylopectin,was at mid-stage of grain filling.The dynamics of ratio of amylose contents to amylopectin contents shapedS-it descended at early stage of grain filling,then ascended at mid-stage,and decreased at late stage.There were significantly positive correlations in amylose contents,amylopectin contents and ratio of amylose contents to amylopectin contents between 1999 and 2000.The differences of amylose contents,amylopectin contents and ratio of amylose contents to amylopectin contents were significant among sampling times.Among varieties the differences of amylose contents,ratio of amylose contents to amylopectin contents were not significant(P0.05),but the difference of amylopectin contents was significant(P0.01).