Abstract:

The difference of yield and yield-related traits between L18 and Y478 under different nitrogen levels was analyzed to find out the relationships with the zmAspAT gene expression pattern. The yield and yield-related traits of L18 and Y478 were evaluated under low and normal nitrogen conditions. The expression profile of the zmAspAT gene was assayed by quantity Real-time PCR. Under normal nitrogen conditions, compared to Y478, the grain yield of L18 significantly increased by 17.21%, kernel number per row also increased significantly, one hundred kernel weight of L18 decreased. Whereas, under low nitrogen levels, the grain yield of L18 remarkably decreased about 20.64%, kernel number per row increased, one hundred kernel weight decreased significantly. The expression of zmAspAT in L18 was down-regulated under N deficiency conditions, but its expression in Y478 was significantly up-regulated during stress. The expression profile of zmAspAT gene in L18 was significantly different from their expression in Y478. The L18 line was a low nitrogen use efficiency introgression line. The different expression levels of the zmAspAT gene in L18 and Y478 under low N conditions led to a low nitrogen use efficiency and grain yield. zmAspAT was an important gene for maize nitrogen use efficiency.