Relationships of Maize Kernel Setting with Carbohydrate and Nitrogen Supply under Controlling Pollination

Abstract

Two different types of maize cultivars Zhengdan 958 and Chaoshi 1 were used, the apical kernel was stimulated to be set by decreasing the pollination of ear basal filaments, and a comparative study was conducted in the change of carbohydrate and nitrogen in early kernel and its relationships with kernel abortion. The results showed that nutrient supply of the apical region of maize ear was significantly improved in the treatment of no-pollination of basal ear region, so that concentration of soluble sugars in cob and kernel and kernel sucrose content increased significantly, starch of the apical kernel accumulated fast, kernel nitrogen content increased also, C/N value was higher, and the apical kernel weight increased fast and developed normally;on the contrary, nutrient supply of the apical region of maize ear was lower in the treatment of complete pollination at the same time, the concen-tration of soluble sugars in cob and kernel and kernel sucrose content were lower, the starch of the apical kernel accumulated slowly, the kernel nitrogen content and the C/N value were lower also, and the apical kernel weight increased slowly and aborted finally. Similar changes between the two maize cultivars in carbohydrate and nitrogen, and kernel growth were observed. These data indicated that the normal growth and development of the apical kernels are accompanied by an adequate carbohydrate and nitrogen supply, the shortage of nutrient supply may be the fundamental cause of kernel abortion.