Study on Evolution of Ear Characteristics of Main Maize Varieties in Different Eras

The analysis of ear characteristics evolution,which was based on split-plot experiment design with main varieties in different eras in China as sub-plot,as well as density as main plot,was carried out.The result showed that the characteristics such as yield,ear length,ear diameter,rows per ear,kernels per row,bald head length,1 000-kernel weight significantly raised,while grain index significantly decreased.Path analysis showed an order about the important contribution ofear characteristics to yield from large to small: ear diameter 1 000-kernel weight kernels per row grain index.The improved of ear diameter,kernel per row,1 000-kernel weight played an important role in yield development.In order to future improve maize production we should put more emphasize on ear diameter and 1 000-kernel weight,raise grain index,and coordinate the relationship between grain index and other character-istics.