关键词: 玉米, 种子, 定向, 叶片, 方位角

Abstract: To testify the feasibility of ordered construction of maize population and provide foundation for seeding machinery design， four experimental treatments of different oriented initial seeds in sowing season with two varieties of maize （Xianyu335， compact type with density of 75 000 plant·hm-2， and Jidan50， flat type with density of 55 000 plant·hm-2） were carried out in this study. Leaf base azimuth and ear azimuth of maize in different treatments were investigated during growth. The relationship between initial seed orientation and spatial distribution of maize leaves were analyzed. The four treatments included: （A） Seeds with embryo plane paralleled to the ground and upward. The long axis of seeds was paralleled to the direction of row， and the tip of seeds was pointed to the north; （B） Seeds with embryo plane paralleled to the ground and upward. The long axis of the seed was perpendicular to the direction of row， and the tip of seeds was pointed to the east; （C） Seeds with embryo plane perpendicular to the direction of row and faced to the north. The tip of seed position was vertically downward; （D） Random seeding. Apparently difference was found in the azimuth of leaves at plant base between different orientation treatments， but the difference was not displayed in those leaves in the upper part of plant. Leaves tended to be more perpendicular to the direction of row in treatment B， in which seeds with embryo plane were paralleled to the ground and upward， and the long axis of the seed was perpendicular to the row direction. Therefore， ordered spatial distribution of maize leaves could be achieved to a certain extent through selecting an appropriate initial seed orientation.

Key words: maize, seed, orientation, leaf, azimuth