充足灌水条件下不同年代玉米品种根系性状比较研究

以我国20世纪50年代以来6个玉米主推品种白鹤、吉单101、中单2号、掖单13、郑单958和先玉335为材料, 在充足灌水条件下研究玉米品种更替过程中的根系性状演变特征。结果表明, 不同年代玉米品种各根系性状间存在差异, 随着品种的更替, 根系平均入土角度呈现减小的趋势, 根系分布更为紧凑。根系性状(根长、根表面积、根体积、根条数、根系干重等)随品种年代的更替表现为“先增后减”的趋势, 1950s～1970s平展型品种趋向于构建逐渐强大根系系统, 以提高根系吸收能力;1980s紧凑型品种趋向于减少高层节根, 以减少“冗余器官”的干物质消耗。与早期品种相比, 近代品种的紧凑型根系不仅增强了对土壤深层水分、养分的吸收, 也促进了干物质向子粒的高效转移和水分利用效率的提高。

Comparative Study on the Characteristics of Maize Root under the Conditions of Saturated Irrigation in Different Eras

The root characteristics of different maize varieties were studied under saturated irrigation conditions with 6 maize cultivars released from 1950s to 2000s, including Baihe, Jidan101, Zhongdan2, Yedan13, Zhengdan958 and Xianyu335. The result showed that there were significant differences in different varieties. With the replacement of varieties, the average root angle decreased gradually and made the root distributions more compact. Other root characteristics such as root length, surface areas, root volume, root numbers, root dry weight increased first and decreased afterwards. Root system of flat-leaf maize from 1950s to 1970s grew larger to increase the absorption capacity, but upright-leaf maize after 1980s reduced the number of upper node roots to reduce the redundant organ's dry matter consumption. Compared with the early varieties, the root characteristics of modern maize increased not only the ability of absorbing soil nutrients and moisture in deep layer but also the dry matter partitioning to kernels and water use efficiency.