摘要： 为探明增密对玉米花丝受精结实能力及衰老进程的影响，以登海605（DH605）和郑单958（ZD958）为材料，比较研究了两个密度（52 500，112 500株/hm²）下玉米果穗花丝受精结实能力及衰老动态。结果表明：增密使花丝生长速率降低，吐出苞叶的时间延迟，整个果穗的花丝可受精持续时间延长，但不影响花丝的衰老特性。与低密度相比，高密度下DH605和ZD958果穗花丝吐出苞叶的时间分别推迟3，1 d，可受精结实持续时间分别延长2 d和1～2 d。高密度下玉米果穗顶部花丝吐丝时间虽晚但仍然有正常受粉结实的潜力。利用分别套袋1～20 d每天统一授粉以及花丝衰老数据进行相关分析，发现果穗可受精花丝百分率与衰老花丝呈极显著相关关系（r²=0.964^***），说明延迟授粉造成的花丝受精结实能力降低主要是由于早吐丝花丝的衰老造成的。总之，增密对吐出苞叶后的花丝衰老时间影响不显著，但显著延长整个果穗花丝衰老时间。

关键词: 玉米, 花丝, 生长与衰老, 受精能力, 密度

Abstract: To clarify the receptivity and senescence of maize silks under high stand density,two cultivars Denghai 605(DH605)and Zhengdan 958(ZD958)were used to analyze the effects of different plant densities(52 500,112 500 plant/ha)on silk receptivity and silk senescence in maize. The results showed that the silk growth rate was decreased at high stand density,result in the duration of silk emergence and silk receptivity for the entire ear were delayed,but the aging process of silk was not affected after silk emergence. Compared with low stand density,the duration of silk emergence and silk receptivity for the entire ear at high stand density were lengthened 3 and 2 days for DH605,respectively,and 1 and 1-2 days for ZD958,respectively. Although,apical silk emergence in maize ear was late,it still had receptivity under high stand density. Further analysis showed that the negative correlation coefficient between percentage of silk receptivity and silk senescence based on the data of synchronous pollination at varying days from 1 to 20 days after first silk emergence was significant(r²=0.964^***). Hence,silk senescence was the primary cause of silk receptivity decreased due to the delay of pollination after silk emergence.In general,the senescence process of silk was not affected at a high stand density,but lengthened the duration of silk receptivity for entire ear.

Key words: Maize, Silk, Growth and senescence, Receptivity, Plant density

中图分类号: 

• S513.01