弱光胁迫对不同耐密型玉米茎秆抗倒伏能力及产量的影响

在大田条件下,研究耐密型玉米品种中单909和非耐密型玉米品种丹玉405穗期不同遮荫条件下(S0,自然光照;S1,遮荫44%;S2,遮荫66%)玉米茎秆抗倒伏能力与产量的关系。结果表明,穗期遮荫后,两种类型玉米品种株高和穗位高升高;茎基部茎节单位长度、干重、穿刺强度、压碎强度、折断力度、产量和穗粒数均随遮荫程度的增加而减小,且非耐密型玉米品种下降幅度大于耐密型玉米品种。随弱光胁迫程度的增加,非耐密型玉米品种倒伏率明显高于耐密型玉米品种,非耐密型玉米品种较耐密型玉米品种对弱光反应敏感,千粒重和结实率下降是导致非耐密型玉米品种产量大幅降低的重要原因。

Effects of Weak Light Stress on Capacity of Stalk Lodging Resistance and Yield of Different Density Resistant Varieties

The relationships between stalk lodging resistance and yield of dense resistant variety ZD909 and non-dense resistant variety DY405 were studied under the natural light(S0), 44% shade(S1) and 66% shade(S2) in the field conditions. The results showed that the plant height and ear position of the two kinds of maize variety both increased after shading in the ear period; the dry weight of stalk basal internodes per unit length, puncture strength, crushing strength, breaking strength, yield and the number of spike grain decreased with the increase of the shade degree, and the decreasing degree of non-dense resistant variety was higher than that of the dense resistant variety; the lodging rate of non-dense resistant variety was significantly higher than that of dense resistant variety with the increase of weak light stress, which indicated that the reaction of non-dense resistant variety to weak light stress was more sensitive, and the decline of 1 000-grain weight and seed setting rate were the key reason for sharply yield decrease of non-dense resistant variety.