高温对夏玉米种子萌发、生理特性及籽粒品质的影响

Effects of High Temperature on Seed Germination, Physiological Characteristics and Seed Quality of Summer Maize

极端高温是阻碍河南玉米生产的主要气象灾害之一,以驻玉216为材料,通过采用室内和田间试验方法,研究高温对玉米种子萌发、品质及生理特性的影响。结果表明:高温对玉米种子的发芽率、发芽势、发芽指数均具有一定的抑制作用,超过32℃发芽指数大幅降低,导致种子活力下降。开花期、灌浆期进行高温处理降低了叶绿素相对含量,对玉米叶片叶绿素形成具有负效应;增加了玉米叶片可溶性糖含量,这是对高温进行的自身抗逆反应,有利于提高抗逆性;降低了地上干物质的累积,其累积量直接影响到玉米最终产量水平。高温处理还增加玉米籽粒粗蛋白质含量,降低粗脂肪、粗淀粉的含量,不利于玉米品质的改善。

Extreme high temperature is one of the main meteorological disasters hindering maize production in Henan Province.Using Zhuyu 216 as material,the effects of high temperature on maize seed germination,quality and physiological characteristics were studied by indoor and field experiments.The results showed that high temperature inhibited the germination rate,germination potential and germination index of maize seeds to some extent.The germination index of maize seeds decreased significantly when the temperature exceeded 32℃,which resulted in the decrease of seed vigor.With high temperature treatment at flowering and filling stage the relative content of chlorophyll was decreased,which had a negative effect on chlorophyll formation in maize leaves.The soluble sugar content in maize leaves was increased,which was the self-stress response to high temperature and was beneficial to improve the stress resistance.The accumulation of dry matter on the ground was reduced,which directly affected the final yield level of maize.High temperature treatment also increased the crude protein content of maize grains and decreased the crude fat and starch content,which was not conducive to the improvement of maize quality.