高温对玉米植株形态与功能、产量构成及子粒养分的影响

以热敏型玉米品种驻玉309为材料,设置两个高温处理,研究不同程度日间高温对玉米产量及穗部性状、物质生产及转运、子粒库容的影响。结果表明,高温(HT1)对玉米产量无显著影响,极高温(HT2)显著降低玉米结实率和产量。植株株高在HT2下表现为降低,叶面积则表现为HT2CKHT1。花期高温胁迫显著降低吐丝期穗位叶净光合速率,但对叶绿素含量无显著影响。HT2降低穗粒数和总干物重,增加了成熟期茎、叶、苞叶干物质占单株地上干物质总重比例。高温胁迫增加子粒粗蛋白含量、可溶性糖含量和淀粉含量。结果显示,HT1处理下玉米通过自身增加物质转运能力应对高温胁迫,HT2通过显著降低穗粒数而影响子粒库容减小,造成不可逆损伤,同时影响了玉米源(叶面积)和流(物质转运与分配)的能力。

Effects of High Temperature on Morphology and Function, Yield Components and Grain Nutrients of Maize Plants

Using heat-sensitive maize variety ZY 309 as the material, two high-temperature treatments were set up to study the effects of different days of high temperature on maize yield and panicle traits, material production and transport, and grain storage capacity. The results showed that HT1 had no significant effect on maize yield, but HT2 significantly reduced maize seed setting rate and yield. The plant height of plants was decreased under HT2, and the leaf area was HT2 > CK > HT1. The high-temperature stress at flowering stage significantly decreased the net photosynthetic rate of panicle leaves, but had no significant effect on chlorophyll content; HT2 decreased the number of kernels and the total dry matter weight, increased the dry matter content of stem, leaf and loquat leaves in the mature stage, and the total weight of dry matter in the plant was increased. The high-temperature stress increased the crude protein content, soluble sugar content and starch content. The results showed that under HT1 treatment, maize increased its translocation capacity to cope with high-temperature stress, while HT2 reduced the grain storage capacity by significantly reducing the number of kernels, which caused irreversible damage and affected maize source(leaf area) and flow(material transport and distribution).