玉米茎叶和根系的生长对干旱胁迫的反应和适应性

Response and Adaptability of the Growth of Leaves, Stems and Roots of Maize to Drought Stress

在人工控制和自然条件下,就玉米茎叶和根系生长对干旱胁迫的反应和适应性进行深入研究,结果表明,玉米地上部茎叶的生长对干旱胁迫的反应比地下部根系敏感,中度干旱胁迫仅在苗期具有促进根系生长发育的作用,而对不同品种玉米其他各生育时期地上部茎叶和地下部根系的生长均有抑制作用。抗旱性较强的玉米品种,在干旱条件下可通过增加叶面积、干物质累积量、根量和根活跃吸收表面积来抵御干旱,以保持正常的生长发育。

The response and adaptability of the growth of stems, leaves and roots of maize to drought stress are lucubrated under the conditions of artificial rain-proof shelter and natural field. The experiment of response of growth of the different maize varieties to moderate drought stress (the soil moisture content was maintained in a range of 45%～50% of the maximum water carrying capacity of soil in farmland) was carried out at seedling stage (June 8), jointing stage (June 25), boot stage (July 8), florescence (July 21) and milking stage (August 13). The results show that the response and adaptability of the growth of stems and leaves of maize to drought stress are more sensitive than that of roots. Moderate drought stress can promote the growth and development of roots of maize only at seedling stage, and it restrains the growth of stems, leaves and roots of the different maize varieties. The maize plants with high drought-resistant capability can grow normally under drought stress by increasing their leaf area, dried-biomass accumulation, active absorption surface area and total absorption area of roots. The experimental results also reveal that the moderate drought stress restrains strongly the growth and development of all the maize varieties at the different stages except the variety of Yuyu 3, which has a high drought-resistant capability, and the reductions of its leaf area, dried-biomass, shooting ratio and active absorption area of roots are less under drought conditions.