不同土壤水分下小麦幼苗出土幼苗生长及叶片光合作用的变化

本文研究了不同土壤水分下小麦(小偃6号)幼苗出土及幼苗生长的变化,结果表明,轻微的土壤水分亏缺使根的伸长加快,根量增加;严重的土壤水分亏缺使根和幼苗生长受抑,干旱下根/冠比增大.土壤水势低于1.80MPa时,幼苗几平不能出土.土壤水势在-0.61MPa时,形成的苗既小又弱,形成弱小苗的原因是叶片光合能力下降、呼吸增加的结果.根据实验结果本文提出,小偃6号向较旱区推广是一慎重的问题.

Changes in Emergence of Wheat Seedling,Seedling Growth and Leaf Photosynthesis Under Different Soil Water Conditions

This experiment studies the effects of soil droughts on the emergence of wheat seedling(Xiao Yan-6),seedling growth and leaf photosynthesis,and analyses the cause of weak seedling being formed under siol drought conditions.The results are as follows:Under soil drought conditions,emergence of seedling takes long time and the ratio of root/shoot increases,if the soil water potential is lower than -1.80 MPa,few seedlings can emerge.Root growthes rapidly and the number of root increases under mild soil drought.Under serious soil drought conditions,the growth of seedling decreases and the root system of seedling are weak,which is caused by decrease in leaf photosynthesis ability and increase in the dark respiration.