土壤水分和种植密度对春小麦叶片气孔的影响

 在不同土壤水分条件下，研究了不同种植密度（１、10、100、1 000、10 000株·m－2）的春小麦 (Triticum aestivum L.) 叶片气孔密度以及气孔分布的变化。结果表明：不同水分和种植密度不仅影响了叶片的气孔密度，而且也影响了其分布。随着种植密度的升高，气孔密度增大，在1 000株·m-2时气孔密度达最大值；当种植密度从1 000株·m-2上升到10 000株·m-2时，气孔密度下降；叶基部气孔数占全部气孔数的比例最大，叶尖最小，但随着种植密度的增大，气孔在叶片上的分布趋向均匀。干旱条件下随种植密度的升高气孔密度及分布的变化趋势与正常水分条件下的一致，但趋势更为明显。说明种植密度增大导致的气孔密度和分布的变化很可能是通过影响水分的供应而造成的。

STOMATAL DENSITIES AND DISTRIBUTIONS OF SPRING WHEAT LEAVES UNDER DIFFERENT PLANTING DENSITIES AND SOIL MOISTURE LEVELS

Spring wheat (Triticum aestivum L.) was grown in five planting densities (1, 10, 100, 1 000 and 10 000 individuals·m-2) and in two soil moisture levels (80% and 40% soil water capacity ). Stomata were counted and measured. The planting densities affected stomatal densities and distributions. Stomatal densities increased as the planting densities changed from 1 to 1 000 individuals·m-2, and decreased significantly at higher planting densities (10 000 individuals· m-2). The maximum stomatal density was found n the leaf base, while the minimum in the leaf apex. Stomatal distribution became more symmetrical with the increase of planting densities. Similar but more pronounced changes in stomatal densities and distributions were found in the drought stressed plants. Therefore, it is concluded that the changes in stomatal densities and distributions were the result of different water conditions induced by the planting densities.