大豆光合日变化的不同类型及其影响因素

用同一品种在不同生育期,不同季节、不同天气以及不同生长条件下研究了大豆的光合日变化。大豆的光合日变化随气候条件,生长环境以及大豆的生育期不同而变化,不遵循一种固定不变的模式,概括起来有单峰型、双峰型、波动型和平缓型四种不同类型。大豆在春、夏、秋三季均能产生午休,土壤水分亏缺使午休加重,在结荚期以前条件适宜的情况下,大豆不易产生午休,此后随着生育期的进展,大豆午休加重,鼓粒期大豆的午休最为严重。

THE DIFFERENT TYPES OF DIURNAL COURSE OF PHOTOSYNTHESIS OF SOYBEAN [Glycine max(L). Merr. ] LEAVES AND RELATED FACTORS

The diurnal course of photosynthesis of soybean leaves in different development stages, seasons and under different weather and growing conditions were studied. The diurnal course of photosynthesis changed under different weather and growing conditions and in development stages instead of following a regular pattern. The patterns could be generalized as four main types: single peak pattern; double peak pattern; fluctuating pattern and smooth pattern. The midday depression of photosynthesis of soybean leaves was observed in spring and autumn as well as in summer. Under high temperature and low humidity weather conditions the midday depression of photosynthesis occurred frequeutly the deficiency of soil water content intensified the depression. Before pod-setting period the depression did not occurred in suitable condition, after that period as the plant became older the midday depression of photosynthesis became more and more intensified.