松嫩平原虎尾草和稗草光合特性的研究

自然条件下,对松嫩平原西部盐碱地区虎尾草和稗草的光合作用日进程进行了观测,结果表明:虎尾草和稗草叶片光合与蒸腾作用的日变化均呈单峰曲线;胞间CO2浓度的日进程呈现早上最高、中午降到最低点、傍晚又升高的特点,基本与其净光合速率的变化相反;虎尾草和稗草的水分利用效率最低值都是出现在上午蒸腾速率最强烈的时候;蒸腾速率与光合速率呈极显著正相关,虎尾草的相关性系数为r2=0.582 9,稗草的相关性系数为r2=0.636 9。图12,参8。

Study on the Photo Synthetic Characteristic of Chloris Virgata and Echinochloa Crusgalli (L.) Beauv of Songnen Plain

Diurnal variations of photosynthesis in the leaves of Chloris virgata and Echinochloa crusgalli(L.)Beauv in the west alkaline district of Songnen plain were studied under natural conditions.The results indicated that the diurnal variation of photosynthesis and transpiration of Chloris virgata and Echinochloa crusgalli(L.)Beauv were single-peaked curves.The diurnal variation of intercellular CO2 concentration(Ci) was the highest in the morning,the lowest at midday and it increased in the afternoon.It was just opposite to net photosynthetic rate(Pn).The water use efficiency(WUE) of Chloris virgata and Echinochloa crusgalli(L.)Beauv were the lowest when the transpiration rate(Tr) were the highest.The net Pn was positively correlated to the Tr.The correlate coefficient of Chloris virgata was r2=0.582 9 and the correlate coefficient of Echinochloa crusgalli(L.)Beauv.was r2=0.636 9.