紫花苜蓿和无芒雀麦叶片光合生理特性研究

Study on photosynthesis characteristics of Medicago sativa and Bromus stamineus

用便携光合系统测定仪对美国无芒雀麦和肇东苜蓿叶片动态光合生理特性进行了研究,结果表明:5月苜蓿单播与混播净光合速率日变化幅度不大,无芒雀麦净光合速率呈双峰型;6月2种牧草的光合速率日动态曲线均为双峰型,有明显的午休现象,而7月为单峰型,没有午休现象。2种牧草单播与混播蒸腾速率变化趋势相似,苜蓿盛花期、无芒雀麦抽穗期的光合速率、蒸腾速率和水分利用效率单混播均最高,苜蓿和无芒雀麦混播叶片光合速率、水分利用效率略高于单播叶片,但在光合午休期间差异不明显。

The photosynthesis characteristics of Medicago sativa cv.Zhaodong and Bromus stamineus in mixed and single pastures were studied.The results showed that the daily change of net photosynthetic rate of alfalfa was little in mixed and single pastures and the net photosynthetic rate of smooth brome was a single-peaked curve in May.The daily dynamic of photosynthetic rate of two species were two-peaked curves and showed an obvious midday depression in June.But the curve was singl-peaked and no midday depression in July.The transpiration rates of two species were similar in mixed and single pasture.In the mixed and single pastures,the net photosynthetic rate,transpiration rate and water use efficiency were highest when alfalfa was in full blooming and smooth brome was in heading stages.The photosynthetic rate,water use efficiency of alfalfa and smooth brome in mixed pasture was slightly higher than the single pasture,but there was no obvious different in midday depression.