紫花苜蓿光能及叶片水分利用效率影响因子分析

Analysis on the influnce factors to utilizing efficiency of light and water for alfalfa

大田条件下,利用C-340df光合仪,对12个紫花苜蓿Medicago sativa品种(初花期)的净光合速率(Pn)、蒸腾速率(Tr)及生态因子(光合有效辐射、大气温度、大气湿度)和生理因子(胞间CO2浓度、气孔导度、叶温)进行测定,探讨影响其光能利用效率(LUE)和叶片水分利用效率(WUE)的主要因子。结果表明:1)品种胖多单株干质量最高,且LUE、WUE显著高于其他品种(P<0.05),属于高光合、低蒸腾、高水分利用品种;2)影响LUE的主要是生理因子(胞间CO2浓度、气孔导度),而影响WUE的则为外界环境因子(光合有效辐射、大气温度、大气湿度)。

To explore the influence factors of light use efficiency （LUE） and water use efficiency （WUE） of alfalfa, the related physiological ecology indexes （Pn, Tr, Gs, Ci, Ta, Tl, RH and PAR） were measured using portable C-340df photosynthesis instrument in the morning of sunny days at early flowering period on 12 four-year-old alfalfa varieties under field conditions. The results showed that： 1） The physiological factors （Ci and Gs） are the key factors that affect the LUE of Alfalfa, while some external enviornmental factors （PAR, Ta and RH） played a role effect on WUE; 2） WUE and LUE of a variety, Medicago sativa cv. Pondus, were significantly （P〈0.05） higher than oth;ers, and with highest dry matter.