几个引种苜蓿品种的生理适应性研究

采用Li-6400便携式光合测定系统,测定已在内蒙古多伦县广泛种植的草原三号及4个引种苜蓿品种(甘农三号、新疆大叶、皇后苜蓿和中兰一号)的净光合速率(Pn)、蒸腾速率(Tr)日变化及其对生理因子、环境因子的响应,并测定生物量。结果表明:(1)皇后苜蓿的生物量(383.3g/m~2)与草原三号的(417.8g/m~2)均较高无显著性差异,新疆大叶、中兰一号和甘农三号生物量分别为325.7,167.7和161.4g/m~2;(2)草原三号、皇后苜蓿和新疆大叶Pn和Tr为"双峰型",甘农三号和中兰一号Pn和Tr为"单峰型";(3)草原三号Pn为10.649μmol/(m~2·s),Tr为4.963mmol/(m~2·s),均最高,引种品种以皇后苜蓿Pn9.195μmol/(m~2·s)和Tr4.919mmol/(m~2·s)最高;(4)光合有效辐射是影响草原三号Pn的主导因子,胞间CO2浓度和相对湿度为影响引种苜蓿品种Pn的主导因子;Gs为影响5个苜蓿品种Tr的主导因子。(5)"双峰型"引种苜蓿品种对当地生态环境的适应性强于"单峰型"。根据4个苜蓿品种在该地的光合特性和生物量表现,认为皇后苜蓿可作为内蒙古多伦县人工草地建植引种的备选品种。

Study on physiological adaptability of four introduced alfalfa (Medicago sativa) cultivars

Net photosynthetic rate (Pn) and transpiration rate (Tr) of Medicago varia cv.Caoyuan No.3 (locally grown) and 4 introduced alfalfa cultivars (M.sativa cv.Gannong No.3,M.sativa cv.Xinjiang Daye,M.sativa cv.Queen and M.sativa cv.Zhonglan No.1) were measured with LI-6400 portable photosynthesis system at Duolun County in Inner Mongolia.The response of Pn and Tr to physiological factors and environmental factors was studied as well.The results indicated that 1) the biomass difference between Queen (383.3 g/m2) and Caoyuan No.3 (417.8 g/m2) was not significant,which were followed by Xinjiang Daye (325.7 g/m2),Zhonglan No.1 (167.7 g/m2) and Gannong No.3 (161.4 g/m2).2) Diurnal variation of Pn in Caoyuan No.3,Queen and Xinjiang Daye showed a double peak curve,while Gannong No.3 and Zhonglan No.1 showed a single peak curve.3) Pn and Tr of Caoyuan No.3 were 10.649 μmol/(m2·s) and 4.963 mmol/(m2·s),Queen had the highest Pn and Tr among 4 introduced cultivars (9.195 μmol/(m2·s) and 4.919 mmol/(m2·s) respectively).4) PAR (Photosynthetic available radiation) was the key factor affecting Pn of Caoyuan No.3,Ci was the key factor affecting Pn of the introduced cultivars.Considering Pn,Tr and biomass,Queen was the best cultivar for the establishment of artificial grassland in Inner Mongolia.