湘西南湿热地区不同秋眠级紫花苜蓿光合特性研究

利用Li-6400光合速率测定系统测定了16种不同秋眠级紫花苜蓿(Medicago sativa L.)品种的净光合速率、气孔导度、蒸腾速率、胞间CO₂浓度、光量子通量密度、水分利用率;同时对不同秋眠级紫花苜蓿草产量进行测定。结果表明:阿尔冈金(Algonquin)、四季旺(Overseason)、维多利亚(Victoria)、WL525、萨兰多(Salado)、WL414、CW403、721丰叶(721Amerilea)、皇后2000(Empress2000)、牧歌,701(Amerigraze701)、丰宝(Powerplant)的光合速率日变化曲线呈双峰型,而CW400、CW680、路宝(Lobo)、猎人河(Hunter River)、盛世(Millenium)呈三峰型,16个品种净光合速率日变化均出现午休现象,其变化规律与秋眠级没有相关性;盛世、牧歌701、丰宝净光合速率较高在20μmolCO₂·m^-2·s^-1以上;牧歌701、路宝、WL525蒸腾速率较高在均在10 mmolH₂O·m^-2·s^-1以上;CW403、721丰叶(721Amerilea)水分利用率较高,达5μmol CO₂·mmol H₂O^-1以上。在湘西南湿热地区环境气候条件下,盛世、牧歌701、丰宝、4季旺等光合能力较强、蒸腾速率高的品种可作推广种植。

Study on the Photosynthetic Characteristics of Alfalfa with Different Fall-dormancy Levels in the Southwest Region of Hunan Province

The diurnal variations of net photosynthesis rate(Pn),stomatal conductance(GS),transpiration rate(Tr),intercellular CO2 concentration(Ci),photon flux density(PFD),and water utilization efficiency(WUE) of 16 alfalfa cultivars with different fall-dormancy levels were measured using Li-6400 Portable Photosynthesis System and the yields were measured at same time.The results show that cultivars Algonquin,Overseason,Victoria,WL525,Salado,WL414,CW403,721Amerilea,Empress2000,Amerigraze701,and Powerplant had the di...