海拉尔地区苜蓿生产性能及影响因子研究

使用 Li-6400光合测定系统田间实地测定在海拉尔地区广泛种植的4个苜蓿品种（黄花苜蓿、杂花苜蓿、肇东苜蓿和龙牧801）的光合因子，并进行了相应产量因子的测定，分析影响苜蓿产量的主要因素。结果表明：不同苜蓿品种的净光合速率（P n ）、蒸腾速率（T r ）、水分利用效率（WUE ）、胞间二氧化碳浓度（C i ）和气孔导度（Gs）日变化曲线并不完全呈双峰曲线，出现峰值的时间也存在差异性；P n 和 Tr 与气孔导度、叶绿素呈显著正相关性（P 〈0.05），与水分利用效率、相对湿度和气温呈负相关（P 〈0.05）。产量与光合因子、环境因子相关性较低；通过主成分分析，株高、有效辐射、宽幅、单株干重、茎干重、叶干重、鲜干比能够较好的反映和预测苜蓿产量；杂花苜蓿在海拉尔地区表现出较好的适应性。

Study on alfalfa productivity and its affecting factors in Hailaer

The photosynthetic characteristics,the diurnal dynamic of photosynthetic characteristics and its yield affecting factors of 4 alfalfa varieties （Medicago sativa cv.Yellow flower,M.varia ,M.sativa cv.Zha-odongand,M.sativa cv.Longmu 801）were studied in field by using a Li-6400 portable photosynthesis system. The results showed that the peak values of Pn ,Tr ,WUE ,Ci and Gs of tested alfalfa varieties occurred at different time.And not all of the tested varieties showed the double-peak daily photosynthetic curve.A significant posi-tive correlation between Pn ,Tr and Gs ,chlorophyll （P〈0.05 ）,and a negative correlation between Pn ,Tr and WUE ,RH and temperature （P〈0.05）were found.There was a low correction between yield and photosynthet-ic factors and environmental factors.The height,PAR,yield,width,dry weight per plant,stem dry matter weight,leaf dry matter weight and fresh to dry matter ratio could reflect and predict the yield.The ariegated al-falfa showed better adaptability in research area.