Abstract: In order to systematically understand the relationship between photosynthetic fluorescence parameters and quality of alfalfa （ Medicago sativa ） in Yinbei saline-alkali land in Ningxia province to screen out the dominant alfalfa varieties， the main photosynthetic fluorescence parameters and quality indexes of four alfalfa varieties were compared by field experiment， variance analysis， correlation analysis and multiple regression analysis. The results showed that among four alfalfa varieties in saline-alkali land， the net photosynthetic rate （P_n） and maximum fluorescence （F_m） and other photosynthetic fluorescence parameters of the alfalfa variety ‘Zhongmu No.3’ were both the highest， indicating the strongest photosynthetic capacity. At the same time， the content of crude protein （CP） and relative feed value （RFV） were the highest. The multiple regression results showed that the formula of crude ash （ASH） model was as follows： crude ash （ASH）=16.45-0.72×non-photochemical quenching （NPQ）-0.40×relative feeding value （RFV）+0.48×transpiration rate （TR）-0.33×crude fat （Ether extract，EE）+0.32×potential activity （F_v/F_o）， R²=0.84. The formula of crude protein （CP） model was as follows： crude protein （CP）=5.48+0.06×relative feeding value （RFV）， R²=0.61. Therefore， ‘Zhongmu No.3’ alfalfa might be an advantageous forage variety with great promotion value in different types of saline-alkali land in Yinbei area of Ningxia province.

Key words: Saline-alkali soil, Photosynthetic fluorescence parameters, Nutritional quality, Variance analysis, Correlation analysis, Multiple linear regression analysis

摘要： 为系统了解宁夏银北盐碱地紫花苜蓿（Medicago sativa）光合荧光参数与品质关系，筛选出具有优势的紫花苜蓿品种。通过大田试验和方差分析、相关性分析和多元回归分析等方法对4个紫花苜蓿品种主要光合荧光参数及品质指标进行比较。结果表明：盐碱地4个紫花苜蓿品种中，‘中苜3号’紫花苜蓿品种净光合速率（Net photosynthetic rate，P_n）和最大荧光（Maximum fluorescence，F_m）等光合荧光参数均较大，光合能力较强，同时粗蛋白（Crude protein，CP）含量和相对饲喂价值（Relative feed value，RFV）高。多元回归结果表明，粗灰分（Crude ash，ASH）模型公式为：粗灰分（ASH）=16.45-0.72×非光化学淬灭系数（Non-photochemical quenching，NPQ）-0.40×相对饲喂价值（RFV）+0.48×蒸腾速率（Transpiration rate，TR）-0.33×粗脂肪（Ether extract，EE）+0.32×潜在活性（Potential activity，F_v/F_o），R²=0.84。粗蛋白（CP）模型公式为：粗蛋白（CP）=5.48+0.06×相对饲喂价值（RFV），R²=0.61。因此，‘中苜3号’紫花苜蓿是宁夏银北地区不同类型盐碱地极具推广价值的优势牧草品种。

关键词: 盐碱地, 光合荧光参数, 营养品质, 方差分析, 相关性分析, 多元线性回归分析