中文摘要：

为确定淹水胁迫下适应性相对较强的苜蓿（Medicago sativa）品种,以‘金皇后’（B1）、‘阿尔金刚’（B2）、‘维多利亚’（B3）、‘巨能551’（B4）和‘巨能耐湿’（B5）为材料,研究了淹水处理对不同苜蓿品种群体质量和品质的影响。结果表明,随着淹水时间增加,不同苜蓿品种草产量之间差异显著,与0d相比1d淹水处理下B3,B4,B5的产量增加,随水淹胁迫时间的增加产量逐渐下降,而B1,B2则随淹水时间延长持续降低,5d时各品种草产量表现为B5〉B1〉B4〉B3〉B2;短期淹水对B1,B3,B5株高有促进作用,之后随时间延长逐渐降低,淹水5d时明显高于B2,B4。淹水5d时,B1,B4,B5的叶片数显著高于B2,B3,而B5的生长速率较0d仅降低15.38%,生长速率显著高于其他品种,其节间数、分枝数、根长和根重也均显著高于其他各品种;同时淹水5d时,B5光合能力显著强于其他品种,表现为B5〉B1〉B4〉B2〉B3;而品质上,B1,B4,B5在水淹胁迫后牧草品质均显著优于B2和B3。综上所述,‘巨能耐湿’（B5）在淹水胁迫下抗逆和恢复能力表现较好,群体质量相对较高,对产量品质影响较小,适宜在我国淮河以南多雨地区推广种植。

英文摘要：

Five alfalfa （Medicago sativa. ） varieties, including ‘ Jinhuanghou ’（B1）, ‘ Aerjingang＇ （B2）, ‘ Weiduoliya＇ （B3）, ‘Juneng No. 551＇ （B4） and ‘Junengnaishi＇ （B5） were selected to investigate the effects of waterlogging stress on population quality and hay quality of different alfalfa varieties and screen the stronger adaptability varieties to waterlogging stress, in this study. The results showed that with flooding time increase, the significant differences presented among yields of various alfalfa varieties, compared with 0 d. Among the yield of 1 d treatment, those of B3, B4, B5 have increased production, then gradually de- cline with the prolonged waterlogging, while the production of B1 and B2 with prolonged flooding time was reduced. The yields of 5 d treatments for each type were ranked as B5 〉 B1 〉 B4 〉 B3 〉 B2. Short- term flooding on B1, B3, B5 stimulates plant height, and restrain growth gradually with the extension of time. The plant heights of B1, B3, B5 were significantly higher than those of B2, B4 at 5 d waterlogging treatments. When flooded with 5 d, leaf number of B1, B4, B5 were significantly higher than B2, B3. Compared with 0 d, the growth rate of B5 only reduced 15.38%, which was significantly higher than those of other varieties. At the same time, the internode number, branch number, root length and root weight of B5 was significantly higher than those of other varieties. Furthermore, photosynthetic capacity of B5 was significantly stronger than the others, which ranked as B5 〉 B1 〉B4 〉 B2 〉 B3. As to hay quali- ty, forage qualities of B1, B4, B5 at water stresses were significantly superior to B2 and B3. Overall, B5 was prior to other cultivars in population quality and hay quality under waterlogging stress, the ‘Juneng- naishi’ could be spreaded in the southern rainy area of the Huaihe River in our country.