Abstract:

The effects of water physiological index of Medicago sativa ‘Xinjiangdaye’ and their correlation under different water stress conditions were studied by pot culture experiments. The results showed that the leaf relative water content, free water content, leaf water potential decreased with the aggravating of water stress. Water saturation deficit, bound water content and bound water/free water increased, leaf water holding capacity strengthened at the same time with the intensification of water stress and prolonged droughts time. The above index under slight water stress did not make a significant change. The correlation coefficient between RWC and bound water/free water was -0.94, it was significantly negatively correlated. The correlation coefficient between RWC and leaf water potential was 0.89 and it was a significant positive correlation; leaf water potential and bound water/free water showed a significant negative correlation; The results helped to understand the response of Medicago sativa ‘Xingjingdaye’ to water stress and provided a theoretical basis for the spreading and cultivation of Medicago sativa ‘Xingjingdaye’ under water-saving irrigation in the arid zone agriculture as well as establishing lasting,stable and high-yielding grassland production system.

Key words: Medicago sativa ‘Xingjingdaye’, Water stress, Leaf relative water content, Leaf water potential

摘要：

应用盆栽试验，对新疆大叶苜蓿（Medicago sativa ‘Xinjiangdaye’）用人工控制土壤含水量分别为田间持水量的90%（充分供水TA）、70%（轻度土壤水分胁迫TB）、50%（中度土壤水分胁迫TC）、30%（重度土壤水分胁迫TD）条件下的水分代谢响应进行了研究。结果表明，随干旱胁迫程度加剧，叶片相对含水量、自由水含量及叶水势呈下降趋势；随干旱胁迫程度的加剧和干旱时间的延长，水分饱和亏、束缚水含量及束缚水/自由水上升且叶片持水力不断增强，轻度土壤水分胁迫并未使以上指标发生显著变化；叶片相对含水量与束缚水/自由水相关系数为-0.94，呈极显著负相关，与叶水势相关系数为0.89，呈显著正相关；叶水势与束缚水/自由水呈显著负相关。

关键词: 新疆大叶苜蓿, 水分胁迫, 叶片相对含水量, 叶水势