干物质累积和脯氨酸累积的水势阈值与小麦抗旱性的关系

Relationship between Dry Matter Accumulation and Water Potential Threshold of Free Proline Accumulation and Wheat Resistance to Drought

在土壤干旱条件下,对水地和旱地小麦品种的叶水势和干物质累积的动态变化进行了比较,在此基础上探讨了两类品种在叶片游离脯氨酸累积量和其大量累积的水势阈值的差别。研究结果表明,水地品种较旱地品种在叶水势和干物质累积上受水分胁迫影响较大。在脯氨酸累积的水势阈值上,旱地品种高于水地品种,即旱地品种在较高的叶水势时就已开始累积脯氨酸,而水地品种则开始于较低的叶水势。这反映了两类品种感受干旱信号的能力是不同的。故建议以脯氨酸大量累积的水势阈值作为评价品种抗旱性的参考。

Under the dry conditions in soil,the changing trends of leaf water potentials and drymatter accumulation were compared among wheat varieties from dry land and irrigatedland respectively.On the basis of which the diffcrcnces between the two kinds of wheatvarieties in free proline levels and leaf water potential threshold causing obvious accumu-lation of free proline were studied.The results show that water stress has greater effectson the leaf water potential and dry matter accumulation of the wheat varieties from irri-gated land than those from dry land.The dryland varieties were higher than the irrigatedland ones in the water potential threshold of proline accumulation,i.e.free proline accu-mulation of the dryland varieties started with higher leaf water potential as compared tothose varieties from the irrigated land.This indicates that the responsive ability of thetwo kinds of varieties resistant to drought is different.Therefore,it is suggested that wat-er potential threshold be regarded as the reference for the evaluation of wheat varietiesresistant to drought.