辣椒开花结果期对干旱胁迫的形态与生理响应

在遮雨网室选用抗旱性较强的农城椒二号和抗旱性较弱的陕蔬2001,研究辣椒在轻度、中度和重度干旱胁迫下不同时间的生长、产量、渗透调节物质、保护酶活性的变化规律及其生理调节机制。结果表明:随干旱胁迫时间的延长,辣椒的株高、分枝数、叶面积、单位面积产量、叶绿素含量和叶片相对含水量的抗旱系数呈下降趋势,下降速率与干旱胁迫程度呈正相关,与品种的抗旱性呈负相关;脯氨酸、丙二醛含量和细胞膜透性相对值随干旱胁迫时间的延长呈上升趋势;POD、SOD、CAT活性和可溶性蛋白相对值随着干旱胁迫时间的延长先升高后下降,抗旱性强的材料增加幅度低于抗旱性弱的材料;可溶性糖含量的相对值在轻度和中度干旱胁迫下呈上升趋势,在重度干旱胁迫下呈上升—下降趋势,且抗旱性强的材料上升速度大于抗旱性弱的材料。相关分析表明,干旱胁迫下,产量与株高、分枝数、叶片叶绿素含量、叶面积、叶片相对含水量抗旱系数呈显著正相关;与细胞膜透性、CAT活性和可溶性蛋白含量抗旱系数呈显著负相关。主成分分析表明,用作辣椒抗旱性鉴定的主要指标是单株产量、株高、叶面积、分枝数、可溶性蛋白、可溶性糖、MDA、叶绿素含量和细胞膜透性及叶片相对含水量,叶片POD、SOD、CAT活性、脯氨酸含量可做为辣椒抗旱性鉴定的次要鉴选指标。

The morphological and physiological responses of hot pepper (Capsicum annuum L.) to drought stress with different intensity during blossom and fruit period

Using Shaanshu 2001 (high drought resistance variety) and Nongchengjiao 2 (low drought resistance variety) as materials, the experiment was conducted in a rain-shelter net house to study the change laws and mechanisms of growth, yield, osmotic adjustment substances, protective enzyme activity of hot pepper under mild, moderate and sever drought stress and different time duration. The results showed that the drought resistance coefficients of plant height, branch number, leaf area, yield per unit area, chlorophyll content and leaf relative water content tended to decrease with the extension of drought stress time, and the decrease rate was positively related to the intensity of drought stress, and negatively related to the drought resistant ability of hot pepper varieties. The relative values of proline, malondialdehyde content and cell membrane permeability showed upward trend with the prolonging of drought stress. With the lasting of drought stress, the relative values of POD, SOD and CAT activities and soluble protein content increased firstly and then decreased, and the increase rate of the high drought resistance variety was lower than that of the low drought resistance variety. The relative value of soluble sugar content showed increase trend under mild and moderate drought stress, and upward to downward trend under severe drought stress, and the increase rate of the high drought resistance variety was larger than that of the low drought resistance variety. The correlation analysis showed that the yield was significantly positively correlated with the drought resistance coefficients of plant height, branch number, chlorophyll content, leaf area and relative water content, whereas it was significantly negatively correlated with the drought resistance coefficients of cell membrane permeability, CAT activity and soluble protein content. The principal component analysis indicated that the principal indicators to identify the drought resistance of hot pepper were yield per plant, plant height, leaf area, number of branches, the content of soluble protein, soluble sugar, chlorophyll, MDA and cell membrane permeability, the relative water content of leaves. And the secondary indicator was the activity of POD, SOD, CAT and proline content.