盐胁迫下嫁接黄瓜和自根黄瓜幼苗的保护酶活性变化

Variation of protective enzyme's activity in grafted and self-rooted cucumber seedlings under salt stress

以云南黑籽南瓜为砧木,以津绿4号黄瓜为接穗,研究了25,50,75mmol/LNaCl胁迫下黑籽南瓜、嫁接黄瓜和自根黄瓜幼苗叶片中保护酶活性的变化以及黄瓜和黑籽南瓜种子的耐盐发芽能力.结果表明:在NaCl胁迫下,黑籽南瓜发芽率仍较高,而黄瓜发芽率明显下降.随着NaCl浓度的增大,各处理的POD和CAT活性均增强,黑籽南瓜的始终保持最高,嫁接黄瓜与黑籽南瓜接近,自根黄瓜最低.随着NaCl浓度的增大,各处理SOD活性都呈下降趋势,但黑籽南瓜下降幅度最小,自根黄瓜下降幅度最大,嫁接黄瓜与黑籽南瓜接近.嫁接黄瓜幼苗的耐盐性强于自根黄瓜幼苗,嫁接苗的耐盐性取决于砧木黑籽南瓜.

The protective enzymes activities in grafted and self-root cucumber seedlings under 25, 50, 75 mmol/L NaCl stress were studied using Yunnan black seed pumpkin as the stock and Jinlu NO.4 cucumber cultivar as the scion. And the germinative ability of Yunan black seed pumpkin and cucumber seeds under stress was studied too. The result showed that Yunan black seed pumpkin maintained a higher germination rate, and that of cucumber dropped signifcantly. Both SOD and CAT activity enhanced along with NaCl concentration increasing. The activity of SOD and CAT in seedlings leaves of black seed pumpkin keeped the highest level all along and the two indexes of grafted cucumber were close to the corresponding levels in black seed pumpkin. Self-root cucumber had the lowest level. The SOD activity of each treatment presented a trend of decreasing. It showed that the grafted cucumber performed better than the self-root cucumber at seedlings stage.