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[摘要]
目的 探索外源一氧化氮(NO)对干旱胁迫下白花蛇舌草Oldenlandia diffusa种子萌发的影响,并确定缓解干旱胁迫的硝普钠(SNP,NO外源供体)最适浓度。方法 用15% PEG 6000模拟干旱胁迫,测定不同浓度梯度SNP处理后干旱胁迫下白花蛇舌草种子的发芽势、发芽率、发芽指数和活力指数。结果 干旱胁迫显著抑制了白花蛇舌草种子的萌发过程。SNP能显著促进干旱胁迫下白花蛇舌草种子的萌发,0.3 mmol/L SNP处理可提高发芽率和活力指数2.78倍和7.77倍;从发芽势和发芽指数来看,0.1 mmol/L和0.3 mmol/L SNP处理效果最佳且二者差异不显著。结论 SNP可显著缓解干旱胁迫对白花蛇舌草种子萌发的不利影响,提高白花蛇舌草种子的抗旱能力,其中以0.3 mmol/L SNP效果最佳。
[Key word]
[Abstract]
Objective To explore the effect of exogenous nitric oxide (NO) on seed germination of Oldenlandia diffusa under drought stress and to determine the optimal concentration of sodium nitroprusside (SNP, exterior nitric oxide donor) for alleviating the drought stress. Methods Using 15% PEG6000 to imitate drought stress, the germination potential, germination rate, germination index, and vigor index of O. diffusa seeds were measured by the treatment of SNP at different concentration. Results The germination process of O. diffusa seeds was significantly suppressed by drought stress. SNP could significantly promote the germination of O. diffusa seeds under drought stress. SNP (0.3 mmol/L) increased the germination rate and germination potential by 2.78- and 7.77-folds, respectively. In the case of germination index and vigor index, SNP (0.1 and 0.3 mmol/L ) showed the maximum positive impact and there was no significant difference between the two SNP concentration treatments. Conclusion SNP could alleviate the negative influence of drought stress on the germination process of O. diffusa seeds and improve the drought-resistant activity. Among all the treatments, the concentration of SNP at 0.3 mmol/L leads to the maximum germination rate.
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[基金项目]
国家科技重大专项(2009ZX09308-002,2012ZX09304006)