中文摘要：

采用喷雾方法,研究水杨酸（SA）和茉莉酸甲酯（MeJA）对棉花幼苗（3~4真叶期）内相关抗虫酚类物质（黄酮、单宁和总酚）质量分数的诱导作用,以明确SA和MeJA对酚类物质的诱导时间及浓度效应。结果表明,随处理时间的延长,SA和MeJA处理后棉叶酚类物质质量分数先升后降,对棉叶诱导作用分别可持续4~8d和12d。MeJA对棉叶酚类物质质量分数的诱导作用较SA显著,且这两种外源物均明显影响棉叶内黄酮、单宁和总酚质量分数。5mmol/L SA和0.5mmol/L MeJA处理棉叶第4天对黄酮、单宁、总酚质量分数的诱导作用显著高于其他浓度和时间处理。总之,外源信号物质对棉叶内酚类物质质量分数的诱导作用,具有激发子差异性、时间持效性和浓度依赖性的特点。

英文摘要：

Methyl jasmonate （MeJA） and salicylic acid （SA） are important endogenous plant signaling molecules which can induce plants to produce insect-resistant materials. To clarify induction time and concentration effect of SA or MeJA on phenolic substances, the article measured the mass fraction of phenolic substances （flavonoids, tannins and total phenols） in Gossypium spp seedlings at 3-4 -leaf stage after spraying SA and MeJA. Results showed that,after spraying SA and MeJA, the mass fraction of phenolics in cotton leaves characterized increase firstly and then decrease, and their inducing effect lasted for 4-8 and 12 days, respectively. MeJA induced significantly higher mass fraction of phenolic substances in cotton leaf than SA, and this two kinds of exogenous substrates could affect the mass fraction of flavonoid, condensed tannins and total phenols in Gossypium spp leaves significantly. The optimal inducing time and concentration are 5 mmol/L for SA and 0.5 mmol/L for MeJA on forth day. In conclusion, the phenolic substances induced by exogenous signal substances characterized different depending on induction substances, as well as their duration and concentrations.