在水分胁迫下根际促生菌A2对小麦萌芽期和苗期的促生效应

为了明确根际促生细菌A2 对植物生长的促生效应，通过室内发芽试验，以PEG6000 4 个浓度处理条件，对A2 菌株3 种发酵产物浸种处理的小麦，采用“胚芽鞘长度法”测定种子发芽势、发芽率、胚芽鞘抗旱指数，同时测定其幼苗叶片脯氨酸含量和可溶性糖含量的变化。结果表明PEG6000 浓度为4%时不同浸种处理的小麦胚芽鞘长度、发芽率、叶片脯氨酸含量、可溶性糖含量等各项指标均无显著差异，PEG6000 浓度为12%时，A2 菌株发酵液浸种的小麦发芽率比无菌水对照组高14.93%，其幼苗叶片脯氨酸含量和可溶性糖含量分别比对照高66.55%，66.92%。说明随着PEG6000 浓度的增加不同浸种处理间的各项指标差异显著或极显著，A2 菌株促进植物生长的同时诱导植物产生抗性物质从而适应不利环境。

Growth-Promoting Effects of Rhizosphere Growth Promoting Bacteria A2 on Germination and Seedling Stage of Wheat Under Water Stress

In order to define the growth-promoting effect of rhizosphere growth promoting bacteria A2 on the growth of plant, by indoor germination test, wheat was treated by four different concentrations of PEG6000, and then soaked in three different fermentation products of A2. The germination potential of seed, rate of germination, and index of coleoptile drought resistance were determined by“Method of Coleoptile Length” respectively. Meanwhile, the content of proline and soluble sugar were measured in leaf. The results indicated that there was no significant difference of coleoptile length, germination rate, proline content and soluble sugar content under the concentration of 4% PEG6000. When PEG6000 concentration reached 12%, the germination rate of wheat was 14.93% higher than that of the control. In addition, the content of proline and soluble sugar were 66.55% and 66.92% higher than those of the control respectively. In conclusion, with the increasing concentration of PEG6000, there was significant difference or very significant difference among indexes with seed soaking treatments. So, the A2 promotes the growth of plant and induces plant producing some resistance substances to adapt to the unfavorable environment.