水分胁迫下丛枝菌根真菌对紫穗槐生长和抗旱性的影响

Effects of arbuscular mycorrhizal fungi on the growth and drought resistance of Amorpha fruticosa under water stress

采用盆栽试验研究了水分胁迫下接种丛枝菌根真菌(AMF)对紫穗槐生长和抗旱性的影响。结果表明:不同水分条件下,接种植株的株高、根系活力、地上和地下干质量高于对照;水分胁迫下菌根侵染率显著高于正常供水下菌根侵染率;接种AMF可以显著增加不同胁迫时期叶片脯氨酸、可溶性糖和可溶性蛋白的积累,尤其到胁迫后期,中度胁迫和重度胁迫下接种植株脯氨酸含量大幅升高;接种AMF可以显著提高抗氧化酶活性,并且使其维持在一个较高水平。随着土壤相对含水量下降,Fv/Fm降低,接种植株始终高于对照;随着水分胁迫时间的延长,ETR、q L在中期下降,对照植株后期不能回升到原有水平,而接种植株可以恢复到接近前期水平;不同水分条件下,接种植株NPQ始终低于对照。研究表明:干旱条件下,接种AMF可以稳定叶绿素荧光参数,并且通过提高根系活力、植株体内渗透调节物质含量和抗氧化酶的活性来促进紫穗槐生长,提高抗旱性。

A pot experiment was conducted to study the effects of arbuscular mycorrhizal fungi（ AMF） on the growth and drought tolerance of Amorpha fruticosa under water stress. The results showed that,with different water treatments,the height,root activity,dry weight of shoots and roots of inoculated plants were higher than those of non-inoculated plants. Mycorrhizal colonization rates under water stress were significantly higher than those under well-watered conditions. At different water-stress periods,the contents of proline,soluble sugar and soluble protein were significantly increased by inoculating AMF,especially at the later period when the content of proline in AMF plants increased dramatically under severe stress and moderate stress. Additionally,inoculation of AMF could promote the activities of antioxidative enzymes in A. fruticosa and maintain them at a high level. Fv/ Fmdecreased with the reduction of soil relative water content and AMF plants always had a higher Fv/ Fmvalue than non-AMF plants over the whole period. ETR and q L decreased at the middle period while the period of water stress was extended,and the values of two parameters could return to almost the original levels in the AMF plants at the later period; however they could not in the non-AMF plants. AMF plants had a lower NPQ than non-AMF plants at all water conditions. The results show that in the drought condition,inoculating AMF could increase the growth and drought resistance of A. fruticosa by keeping the chlorophyll fluorescence parameters stable,promoting the activities of roots,accumulation of osmolytes and activities of antioxidative enzymes.