丛枝菌根真菌对茶树耐盐性的影响

Influence of AMF on salt tolerance of tea

【目的】研究盐胁迫下接种丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)对茶树根系侵染率、生长、耐盐性及茶树根际土壤酸性磷酸酶活性的影响,探索AMF提高茶树植株耐盐性的生理机理。【方法】以1年生茶树品种‘乌牛早’扦插幼苗为试验材料,采用盆栽试验,向盆土中接种丛枝菌根真菌,以接种灭菌接种物为对照,在幼苗移栽后2个月进行5,10,15,20,25,30mmol/kg 6个盐胁迫处理,分别于处理后50和100d测定茶树株高、根系菌根侵染率及叶片游离脯氨酸、丙二醛含量,100d时测定地径、主根长度、生物量、茶树叶片膜透性及根际土壤酸性磷酸酶活性,并运用模糊综合评判法对各处理的茶树生长质量进行鉴评。【结果】随着盐胁迫浓度的增加,AMF对茶树根系的侵染率逐渐降低,茶树株高、地径、生物量显著降低,生长质量下降,叶片游离脯氨酸、丙二醛含量和膜透性显著增加;与对照相比,在6个盐浓度下接种AMF后,茶树的生长量均有所增加,生长质量明显提高,叶片游离脯氨酸、丙二醛含量和膜透性均有所降低,茶树根际土壤酸性磷酸酶活性均明显提高,但其随着盐浓度的升高而下降。【结论】盐胁迫能抑制茶树的生长,而AMF可通过显著促进茶树体内渗透调节物质的积累和根际土壤酸性磷酸酶活性的提高,有效降低植株体内膜脂的过氧化水平,从而缓解盐胁迫对茶树的伤害,促进茶树在盐胁迫环境中的生长。

[Objective] This study was conducted to investigate the effects of arbuscular mycorrhizal fungi （AMF） on colonization rate of the roots,growth,salt tolerance and the activity of soil acid phospha- tase of tea plant under salt stress. [Method] Camellia sinensis （L.） O. Kountze var. ＂Wuniuzao＂ was used as test material for pot experiment. AMF was inoculated to the pots while sterilization inoculum was used as the control. 6 salinity levels, 5,10,15,20,25, and 30 mmol/kg, were considered. Plant height, AMF colo- nization rate,proline content and malondialdehyde content were measured 50 d and 100 d after treatment, and stem diameter, taproot length, biomass, leaf membrane permeability and activity of acid phosphatase were measured 100 d after treatment. At last,fuzzy comprehensive evaluation was used to authenticate the growth of tea plant. [Result] With the increase of the salt stress,AMF colonization rate of the roots gradu- ally reduced, the growth significantly decreased, the growth quality declined, while the free proline and ma- londialdehyde （MDA） contents and the membrane permeability in the leaves significantly increased. Com- pared to the control,the growth of tea tree in AMF treatment groups were significantly higher, while the free proline and MDA contents and the membrane permeability in the leaves were lower. The activity of soilacid phosphatase was increased compared to the control while it decreased with the increase of the salt stress. [Conclusion] The growth of tea plant was inhibited by salt stress, while AMF could alleviate the in- hibition by enhancing osmotic adjustment, raising the activities of acid phosphatase, and decreasing the membrane lipid peroxidation.