丛枝菌根真菌对辣椒光合特性及根际微生物多样性和酶活性的影响

Effects of Arbuscular Mycorrhizal Fungi on Characteristics of Photosynthesis,Microbial Diversity and Enzymes Activity in Rhizosphere of Pepper Plants Cultivated in Organic Substrate

在育苗和栽培基质中添加具有生物活性的微生物群体是改善无土栽培有机基质性状和提高应用效果的重要途径。该试验通过在辣椒育苗和栽培基质中添加丛枝菌根真菌制剂恩益碧(NEB-F),研究了AMF对辣椒生长、果实产量、光合特性以及根际微生物多样性和酶活性的影响。结果显示:(1)基质添加AMF显著促进了辣椒植株生长,并明显提高了产量。(2)AMF处理显著提高了辣椒植株叶片的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、水分利用效率(WUE),而使胞间二氧化碳浓度(Ci)显著降低,同时对辣椒叶片最大光化学效率(Fv/Fm)的影响不大,而使实际光化学效率(ФPSⅡ)、光化学猝灭(qP)和表观光合电子传递效率(ETR)显著提高。(3)基质添加AMF显著增加基质中细菌、放线菌数量,而降低真菌数量,并明显提高了根际微生物多样性指数以及过氧化氢酶、碱性磷酸酶和尿酶活性;添加AMF基质中的细菌、真菌、放线菌数量均与其过氧化氢酶、脲酶、碱性磷酸酶之间呈显著或极显著正相关关系。研究表明,基质添加AMF不仅增大了辣椒叶片气孔导度,而且促进电子传递速率,提高CO2同化利用效率和净光合速率;同时促使辣椒根际微生物区系从低肥力的"真菌型"向高肥力的"细菌型"转化,提高根际微生物多样性和酶活性,有助于维持辣椒根际生态系统的稳定性与和谐性,从而促进辣椒幼苗生长,并提高产量。基质中添加AMF是提高有机基质应用效果的有效途径。

One of the important ways to improve the properties and application effect is to add microbial community with biological activity into organic cultivation substrate. In this experiment, the effects of ar- buscular mycorrhizal fungi （AMF） on seedling growth, enzyme activities in rhizosphere of Capsicum annuum L. fruit yield, photosynthesis, microbial diversity and plants were investigated by adding AMF in organic substrate during seedling and cultivation. The results showed that： （1）The growth of pepper seedlings was promoted. （2）The net photosynthetic rate（P.）,stomatal conductance（G~）,transpiration rate（Tr） and wa- ter use effieiency（WUE） were significantly increased while intercellular CO2 concentration（Ci） was de- creased. Meanwhile,it has little effect on the maximum photochemical efficiency（Fv/Fm）, but the actual photochemical efficiency （OPsl）, photochemical quenching （%） and table electron transport efficiency （ETR） were increased by AMF,moreover,resulting in robust seedlings and higher yield. （3）The amount of bacteria and actinomycetes in rhizosphere of pepper plants was increased by AMF,but the amount of fungi was decreased,and the Shannon-Wiener and Shannon index of microbial diversity, the activities of catalase, urease and alkaline phosphatase in organic substrate were enhanced. Furthermore, the correlation coeffi- cient between amount of bacteria, actinomycetes, fungi and activities of enzymes such as catalase, urease and alkaline phosphatase in AMF substrate reached to a significant or extremely significant level. Our results suggested that AMF increased stomatal conductance of Pepper leaves and improved electron transfer rate, raised CO2 assimilation efficiency and net photosynthetic rate,meanwhile it also promoted the transforma- tion process of substrate from low-fertility caused by fungi to high-fertility caused by bacteria, and en- hanced microbial diversity and enzyme activities. AMF helps maintain the stability and harmony in rhizo- sphere ecological system of pepper plants, lead to more rapid seedlings growth and higher yield. In conclu- sion,it is an effective way to improve the application effect of organic substrate by adding AMF.