3株蒜头果内生木霉的鉴定及其对幼苗的促生作用研究

【目的】鉴定3株蒜头果内生木霉，并探讨其对幼苗生长发育的影响，为蒜头果内生木霉资源的利用及优质苗木培育提供参考。【方法】采用分子系统学和形态学方法,鉴定3株分离自蒜头果茎部和根部的内生木霉。通过接种效应试验，测定根施3种木霉菌液和无菌水（对照）后，蒜头果幼苗的生长性状、生物量、叶绿素含量、抗氧化酶活性、可溶性糖和可溶性蛋白含量以及木霉的根系定殖率，并结合各项指标的隶属函数值对不同处理的蒜头果幼苗品质进行综合评价。【结果】通过构建木霉属菌种系统发育树以及对菌落形态和微观结构的观察，确定3株内生木霉分别为哈茨木霉（Trichoderma harzianum，SF15）、贵州木霉（T. guizhouense，SF548）和绒毛木霉（T. tomentosum，SF434）。接种菌株SF15和SF548的蒜头果幼苗株高增量、叶片增量显著高于对照，3种木霉处理的幼苗茎粗增量均显著高于对照。接种菌株SF15和SF548的蒜头果幼苗主根长和根部吸器数量显著高于对照，而最大吸器直径显著低于对照，且不同处理组的蒜头果幼苗主根长与根部吸器数量呈一定正相关，而与最大吸器直径呈一定负相关。接种菌株SF15和SF548的幼苗地下、地上、全株鲜质量及干质量均显著高于对照，接种菌株SF434的处理组全株鲜质量及地下和全株干质量显著高于对照。3个接菌组蒜头果幼苗叶片叶绿素含量，POD、SOD、CAT活性以及可溶性糖和可溶性蛋白含量均显著高于对照。接种菌株SF15和SF548的蒜头果幼苗根系定殖率分别为64.25%和61.78%，显著高于接种SF434的根系定殖率55.57%。基于各项测定指标的隶属函数值，不同处理组幼苗品质的综合排名为：接种SF15的处理>接种SF548的处理>接种SF434的处理>对照。【结论】3株蒜头果内生木霉对幼苗生长、生物量、叶绿素含量、抗氧化酶活性以及可溶性糖、可溶性蛋白含量的提高有积极促进作用，其中菌株SF15和SF548的促生效果较为显著，为蒜头果潜在的促生菌株。

Identification of three endophytic Trichoderma strains from Malania oleifera and their growth promoting effects on seedlings

【Objective】Three endophytic Trichoderma strains in Malania oleifera were identified and their effects on growth and development of seedlings were explored, so as to provide reference for the utilization of endophytic Trichoderma resources in M. oleifera and the cultivation of high-quality seedlings.【Method】Three endophytic Trichoderma strains isolated from stems and roots of M. oleifera were identified by molecular systematics and morphological methods.Through the inoculation effect test,growth traits,biomass,chlorophyll content,antioxidant enzyme activities,soluble sugar and soluble protein contents,as well as Trichoderma root colonization rate of M. oleifera seedlings treated with three kinds of Trichoderma liquids and sterile water (control) were determined.The quality of M. oleifera seedlings in different treatments was also comprehensively evaluated by the membership function values of all indexes.【Result】Based on the phylogenetic tree of Trichoderma strains and the colony morphology and microstruction,the three endophytic Trichoderma strains were identified as Trichoderma harzianum (SF15),T. guizhouense (SF548) and T. tomentosum (SF434),respectively.The plant height increment and leaf increment of M. oleifera seedlings inoculated with strains SF15 and SF548 were significantly higher than those of the control,and the stem diameter increment of seedlings treated with three Trichoderma strains was significantly higher than that of the control.The main root length and haustorium number of M. oleifera seedlings inoculated with strains SF15 and SF548 were significantly higher than those of the control,while the maximum haustorium diameter was significantly lower.The main root length of M. oleifera seedlings in different treatments was positively correlated with the number of root haustorium,while negatively correlated with the maximum haustorium diameter.The fresh weight and dry weight of underground,aboveground and whole plant of seedlings inoculated with strains SF15 and SF548 were significantly higher than those of the control.The fresh weight of whole plant and dry weights of underground and whole plant of seedlings inoculated with strain SF434 were significantly higher than those of the control.The chlorophyll content,POD,SOD and CAT activities,as well as soluble sugar and soluble protein contents in leaves of M. oleifera seedlings in the three inoculation treatments were significantly higher than those in the control.The root colonization rates of M. oleifera seedlings inoculated with strains SF15 and SF548 were 64.25% and 61.78%,which were significantly higher than those inoculated with SF434 (55.57%).Based on the membership function value of each index,the comprehensive ranking of seedling quality was in the order of SF15>SF548>SF434>control.【Conclusion】Three endophytic Trichoderma strains from M. oleifera had positive promoting effects on seedling growth,biomass,chlorophyll content,antioxidant enzyme activities,and soluble sugars and soluble protein contents.Strains SF15 and SF548 had significant growth promoting effects and were potential growth promoting fungi for M. oleifera seedings.