3种滇牡丹根际木霉的促生功能及其对幼苗生长的影响

【目的】揭示3种滇牡丹根际木霉的促生功能,并探讨其对幼苗生长发育的影响,为根际木霉的资源利用及滇牡丹的品质提升提供依据。【方法】以滇牡丹根际真菌康宁木霉(Trichoderma koningii)、近渐绿木霉(T. paraviridescens)和哈茨木霉(T. harzianum)为研究对象,分别测定其产吲哚乙酸(IAA)、产铁载体能力及溶磷和解钾活性,探讨接种与未接种目标菌株对滇牡丹幼苗生长、生物量、叶绿素含量和抗性相关生理指标的影响,并采用隶属函数值法对植株品质进行综合评价。【结果】T. harzianum和T. koningii具有产IAA能力,其中T. harzianum能力较强;仅T. koningii有产铁载体能力,接种该菌后滇牡丹幼苗铁含量是其他处理的3~5倍;3种木霉均无溶磷活性,但接种T. paraviridescens的幼苗土壤和根系酸性磷酸酶活性显著高于其他处理(P<0.05,下同);仅T. harzianum有解钾活性,接菌后幼苗的土壤速效钾和植株全钾含量最高。接种T. paraviridescens幼苗的株高和叶片增量数值最高,分别为3.23 cm和3.70片,茎粗也最粗,同时叶绿素含量及叶片、根部的超氧化物歧化酶(SOD)活性、根部的过氧化氢酶(CAT)活性最高。接种T. koningii幼苗的叶片可溶性糖(SS)含量及接种T. harzianum幼苗的叶片可溶性蛋白(SP)含量显著高于其他处理,接种3种木霉的处理组根部SS和SP含量显著高于未接种处理。结合主成分分析和隶属函数值进行综合评分,幼苗质量由高到低依次为T. paraviridescens>T. harzianum>T. koningii>未接种。【结论】接种3种根际木霉对滇牡丹幼苗的营养吸收、光合作用及抗性诱导有积极的促进作用。其中,经T. paraviridescens处理的幼苗生长性状指标、叶绿素含量及抗氧化酶活性显著提高,为滇牡丹理想的促生菌。

Growth promoting function of three Trichoderma species in Paeonia delavayi rhizosphere and their effects on seedling growth

【Objective】To reveal growth promoting functions of three Trichoderma species in Paeonia delavayi rhizosphere,and to discuss their effects on growth and development of seedlings,so as to provide statistical support and reference for the resources utilization of rhizosphere Trichoderma and the quality improvement of P. delavayi.【Method】Rhizosphere fungi,Trichoderma koningii,T. paraviridescens and T. harzianum,were used to determine the indoleacetic acid(IAA)producing ability,siderophore-producing ability,phosphorus-dissolving and potassium-solubilizing activity. Effects of inoculated and uninoculated target strains on growth,biomass,chlorophyll content and resistance-related physiological indicators of P. delavayi seedlings were discussed,and the membership function value method was used to comprehensively evaluate the plant quality.【Result】T. harzianum and T. koningii had IAA producing ability,of which T. harzianum had the stronger ability. Only T. koningii had the ability to produce siderophore,and the iron content of P. delavayi seedlings inoculated with T. koningii was 3-5 times higher than that of other treatments. The three Trichoderma species had no ability of dissolving phosphorus,while the soil and root acid phosphatase activity of plants inoculated with T. paraviridescens were significantly higher than those of the other treatments(P<0.05,the same below). Only T. harzianum had the potassium-solubilizing activity,and content of soil available potassium and plant total potassium after inoculation were the highest. Furthermore,plant height and leaf increments of P. delavayi seedlings inoculated with T. paraviridescens were the highest,which were 3.23 cm and 3.70 pieces,respectively. The stem diameter was the thickest. Meanwhile,the chlorophyll content,superoxide dismutase(SOD)activities in leaves and roots and catalase(CAT)activity in roots were the highest. The content of soluble sugar(SS)in leaves inoculated with T. koningii and that of soluble protein(SP)in leaves inoculated with T. harzianum were significantly higher than those in the other treatments. The content of SS and SP of roots inoculated with Trichoderma spp. were significantly higher than those of control. Considering principal component analysis and membership function value,the seedling quality in different treatments was comprehensively scored,from high to low,as follows: inoculation with T. paraviridescens treatment>inoculation with T. harzianum treatment>inoculation with T. koningii treatment>uninoculated treatment.【Conculsion】Inoculation of the three Trichoderma species in rhizosphere has positive effects on nutrient absorption,photosynthesis and resistance induction of P. delavayi seedlings.Growth traits,chlorophyll content and antioxidant enzyme activity of seedling treated with T. paraviridescens are improved significantly,which is an ideal growth promoting fungus for P. delavayi.