新疆野苹果根围木霉分离鉴定及生防特性研究

Isolation,Identification and Biocontrol Characteristics of Trichoderma from the Rhizosphere Soil of Malus sieversii

为了给防治新疆野苹果病害提供生防性能优良的木霉菌株,利用孟加拉红平板分离法进行新疆巩留县野苹果根围木霉菌株分离,通过形态特征和ITS rDNA序列比对进行菌种鉴定,利用平板对峙试验检测分离木霉抑菌能力,用NBT染色和根部观察检验木霉诱导后新疆野苹果幼苗叶片活性氧含量、抗病和促生能力。结果表明:分离鉴定出俄罗斯木霉22株,渐绿木霉13株,哈茨木霉4株。从长势和产孢量等特性上看,俄罗斯木霉T7和哈茨木霉T2为新疆野苹果根围优势生防木霉菌种。哈茨木霉T2对尖孢镰刀菌的抑菌率为75.47%,对链格孢菌的抑菌率为78.17%。俄罗斯木霉T7对尖孢镰刀菌的抑菌率为79.66%,对链格孢菌的抑菌率为91.53%;NBT染色发现木霉处理后野苹果苗叶片活性氧含量降低,叶片染色颜色更浅。总之,木霉能有效抑制病原菌生长,能有效减少新疆野苹果幼苗中活性氧含量,促进和保护根系生长。本研究为防治新疆野苹果病害防治提供生防性能优良的木霉菌株,为苹果病害的生物防治提供可以借鉴的方法。

In order to provide excellent biocontrol Trichoderma strains in preventing and treating of Malus sieversii diseases,the Trichoderma strains from the Malus sieversii roots in Gongliu County,Xinjiang were isolated by Bengal red plate separation method.The morphological characteristics and ITS rDNA sequence alignment were used to identify the strains.The antifungal ability of Trichoderma was detected by the plate confrontation test.NBT staining and root observation were used to test the active oxygen content,disease resistance and growth-promoting ability of M.sieversii seedlings after Trichoderma induction.The results showed that 22 strains of Trichoderma rossicum,13 strains of T.viridescens and 4 strains of T.harzianum were isolated and identified.From the characteristics of growth and sporulation,T.rossicum T7 and T.harzianum T2 are the dominant biocontrol species of Trichoderma spp.from the roots of M.sieversii.The inhibition rate of T.harzianum T2 against F.oxysporum was 75.47%,the inhibition rate against A.alternata was 78.17%,and the inhibition rate of T.rossicum T7 against F.oxysporum was 79.66%,the inhibition rate against A.alternata was 91.53%.NBT staining showed that the active oxygen content in the leaves of M.sieversii seedlings decreased after Trichoderma treatment,and the staining color of the leaves was lighter.In conclusion,Trichoderma can effectively inhibit the growth of pathogenic bacteria,effectively reduce the active oxygen content in M.sieversii seedlings,and promote and protect root growth.This study provides a Trichoderma strain with excellent biocontrol performance for the prevention and control of M.sieversii disease in Xinjiang,and provides a method for biological control of M.sieversii diseases.