铁皮石斛梢枯病病原菌分离鉴定及淀粉酶产色链霉菌代谢产物对其防治效果

Isolation&Identification of the Die Back Pathogen from Dendrobium officinale and Control Effect by Streptomyces diastatochramogenes Metabolites

梢枯病是浙江省武义县寿仙谷铁皮石斛种植基地一种常见的真菌病害,严重影响铁皮石斛的产量与品质,而鉴定枯梢病的病原菌是有效防治该病害的前提条件。本文通过对铁皮石斛染病组织培养、病原菌分离纯化,柯赫法则验证、形态学观察与基因序列比对分析(Alta1、EF-1α、RPB2、ATP、His 3)等,明确了引起浙产铁皮石斛梢枯病的病原菌为链格孢菌Alternaria alternata。淀粉酶产色链霉菌Streptomyces diastatochromogenes 1628代谢产物对链格孢菌菌丝生长有较强的抑制作用,IC_(50)为0.461%(体积浓度)。田间试验结果表明,在7和14 d的校正防效分别为68.35%和65.97%,均显著高于阳性对照50%多菌灵。本研究明确了铁皮石斛梢枯病病原菌的分类地位,并获得能够有效抑制该病原菌的微生物抑菌物质淀粉酶产色链霉菌代谢产物,为后续浙产铁皮石斛梢枯病的防治提供了实践依据。

Die back is a common disease of Dendrobium officinale in Shouxianggu planting base,Wuyi County,Zhejiang Province.This disease seriously affects the yield and quality of D.officinale.In this study,the pathogen of D.officinale die back was isolated and confirmed by culturing the die back tissue,isolation and purification of the pathogen and verification via Koch's rule.Furthermore,the pathogen was identified as Alternaria alternata by morphological observation and gene sequence analysis(Alt a1,EF-1α,RPB2,ATP,His 3).In order to inhibit the pathogen,the fermentation products of Streptomyces diastatochromogenes 1628 was applied and showed strong inhibit effect on hyphal growth of A.alternata,and IC_(50) was 0.461%(volume concentration).Field experiment results showed that the control effects on die back disease were 68.35%and 65.97%at 7 days and 14 days,respectively,which were higher than that of 50%carbendazim(positive control).This study showed the taxonomic status of the pathogen of D.officinale die back,and tested the biocontrol effect of S.diastochromogenes 1628 fermentation products.Our research results provide a basis for the prevention and control of D.officinale die back.