| 摘要: |
| 为四川省雅安市石棉县核桃炭疽病病害防治提供依据，对该地区发病叶片、果实和枝干分别进行发病组织培养、分离纯化，通过致病性测定、菌落形态观察和rDNA-ITS序列测定对病原菌进行鉴定，并采用菌丝生长速率法和孢子萌发法，室内测定25种杀菌剂配方对病原菌菌丝生长和孢子萌发的抑制作用。结果表明：1）病原菌经分离纯化后得到的9个菌株，根据各菌株在PDA平板正反面的不同形态分为2类，分别选择1个具有代表性的菌株P51和P57作后续鉴定。2个菌株接种果实和叶片后发病率均为100%，病原重分离均得到接种的病原，其形态特征均与刺盘孢属Colletotrichum gloeosporioides真菌相似；将2个菌株rDNA-ITS序列与Genbank中相关菌株的ITS序列进行同源性比较，发现其与C.gloeosporioides真菌同源性达到100%。使用DNAMAN6.0邻接法进行序列同源性比对并构建系统发育树，菌株P51、P57与已鉴定为C.gloeosporioides的AB981196、HQ645082、KC355249和KJ676453以自展支持率100%聚类在一起。2）杀菌剂配方筛选：100%链霉素3 000倍液等5种配方对病原菌菌丝生长抑制作用最强，不同配方之间差异不显著；100%链霉素3 000倍液等4种配方之间差异不显著，对病原菌孢子萌发抑制作用最强，对菌丝生长和孢子萌发抑制作用都强的是100%链霉素3 000倍液、25%咪鲜胺500倍液、50%福美双500倍液、70%甲基硫菌灵500倍液。通过上述研究结果可以确定引起雅安地区核桃炭疽病的病原为刺盘孢属C.gloeosporioides真菌；100%链霉素3 000倍液、25%咪鲜胺500倍液、50%福美双500倍液、70%甲基硫菌灵500倍液4种配方对C.gloeosporioides真菌生长萌发抑制作用最强。 |
| 关键词: 核桃炭疽病 病原鉴定 Colletotrichum gloeosporioides 抑菌药剂 |
| DOI：10.11841/j.issn.1007-4333.2016.12.06 |
| 投稿时间：2016-03-04 |
| 基金项目:四川省农作物育种攻关项目（2011NZ0098-10） |
|
| Pathogen identification of walnut anthracnose and fungicide screening |
|
HUANG Xiong, WANG Lin-ying, XIAO Qian-wen, PU Guang-lan, HE Wen-chun
|
| (College of Forestry, Sichuan Agricultural University, Chengdu 611130, China) |
| Abstract: |
| To provide theory basis of preventing walnut anthracnose in Shimian County,Yaan City,Sichuan Province,infected walnut leave,fruits and twigs samples were collected from this area.Culturing,separation and purification of pathogen were conducted.And themorphological characteristics,pathogenicity and the DNA sequence of ribosomal ITS of pathogen were analyzed for pathogen identification.Twenty-five fungicide formulas screening was determined by mycelial growth rate test and spore germination assay in laboratory.1)The results showed that:Nine isolates in total were morphologically identified According to their differences in colony morphology on the above and back side of PDA plate.These isolates were divided into two groups based on colony morphology,and isolates P51 and P57 belonged to each group were selected for follow-up analyses.The pathogenicity tests showed that symptoms caused by these two isolates were identical to those observed in field and the same pathogen was re-isolated from the diseased tissues.The biological characteristics indicated these isolates belonged to Colletotrichum gloeosporioides species complex.By sequence comparison with the related sequence in GenBank,it showed that the sequence homology was 100%.The result of phylogenetic tree indicated that isolates P51 and P57 were classified into one group of C.gloeosporioides including isolates AB981196,HQ645082,KC355249 and KJ676453.2)Fungicide screening:Five fungicides formulas including 100% streptomycin 3 000 times diluted strongly affected the growth of mycelium.Among which,four fungicides formulas were most efficient on exhibiting spore germination.100% streptomycin 3 000 times diluted,25% prochloraz 500 times diluted,50% thiram 500 times diluted,and 70% thiophanate-methyl 500 times diluted strongly affected both the growth of mycelium and exhibiting spore germination.This study suggested that the pathogen of walnut anthracnose in Yaan was C.gloeosporioides.And the best fungicides formulas were 100% streptomycin 3 000 times diluted,25% prochloraz 500 times diluted,50% thiram 500 times diluted,70% thiophanate-methyl 500 times diluted. |
| Key words: walnut anthracnose pathogen identification Colletotrichum gloeosporioides fungicide screening |
