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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。
In order to provide basis for prevention and treatment of anthracnose disease of walnut in Shimian County, Ya’an City, Sichuan Province, the pathogen, the fruit and the branch of diseased leaves, fruit and branch were cultivated and isolated respectively. Pathogenicity, colonies morphology and rDNA- The mycelium growth rate method and spore germination method were used to determine the inhibitory effect of 25 fungicide formulations on mycelial growth and spore germination of pathogenic bacteria. The results showed that: 1) Nine isolates of pathogenic bacteria were divided into two groups according to different morphologies of the front and back of PDA plates. One representative strains, P51 and P57, were selected for subsequent identification. The pathogenicity of the two isolates were all 100% after inoculation of fruit and leaves. The pathogenicity of the two isolates were all inoculated with the pathogen, and their morphological characteristics were similar to those of Colletotrichum gloeosporioides. The rDNA-ITS sequences of two isolates were correlated with Genbank The ITS sequences of the isolates were compared for homology and found to have 100% homology with the C. gloeosporioides fungi. Sequence homology alignments were performed using the DNAMAN 6.0 contig and phylogenetic trees were constructed. Strains P51 and P57 were clustered together with AB981196, HQ645082, KC355249 and KJ676453, which were identified as C. gloeosporioides with 100% self-deployment support. 2) Fungicide formula screening: 5% 100% streptomycin and other five kinds of formula on the pathogen mycelium growth inhibition the strongest, the difference between the different formulations was not significant; 100% streptomycin 3000 times 4 No significant difference between the formula, the spore germination of the strongest inhibitory effect on mycelial growth and spore germination are strong inhibition of 100% streptomycin 3000 times, 25% prochloraz 500 times, 50% Fortune double 500 times, 70% thiophanate-methyl 500 times. According to the above results, the pathogen causing anthracnose of walnut in Yaan was identified as C. gloeosporioides fungus of 100% streptomycin, 500 times of 25% prochloraz, 50% of thiram 500 times , 70% thiophanate-methyl 500 times four kinds of formulations of C. gloeosporioides fungal growth and germination of the strongest inhibitory effect.