Pathogen Diversity Of Sooty Blotch From Qin Yu Qian And Other Provinces In China

Sooty blotch and flyspeck is one of the most common diseases of apple,especially on unbagged apple fruits.SBFS fungi live on fruit surface and form smudges,reducing fruit quality and causing significant economic losses to growers.In recent years,SBFS catching more attention with the increasing prevalence of apple production without bagging.This research aimed to determine the taxonomic diversity of SBFS fungi in Shaanxi,Henan,Guizhou and other provinces in China.A total of 167 fruit samples bearing SBFS signs were collected in September,2015,which included 122 apple fruit samples from Shaanxi Province,8 samples from Henan Province,16 plum fruit samples from Guizhou Province,13 samples from Gansu Province and 8 samples from Qinhai Province.From these samples,92 purified strains were obtained.Main results from a characterization of these strains are as follows:(1)Based on symptom differences,the 167 samples were divided into 7 types:ridged-honeycomb,compact spot,fuligious,dipersive spot,flyspeck,ramose,and punctate.Among them,flyspeck accounted for 7.6%(13);compact spot accounted for 5.5%(9);dipersive spot accounted for 15.3%(26);fuligious accounted for 12.5%(21);ridged-honeycomb accounted for 9%(15);ramose accounted for 36.1%(60);punctate accounted for 13.9%(23).(2)Based on morphological characteristics and phylogenetic analysis,the strains were classified into 10 genera: Dissoconium,Houjia,Strelitziana,Mycosphaerella,Pseudoveronaea,Acremonium,Ramichloridium,Stomiopeltis,Peltaster,and Wallemia.(3)We identified six new species which were Wallemia liandaowanensis,Wallemia guizhouensis,Acremonium liquanensis,Acremonium mali,and Dissoconium mali.We reported two new records that Pseudoveronaea ellipsoidea,Dissoconium aciculare,Strelitziana albiziae.We also found a new pathogenic species,Strelitziana albiziae.