Identification Of Pathogens Of Four Medicinal Plant

Traditional Chinese herbal medicine is the quintessence of Chinese culture and treasure,which has medicinal and health care effect in the treatment and prevention of mankind diseases.In recent years,the government has payed more and more attention to traditional Chinese medicine,so that a great number of traditional Chinese medicinal herbs were planted,and become the primary economic channel for farmers or enterprises.However,with planting of traditional Chinese medicinal herbs in large areas,some pests occurred,especially,some diseases occurred more seriously,Meizhou is playing more and more attention to traditional Chinese medicinal industry.But some medicinal herbs diseases took place seriously every year,and caused great impact to traditional Chinese medicinal herbs production.But the kinds of traditional Chinese medicinal herbs diseases were not known clear.The purpose of this study was to determinate the pathogens of these diseases based onbiological characteristics test and molecular identification,the results were shown in the following: 1.Identificationof pathogen of anthracnose in Zanthor?lum nitidum(Roxb.)DC.According to Koch's postulate,the pathogenic fungi isolateLiangmianzhen was obtained by isolating and pathogenicity test.The pathogenic isolate Liangmianzhen was identified based on analysis of internal transcribed spacer(ITS)of ribosomal DNA and glycerol aldehyde-3-phosphate dehydrogenase(GAPD)gene.The results showed that,the ITS sequence was amplified from isolate Liangmianzhen with primers ITS1 and ITS4,obtaining a PCR product of 556 bp.A BLAST search in GenBank revealed the highest similarity(99%)to sequences of Colletotrichum gloeosporioides,Colletotrichum boninense,Colletotrichum karstii,Colletotrichum nicotianae,Alternaria alternata and Colletotrichum kahawae.Then,amplifocation of gapd gene of isolate Liangmianzhen was conducted with primers GDF1 and GDR1,obtaining a PCR product of 263 bp.A BLAST search in GenBank revealed the highest similarity(99%-100%)to sequences ofColletotrichum gloeosporioides,Colletotrichum boninense and Colletotrichum karstii,by construction of phylogenic tree between isolate Liangmianzhen and the related isolates from GenBank,the pathogenic isolate Liangmianzhen and Colletotrichum karstii was in a clade,the bootstrap value was 100%.So,the pathogen of anthracnose of Zanthor?lum nitidum was preliminarily identified as Colletotrichum karstii.2.Identification of pathogen of branch blight in Ilexasprella(Hook.et.Arn)Champ.ex Benth.According to Koch's postulate,the pathogenic isolate Gangmei was obtained by isolating and pathogenicity test.The pathogenic isolate Gangmei was identified based on analysis of internal transcribed spacer(ITS).The results showed that,the ITS sequence was amplified from isolate Gangmei with primers ITS1 and ITS4,obtaining a PCR product of 524 bp.A BLAST search in GenBank revealed the highest similarity(99%)to sequences of Pestalotiopsis microspora,Pestalotiopsis virgatula and Pestalotiopsis clavispora,by construction of phylogenic tree between isolate Gangmei and the related isolates from GenBank,the pathogenic isolate Gangmei and Pestalotiopsis microspora was in a clade.So,the pathogen of branch blight in Ilex asprellawaspreliminarily identified as Pestalotiopsis microspora.3.Identification of pathogenof leaf spot in Evodia lepta(Spreng.)Merr.According to Koch's postulate,the pathogenic fungi isolate Sanchaku was obtained by isolating and pathogenicity test.The pathogenic isolate Sanchaku was identified based on analysis of ribosomal internally transcribed spacer(ITS).The results showed that,ITS sequence was amplified from isolate Sanchaku with primers ITS1 and ITS4,obtaining a PCR product of 544 bp.A BLAST search in GenBank revealed the highest similarity(99%)to sequences of Alternaria alternata,Alternaria solani,Alternaria tenuissima,Alternaria porri and Alternaria brassicae,by construction of phylogenic tree between isolate Sanchaku and related isolates from GenBank,the pathogenic isolate Sanchaku and Alternaria alternata was in a clade,but,the bootstrap value was 62%.So,the pathogen of leaf spot of Evodia leptawaspreliminarily identified as Alternaria sp..4.Identification of pathogenof stem wilt in Murraya paniculata(L.)Jack.According to Koch's postulate,the pathogenic fungi isolate Qianlixiang was obtained by isolating and pathogenicity text.The pathogenic isolate Qilixiang was identifided based on analysis of ribosomal internally transcribed spacer(ITS).The results showed that,the partial sequence of ITS was amplified from isolate Qianlixiang with primers ITS1 and ITS4,obtaining a PCR product of 549 bp.A BLAST search in GenBank revealed the highest similarity(99%)to sequences of Curvularia eragrostidis,Curvularia borreriae,Curvularia trifolii,Curvularia brachyspora and Curvularia intermedia,by construction of phylogenic tree between isolate Qianlixiang and related isolates from GenBank,the pathogenic isolate Qianlixiang and Pestalotiopsis microspora was in a clade,the bootstrap value was 100%.So,the pathogen of stem wilt of Murraya paniculata was preliminarily identified as Curvularia eragrostidis.