The Phylogenetic Taxonomy Of Botryosphaeriaceae Fungi

Disease types of tree canker like canker,rot bark, rot,stem rot,ring rot,scab,gum,tumor,deadwood, sprike top,and so on.They can severely harm a variety of ecological andeconomical tree such as poplar,apple,pear,pomegranate and pine tree.In China tree cankerare generally caused by fungal pathogens. Among them, Botryosphaeria Cas. is deemed tobe the most important fungal group.Taxonomy and identification of Botryosphaeria fungibased on their teleomorphs and anamorphs,primarily anamorph characteristics.Therefore,there are numberous anamorph types corresponding to Botryosphaeria fungi,andthe determination of them have a lot of confusion. So taxonomy of Botryosphaeria fungi isalso all the time one of hot spot of fungal taxonomy.In recent years,fungal systemiticsstudies had found that in conventional sense Botryosphaeria fungi is composed of multiplemonophyletic groups,which are corresponding to different gebera ofBotryosphaeriaceae.This study was primarily system investigating tree canker of Hebeiprovince,pathogens isolation,identificating and systematic classificating Botryosphaeriaand relative pathogens.The aim was to find out distribution characteristics of tree cankerin Hebei province and corresponding relation between tree canker disease and pathogensunder new classification system,and to study genetic diversity of Botryosphaeria dothideaisolates which were collected from three different regions such as Shaanxiprovince,Shandong and Chongqing.In this study,using116isolates of Botryosphaeriaceae fungi which were collectedeight cities,ten counties of Hebei as materials, the characteristics of those isolates inculture,morphology and phylogenetic relationship were analyzed and identified.Molecularmarkers of RAPD and ISSR were used to clarify the relationship and geneticdifferentiation of Botryosphaeria dothidea which collected different host plants ofShandong,Shaanxi and Chongqing.Using M13molecular marker and phylogeneticanalysis,43isolates were studied.,which were collected Hebei,Shandong,Shaanxi,Siquanand Chongqing of China.The main results of the study are as follows:1. Pathogenic fungi causing tree canker of Hebei province were studied.12genus,12species plants were reported as new hosts of Botryosphaeria and other related fungi inChina,which included Euonymus japonicus Thunb., Broussonetia papyrifera(L.)Vent,Platycladus orientalis (Linn.) Franco., Lonicera maackii (Rupr.)Maxim., Forsythia suspensa (Thunb.) vahl., Cercis chinensis Bunge., Magnolia soulangeana Soul.,Pistacia vera L., Rhus typhina Nutt., Zanthoxylum bungeanum Maxim., Prunus blireana cv.Meiren, Euphorbia milii var.splendens (Bojer ex Hook)Ursch.2. Using characters of cluture,morphology and molecular systematics,116pathogenicfungi causing tree canker of Hebei province were identified as Botryosphaeria dothidea,“B”.stevensii,“B”.obtusa,“B”. sarmentorum and Guignardia citricarpa,which werebelong to Botryosphaeriaceae.3. In the process of inducing spore-bearing of pathogenic fungi causing tree canker, itwas discovered that WA medium contained Pinus armandii Franch needles and Pinusponderosa needles as materials can induce Botryosphaeriaceae fungi to produce spore.Butunder the same culture conditions, Pinus ponderosa needles was easier to inducespore-bearing than Pinus armandii Franch needles.4.Morphology assay, rDNA-ITS and EF-1α sequences analysis were used to identifiedfirstly that new pathogen of alder canker in China is B. dothidea.5. The results of RAPD and ISSR cluster analysis are as follows: The NJ clusteringtree built based on Euclid or Dist distance coefficient showed that42experimental strainscollected Shandong,Shaanxi and Chongqing can be divided into four RAPD/ISSR groups,group Ⅳ is the largest group which included19strains according for45%of all42strains;UPGMA cluster analysis indicated that genetic similarity coefficient of42B.dothideaisolates is0.82-0.99,which were divided into three RAPD/ISSR groups; UPGMAclustering tree had very few group and internal branch is not obvious，so the best tree is theNJ clustering tree built based on Euclid or Dist distance coefficient; B. dothidea existedintraspecific genetic differentiation,which had a certain correlation with hosts andterritorial sources.6. Primer M13produced stable and differential bands in different pathogenic fungi oftree canker which corresponded to different M13band types.Therefore, M13molecularmarker technique can rapidly distinguish pathogenic fungal groups causing tree canker.