Study On The Taxonomy Of Colletotrichum Corda Et Al. In China And Biological Peculiarity Of Colletotrichum Gloeosporioides (Penz.) Sacc. In Mango

Colletotrichum Corda had a widely geographical distribution and hosts. It caused seriousdiseases on different plants, especially for tropical crops. Therefore, it had very importantposition among phytopathogenic fungi. In this study, we retrospected research history of thetaxonomy of Colletotrichum Corda and expatiated on the evolvement of ColletotrichumCorda’s appellation, and also appraised traditional classifical system which represented bySaccardo (1882-1921) and neoteric classifical system that brought forward by Arx(1957,1970)&Sutton (1980), respectively. In addition, we also performed characterization ofbiology of Colletotrichum gloeosporioides (Penz.) Sacc. in Mango.1. Based on Von Arx&Sutton’s neoteric classifical system and the principle for naturialmorphology, and accompanied with host range, we studied more than400genusColletotrichum specimens that preserved in our lab and other related departments in Chinaincluding70genus collected recently. In total46species and form sp. are recognized andidentifed in this study. Among them, there are4new species: Gloeosporium blumeae，Gloeosporium machilicola， Gloeosporium passigloricolum， Colletotrichum stephaniae；one new species: Colletotrichum complanatum；12firstly discovered specie:Gloeosporium capparidis， Colletotrichum manihoticola， Colletotrichum piperis，Colletotrichum rubicola， Melanconium stictoides, Gloeosporium theobromicolum,Cylindrosporium triostei, Gloeosporium nanoti，Gloeosporium begoniae，Gloeosporiumbryophylli，Gloeosporium cinnamomi，Gloeosporium sanguisorbae；3mainland newlydistribution: Colletotrichum phalaenopsidis, Colletotrichum althaeae, Gloeosporium cassiaesiameae. A detail description for all species, drawings and some pictures were given in thetext. In addition, we offered a key of these species.2. Eighteen isolates of Colletotrichum gloeosporioides (Penz.) Sacc. were collected fromthirteen mango varieties of six places in Ynnan province. The cultivation character andpathogenetic comparisons of these isolates were observed and recorded. The representativestrong pathogenic strains were selected which offered materials for study of infection processand enzyme activity. Sannian mango were inoculated by strong pathogenic isolate. Theultrastructure of infection process of C. gloeosporioides on leaf and fruit, host pathology in infection process and fungi cell change after treatment of fungicide were observed by lightmicroscopy and election microscopy. In addition, the activity of peroxidase (POD),phenylalanine ammonialyase (PAL), and polyphenol oxidase (PPO) of mango fruit weredetected by spectrophotometer in infection process of C. gloeosporioides. The resultsindicated that the cultivation character of eighteen isolates of C. gloeosporioides is different.The pathogen with stronger pathogenicity has light color, thin and strong adhesive hyphae,and produced plentiful spores early. The pathogen with weaker pathogenicity has dense andheavy color hyphae, and produced few spores late. CG16was screened as strong pathogenicstrains. It needs one and half days from inoculation to symptom. After inoculation, primaryand secondary hyphae were found in infected tissue. Primary haphae extended between hostcells, host cells collapsed because of pathogen infecting. Second hyphae extended quickly andpropagated with dispersion or bundle. Hyphae first formed a funnel-shaped hyphal cone andproduced a septum near host cell wall in infection process, there was a striction near the hostcell wall, primary hyphae became swollen normal hyphae after penetrating host cell wall.During infection process, pathological change happened. The host cell wall became deformedand thin because of hyphal invasion, cellular protoplasm of host cells became disorganized,chloroplast in the infected host tissue disintegrated, chloroplast envelope was distorted anddisorganized partly. The effect of fungicide on pathogen is obvious. The fungi cell wallbecame thick, and organelle was disorganized, hyphae was dying. There was much hyphaeetravasation between hyphae and host after treatment.During the pathogen infecting process, the activities of POD, PPO and PAL in infectedmango pericarp were higher than health mango pericarp. It was indicated that POD, PPO, andPAL were involved in the occurrence of indeced resistance. Enzyme activities increased withinoculation days, the change of three kinds of enzymes activities inoculatecd by CG16ismore evident than that inoculated by CG8. It meant that the pathogen with strongerpothogenicity could induce mango fruit produced more enzyme than that less pathogenicity.Five days after inoculation by CG16, the POD activities were the highest, and then, resistanceability declined with disorganization of host cells, the change of POD activity fell, the changeof PPO activity was somewhat similar to POD. The activities of PAL were the highest threedays after Mango fruit inoculated by CG16, and then fell sharply. The change of enzymeactivities of mango inoculated by CG8was delayed compared with CG16, that is enzymeincreased slowly, peak hours pushed off, and fell off slowly after inoculation.