| Grapes（Vitaceae Vitis L.）have important economic value worldwide.Grapevine ripe rot is distributed in most of the grape growing areas in the country,and it is one of the most serious grape diseases that affects the yield and quality of fruits.To study the interaction between grapes and pathogenic bacteria to clarify the pathogenic mechanism of pathogenic bacteria and the response mechanism of grapes is important.Two isolated strains were selected to study the biological characteristics,and the morphology and pathogenicity of the two were compared.After that,study on the interaction between Colletotrichum on grape and grape’s accessions with different resistance was carried out.The research results obtained are as follows:（1）On the basis of the previous study in laboratory,two strains were selected which are Colletotrichum viniferum strain Cv YL2a and Colletotrichum gloeosporioides strain YLRG13,and the biological characteristics were studied after molecular identification.The differences in morphology and pathogenicity of the two were compared.Strong and large spore yield,Cv YL2a was selected for subsequent inoculation.（2）Three kinds of grape accessions were identified for their resistance to C.viniferum in leaves.The infection characteristics of grapevine ripe rot on the leaves of the highly susceptible grape accession’Thompson Seedless’and the leaves of the disease-resistant grape accession’Liuba-8’and’Beaumont’were quite different.There were differences in the germination rate of conidia,the rate of appressorium formation,the time point and formation rate of penetration pegs.In terms of the formation of vesicles,primary hyphae and secondary hyphae,among the three accessions,the only one that can be observed secondary hyphae is the high-sensitivity accession Thompson Seedless.That is to say,only on the high-sensitivity accession Thompson Seedless,Colletotrichum viniferum strain Cv YL2a completed the whole process of semi-biotrophic form from biotrophic form to death trophic form.On the banks of the disease-resistant accession’Beaumont’,only the biotrophic process was completed,while on the leaves of the highly resistant accession,Liuba-8,the vesicles and hyphae were not observed after the formation of penetration pegs.（3）The two kinds of grape accessions were identified for their resistance to Colletotrichum viniferum in fruit.The invasion of grapevine ripe rot on the fruit of high-susceptibility grape accession’Thompson Seedless’and the fruit of medium resistance grape accession Beaumont was quite different.In terms of the formation of appressorium and the formation of penetration pegs,the medium-resistance accession and the high-sensitivity accession of the riverbank were one time point later.C.viniferum also completed the production of vesicles,the formation of primary and secondary hyphae on the high-sensitivity accession of Thompson Seedless fruit,which is a typical semi-trophic type.However,vesicles were only observed at 3d on the banks of the medium-resistant accession,and did not observed expand and differentiate into primary hyphae.（4）The production rate of H2O2 in the affinity system composed of the leaves of the susceptible grape accession Thompson Seedless and C.viniferum was lower than that of the incompatibility system composed of the leaves of the resistant grape accession’Liuba-8’and’Beaumont’and C.viniferum system.It shows that the defense responses of resistant and susceptible grape accessions to the invasion of C.viniferum are quite different and H2O2 may be one of the key responses in the defense response of grapes to the invasion of C.viniferum. |
