Histopathological Study Of The Interaction Between Of Different Resistant Grapes And Elsino? Ampelina

Grapes are one of the main economically cultivated fruit trees in China.Most of the mainstream varieties cultivated in China and the world are Vitis vinifera of good quality,but they are susceptible to fungal diseases,including grape anthracnose caused by Elsino? ampelina(de Bary)Shear.With the development of wine industrialization and its products,and the widespread promotion of grape cultivation,grape anthracnose has threatened the grape industry in many places,causing huge economic losses.At present,the main use of chemical control for the prevention and treatment of anthracnose,and the harm caused by chemical control could not be ignored.Therefore,how to enhance the grape's own disease resistance and find a long-term effective disease resistance breeding germplasm has become a hot spot.The Chinese wild grape germplasm is a relatively precious resource for resistance,but the difference in resistance characteristics and potential mechanism of susceptible grapes and resistant grapes for E.?ampelina is poorly understand.In this study,one resistant cultivar,‘Shang-24'(Vitis quinquangularis),and two susceptible cultivars,‘Tangwei'(Vitis davidii)and ‘Thompson Seedless'(Vitis vinifera),were selected as research materials.The objective was to compare the characteristics of pathogen development and host response between susceptible and resistant grapevine cultivars using multiple microscopic observations and expression profiling of defense-related genes.The main results are as follows:1?The leaves of three different genotypes were inoculated with E.?ampelina,and it was found that after the third days of inoculation,brown and round spots appeared in ‘Tangwei' and ‘Thompson Seedless'.Eventually,the infected leaves gradually shrink and necrosis.However,there was no obvious lesion in ‘Shang-24'.Quantitative statistical analysis of germination in E.?ampelina conidia after 48 hours of infection.It was found that the germination rate of conidia was more than 70% after infection of ‘Tangwei' and ‘Thompson Seedless',while the germination rate of conidia in ‘Shang-24' was only 9.5%.2 ? Fluorescent staining and ultrastructural techniques were used to observe that E.?ampelina infected grape leaves.It was found that E.?ampelina tended to aggregate and grow,and generally produced more than one germ tubes in ‘Tangwei' and ‘Thompson Seedless'.Clusters of hyphae were observed that had many mycelia with monilioid hyphae in the later stage of infection.Most of the spores colonized in intercellular space of host cell.The surface of damaged mesophyll cell was collapsed,the cuticle was degraded.However,when E.?ampelina infected ‘Shang-24',mycelial growth was inhibited and long and full mycelium could not be formed,so it could not invade the successful host cells quickly.3?The ultrastructure showed that after ‘Shang-24' was infected with E.?ampelina,the spores had a lot of cavities,and the mycelium was covered with a lot of electronic compacts.The mesophyll cells were lightly lysed and mycelium was inhibited from growing.However,after ‘Tangwei' and ‘Thompson Seedless' were infected,the vaccinia quickly invaded and successfully colonized the host cells,causing the host cells to be damaged and unable to complete the normal metabolic history.But in ‘Shang-24',the pathogens could not infect the host cells more quickly and had little effect on the host cells.4?The qRT-PCR technology was used to perform fluorescent quantitative expression analysis on six genes related to physiological and biochemical metabolism and plant defense after inoculation of pathogenic E.?ampelina against disease-resistant and susceptible grapes.The results showed that most of the genes were induced by pathogenic fungi in the disease-resistant ‘Shang-24' strain and the expression level was up-regulated;while in disease-susceptible ‘Thompson Seedless',the expression levels of these genes showed little or no change in expression levels compared to the control without inoculation with pathogenic fungi.In ‘Shang-24',the expression of related genes is earlier than that of susceptible grape ‘Thompson Seedless',which indicates that when pathogens infect plants,resistant varieties first induce the production of certain defensive substances to resist the invasion of pathogens,thereby reducing the damage caused to plants damage.