Invasion Procedure And Effects On Physiological Characteristics Of Uncinula Necator In Grape Leaves

In order to explore the invasion procedure and the effects on physiological indicators of infected grape leaves by grape powdery mildew. Using the material of vitis vinifera individual 15-1-9 and 6-12-2 and Chinese wild vitis Baihe35-1, transit the powdery mildews in grape-free vaccine leaves purification the strains, vitro powdery mildew conidia to observed the germination process, besides, we observed the microstructure and ultrastructure after infection and observed the changes of leaves major organelle, at the same time, inoculated grape powdery mildew and determined the major physiological characteristics of changes in grape leaves in a period of the time. The major findings are as follows:1. Take the diseased leaves tablet free vaccine leaves, when the leaves surface have white spots, continue to transferred the health leaves on garpe-free vaccine, after 5～6 times the stains can be purified and save.2. Conidia began to germinate in the 2～6 h, germ tube 6～10 h began to stretch, 10～12 h appressoria began to information, 12～24 h the haustorium formation and grow hyphae, after 48 h second conidia stems appeared. For the specificity of grape powdery mildew, this experimental methods can host the conidia survive 5～6 d, this is a useful exploration.3. Inoculation of powdery mildew conidia, seeding growth in grape leaves surface. In addition, the grape powdery mildew infected leaves only positive epidermal cells.4. Inoculated grape powdery mildew conidia, conidia germination, first produce germ tubes, in the top of the germ tubes produced leaf-shape appressoria, in the process some enzymes participation and degradation the leaf epidermis to help attachment and penetration. In post-infection, conidia can not germination and hyphae dissociation.5. By transmission electron microscopy techniques, we observed the structure of haustorium, the shapes like round ball and crab-shape, deep in the epidermal cells to absorb nutrients.6. After inoculation 30 d chloroplast and cell nucleus destroyed, but the mitochondria have a little impact.7. Leaves were not inoculated contrast with Inoculation grape powdery mildew after 30 d measured the major physiological results showed that infection leaves of CAT, POD, PAL, Chitinase activities andβ-1,3- glucanase activities first increased and then decreased, the lignin content and MDA upward, while PPO activities downward.