Effects Of Different Silicon Compounds On The Main Diseases Of The Post-harvest Grape And Their Action Mechanism To Pathogen

In this paper,the effects of different silicon compounds on the main diseases of post harvest Red Globe and the mechanisms of Si mediated the resistance of Red Globe were investigated,the results are as follows.(1)Botrytis cineria and some bacteria was isolated from no symptoms of Red Globe fruit in Lanzhou and the main diseases of post harvest Red Globe were caused by B. cinerea, Alternaria sp, C. herbarum, Penicillium sp and Rhizopus sp.etc. In the normal temperature, B. cinerea and Alternaria sp were main pathogens caused diseases of post harvest Red Globe.(2)The nature disease incidence of the post-harvest grape was induced by supplying silicate nano-particles and sodium silicate. The disease of the post-harvest grape was significantly reduced by application silicate nano-particles and sodium silicate.(3)The effect of different silicon compounds on the conidia germination was investigated, and it was found that there was no difference between supplying silicon and control.(4)The mycelial growth of B. cinerea and Alternaria was determined by measuring colony diameter, the result showed treatment with silicate nano-particles and sodium silicate were significantly inhibited the mycelial growth of Alternaria. (5)The activity of β-1,3-glucosidase, polyphenoloxidase(PPO) and phenylalanine ammonia lyase(PAL) were markedly increased by treatment with three kinds of silicon compounds. The results showedβ-1,3-glucosidase activity increased 1.2 to 1.5 times, PAL activity increased 1.5 to 2 times and PPO activity increased in fruit ,but there was no apparent increase in fruit stalk by treated with sodium silicate. These results suggest the post-harvest grape resistance was enhanced with the increase of these enzyme activities by treatment with three kinds of silicon compounds.(6)Si relative content in fruit walls and fruit stalks were investigated by electron microscope and X-ray microanalysis. Si relative content in fruit walls is higher than in fruit stalk treated with sodium silicate, while there is no apparent difference between fruit stalk and fruit walls treated with silicate nano-particles and teraethyl orthosilicate(TEOS). These results showed Si relative content in the colony and diseased and health tissue was relatively higher. Using electron microscope, few conidia were found in colony treated with silicate nano-particles, a few conidia treated with sodium silicate,a large number of conidia in control. These results suggest that conidial production was prevented by supplying Si.All the results indicated that the main diseases of post harvest Red Globe were significantly reduced by the different silicon compounds, This research will lay the foundation for application of silicon compounds to control the diseases of post-harvest grape in the future.