Pathophysiology And Control Of Postharvest Anthracnose Of Loquat Caused By Colletotrichum Gloeosporioides

The effect of the temperature, humidity and acidity alkalinity on Colletitrichum gloeosporiodes hyphal growth rate, conidia germination were conducted. Also the effects of temperature and acidity alkalinity on hvphal growth in liquid culture medium were studied. The results reported as follows: the growth temperature range from 10℃to 35℃the hyphal could survived, and it was optimum at 28℃. It was beneficial for conidia germination from 20℃to 30℃, it was optimum at 25℃. Colletitrichum gloeosporiodes incubated by liquid culture medium, the hyphal dry weight was the heaviest at 28℃than that of other temperature. Conidia germination requested strict humidity condition, it germinated only in free water or in water film. There was a wild scope of acidity alkalinity in hyphal growth and conidia germination, the pH scope ranged from 3 to 10, pH4-6 was optimum.The hyphal could utilized many carbohydrates and nitrogen sources, but the utilization effects of diverse carbon and nitrogen sources were different. The best carbon sources were lactose and mannitol, the worst carbon source was glycerol. DL-cystine,glycin and urea were the best nitrogen sources,but (NH4)2SO4 had the relatively low effect.The continuous light was beneficial for the hyphal growth,samely continuous darkness wasn't benefit for its growth.After inoculating postharvest loquats with colletitrichum gloeosporiodes, the activities of peroxidase (POD) and phenylalanine ammonia-lyase (PAL) were studied. Results showed that the activities of POD and PAL were significantly ascended, the maximum of them appeared on the second day after inoculating, and the second maximum of POD activity appeared on the 5th day.That is the activities of these enzymes markedly increased with increase of the time course of infection and the disease expansion. The activities ofβ-1,3-glucanase and chitinase in loquat fruits were both induced after inoculating colletotrichum gloeosporioides, both of them appeared the maximum on the 3th day,and the activities ofβ-1,3-glucanase were increased in larger scope than those of chitinase. Activities of the cell wall degrading enzymes (CWDEs) PG and Cx produced by colletotrichum gloeosporioides were induced ,the peaks of PG and Cx activity appeared on the second day and 1.5th day respectively after inoculation.When the diameter of lesion was 1cm,from the lesion to the edge of healthy flesh ,the activities of POD,PAL,chitinase,β-1,3-glucanase,PG and Cx reduced gradually.In vitro test results showed that the five phenolic compounds and seven fungicides could inhibit the growth of c.gloeosporioides except phloroglucinnol, but the concentration of...