The Preliminary Study Of Resistance Induced And Fresh-Keeping By Jinggangmycin-A On Grape

JinggangmycinA (J-A)has been well known as an antibiotic to control rice sheath blight cause by Rhizoctonia solani.lt is a secondary metabolite from streptomyces with antifugal activity against plant pathogens, it does not kill the fungi, but causes hyphal growth anomalies and decreases pathogen virulence.The concentration 25ug/ml J-A could not inhibit the pathogen growth directly showed an effective control activity on the rate of accidence-diease of grape after picking. Moreover, the activity of chitinase and P -1, 3-glucanase was significantly increased. The result showed that the both activity of chitinase and P -1, 3-glucanase reached the peak after spraying J-A. Meanwhile, changes of contents of trehalose in grape were studied. Contents of trehalose were significantly increased by J-A treatments after 3 days.The correlation between Trehalos and Trehalase activity is clear.After picking 5days, the result showed that the contents of VitaminC, titratable sour, soluble sugar, peel section were decreased gradually and the rate of losing-water was raising gradually. But J-A treatment could retard them decreasing ?, especially the concentration 25ug/ml J-A . We proposed that the concentration 25ng/ml J-A was possible to be accepted as a practical concentration.