Studies On Fungicide Resistance In Field Of Botrytis Cinerea And Its Control

Monitoring of fungicide resistance to 3 different types fungicide of Botrytis cinerea,which were isolated from tomato collected in 4 different level of fungicide applicationgreenhouse of Heilongjiang Province during June-July in 2005. The level and frequency ofresistance of different class of strains were carried out. The sensitivity and cross-resistance ofdifferent class of strains collected from greenhouse to fungicide were examined. The fitness ofdifferent class of strains was studied. The resistance mechanism to carbendazin, procymidoneand diethofencarb was evaluated. It was very important to control Botrytis cinerea by usingTrichoderma in strategy of fungicide resistance management, and also studied the colonizingability and the fermentation condition for Trichoderma.The results could be summarized asfollows:The result showed that the percentages of resistance to carbendazin, procymidone anddiethofencarb were100ï¼…in Harbin Hada, the percentages of resistance tocarbendazin, procymidone and diethofencarb were 100ï¼…,80ï¼…,84ï¼…. the percentages ofresistance to earbendazin, procymidone and diethofencarb were 100ï¼…,64ï¼…,76ï¼…. thepercentages of resistance to carbendazin, procymidone and diethofencarb were 100ï¼…,38ï¼…,66ï¼….The multiple resistant strains can maintain their resistance after 9 successive incubation onthe fungicide free PDA. The multiple resistant strains, sensitive strains and other class ofstrains showed similar radial growth rates, but multiple fungicide resistance strains had fewerconidia and most sclerote than sensitivity strains. In all trial strains the osmotice sensitivity of60-1 is the biggest.The result showed that upon treatment with carbendazin, procymidone and diethofencarb, thesensitive strain had been absorbed banding activity, it can absorb lots of carbendazin, but it didnot show that activity to those resistant strains to carbendazin. Diethofencarb caused moreelectrolyte leakage of the multiple fungicide resistant strains when the concentration waslower(0.1mg/L). Celler leakage from different class of strains did not differ after fewer hoursincubation. It showed that multiple fungicide resistant strains(35) could have more electrolyteleakageThe activities of phenylanine ammonia-lyase, cellulase and pectase of different class ofstrains were increased when they treated with limited concentration ofcarbendazin, procymidone and diethofencarb after limited time, but their activity were notcorrelated to fungicide sensitivity.Colonizing ability of Trichoderma could be affected by the existence of Botrytis cinerea inphyllosphere before Trichoderm initiated colonization which associated with the competition to exudates and space in phyllosphere between the two fungi, therefore Trichoderma should beused before Botrytis cinerea invaded leaf to promote the biocontrol agent colonization ahead ofpathogen infection.The control effect of pyrimethanil was 65.25ï¼…to Botrytis cinerea.It was all better than theeffect of Trichoderma (51.83ï¼…). but the different treatment of mixing pyrimethanil andTrichoderma was better than the pure treatment, they can up to 68.76ï¼…and 70.45ï¼….