1种辣椒新炭疽病的初步鉴定及室内药剂筛选

炭疽病是辣椒上的重要病害，影响了辣椒的产量与品质。生产中，在“辛香15号”辣椒上发现了1种新炭疽病，仅在辣椒果实上发生，典型病斑为椭圆形，周围水渍状，中间呈黑色同心轮纹，无小黑点出现，对常用杀菌剂不敏感；保湿后镜检发现，该病菌产生分生孢子盘，无刚毛，分生孢子近长椭圆形，无色，单孢，大小为12．5μm×3．75μm，有油球，一端稍尖；进一步分离培养病原菌并通过柯赫氏法则验证后，初步将其鉴定为尖孢炭疽菌（Collectotrichum acutatum Simmonds）。为了获得对该病效果好的化学药剂，采用牛津杯法测定了8种化学药剂对病菌的抑制效果，结果表明：250g/L丙环唑乳油3000倍液抑制效果最好且药效持续时间长，可作为该病的候选药剂。本试验结果可为防治尖孢炭疽菌引起的辣椒炭疽病提供理论依据和用药参考。

Identification of a New Anthracnose of Peppers and Screening of Fungicides

Anthracnose was an important disease of peppers, influencing their yield and quality. A new anthracnose only appearing on the pepper fruits was found in the production of pepper cultivars XinXiang 15. Its typical lesion was oval in shape with tawny powder at the center, and with outer water soaked zones, but without concentric black dots. The new anthracnose was difficult to control by using the general fungicides. It was found that no seta was observed on conidia. Conidia were single-celled, 12.5 μmx3.75 μm in size, with a sub-acute end and oil droplets in each cell after keeping the humidity and detecting the mildew by microscope. The pathogen was identified as Collectotrichum acutatum Simmonds after isolating and culturing and validating by Koch＇s Rule. In order to obtain the better fungicides to control the new anthracnose disease, inhibition effects of 8 fungicides against the fungal from pepper cultivars XinXiang 15 were detected by Oxford-Cup in vitro. The results showed that 250 g/L propiconazole EC diluted 3 000 times had obvious inhibition effects and long duration time, which could be regarded as a candidate fungicide to control the new anthracnose caused by Collectotrichum acutatum on peppers. This research provided theoretic evidences and fungicide references for the new anthracnose control.