Guo X W, Fernando W G D
Department of Plant Science, University of Manitoba, Winnipeg, MB, Canada, R3T 2N2.
Plant Dis. 2005 Jan;89(1):97-104. doi: 10.1094/PD-89-0097.
Seasonal and diurnal patterns of spore dispersal by Leptosphaeria maculans, which causes blackleg disease of canola, were studied in two consecutive field seasons using a 7-day Burkard spore sampler and rotorod impaction spore samplers. Ascospores of L. maculans were trapped from mid-June to the end of July, whereas pycnidiospores were trapped from mid-July until the end of July or early August. Ascospores and pycnidiospores were trapped between 9:00 P.M. and 4:00 A.M., when air temperatures were 13 to 18°C and relative humidity was >80%. Peak ascospore and pycnidiospore dispersal was associated with rain events. Peak ascospore dispersal was found to occur several hours after rainfall ≥2 mm, and ascospore dispersal continued for approximately 3 days after such events. Peak pycnidiospore dispersal occurred during the same hours as rain events. More ascospores and pycnidiospores were carried in the direction of prevailing winds than in other directions. To the south of the inoculated area, the gradients of disease incidence and stem disease severity were -19.2 and -0.8 m, respectively. Disease incidence and stem severity declined by 50% 12.5 and 5.5 m from the inoculated area, respectively. To the north of the inoculated area, the gradients of disease incidence and stem severity were -21.5 and -0.7 m, respectively. Disease incidence and stem severity declined by 50% 14.0 and 5.2 m from the inoculated area, respectively. In 2001, ascospores and pycnidiospores were trapped within 25 m of the inoculated area, whereas pycnidiospores were trapped up to 45 m from the inoculated area.
在连续两个田间季节中，使用7天的伯克德孢子采样器和旋转棒撞击式孢子采样器，对引起油菜黑胫病的黄斑小球腔菌（Leptosphaeria maculans）的孢子传播季节性和昼夜模式进行了研究。黄斑小球腔菌的子囊孢子于6月中旬至7月底被捕获，而分生孢子器孢子则于7月中旬至7月底或8月初被捕获。子囊孢子和分生孢子器孢子在晚上9点至凌晨4点之间被捕获，此时气温为13至18°C，相对湿度>80%。子囊孢子和分生孢子器孢子的传播高峰与降雨事件相关。发现子囊孢子传播高峰出现在降雨量≥2毫米的降雨事件数小时后，并且在此类事件后子囊孢子传播持续约3天。分生孢子器孢子传播高峰与降雨事件发生在同一时间段。更多的子囊孢子和分生孢子器孢子是顺着盛行风的方向传播，而非其他方向。在接种区域以南，病害发生率和茎部病害严重程度的梯度分别为-19.2和-0.8米。病害发生率和茎部严重程度在距离接种区域12.5米和5.5米处分别下降了50%。在接种区域以北，病害发生率和茎部严重程度的梯度分别为-21.5和-0.7米。病害发生率和茎部严重程度在距离接种区域14.0米和5.2米处分别下降了50%。2001年，子囊孢子和分生孢子器孢子在距离接种区域25米范围内被捕获，而分生孢子器孢子在距离接种区域最远45米处被捕获。
