Mila A L, Yang X B
Department of Plant Pathology, Iowa State University, Ames 50011.
Plant Dis. 2008 Jan;92(1):78-82. doi: 10.1094/PDIS-92-1-0078.
The effects of fluctuating soil temperature and water potential on sclerotial germination and apothecial production by Sclerotinia sclerotiorum were investigated in growth chamber experiments. In the temperature experiments, temperature fluctuations of 4, 8, 12, and 16°C around a median of 20°C, and a constant of 20°C, were tested. Daily temperature fluctuations of 8°C resulted in highest levels of sclerotial germination and apothecial production. The earliest appearance of apothecia occurred in the 8°C fluctuation treatment, 24 days after the start of the experiment. Sclerotia in the 12°C fluctuation treatment germinated last; its first sclerotium germinated 44 days after experiment initiation. For the soil water potential experiments, constant saturation (approximately -0.001 MPa) and three levels of soil water potential fluctuation from saturation-"low" (-0.03 to -0.04 MPa), "medium" (-0.06 to -0.07 MPa), and "high" (-0.09 to -0.1 MPa)-were tested. Constant saturation yielded the highest number of germinated sclerotia and apothecia. All soil water potential fluctuations were detrimental to sclerotial germination and apothecial production, with sclerotial germination under fluctuating moisture conditions less than a tenth of that occurring under constant saturation. The first sclerotium in the constant saturation treatment germinated in 35 days; however, 76 days were required in the high soil water potential fluctuation treatment.
通过生长室实验研究了土壤温度和水势波动对核盘菌菌核萌发及子囊盘产生的影响。在温度实验中，测试了围绕20°C中位数上下波动4°C、8°C、12°C和16°C以及恒定20°C的情况。每日8°C的温度波动导致菌核萌发和子囊盘产生水平最高。子囊盘最早出现在8°C波动处理组，实验开始后24天出现。12°C波动处理组的菌核最后萌发；其首个菌核在实验开始44天后萌发。在土壤水势实验中，测试了恒定饱和状态（约-0.001 MPa）以及从饱和状态到“低”（-0.03至-0.04 MPa）、“中”（-0.06至-0.07 MPa）和“高”（-0.09至-0.1 MPa）三个水平的土壤水势波动情况。恒定饱和状态下萌发的菌核和产生的子囊盘数量最多。所有土壤水势波动均对菌核萌发和子囊盘产生不利，在水分波动条件下菌核萌发率不到恒定饱和状态下的十分之一。恒定饱和处理组的首个菌核在35天萌发；然而，在高土壤水势波动处理组则需要76天。
