Nepal Achala, Del Río Mendoza Luis E
Department of Plant Pathology, North Dakota State University, Fargo 58108.
Plant Dis. 2012 Sep;96(9):1315-1322. doi: 10.1094/PDIS-10-11-0889-RE.
The relationship between moisture content and carpogenic germination (CG) of Sclerotinia sclerotiorum sclerotia and the dynamics of sclerotial water imbibition were studied in a controlled environment. The study was conducted using laboratory-produced sclerotia from seven S. sclerotiorum isolates. The quantity and rate of water imbibition by three sizes of sclerotia was determined gravimetrically in silty clay, sandy loam, and sandy soils maintained at 100, 75, 50, and 25% of soil saturation and in distilled water. Smaller sclerotia imbibed water at a significantly faster rate (P = 0.05) than larger sclerotia in water and in soil at all saturation percentages. When buried in soil, small, medium, and large sclerotia were fully saturated within 5, 15, and 25 h, respectively, in all three soil types and moisture percentages. The effect of sclerotia moisture content on CG was evaluated on sclerotia maintained at 95 to 100, 70 to 80, 40 to 50, and 20 to 30% of their water saturation capacity using cool mist humidifiers. Sclerotial moisture content significantly influenced CG (P = 0.05). Maximum CG was observed on fully saturated sclerotia, while no CG was observed below 70 to 80% of saturation. These findings help explain S. sclerotiorum's ability to produce apothecia in soils with relatively low moisture levels.
在可控环境下，研究了核盘菌菌核的水分含量与产孢萌发（CG）之间的关系以及菌核水分吸收动态。该研究使用了从7个核盘菌分离株实验室培养产生的菌核。通过重量法测定了三种大小的菌核在粉质粘土、砂壤土和砂土中，以及在蒸馏水中的吸水量和吸水速率，土壤保持在土壤饱和度的100%、75%、50%和25%。在所有饱和度百分比下，较小的菌核在水和土壤中的吸水速率明显快于较大的菌核（P = 0.05）。当埋入土壤中时，在所有三种土壤类型和湿度百分比条件下，小、中、大菌核分别在5、15和25小时内完全饱和。使用冷雾加湿器，对保持在其水饱和容量的95%至100%、70%至80%、40%至50%和20%至30%的菌核，评估了菌核水分含量对产孢萌发的影响。菌核水分含量对产孢萌发有显著影响（P = 0.05）。在完全饱和的菌核上观察到最大产孢萌发率，而在饱和度低于70%至80%时未观察到产孢萌发。这些发现有助于解释核盘菌在相对低湿度土壤中产生子囊盘的能力。
