Stanosz G R, Blodgett J T, Smith D R, Kruger E L
Department of Plant Pathology, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706-1598, USA.
Department of Forest Ecology and Management, University of Wisconsin-Madison, 1630 Linden Drive, Madison, WI 53706-1598, USA.
New Phytol. 2001 Mar;149(3):531-538. doi: 10.1046/j.1469-8137.2001.00052.x.
• The role of water stress in the initiation of collar rot by Sphaeropsis sapinea in asymptomatically colonized Pinus resinosa seedlings is reported. • Mortality and frequency of identification of the pathogen was quantified for seedlings subjected to different water regimes or watering regime-fungicide (benomyl) combinations in glasshouse experiments. • In experiment 1, seedling mortality ranged from 8% of repeatedly watered seedlings to 50% of those in the driest regime; data analysis indicated a high probability that mortality was not independent of watering regime. Seedlings developed symptoms resembling those of Sphaeropsis collar rot, and S. sapinea was identified from living (42%) and dead (92%) seedlings. In experiment 2, mortality of repeatedly watered seedlings was low, irrespective of fungicide application. For nonwatered seedlings, however, mortality was greater among seedlings not treated with fungicide (61%) than among benomyl-treated seedlings (37%); data analysis indicated a high probability that mortality was not independent of fungicide treatment. • Sphaeropsis sapinea can act as a latent pathogen; physiological alteration, through water stress, can effect release from the quiescent condition to result in rapid disease development.
• 报道了水分胁迫在无症状定殖的北美短叶松幼苗中，由松球壳孢菌引发根颈腐烂病过程中的作用。
• 在温室试验中，对处于不同水分条件或水分条件 - 杀菌剂（苯菌灵）组合下的幼苗，病原菌的死亡率和鉴定频率进行了量化。
• 在实验1中，幼苗死亡率从反复浇水的幼苗的8%到最干旱条件下的50%不等；数据分析表明死亡率极有可能并非独立于浇水条件。幼苗出现了类似松球壳孢菌根颈腐烂病的症状，并且从存活（42%）和死亡（92%）的幼苗中均鉴定出了松球壳孢菌。在实验2中，反复浇水的幼苗死亡率较低，与是否施用杀菌剂无关。然而，对于未浇水的幼苗，未处理杀菌剂的幼苗死亡率（61%）高于苯菌灵处理的幼苗（37%）；数据分析表明死亡率极有可能并非独立于杀菌剂处理。
• 松球壳孢菌可作为潜伏性病原菌；水分胁迫引起的生理变化可促使其从静止状态转变为快速发病状态。
