Porter L D, Johnson D A
USDA-ARS, Vegetable and Forage Crops Research Unit, Prosser, WA 99350.
Department of Plant Pathology, Washington State University, Pullman 99164-6430.
Plant Dis. 2007 Jul;91(7):835-841. doi: 10.1094/PDIS-91-7-0835.
Currently, there is no information on the viability of sporangia in soil of the new metalaxyl-resistant genotypes of Phytophthora infestans in the semiarid Columbia Basin of Washington and potato-growing regions throughout the world. Sporangia of metalaxyl-resistant US-8 and US-11 clonal lineages of P. infestans survived a maximum of 23 to 30 days in a Shano silt loam and a Quincy loamy fine sand. There were no significant differences between soil types in area under the spore survival curve (AUSSC) in two trials, however, sporangia of P. infestans in the Quincy sand had a significantly greater mean maximum days of sporangia survival (MDSS) than did the Shano silt loam in one of two trials. AUSSC and MDSS were significantly greater (P < 0.05) for sporangia in wet soil than in dry soil under shaded conditions. Mean AUSSC and MDSS significantly decreased (P < 0.01) under nonshaded conditions versus shaded conditions. Three metalaxyl-resistant isolates (two US-8 and one US-11) of P. infestans did not significantly differ (P < 0.05) in AUSSC and MDSS.
目前，对于华盛顿半干旱哥伦比亚盆地以及全球马铃薯种植区中，新的抗甲霜灵基因型致病疫霉在土壤中的孢子囊活力尚无相关信息。致病疫霉抗甲霜灵的US-8和US-11克隆谱系的孢子囊，在沙诺粉质壤土和昆西壤质细砂中最多存活23至30天。在两项试验中，土壤类型之间的孢子存活曲线下面积（AUSSC）没有显著差异，然而，在两项试验中的一项里，致病疫霉在昆西砂中的孢子囊平均最大存活天数（MDSS）显著高于沙诺粉质壤土。在遮荫条件下，湿土中孢子囊的AUSSC和MDSS显著高于干土（P < 0.05）。与遮荫条件相比，非遮荫条件下平均AUSSC和MDSS显著降低（P < 0.01）。致病疫霉的三个抗甲霜灵分离株（两个US-8和一个US-11）在AUSSC和MDSS方面没有显著差异（P < 0.05）。
