Phytopathology. 2001 Oct;91(10):973-80. doi: 10.1094/PHYTO.2001.91.10.973.
ABSTRACT Phytophthora capsici isolates were recovered from pepper and cucurbit hosts at seven locations in Michigan from 1998 to 2000. Isolates were characterized for compatibility type (CT), mefenoxam sensitivity (MS), and amplified fragment length polymorphism (AFLP) marker profiles. In total, 94 AFLP bands were resolved. Individual populations were highly variable. Within populations, 39 to 49% of the AFLP bands were polymorphic and estimated heterozygosities ranged from 0.16 to 0.19. Of the 646 isolates fingerprinted, 70% (454) had unique AFLP profiles. No clones were recovered between years or locations. Pairwise F statistics (Phi(ST)) between populations from different locations ranged from 0.18 to 0.40. A tree based on unweighted pair-group method with arithmetic average cluster analysis indicates discrete clusters based on location. Isolates from the same location showed no clustering based on the year of sampling. Analysis of molecular variance partitioned variability among (40%) and within populations (60%). The overall estimated Phi(ST) was 0.34 (SD = 0.03). A1/A2 CT ratios were approximately 1:1, and MS frequencies were similar between years for the two locations sampled over time. These data suggest that P. capsici persists in discrete outcrossing populations and that gene flow among locations in Michigan is infrequent.
摘要 1998 年至 2000 年间，从密歇根州的七个地点的辣椒和葫芦科作物宿主中分离出辣椒疫霉。对分离株的亲和型（CT）、甲霜灵敏感性（MS）和扩增片段长度多态性（AFLP）标记图谱进行了特征分析。共解析了 94 个 AFLP 带。各个种群的变异性很高。在种群内，39%至 49%的 AFLP 带是多态的，估计杂合度范围从 0.16 到 0.19。在被指纹识别的 646 个分离株中，70%（454 个）具有独特的 AFLP 图谱。在不同年份或地点之间没有克隆体被回收。来自不同地点的种群之间的成对 F 统计量（Phi(ST)）范围从 0.18 到 0.40。基于非加权对群法与算术平均聚类分析的树状图表明，根据地点存在离散的聚类。来自同一地点的分离株根据采样年份没有聚类。基于分子方差分析，种群间（40%）和种群内（60%）的变异性进行了划分。总体估计的 Phi(ST)为 0.34（标准差=0.03）。A1/A2 CT 比例约为 1:1，且随着时间的推移，在两个采样地点，MS 频率在两年之间相似。这些数据表明，辣椒疫霉在离散的异交种群中持续存在，密歇根州各地点之间的基因流动很少。
