从生物学、致病力、对甲霜灵的敏感性等侧面对海南岛19个县市的芋疫霉菌(Phytophthora colocasiae Racib)进行研究,结果表明:芋疫霉种下存在丰富的多样性。孢囊形态差异显著,长宽比1.36~2.6,大小从(17.5-)39.5(-82.5)×(10.0-)23.3(-35.0)μm到(40.0-)56.0(-92.5)×(22.5-)30.5(-40.0)μm。大部分菌株的最适生长温度25～30 ℃,最适温度下各菌株的生长速率差异显著,从0.562 cm/d到0.829 cm/d。两种交配型(A1:A2)比例接近于1。各菌株对芋头材料的致病力有明显不同。对甲霜灵的敏感性也显著不同, EC50值0.077μg/mL～0.448μg/mL。生物学、致病力、对甲霜灵的敏感性等性状的分布似乎与地理位置有关。多元聚类将19个菌株分成6类。%Nineteen strains of Phytophthora colocasiae obtained from different locations in Hainan Island were tested for morphological characteristics growth rate virulence to taro and sensitivity to Metalaxyl. The Results showed that there was considerable diversity within this species. The sporangial sizes of different strains were significantly different with L/B ratio ranging from 1.36 to 2.6. The optimum temperature for growth of most of the strains (17 strains) was 25 ℃. However the growth rate under the optimum temperature varied considerably among these strains ranging from 0.562 cm/d to 0.828 cm/d. Virulence test with inoculating the strains on taro materials indicated that the virulence of these strains was significantly different from each other. Sensitivity to Metalaxyl was also evidently different with the values of EC50 ranging from 0.077 μg/mL to 0.448 μg/mL. The morphological characteristic distribution had something to do with the geographical position. The 19 strains were divided into 6 groups according to cluster analysis.
展开▼
