Al-Rawahi A K, Hancock J G
College of Agriculture, Sultan Qaboos University, Sultanate of Oman, Berkeley 94720-3112.
Center for Biological Control and Division of Insect Biology, University of California, Berkeley 94720-3112.
Plant Dis. 1998 Oct;82(10):1100-1106. doi: 10.1094/PDIS.1998.82.10.1100.
Pythium oligandrum was a parasite of Verticillium dahliae in dual culture, impeding the latter's ability to grow and form microsclerotia. Variation occurred among isolates of P. oligandrum in their parasitism toward isolates of V. dahliae, and isolates of V. dahliae expressed a range of susceptibilities to parasitism by P. oligandrum. Temperature and matric potential significantly affected interactions between these fungi. Populations of P. oligandrum in the rhizosphere of pepper (Capsicum annuum) were similar in a potting soil infested and noninfested with V. dahliae, but the populations of V. dahliae in combined samples of rhizosphere and nonrhizosphere soil of pepper were significantly lower in the presence of P. oligandrum than in its absence. In greenhouse experiments with pepper grown in soil infested with V. dahliae, shoot and fruit weights were significantly higher in the presence of P. oligandrum than in its absence. However, when soil was infested only with P. oligandrum, fresh weights of shoots and fruits were 40 to 50% higher than when plants were grown in its absence, evidence that this fungus significantly promoted growth of this crop. Therefore, processes responsible for improved plant health associated with soil treatment with P. oligandrum could be the result of complex interactions between pathogen, host, and mycoparasite.
寡雄腐霉在对峙培养中是大丽轮枝菌的寄生菌，会抑制后者的生长和形成微菌核的能力。寡雄腐霉不同分离株对大丽轮枝菌分离株的寄生作用存在差异，大丽轮枝菌分离株对寡雄腐霉的寄生作用也表现出不同程度的敏感性。温度和基质势显著影响这些真菌之间的相互作用。在接种和未接种大丽轮枝菌的盆栽土壤中，辣椒（Capsicum annuum）根际的寡雄腐霉数量相似，但在有寡雄腐霉存在的情况下，辣椒根际和非根际土壤混合样本中的大丽轮枝菌数量显著低于无寡雄腐霉时。在温室试验中，在接种大丽轮枝菌的土壤中种植辣椒，有寡雄腐霉存在时地上部和果实重量显著高于无寡雄腐霉时。然而，当土壤仅接种寡雄腐霉时，地上部和果实的鲜重比未接种该菌时高出40%至50%，这表明该真菌显著促进了这种作物的生长。因此，与用寡雄腐霉处理土壤相关的植物健康改善过程可能是病原体、寄主和真菌寄生菌之间复杂相互作用的结果。
