Functional response of the fungus Hirsutella rhossiliensis to the nematode, Heterodera glycines

• Published in: Science China. Life sciences 2015-07, Vol.58 (7), p.704-712
• Main Authors: Shu, Chi, Lai, YiLing, Yang, EnCe, Chen, SenYu, Xiang, MeiChun, Liu, XingZhong
• Format: Article
• Language: English
• Subjects: Animals; Ascomycota - physiology; Biomass; Biomedical and Life Sciences; Glycine max; Heterodera glycines; Hirsutella rhossiliensis; Life Sciences; Nematoda; Nematoda - physiology; Research Paper; 功能反应; 功能性反应; 大豆孢囊线虫; 大豆胞囊线虫; 生态系统健康; 生物测定; 真菌性; 被毛
• ISSN: 1674-7305; 1869-1889
• DOI: 10.1007/s11427-015-4868-6

Functional response is a key index in determining the population fluctuation in predation. However, the lack of operable research system limits the studies on functional response of fungal predators. Hirsutella rhossiliensis is a dominant parasite of the soybean cyst nematode, Heterodera glycines. In a soil microcosm bioassay, we determined fungal biomass at different days within 21 days after inoculation, and parasitism rate of H. glycines by the fungus was determined. The functional response of H. rhossiliensis to H. glycines was established and found to be Holling＇s type Ill, which was influenced by mycelial densities. Meanwhile, we conducted anti-fungal analysis of metabolic fractions extracted from H. rhossiliensis to explain the potential mechanism of the intraspecific competition illustrated by functional response. The result of anti-fungal experiments indicated that the fungal predators had more complicated interaction at population level than expected, which might be regulated by self-inhibition metabolite（s）. This study was the first functional response study of fungal predators in microcosm. With the in- creasing recognition of emerging fungal threats to animal, plant, and ecosystem health, the methodologies and hypotheses proposed in this study might inspire further research in fungal ecology.