Effects of Nutrients on The Trapping Ability of Nematode-Trapping Fungi

• Main Authors: Chien-Yi Lin, 林玠誼
• Other Authors: 蔡東纂
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/27537719639665949343

碩士 === 國立中興大學 === 植物病理學系 === 92 === Sixty one rhizosphere soil samples from various crops in Taiwan were collected and nematode-trapping fungi were isolated by sprinkling methods. The soil pH value, soil texture, and the quantity of soil organic substrates of each soil sample were analyzed to investigate the relationships between environmental factors and the occurrence of nematode-trapping fungi. Nematode-trapping fungi was found in 68.85% of soil samples. The nematode trapping-fungi were present in the soils containing organic substrates higher than 4 %. The best growth temperature of these five nematode-trapping fungi, Arthrobotrys cladodes, A. musiformis, Dactylaria borchopaga, Monacrosporium eudermata and M. ellipsosporium were 28 ℃, and the optimal pH value for growth was from 5 to 9. It was found that net-forming fungi grew faster than knob-forming and ring-forming fungi. Adjusted the nitrogen source in Czapek’s medium to 1%, all these five nematode-trapping fungi grew slower. M. eudermata showed the best trapping ability (50%) to Aphelenchoides besseyi on the Czapek’s medium with 0.5% maltose & 0.2% NaNO3. However, nematode trapping ability would be reduced when carbon source raised to 3% or when either carbon or nitrogen source were lowered under 0.2%. In the green house tests, mixtures of organic substances and milk powder were adjusted to 2.5 C/N ratio, then served as the nutrient source for M. eudermata , used as a biological control agent of Meloidogyne incognita. The treatment of a mixture of soybeans meal, milk powder and M. eudermata showed significant good results on the control of M. incognita, and the plant top weight of Ipomoea reptans increased 90.9% compare to the blank control.