Olivares Concepción Ma, López-Llorca Luis Vicente
Departamento de Ciencias Ambientales y recursos Naturales, Universidad de Alicante, Alicante, Spain.
Rev Iberoam Micol. 2002 Jun;19(2):104-10.
We have investigated the presence of fungal egg-parasites in Spanish soils with plant endoparasitic nematodes. Nine out of 68 samples (13%) yielded fungal parasites. The most common (seven strains) was Pochonia chlamydosporia var. chlamydosporia (= Verticillium chlamydosporium var. chlamydosporium), but Lecanicillium lecanii (= Verticillium lecanii) and Paecilomyces lilacinus were also found. Most strains were from cyst nematodes (Heterodera avenae or Heterodera schachtii). Biological factors related with the development and performance of these fungi as biocontrol agents were assessed in laboratory tetsts. Germination for most strains was around 90-100%. Higher biomass values were obtained, for most fungal strains, with complete or yeast extract peptone-glucose liquid media. P. lilacinus and L. lecanii showed the highest sporulation rates (1.0 x 10(9); and 1.5 x 10(10); conidia/g mycelium). All strains had optimum growth at 25 degrees C. High temperature (40 degrees C) was lethal to all fungi but low temperature (5 degrees C) allowed growth of L. lecanii. Most strains showed best growth close to pH 7. Several P. chlamydosporia strains produced diffusible pigments close to pH 3. Lack of moisture (aw = 0.887) in growth medium reduced but never arrested fungus growth. Proteolytic activity was, for all strains, the earliest and highest enzymatic activity. Amylolytic and pectinolytic activities showed the lowest values and the latter was undetectable for most strains. Pathogenicity (70-100percnt; egg infection) and severity (35-40 penetrating hyphae/egg) on Meloidogyne javanica were high for most strains tested. Our results show that agricultural soils in Spain contain fungal parasites susceptible to be biocontrol agents for plant-parasitic nematodes.
我们研究了西班牙存在植物内寄生线虫的土壤中真菌性卵寄生生物的情况。68个样本中有9个（13%）检测到了真菌寄生虫。最常见的（7个菌株）是厚垣普可尼亚菌厚垣孢变种（= 轮枝状菌厚垣孢变种），但也发现了蜡蚧轮枝菌（= 轮枝状菌）和淡紫拟青霉。大多数菌株来自孢囊线虫（燕麦孢囊线虫或甜菜孢囊线虫）。在实验室试验中评估了与这些真菌作为生物防治剂的发育和性能相关的生物学因素。大多数菌株的发芽率约为90% - 100%。对于大多数真菌菌株，在完全培养基或酵母提取物蛋白胨 - 葡萄糖液体培养基中可获得更高的生物量值。淡紫拟青霉和蜡蚧轮枝菌的产孢率最高（分别为1.0×10⁹和1.5×10¹⁰分生孢子/克菌丝体）。所有菌株在25℃时生长最佳。高温（40℃）对所有真菌都是致命的，但低温（5℃）时蜡蚧轮枝菌仍能生长。大多数菌株在接近pH 7时生长最佳。几个厚垣普可尼亚菌菌株在接近pH 3时产生可扩散色素。生长培养基中水分缺乏（水活度 = 0.887）会降低但不会阻止真菌生长。对于所有菌株，蛋白水解活性是最早且最高的酶活性。淀粉酶活性和果胶酶活性值最低，大多数菌株检测不到后者的活性。大多数测试菌株对爪哇根结线虫的致病性（卵感染率70% - 100%）和严重程度（每个卵有35 - 40条穿透菌丝）都很高。我们的结果表明，西班牙的农业土壤中含有可作为植物寄生线虫生物防治剂的真菌寄生虫。
