Fungal parasitism of soybean cyst nematode, Heterodera glycines (Nemata: Heteroderidae), in differing cropping-tillage regimes
Fungal parasitism of soybean cyst nematode, Heterodera glycines (Nemata: Heteroderidae), in differing cropping-tillage regimes
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DOI：
10.1016/s0929-1393(96)00125-4
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发表时间：
1997-01-01
影响因子：
4.8
通讯作者：
Tyler, DD
中科院分区：
文献类型：
--
作者：
Bernard, EC;Self, LH;Tyler, DD
通过2年田间试验，研究了大豆-小麦两熟、少耕或免耕对大豆胞囊线虫（Heterodera glycines）的拮抗作用。每月取样6个处理：圆盘10 cm深，然后是辊耙;凿犁20 cm深，然后是圆盘和辊耙;犁板15 cm深，然后是圆盘和辊耙;前一年大豆残茬免耕（NT-大豆）;小麦覆盖作物免耕（NT-1）;小麦覆盖作物后免耕（NT-7）。每种处理方法在相同的地块上应用长达7年。在适当的每月间隔，线虫孢囊，女性和卵收集和真菌的存在下，这是确定物种水平的类群进行了测定。种植耕作制度对感染的青少年，包囊内的卵数，和包囊的垂直分布的数量的影响进行了测定。在这项研究中的鸡蛋和女性菌群的相似性进行了检查。共鉴定出61个种级真菌分类群，沿着20个非产孢分离株，它们通过外观、生长模式和颜色彼此区分。茄病镰刀菌是最常见的47种侵染孢囊。茄病镰刀菌（Fusarium solani）和F.在田间采集的20种雌虫中，尖孢镰刀菌是最常见的;尖孢菌是21个分类群中最常见的。从鸡蛋中分离到的38种真菌中，淡紫拟青霉最为常见。各处理间被寄生的雌虫和卵的比例基本相同，但对淡紫拟青霉和厚垣轮枝菌的寄生率有一定影响。雌性的寄生率在7月和8月相对较低，但在9月增加了两倍。卵寄生率一般低于10%，无论采样时间。孢囊的垂直分布对采样精度没有明显的影响，因为孢囊集中在顶部25厘米，在两个不同的治疗（犁板犁，NT-7）。没有一致的治疗效果，在冬季或春季的土传感染性青少年的密度，也不是每个囊肿的平均卵数。根据本研究与以往四项研究的相似性指数，对H.提出了大豆菌群。
A 2 year field study was designed to determine if soybean-wheat double-cropping and reduced or no tillage altered the soil mycoflora antagonistic to the soybean cyst nematode, Heterodera glycines. Six treatments were sampled monthly: disc 10 cm deep, followed by roller harrow; chisel plow 20 cm deep, followed by disc and roller harrow; moldboard plow 15 cm deep, followed by disc and roller harrow; non-tillage in the previous year's soybean stubble (NT-Soy); non-tillage in standing wheat cover crop (NT-1); non-tillage after wheat cover crop (NT-7). Each treatment had been applied to the same plots for up to 7 years. At appropriate monthly intervals, nematode cysts, females, and eggs were collected and assayed for the presence of fungi, which were identified to species-level taxa. Effects of cropping-tillage regimes on numbers of infective juveniles, numbers of eggs within cysts, and vertical distribution of cysts were determined. Similarities of egg and female mycofloras in this study to those of previous studies were examined. A total of 61 species-level fungal taxa were identified, along with 20 non-sporulating isolates distinguished from one another by appearance, growth pattern, and color. Fusarium solani was the most frequent of 47 species infesting cysts. Fusarium solani and F. oxysporum were the most frequent of 20 taxa isolated from field-collected females; in females produced on soybean plants grown in field soil in the greenhouse, F. oxysporum was the most frequent of 21 taxa. Paecilomyces lilacinus was the most common fungus among the 38 species isolated from eggs. For all fungi, percentages of parasitized females and eggs were similar in all treatments, but some treatments affected the parasitism rates of Paecilomyces lilacinus and Verticillium chlamydosporium. Parasitism of females was relatively low in July and August, but tripled in September. Egg parasitism was generally below 10% regardless of sampling time. Vertical distribution of cysts had no discernible effect on sampling precision, since cysts were concentrated in the top 25 cm in two dissimilar treatments (moldboard plow, NT-7). No consistent treatment effects were seen on densities of soil-borne infective juveniles in winter or spring, nor on average numbers of eggs per cyst. Based on similarity indices among this study and four previous studies, a biogeography of H. glycines mycofloras is proposed.