Smiley R W
Oregon State University, Columbia Basin Agricultural Research Center, Pendleton 97801.
Plant Dis. 2012 Jun;96(6):820-826. doi: 10.1094/PDIS-10-11-0892.
The cereal cyst nematode Heterodera avenae can be extracted from soil using several different floatation or elutriation methods. Automated methods are prohibitively expensive for use in small labs and, for optimal efficiency, floatation methods require that the soil be air dried for an extended period. A method which suspends soil particles in a water column above a fluidizing plate was reported as being most efficient with wet and dry soils. Use of the fluidizing column for extracting H. avenae has not been reported in the United States and materials to construct the column using contemporary components have not been described. Objectives of this research were to construct a column with components available in the United States, and to compare numbers of cysts and eggs plus juveniles (from cysts) extracted by the column and three other floatation methods: Fenwick can, flask, and Cobb sieving. From a soil containing recently produced (more dense) cysts, the column extracted at least 18% more cysts and 23% more eggs plus juveniles than the Fenwick and flask methods. The fluidizing column was found to be useful for small laboratories because it is inexpensive ($253 for two columns), easily and quickly constructed by nonprofessional labor, and produces adequately repeatable results.
燕麦孢囊线虫可通过多种不同的漂浮或淘洗方法从土壤中提取。自动化方法对于小型实验室来说成本过高，而且为了达到最佳效率，漂浮方法要求土壤长时间风干。一种将土壤颗粒悬浮在流化板上方水柱中的方法被报道对湿土和干土最为有效。在美国尚未有使用流化柱提取燕麦孢囊线虫的报道，也未描述使用现代组件构建该柱的材料。本研究的目的是用美国现有的组件构建一个柱，并比较该柱与其他三种漂浮方法（芬威克罐法、烧瓶法和科布筛分法）提取的孢囊以及卵加幼虫（来自孢囊）的数量。从含有新产生（密度更大）孢囊的土壤中，该柱提取的孢囊比芬威克罐法和烧瓶法至少多18%，卵加幼虫多23%。流化柱被发现对小型实验室有用，因为它成本低廉（两根柱253美元），非专业人员就能轻松快速构建，且能产生足够可重复的结果。
