Bellvert Joaquim, Crombie Kieran, Horgan Finbarr G
TEAGASC, Agri-Research and Advisory Authority, Oak Park Research Centre, Carlow, Co. Carlow, Ireland Current address: Institut de Recerca i Tecnología Agroalimentàries (IRTA), Avenida Alcalde Rovira i Roure, 191, 25198 Lleida, Cataluña, Spain.
J Nematol. 2008 Mar;40(1):30-4.
The Fenwick can and Schuiling centrifuge are widely used to extract nematode cysts from soil samples. The comparative efficiencies of these two methods during cyst extraction have not been determined for different soil types under different cyst densities. Such information is vital for statutory laboratories that must choose a method for routine, high-throughput soil monitoring. In this study, samples of different soil types seeded with varying densities of potato cyst nematode (Globodera rostochiensis) cysts were processed using both methods. In one experiment, with 200 ml samples, recovery was similar between methods. In a second experiment with 500 ml samples, cyst recovery was higher using the Schuiling centrifuge. For each method and soil type, cyst extraction efficiency was similar across all densities tested. Extraction was efficient from pure sand (Fenwick 72%, Schuiling 84%) and naturally sandy soils (Fenwick 62%, Schuiling 73%), but was significantly less efficient from clay-soil (Fenwick 42%, Schuiling 44%) and peat-soil with high organic matter content (Fenwick 35%, Schuiling 33%). Residual moisture (<10% w/w) in samples prior to analyses reduced extraction efficiency, particularly for sand and sandy soils. For each soil type and method, there were significant linear relationships between the number of cysts extracted and the numbers of cysts in the samples. We discuss the advantages and disadvantages of each extraction method for cyst extraction in statutory soil laboratories.
芬威克罐和舒林离心机被广泛用于从土壤样本中提取线虫孢囊。对于不同土壤类型和不同孢囊密度的情况，尚未确定这两种方法在孢囊提取过程中的相对效率。此类信息对于必须选择一种方法进行常规、高通量土壤监测的法定实验室至关重要。在本研究中，使用这两种方法对接种了不同密度马铃薯孢囊线虫（罗斯托克球孢囊线虫）孢囊的不同土壤类型样本进行了处理。在一个实验中，对于200毫升的样本，两种方法的回收率相似。在第二个实验中，对于500毫升的样本，使用舒林离心机的孢囊回收率更高。对于每种方法和土壤类型，在所有测试密度下孢囊提取效率相似。从纯砂（芬威克法72%，舒林法84%）和天然砂质土壤（芬威克法62%，舒林法73%）中提取效率较高，但从粘土（芬威克法42%，舒林法44%）和高有机质含量的泥炭土（芬威克法35%，舒林法33%）中提取效率显著较低。分析前样本中的残余水分（<10% w/w）会降低提取效率，尤其是对于砂土和砂质土壤。对于每种土壤类型和方法，提取的孢囊数量与样本中的孢囊数量之间存在显著的线性关系。我们讨论了法定土壤实验室中每种孢囊提取方法的优缺点。
