Baidoo Richard, Mengistu Tesfamariam Mekete, Brito Janete A, McSorley Robert, Stamps Robert H, Crow William T
Entomology and Nematology Department, University of Florida, Gainesville, FL 32611.
Florida Division of Plant Industry, Gainesville, FL 32608.
J Nematol. 2017 Sep;49(3):311-315.
is considered as the primary agent responsible for soil suppressiveness to root-knot nematodes widely distributed in many agricultural fields. A preliminary survey on a field where the grower had experienced a continuous decline in productivity caused by showed that the nematode was infected with . For effective control of the nematode, the bacterium and the host must coexist in the same root zone. The vertical distribution of and its relationship with the nematode host in the soil was investigated to identify (i) the vertical distribution of endospores in an irrigated field and (ii) the relationship among endospore density, J2 population density, and host plant root distribution over time. Soil bioassays revealed that endospore density was greater in the upper 18 cm of the top soil compared with the underlying depths. A correlation analysis showed that the endospore density was positively related to the J2 population density and host plant root distribution. Thus, the vertical distribution of was largely dependent on its nematode host which in turn was determined by the distribution of the host plant roots. The was predominant mostly in the upper layers of the soil where their nematode host and the plant host roots are abundant, a factor which may be a critical consideration when using as a nematode biological control agent.
被认为是许多农业田地中广泛分布的对根结线虫具有土壤抑制作用的主要因子。对一块田地进行的初步调查显示，种植者因[未提及的某种情况]导致生产力持续下降，该线虫感染了[未提及的某种物质]。为有效控制线虫，细菌和宿主必须在同一根区共存。研究了[未提及的某种细菌]在土壤中的垂直分布及其与线虫宿主的关系，以确定：（i）灌溉田地中[未提及的某种细菌]内生孢子的垂直分布；（ii）内生孢子密度、[未提及的某种线虫]J2种群密度和宿主植物根系分布随时间的关系。土壤生物测定表明，与下层深度相比，表层土壤上部18厘米处的内生孢子密度更大。相关性分析表明，内生孢子密度与J2种群密度和宿主植物根系分布呈正相关。因此，[未提及的某种细菌]的垂直分布很大程度上取决于其线虫宿主，而线虫宿主又由宿主植物根系的分布决定。[未提及的某种细菌]主要存在于土壤上层，那里线虫宿主和植物宿主根系丰富，这一因素在将[未提及的某种细菌]用作线虫生物防治剂时可能是一个关键考虑因素。
