Fraedrich Stephen W, Cram Michelle M
USDA Forest Service, 320 Green St., Athens, GA 30602.
Plant Dis. 2002 Jul;86(7):803-807. doi: 10.1094/PDIS.2002.86.7.803.
A Longidorus species was consistently associated with patches of stunted and chlorotic loblolly pine seedlings at a forest-tree nursery in Georgia. Seedlings from affected areas had poorly developed root systems that lacked lateral and feeder roots. Longidorus population densities in composite soil samples from the margins of patches ranged from 9 to 67 nematodes per 100 cm of soil. In a growth chamber experiment, seedling root dry weight decreased with respect to the initial Longidorus dose as well as the final Longidorus populations in containers. The dry root weight of seedlings were 0.117, 0.090, 0.066, and 0.065 g in containers initially infested with 0, 50, 100, and 200 Longidorus, respectively. Lateral and fine roots were lacking on seedlings at the highest doses. Populations of Longidorus increased in all containers during the experiment. Damage to loblolly pine seedlings caused by Longidorus is a previously undescribed problem in southern pine nurseries. Proper diagnosis of the problem by nematode testing laboratories may require the use of extraction techniques specific for larger nematodes such as Longidorus.
在佐治亚州的一个林木苗圃中，一种长针线虫属物种一直与一片片发育不良和褪绿的火炬松幼苗有关。受影响区域的幼苗根系发育不良，缺乏侧根和须根。斑块边缘复合土壤样本中的长针线虫种群密度为每100厘米土壤中有9至67条线虫。在生长室实验中，幼苗根干重随着初始长针线虫剂量以及容器中最终长针线虫种群数量的增加而降低。最初接种0、50、100和200条长针线虫的容器中，幼苗的干根重分别为0.117、0.090、0.066和0.065克。最高剂量下的幼苗缺乏侧根和细根。实验期间，所有容器中的长针线虫种群数量都增加了。长针线虫对火炬松幼苗造成的损害是南方松苗圃中一个以前未被描述过的问题。线虫检测实验室要对该问题进行正确诊断，可能需要使用针对长针线虫等较大线虫的特定提取技术。
