Pinkerton J N, Kraus J, Martin R R, Schreiner R P
U.S. Department of Agriculture, Agricultural Research Service, Horticultural Crops Research Laboratory, Corvallis, OR 97330.
Plant Dis. 2008 Mar;92(3):364-371. doi: 10.1094/PDIS-92-3-0364.
Population dynamics of Xiphinema americanum and transmission of Tomato ringspot virus (ToRSV) were studied in a red raspberry field in Washington State. Population densities of X. americanum were highest in the winter, lowest in the summer, and were correlated with precipitation (R = 0.42). All nematode stages were present throughout the year. Gravid females were observed only in the spring, indicating one generation per year. The sequence of the coat protein of the ToRSV from this field was similar to those of other raspberry isolates from the Pacific Northwest. Cucumber seedlings were planted in soil collected monthly from the field and were evaluated for nematode transmission of ToRSV by enzyme-linked immunosorbent assay (ELISA). The proportion of assay plants infected with ToRSV was negatively correlated with nematode densities (R = 0.31). In another study, ToRSV was detected by ELISA in fine roots of raspberry plants 5 months after planting in field soil infested with viruliferous nematodes, in all subterranean portions of plants after 12 months, and in all aerial portions the second year. The rate of spread of ToRSV in a raspberry field was 70 cm per year. These results suggest that the rate of ToRSV spread is limited by systemic spread of virus in plants when nematode-infested soil is not transported in the field.
在美国华盛顿州的一个红树莓种植园中，研究了美洲剑线虫的种群动态以及番茄环斑病毒（ToRSV）的传播情况。美洲剑线虫的种群密度在冬季最高，夏季最低，且与降水量相关（R = 0.42）。线虫的各个虫态全年均有出现。仅在春季观察到怀卵雌虫，表明该线虫每年繁殖一代。该种植园中ToRSV外壳蛋白的序列与太平洋西北地区其他树莓分离株的序列相似。将黄瓜幼苗种植在每月从该种植园中采集的土壤中，并通过酶联免疫吸附测定（ELISA）评估ToRSV通过线虫传播的情况。感染ToRSV的检测植株比例与线虫密度呈负相关（R = 0.31）。在另一项研究中，在种植于感染带毒线虫的田间土壤中的树莓植株细根中，种植5个月后通过ELISA检测到ToRSV；12个月后在植株的所有地下部分检测到ToRSV；第二年在所有地上部分检测到ToRSV。ToRSV在树莓种植园中的传播速度为每年70厘米。这些结果表明，当田间不运输感染线虫的土壤时，ToRSV的传播速度受病毒在植物体内的系统传播限制。
