甘肃天水麦田土壤线虫种群结构与土壤健康指数初探

Nematode Populations and Soil Health Index in Wheat Fields of Tianshui Gansu in China

首次对甘肃天水清水县小泉乡麦田土壤线虫种群进行了探索性调查分析,获得了麦田线虫种群构成关系的初步数据,并根据营养类群将线虫划分为:植物寄生线虫(Phytophage nematode)、食细菌线虫(Bacte-rivorous nematode)、昆虫线虫(Insect nematode)、食真菌线虫(Fungivorous nematode)、杂食/捕食线虫(Om-nivore/Predator nematode)5大类群。研究结果表明,甘肃天水麦田土壤线虫涉及4目9科11属,其中植物寄生线虫涉及2目6科6属;非植物线虫共涉及2目3科5属。植物寄生线虫占绝对优势,占线虫总数的67.7%,食细菌线虫占总数的27.4%,昆虫线虫占总数的4.15%,杂食/捕食类线虫不足1%,未发现食真菌线虫。瓦斯乐斯卡平均指标(WI值)为0.401,远远低于土壤健康一般指数1.000。该结果初步反映了同一个地块多年连续种植小麦引起的严重土壤健康问题,为天水地区种植规划和结构调整提供了可靠的科学依据。

The nematode populations of wheat fields in Xiaoquan village, Qingshui county, Tianshui city, Gansu province of China were investigated preliminarily. The relationship of nematode populations and their quantities was presented. The recorded nematodes were divided into five trophie groups ： Phytophage nematode, Baeterivorous nematode, Insect nematode, Fungivorous nematode and Omnivore/Predator nematode. The results showed that the observed nematodes in the wheat fields in Tianshui region belong to 11Genus in 9 Families of 4 Orders, among which beneficial （non plant feed ing） nematodes were related to 2 orders, 6 families and 6 genus and harmful （plant parasitic） nematodes were related to 2 orders, 3 families and 5 genus. The phytophage nematodes were absolutely dominant, accounted for 67.7% of total nematodes, bacterivorous nematodes for 27.4%, insect nem atodes for 4.15% and omnivore/ predator nematodes for 1%. Fungivorous nematodes were not been found in this study. Wasilewska index was only 0. 401 which was much lower than 1. 000, a general index of soil health. The index data indicated the health problem of soil, caused by wheat replanting year after year on the same fields. The results of this study could contribute to be basic data for Tian- shui crop planning and adjusting.