象耳豆根结线虫初始种群密度对黄瓜生长的影响

Effect of Initial Population Density of Meloidogyne enterolobii on Cucumber Growth in Greenhouse

通过室内接种方法测定土壤中接种象耳豆根结线虫(Meloidogyne enterolobii)二龄幼虫不同初始密度(0、0.125、0.25、0.5、1、2、4、8和16条/cm3)对黄瓜生长的影响。研究结果表明,黄瓜受损程度与象耳豆根结线虫初始接种密度呈正相关,随着接种密度的增加,形成的根结指数不断提高,而黄瓜植株高度和苗鲜重相比对照均表现为下降,即发病程度逐渐加重。当土壤中象耳豆根结线虫二龄幼虫的初始接种密度为0.25条/cm3,即可对黄瓜的株高和植株鲜重产生显著危害,初始密度为8条/cm3处理,则可导致黄瓜植株死亡。该研究结果可为制定象耳豆根结线虫的防治指标提供理论依据。

The effects of initial population levels of Meloidogyne enterolobii [0, 0.125, 0.25, 0.5, 1, 2, 4, 8and 16 second stage juvenlies（J2） per cm3 of soil] on cucumber were investigated with pot planting in a greenhouse. The results showed that there is a positive relationship between the initial population density of the nematode and the extent of damage it cause to cucumber. Both shoot height and shoot fresh weights were decreased as increasing initial densities of the nematodes, but the disease index was increased. When the initial inculcation density of M. eneterolobii reached to 0.25 J2 per cm^3 of soil, either cucumber shoot height or fresh weight was reduced significantly. Moreover, inoculation of cucumber with eight J2 of M.eneterolobii could lead to plant dead. These results provide a possibility to estimate the economic threshold, which is needed for evaluation efficacy of nematode control.