拟禾本科根结线虫种群密度与旱稻产量损失的关系

Relationships Between Population Densities of Meloidogyne graminicola and Yield Loss of Upland Rice

本研究旨在探讨土壤中拟禾本科根结线虫(Meloidogyne graminicola)的初始种群密度对旱稻产量损失的影响。通过室外网室盆栽试验,在旱种旱管模式下测定了土壤不同初始种群密度对旱稻产量和线虫繁殖的影响。研究结果表明,在2~200个卵和二龄幼虫/100 cm^(3)土的初始种群密度下,旱稻根长、根重、株高、分蘖数、穗长、千粒重和单盆谷粒重与土壤线虫初始种群密度呈极显著负相关,符合一元回归方程;旱稻产量随着土壤初始种群密度的增加,其损失率增加,在初始密度为2个卵和二龄幼虫/100 cm^(3)土时,旱稻产量损失率为28.4%,接种密度为200个卵和二龄幼虫/100 cm^(3)土时,损失率最大,为67.8%;随着线虫初始种群密度的增加,线虫的繁殖系数呈现降低的趋势。利用Seinhorst模型,初始线虫种群密度与相对产量的关系式为Y=0.24+0.76(0.3252)(Pi)。在旱种旱管模式下,拟禾本科根结线虫在2~200个卵和二龄幼虫/100 cm^(3)土的初始种群密度下与旱稻产量损失呈极显著正相关,表明拟禾本科根结线虫对旱稻的危害风险性较高。

To determine the relationship between population density of Meloidogyne graminicola and yield loss in upland rice,the effects of Meloidogyne graminicola initial population density(Pi)on the yield of upland rice and reproduction of nematodes were evaluated in pot experiments under the screen house condition with dry planting and management.The results revealed a linear regression relationship where rice parameters such as root length,root weight,plant height,tiller number,panicle length,1000-seed weight and single basin grain weight decreased as Pi increased.The yield loss ranged from 28.4%at a Pi of 2 eggs and J2/100 cm^(3) soil to 67.8%at a Pi of 200 eggs and J2/100 cm^(3) soil.The reproduction factor of nematodes followed a declining trend with Pi.The relationship between population density and relative yield followed the Seinhorst model,Y=0.24+0.76(0.3252)(Pi).A significant positive correlation was noted between upland rice yield loss and Pi of 2 to 200 eggs and J2/100 cm^(3) soil under dry planting and management,indicating a high risk of harm to upland rice caused by M.graminicola.