南方根结线虫Me3毒性与非毒性群体对寄主趋向性和侵染能力的比较

 探究南方根结线虫Me3毒性与非毒性群体对抗感寄主趋向性和侵染能力,为揭示毒性群体致病机理及防治根结线虫策略提供理论依据。使用以水琼脂为介质的研究方法,通过对比分析辣椒抗病品种HDA149和感病品种茄门根尖附近聚集的2龄幼虫(J2)数量,来揭示南方根结线虫对抗感辣椒品种根尖的趋向性效应,并利用实时荧光定量 PCR 检测侵入到辣椒根系的毒性与非毒性线虫数量,对其侵染能力进行比较。J2 趋向性试验结果显示,在相同的时间点,HDA149 和茄门辣椒根尖处附近聚集的毒性群体 J2 数量总是显著多于非毒性群体的 J2数量;J2 对抗感辣椒的选择性结果表明,不论是毒性群体还是非毒性群体的 J2,在相同的时间点,茄门根尖附近聚集的线虫数量显著多于HDA149根尖附近的线虫数量;荧光定量 PCR 检测线虫侵染结果显示,毒性群体 J2侵入到辣椒根系的数量相对非毒性群体的 J2 更多。总之,相比南方根结线虫Me3非毒性群体,毒性群体的 J2 对寄主根系有较强的趋向性,并且侵染效率更高;相比于抗性寄主,Me3毒性群体和非毒性群体的 J2 对感病寄主有更强的选择性。

Comparison of the chemotaxis and the infection ability of Me3 virulent and avirulent populations of Meloidogyne incognita to host root

In order to understand the pathogenic mechanism of Me3 virulent population from Meloidogyne incognita and to provide the theoretical support for control strategy, the chemotaxis and infection of Me3 virulent and avirulent populations to resistant and susceptible host plants were analyzed. The chemotaxis potential of M. incognita populations on resistant pepper cultivar HDA149 and susceptible Qiemen were explored through analyzing the number of second-stage juveniles (J2) attracted by the root tip of pepper on the medium of water agar gel. Quantitative RT-PCR (q-PCR) was used to confirm the number of virulent population and avirulent population invading the host roots, and according to the result of q-PCR, we can directly estimate the infection ability of virulent and avirulent populations on host plants. The results showed that the numbers of J2s from virulent population gathered around the root tips of the susceptible and resistant pepper were both significantly higher than that from the avirulent population at different post-inoculation time. Furthermore, the analysis of the selective ability of M. incognita to host plants revealed that the numbers of J2s from virulent and avirulent populations gathered around the root tip of the Qiemen pepper were both significantly higher than that of the HDA149 pepper at different post-inoculation time.Based on the results of q-PCR, we can see that it is easier for virulent population infecting the host plant roots compared with avirulent population. In summary, the chemotaxis and infection potential of J2s from Me3 virulent population of M. incognita to root of host plants was stronger than that from the avirulent population,and the selectivity of J2s from both populations to the susceptible host plant were stronger than that to the resistant host plant.