胞囊线虫侵染不同抗性大豆品种根系的组织病理学差异研究

为明确对大豆胞囊线虫病具有不同抗性的小黑豆品种的抗性机制,利用石蜡切片技术对线虫侵染不同抗性大豆品种根系的组织病理学差异进行了研究。结果表明:在侵染初期,抗感品种侵入根内的线虫数量没有明显差异,抗病品种形成合胞体的时间要早于感病品种辽豆15,哈尔滨小黑豆较早地在中柱内形成了合胞体,抗侵入能力较弱。随着线虫的侵染,抗病品种逐渐形成过敏性坏死反应,阻止线虫发育使根内形成非常少量的雌虫,其中灰皮支黑豆根内几乎没有雌虫形成,抗发育能力最强。感病品种辽豆15根内没有发生过敏性坏死反应形成了大量雌虫。在寄主维管束中,侵染后期中柱内形成的合胞体会使感病品种辽豆15木质部外移,根内导管数量减少,不利于水分运输的安全性。而3个抗病品种小黑豆的木质部组织结构没有发生病变,利于大豆的正常生长。

Comparative Histological Structure of Different Resistant Soybean Roots to Soybean Cyst Nematode

Paraffin sections technique were used to compare the histological structure of different resistant soybean roots,aiming to determine the resistance mechanism of different small black soybean cuhivars.The result showed that in the early days of infection there was no significant difference in the number of second stage juveniles inside soybean roots between different resistant cultivars.The formation of synctium in the resistant cultivars was earlier than susceptible cultivars.Harbin small black soybean early formed the syncytial in stele and hardly resistant the invasion.With the nematode infection,resistant cuhivars evolved hypersensitive reaction to prevent nematode development forming a very small number of female in roots where almost no females formed in Huipizhi Heidou root,the strongest anti-development.Susceptible cultivar Liaodou 15 had no hypersensitive response occurred within the root formation of a large females.In the host's vascular bundles,the xylem of susceptible cultivar Liaodou 15 moved outward and the xylem vessel would be reduced in the late infection that was not conducive to the safety of water transportation.However,the structure of xylem didn't change in the three resistant cultivars and was good for the growth of soybean.