桃根系与南方根结线虫早期互作的组织病理学研究

Histopathological of the Early Interactions Between Peach Roots and Meloidogyne incognita

为研究桃根系与根结线虫互作的组织结构变化及抗病机理,对抗病种质‘白根甘肃桃1号’(Prunus kansuensis‘Baigen Gansu Tao 1’)和感病种质‘贝蕾’(P.persica‘Bailey’)实生幼苗进行室内人工接种南方根结线虫(Meloidogyne incognita),并对接种后6、12、18、24、30、36、42和48 h的根尖进行染色观察及接种后0、6、12、36、60和84 h的根尖组织结构变化进行石蜡切片观察。染色结果表明,根结线虫侵染‘白根甘肃桃1号’和‘贝蕾’的规律基本一致:在接种12 h后开始侵入,接种12~30h线虫数量逐渐增加,然后线虫沿维管束向上移动,根尖线虫数量趋于减少。但与‘贝蕾’相比,‘白根甘肃桃1号’的根结线虫侵染数量显著降低,在接种30 h时仅为‘贝蕾’线虫侵染数的28%。石蜡切片结果显示‘白根甘肃桃1号’根结构受破坏程度明显较低,侵入的线虫主要聚集在一定区域,且在侵染84 h时线虫聚集区域周围的细胞出现坏死反应。

To study the changes in tissue structures and resistance mechanisms that occur due to the interaction between peach roots and root knot nematodes,seedlings of the resistant Baigen Gansu Tao 1(Prunus kansuensis)and the susceptible Bailey(P. persica)were inoculated with Meloidogyne incognita using artificial indoor inoculation. Root tips were observed by staining at 6,12,18,24,30,36,42 and 48 h after inoculation,and the tissue structure of the root tips was observed by paraffin section at 0,6,12,36,60 and 84 h after inoculation. Staining results showed that the infection law of Baigen Gansu Tao 1 and Bailey were roughly similar:Root knot nematodes began invading at 12 h after inoculation,and the number of root knot nematodes increased gradually during the period between 12 h to 30 h after inoculation. The number of root knot nematodes present in the roots subsequently decreased as the organisms began their upward movement along the plants' vascular bundles. Compared to Bailey,at 30 h after inoculation Baigen Gansu Tao 1 were infected with root knot nematodes at a significantly lower rate:Only 28% of that of Bailey. Paraffin section results showed that the structural damage to inoculated Baigen Gansu Tao 1 was much less severe than in inoculated Bailey. Nematodes gathered in certain areas,whichled to cells necrosis at the gathering sites at 84 h after inoculation.