燕麦镰刀菌侵染蕨麻根部的显微及超微结构观察

Microscopic and ultrastructural characteristics of the root of Potentilla anserine infected by Fusarium avenaceum

以蕨麻(Potentilla anserina L.)的健康块根为对照,对燕麦镰刀菌(Fusarium avenaceum)侵染后的蕨麻块根进行了形态学观察。利用石蜡切片、超薄切片及显微摄像方法研究了病根的解剖结构及表面超微结构,探究了真菌的侵入与定殖规律,为进一步从细胞和亚细胞水平研究蕨麻根腐病致病机理提供理论依据。结果表明:致病真菌的侵染可以显著影响蕨麻形态,真菌通过块根自然孔隙和机械伤口侵入,由外向内深入破坏表皮及内部结构,块根外部出现病斑、腐烂,内部细胞变形。病原真菌侵染具选择性,主要集中于蕨麻块根韧皮部薄壁细胞,且形态多样。块根感病病变主要分为初期、后期和晚期三个阶段,由外向内病情逐渐加深,被侵染细胞出现质壁分离、内含物减少等现象。感病蕨麻外观及品质均受影响。

This study aimed to comparatively investigate the morphology of the diseased fern tubers caused by pathogenic fungus Fusarium avenaceum with the healthy root tuber of Potentilla anserina L.as a control.Paraf-fin section,ultrathin section,and micrograph methods were used to study the anatomical structure and surface ultrastructure of the diseased root.The explored invasion and colonization rules of this fungus at the cell and sub-cellular level would provide a theoretical ground to understand the cellular mechanism of Potentilla anserine root rot.The results showed that the fungal infection could significantly affect the morphology of Potentilla anserinaroots.The fungus invaded through the natural pores and mechanical wounds of the root tube and de-stroyed the epidermis and internal structure from the outside to the inside.The root tuber appeared disease spot-son the root surface and putrefactied later,and the internal cells were deformed.In addition,the infection of pathogenic fungus was selective and the fungal mycelia with varied morphologies were mainly concentrated in the phloem parenchyma cells of the tuberous roots of Potentilla anserine.The infection gradually deepened from the outside to the inside,and the infected cells appeared plasmolysis and decreased contents,which affected the appearance and quality of Potentilla anserine root tuber.