对羟基苯甲酸胁迫下尖孢镰刀菌侵染草莓根系的组织结构观察

以‘丰香’(Toyonoka)和‘土特拉’(Tutela)草莓品种为试材,利用石蜡切片技术研究了在自毒物质对羟基苯甲酸胁迫下,尖孢镰刀菌草莓专化型(Fusarium oxysporum f.sp.fragariae)侵染根系引起的组织结构变化。结果表明:对羟基苯甲酸胁迫下,尖孢镰刀菌菌丝在‘丰香’和‘土特拉’根系中的侵染速率明显加快,对根系表皮、皮层、中柱薄壁细胞及导管壁结构的破坏程度也明显加重,且对‘丰香’的破坏程度明显重于‘土特拉’。对羟基苯甲酸胁迫显著提高了‘丰香’和‘土特拉’根系组织含菌丝导管的比例,分别为22.5%和15.8%;但‘土特拉’根系含胶状物导管的比例为26.3%,明显高于‘丰香’(16.3%)。在对羟基苯甲酸胁迫下,‘土特拉’根系组织产生胶状物比‘丰香’早。‘土特拉’单独接菌处理根系内含有侵填体导管的比例为1.6%,明显高于‘丰香’单独接菌处理和对羟基苯甲酸胁迫下‘土特拉’接菌处理(1.0%和1.2%)。对羟基苯甲酸胁迫下接种尖孢镰刀菌可明显加重草莓根系组织受损程度,且‘丰香’枯萎病发生较重。

Observation on Histological Structure of Strawberry Roots After Inoculating Fusarium oxysporum f. sp. fragariae Under 4-hydroxybenzoic Acid Stress

Two strawberry（Fragaria × ananassa Duch.）cultivars Toyonoka and Tutela as material，we studied the histological structure of strawberry roots，which infected by F. oxysporum f. sp. fragariae under the autotoxin 4-hydroxybenzoic acid stress by using paraffin slice. The results showed that the infection rate of hyphae of F. oxysporum f. sp. fragariae in root tissues of Toyonoka and Tutela under 4-hydroxybenzoic acid stress was faster than the treatment of only fungi-inoculated. The damages to the epidermis cells，cortex cells，stele cells and duct walls of Toyonoka and Tutela roots were more serious than the treatment of only fungi-inoculated，respectively. Moreover，the damage to the above-mentionedroot cells of Toyonoka was more serious than that of Tutela under 4-hydroxybenzoic acid stress. The proportions of vessel infected by hyphae both in the roots of Toyonoka and Tutela were increased significantly under 4-hydroxybenzoic acid stress，with 22.5% and 15.8%，respectively. The proportions of catheter with jelly was 26.3% in Tutela roots，which was higher than in Toyonoka roots with 16.3%. Under 4-hydroxybenzoic acid stress，the tylosis produced in root vessels of Tutela earlier than in root vessels of Toyonoka. The proportions of vessel with tylosis in roots of Tutela was 1.6%，higher significantly than in Toyonoka with 1.0% at both of them treated only by inoculating F. oxysporum，and higher significantly than in Tutela with 1.2% treated by inoculating F. oxysporum under 4-hydroxybenzoic acid stress. The damage to the strawberry root tissue significantly increased after inoculating F. oxysporum under 4-hydroxybenzoic acid stress，and Toyonoka roots wilt disease was more serious.