根瘤蚜侵染对不同抗性葡萄品种根系超微结构的影响

【目的】探讨不同抗性葡萄品种对葡萄根瘤蚜Daktulosphaira vitifolia Fitch侵染后的组织结构响应。【方法】以砧木140Ru (Vitis rupestris×V. berlandieri)和栽培品种赤霞珠Vitis vinifera cv. Cabernet Sauvignon离体三级根及140Ru盆栽苗为试材接种根瘤蚜卵， 接种两周后取刺吸位点组织作超薄切片并观察超微结构变化， 取盆栽140Ru不同时期根结测定多酚含量。【结果】超微结构显示， 砧木140Ru根系周皮层最外层细胞壁的厚度（1 031.25 nm）及周皮层细胞层数（6～7层）显著高于赤霞珠品种的周皮层细胞厚度（543.75 nm）及层数（3～4层）， 140Ru根系韧皮部酚类物质含量比赤霞珠高出35％； 侵染后， 砧木140Ru周皮层细胞第3层以内的细胞壁加厚并积聚大量的多酚类物质， 140Ru葡萄新根被根瘤蚜侵染后多酚含量呈升高趋势， 在接种20 d时是对照的2.4倍； 赤霞珠粗根被根瘤蚜侵染后薄壁细胞中细胞质变浓， 出现大量淀粉粒， 线粒体及内质网数量增多。【结论】砧木140Ru的周皮层组织结构较赤霞珠不利于根瘤蚜口针穿刺， 被根瘤蚜侵染后发生了不利于根瘤蚜侵染取食的变化。

Effects of phylloxera infestation on the root ultrastructure of grape cultivars with different resistance

Aim] To investigate the effects of phylloxera infestation on the root ultrastructure of grape cultivars with different resistance.Methods] Excised tertiary roots of rootstock 140Ru(Vitis rupestris×V.berlandieri) and Vitis vinifera cv.Cabernet Sauvignon and potted 140Ru were inoculated with phylloxera eggs.After two weeks,tissues at the probing sites were collected to make ultrathin section and the transmission electronic microscope was used to observe the changes of ultrastructure,and potted 140Ru nodosities in different stages were collected to examine the phenol content.Results] The outermost periderm cell wall in 140Ru(1 031.25 nm) was thicker than that in Cabernet Sauvignon(543.75 nm),and the number of periderm cell layers in 140Ru(6-7 layers) was more than that in Cabernet Sauvignon(3-4 layers).The total phenol content of 140Ru tertiary roots was 35% higher than that of Cabernet Sauvignon.After phylloxera infestation,the cell wall of 140Ru periderm cells from the third layer became thicker,and much more polyphenol materials were accumulated in the periderm cells.Total phenol content of 140Ru nodosities kept increasing after phylloxera infestation,which was 2.4 times as high as the control at 20 d after inoculation.After phylloxera infestation,the cytoplasm concentration of Cabernet Sauvignon became higher,and the numbers of starch granule,mitochondria and endoplasmic reticulum also increased.Conclusion]Periderm structure of 140Ru impedes the penetration of phylloxera stylet compared to that of Cabernet Sauvignon,and the phylloxera infestation causes the changes unfavorable to phylloxera feeding.