Abstract: 【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.

Key words: Grape, phylloxera, Rootstock 140Ru; Vitis vinifera cv. Cabernet Sauvignon, root ultrastructure, phenol content, starch granules