Abstract: Nodosity formation in grapes with different resistance to grape phylloxera (Daktulosphaira vitifoliae Fitch) infestation was studied by potted plant test of inoculation. Number, weight, and contents of carbohydrates and proline of nodosities were tested. The result showed that the rootstocks 5BB, 1103P, SO4, 3309C and 101-14Mgt did not produce nodosities after infected by phylloxera, while the rootstocks 140Ru, Lot and 110R produced a little nodosities but no tuberosities. The rootstock Beta and cultivars Cabernet Sauvignon, Kyoho and Tamina, however, produced lots of nodosities and tuberosities with the roots perished seriously. The more susceptible varieties had more and larger nodosities. The nodosity accounted for 40.02%, 37.08% and 35.36% of the total weight of Tamina,Kyoho and Cabernet Sauvignon, respectively. The total weight per 100 nodosities in the three cultivars reached 4.4, 3.5 and 4.3 times of that of 140Ru, respectively. The average reduction of cane growth of 140Ru, Lot and 110R was 16.5%, while 43% for the four highly susceptible varieties. The assay of correlation between nodosity weight and nutrient accumulation in nodosities showed that they were significantly positively correlated:  nodosity weight was positively correlated with the increment of starch, sugar and proline.

Key words: Grape phylloxera, grape cultivars, resistance, phylloxera infestation, nutrition, nodosity, tuberosity