| This study was carried out during 2005～2006 in the grape yard of Peng Lai to investigate the root system architecture and the effects of rootstocks on the physiological characteristics, growth and fruit bearing of nine grafted and two own-rooted wine grape plants. The results were shown as follows:1. There was significant difference among five rootstocks′root architecture. 110R and 1103P belonged to sinker roots, with the emergence angles ranging from 20 to 40°and more than 60% roots concentrating at 20～60 cm soil layers. While 420A, S04 and 3309C belonged to feeder roots, i.e.,the emergence angles of 420A and S04 ranged from 80 to 90°and that of 3309C was 40～90°, and more than 50% roots concentrated at 0～20cm surface soil layers. Also, the own-rooted wine grape Chardonnay and Cabernet Sauvignon belonged to feeder root.2. Although the grafted varieties had some feedback effects on the rootstocks, the inherent characteristics of the rootstocks were not altered. The grafted varieties mainly affected the root distribution and the root number of the rootstocks, for example, 1103P's root vertical distribution was deeper for Avola/1103P than for Sangiovese/1103P and Frankisch/1103P. While SO4's root number was significantly less for Sangiovese/SO4 than for Verdicchio/SO4 and Prosecco/SO4.3. The percentage of root bark was distinctly different for different rootstocks of different root architectures. 110R and 1103P had strong tap roots and high-percentage big root, with their percentage of root bark up to 73.78% and 70.72%, respectively. Whereas S04,420A and 3309C belonged to thin root style, with their percentage of root bark 50～57%. So was the Cabernet Sauvignon, with its percentage of root bark 55.46%. Although Chardonnay had high-percentage root bark (60.96%), its root cortex was crisp, which fell off easily.4. Different soil bulk density affected the root architecture of Cabernet Sauvignon, especially below 40-cm soil layer. With the soil bulk density ranging from 1.23 to 1.47g·cm-3 below 40cm soil layer, the emergence angles were below 45°,and the root vertical distribution was deep, with more than 30% roots in 60～80cm soil layer. When the soil bulk density climbed to 1.47～1.65 g·cm-3 and 1.58～1.75 g·cm-3 below 40cm soil layer, the emergence angles were above 60°and the root concentrated at 0～20cm surface soil layer. And there were no roots in the deep soil. In the same yard, deep digging improved the root growth and the root number of M/110R, up 267% and 150% in 40～60cm and 60～80cm soil layer, respectively. The fine root ratio amounts to 92.8%, up 7.7 percentage points, and it was 2 times as many as that before deep digging. Therefore, deep digging contributed to improve the root architecture.5. The photosynthesis of grafted plants was significantly affected by different rootstocks after 30 days′natural droughts. The diurnal variation of Pn and WUE of M/110R was higher than that of M/420A and M/SO4 in all determined time, and the difference value was the largest at 14:00 o′clock, with 19.67%, 58.70% higher in Pn and 60.32%, 101.61% higher in WUE, respectively. M/110R had higher Gs and lower Tr, while Tr of M/3309C was lower than M/420A and higher than M/110R. The diurnal variation of chlorophyll fluorescene showed that Fv/Fm andФPSⅡof M/3309C decreased by 24.88% and 24.26%, then followed M/420A, M/110R decreased least.And Fv/Fm of M/110R was relatively high and restored quickly after noon, so it had high PSⅡactivity and light energy transform efficiency. The root WSD of different rootstocks ranged from 7 to 13%, and the order of dehydration-resistance ability from large to small was: 110R, 1103P, 420A, S04, 3309C. And there was significantly negative correlation between WSD and the percentage of root bark, and the correlation coefficient r=-0.9244.6. Different rootstocks obviously affected the growth of the grafted varieties. For Malvasia grafted on 3 different rootstocks, the internode length of M/110R was longer than that of M/420A and M/3309C,the diameter of M/110R was wider than that of M/420A and M/3309C. Sangiovese grafted on 2 different rootstocks, the internode length of S/1103P was longer than that of S/SO4 and the diameter was wider than S/SO4.7. Different rootstocks obviously affected the fruit bearing and the soluble solid content of the grafted varieties. For Malvasia grafted on 3 different rootstocks, all index of M/110R were higher than that of M/420A and M/3309C, such as 21.13% and 7.68% higher in single plant yield, 14.49% and 12.86% higher in fruit spike weight, 24.91% and 9.09% higher in per fruit mass, 1.4 and 2.1percentage points higher in soluble solids contents, respectively. For Sangiovese grafted on 2 different rootstocks, the single plant yield of S/1103P was 10.8% more than that of S/SO4, but the fruit spike weight and single fruit mass were 8.83%, 17.14% lower than S/SO4 respectively. There was no difference in soluble solid contents and both were 17.6%.8. The rootstocks had different ability to absorb N, P, K. For the petiole in July, the total N content was low, ranging from 0.9 to 1.1%, S/1103P and M/110R had a higher contents, while M/420A had a lower contents; the total P contents was 0.08～0.12%, in an abundant level, which of M/3309C was higher and S/SO4 was lower. The total K contents varied widely between 0.23～0.65%, and M/110R has high contents while S/SO4 was the lowest. K was needy in the yard.9. The storage reserves in roots and canes were determined in Late October. Soluble sugar content and starch content were high in M/110R and S/1103P, and was relatively low in M/420A, M/3309C, S/SO4. Starch content in coarse roots was higher than that in fine roots and in canes, while soluble sugar content in canes was much higher than that in roots. |
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