Studies On Salt Tolerance Of Grape Rootstock And Characteristics Of Rootstock-scion Interaction

Grape rootstock is great importance in grapevine growing, which are very beneficial for the sustainable development of grapevine and wine. The grape rootstock is a decisive factor of grape adaption to salinity and improve grape salt tolerance ability to screen and breed salt tolerance on rootstock. Evaluating for salt tolerance ablity of different rootstocks is one of the most important procedue. In this thesis, the experiment on in vitro culture technology and has been built by simple culture technology. Six rootstocks in simple culture were tested for tolerance to different NaCl concentrations. During NaCl stress, several index such as rootstock seedling of salt tolerance index, morality, rooting rate, proliferation multiple, biological yield and tissue water content were investigated. Variations of free proline, protein content, soluble sugar content, plasma membrane permetability, chlorophyll content and Na+/K+ in leaf were detected, the salt tolerance of six rootstock were screened. Another experiment is three grapevine cultivars grafted on 520A, performance and some physiological indexes were compared with own-rooted . The results is showed that: 1. Over 50 days of NaCl stress, biological yield, proliferation multiple and rooting length were negatively rlated to saline level. Salt injury index were positively related to saline levels. It likely was used screening salt torlance of six rootstocks, while rooting rate was not related to saline levels. 2.During salt stress, tissue water content reduced with the increasing of salinity levels, but the variation was not obvious, especial low salinity levels. Variation of plasma membrane permetability of stem and MDA in leaf could screen the salt tolerance of rootstock. The soluble sugar content in leaf significantly increased with the increasing of salinity levels. In same saline, the change in different cultivars was different. It cound be used to evaluate salt tolerance of different rootstocks expect tissue water content. 3.The chlorophyll content was decreased and the variation of content can reflected the salt tolerance of different rootsock. It can be used to evaluate salt torlance of six rootstocks. The change of K+ content was not obvious for different rootstocks in different salt level. Ratio of K+/Na+ was gradualy reduce with the increasing of salt concention and reflect the salt tolerance of different rootstocks. The ratio K+/Na+just could be used as evaluation index.. 4.The free proline content increased and soluble protein content decreased gradully with th increasing of salinity concentration. But the relationship and role between proline and protein were not cleared under salt stress, proline and protein content cound not be used as evaluation index. 5.The six rootsocks could be divided into three groups:(1)salt tolerance group, including 520A and 5BB. (2) the moderately salt tolerance group is Beta and shengqiaozhi .(3) the salt sensitive group , including 3309C and SO4. 6. Phenological phases of the scion is enormous variation than own-rooted, buded earier and leaf fall later than own-rooted when three grapevines were grafted onto 520A. Buded rate through the winter in grafted was higher than own-rooted. The growth potential in grafted was different in different scion, shoot length,leaf area and stem length in grafted was significantly higher than own-rooted for Merlot Noir and Pinot Chardonnay. For Italy Reisly, the leaf area in grafted become small, shoot length and stem length were not signifcant difference between grafted and own-rooted. 7.The chlorophyll content and tissue water content in grafted was improved, transpiration intensity and water potential were reduced when three grapevine were grafted on 520A. Merlot Noir and Pinot Chardonnay onto 520A had smaller cluster and fruit with higher TA and lower TSS than own-rooted, but Italy reisly onto 520A had small cluster and biger fruit with higher TSS and lower TA than own-rooted. 8. In cold stress, the cold tolerance of grafted was improved remarkably in comparision with own-rooted. For instance, the electrolytll leakage,MDA and lethaltemperature of shoot are greatly reduced. The soluble protein,free proline,soluble sugar and CATase active were remarkably higher than owen-rooted. The buded rate was higher than own-rooted when grafted and rooted were uncovered in winter.