Sobrevivência de enxertos de videira e a relação com o estresse oxidativo

Abstract

Compatibility between rootstock and scion is one of the factors that directly influence the success of grafting and can vary significantly among grapevines and their clones. The aim of this study was to evaluate the survival rate and quality of grapevine seedlings from different combinations of scions and rootstocks, and their relationship with oxidative stress. The experimental design was a randomized complete block with 4 replications and 15 experimental units (grafts), in a 4 x 5 factorial arrangement. Factor A consisted of 4 different rootstocks ('IAC 572 Jales', 'IAC 766 Campinas', 'Paulsen 1103', and 'Freedom'), and factor B consisted of 5 different scion cultivars ('BRS Carmem', 'BRS Magna', 'Bordô', 'Isabel Precoce', and 'Concord Clone 30'). At 90 days, the following parameters were evaluated: survival percentage, number of leaves, leaf area, number of roots, shoot length, longest root length, fresh and dry mass of leaves, roots, and stems. The evaluation of oxidative stress was performed on two combinations with high survival rate and two combinations with low survival rate at 0, 10, and 20 days after removal from the forcing chamber. Peroxidase (POX) and superoxide dismutase (SOD) activities, as well as hydrogen peroxide (H2O2) and malondialdehyde (MDA) concentrations, were quantified. The scion/rootstock combination that resulted in the best initial development of grapevine seedlings was 'IAC 572 Jales' with 'BRS Carmem'. 'IAC 572 Jales' also promoted good initial development with 'BRS Magna' and 'Concord Clone 30' as scions. The rootstock 'Freedom' induced good initial development in the 'BRS Bordo' cultivar. 'Paulsen 1103' and 'IAC 766 Campinas' were the rootstocks that resulted in the lowest initial development of seedlings. 'Paulsen 1103' showed low compatibility with 'Isabel Precoce', although this scion cultivar exhibited reduced overall development. The two combinations with high survival rate showed higher levels of SOD and MDA, and lower levels of POX and H2O2. Therefore, it was concluded that the rootstocks that promoted the highest survival rate and initial development of seedlings were 'IAC Jales', ‘Paulsen 1103’ and 'Freedom'. Higher levels of SOD and MDA, and lower levels of POX and H2O2 are correlated with higher graft survival rates.