Organogênese in vitro e diagnose viral em videiras cultivadas no Vale do São Francisco

Abstract

The viticulture is an important economical activity in the irrigated agriculture of the São Francisco river Valley. The application of tissue culture technic on certified free selects genotypes of viruses are important for the sustentability of the activity. In vitro organogenesis was studied as requisite for future investigations for genetic transformation studies. Explants of leaves with petiole, originated from in vitro axillary shoots, of seven grapevines cultivars, were induced in culture medium NN, supplemented with growth regulators. The evaluation was carried out 75 days after explant inoculation analyzing the percentage of explants with adventitious regeneration and rate of regeneration per explant. A note system was used for the rate of regeneration per explant. The percent of explant regeneration varied from 0%, in Benitaka cultivar and the control, up to 50%, in Superior Seedless cultivar. The cultivars with rate more than 7 regenerants per explants were: Petit Shiraz (15,0 μM de BAP + 0,1 μM ANA) and Red Globe (10,0 μM de BAP + 0,1 μM ANA). For certified free selects genotypes of viruses, diagnostic test DAS-ELISA (Enzyme-Linked Immuno Sorbent Assay) was used aiming to evaluate its efficiency to detect virus in grapevine under tropical conditions of high temperatures. In this case, were investigated the presence of Grapevine leafroll virus 1 (GLRaV-1), Grapevine leafroll virus 3 (GLRaV-3), Grapevine virus A (GVA), Grapevine fanleaf virus (GFLV) and Grapevine fleck virus (GFkV) in four grapevine cultivars. The presence of GLRaV-3 in Benitaka (80%), Superior Seedless (60%) and Itália (40%) cultivars was detected in samples of petiole and leaf veins of adult leaves. The presence of GVA in Superior Seedless (40%), IAC-313 (40%) and Benitaka (20%) cultivars were detected in samples of petiole and leaf veins of adult leaves, lamina of adult leaf and petiole and leaf veins of young leaves. The presence of GFLV in Benitaka (20%) was detected in samples of petiole and leaf veins of adult leaves. It was not detected GLRaV-1 and GFkV.