Callogenic potentiality of leaf segments and shoot proliferation response of Vitis spp. genotypes

Abstract

Callogenesis from leaf segments of eight Viis spp. genotypes was studied in the presence of 5 or 10 μM 2,4‐D and/or 2 or 4 μM 6‐BAP, wih or wihout 5 μM NAA, in full‐ or half‐strength Murashige and Skoog (MS) medium. Best qualiy of callus was obtained at 2 or 4 μM 6‐BAP in combination wih 5 μM NAA and full‐strength MS medium. In contrast, 5 or 10 μM 2,4‐D wih 5 μM NAA gave callus of poor qualiy. No callus developed in the absence of exogenous plant growth regulators. NAA alone caused development of roots. Fresh weight of callus ranged from 20 to 714 mg. Although other combinations of plant growth regulators could result in the development of high quantiies of callus in most tested genotypes, quantiy was not always accompanied by high qualiy. Preliminary results are also presented on shoot formation from callus of cv. Sultanina, which was obtained after two subcultures on MS medium containing 2 μM 6‐BAP and 5 μM NAA; one on hormone‐free MS medium and culture at 4°C; and a last one on a modified MS medium supplemented wih 13 μM 6‐BAP and 1 μM GA₃. In addiion the proliferation potential of apical shoot segments of 12 Viis spp. genotypes was studied in four culture media and six concentrations of 6‐BAP and kinetin. MS medium supplemented wih 6‐BAP at 2–5 μM was the most effective combination for inducing shoot proliferation. Quantiative response varied among genotypes. The vinifera cultivars exhibied higher shoot proliferation response than the rootstock cultivars.