In Vitro Establishment, Conservation and its Implications for Grape Germplasm Biodiversity

A series of experiments were carried out to establish the in vitro cultures from the explants taken from the field gene bank after surface sterilization of seven different grape accessions. Seven accessions of grape germplasm were tested on 75% Murashige-Skoog media containing varying levels of inorganic salts. Among all the accessions, maximum viability (90%) and shoot length (4.18 cm) and highest no. of nodes (3.6) were achieved in 4472 (18). Moreover, response of cultures to different treatments was found to be dependent on the accession and the duration of the treatment. In another set of experiments two different kinds of osmotics, namely, sorbitol and mannitol were used to study the growth retardation of in vitro grown grape cultures. Each of the two was separately supplemented in the 75% MS media at different concentrations i.e. 0, 0.01, 0.05, 0.2, 1.0 or 1.5 g/l under standard light and temperature. Observations on eight different parameters viz. Viability, Mortality, Contamination, Shoot number, Shoot length, Number of nodes, Shoot mass, Root mass and Chlorophyll content were performed. The results revealed that there was a decline in culture growth along with the increase in the concentration of either sorbitol or the mannitol. The retardation effect was found to be maximal at the highest concentration of either sorbitol or mannitol. The latter proved slightly better than the former in inducing growth retardation to the accession under study.