Standardization of micropropagation protocol for grape rootstock Dog Ridge

Abstract

In the present study, attempt was made to standardize in vitro micropropagation protocol of grape rootstock Dog Ridge. Among two explants compared (axillary bud and shoot tip), axillary buds registered superior shoot proliferation response (75.81%) compared to shoot tips (40.38%) during January to March in Coimbatore conditions. Full strength Murashige and Skoog (MS) medium supplemented with 6-Benzylaminopurine (BAP) 2.0 mg l-1 produced the highest bud sprouting response of explants. Addition of 0.2 mg l-1 1-Naphthaleneacetic acid (NAA) along with BAP 2.0 mg l-1 was found effective for producing maximum number of lengthier multiple shoots within short time and MS medium fortified with BAP 2.0 mg l-1 and gibberellic acid (GA3) 0.5 mg l-1 resulted in elongated shoots. Half-strength MS medium with 2.0 mg l-1 Indole-3 butyric acid (IBA) and 200 mg l-1 activated charcoal resulted in the maximum in vitro root induction of 83.00% within 11.74 days. For hardening of in vitro rooted plantlets, a combination of pot mix (1:1:1 of sand +soil +farm yard manure) and vermicompost in 1:1 proportion was found to be optimum (86.67% ex vitro survival).