Int.J.Curr.Microbiol.App.Sci (2019) 8(2): 2108-2117 2108 Original Research Article https://doi.org/10.20546/ijcmas.2019.802.244 Standardization of in vitro Hardening Strategies for Tissue Cultured Wine Grape (Vitis vinifera L) Genotypes Rahul Dev 1* , S.K. Singh 2 , Vishambhar Dayal 2 , Kamlesh Kumar 3 and Traloki Singh 4 1 CAZRI, RRS, Kukma-Bhuj, Gujarat 370 105 2 ICAR Research Complex for NEH Region, Mizoram Centre 3 CIAH Bikaner 4 SMSCAZRI, KVK, Kukma-Bhuj, Gujarat 370 105 *Corresponding author ABSTRACT Introduction Grapevines (Vitis sp.) are one of the major horticultural crops grown throughout the world and it has emerged as an important fruit crop of India too. At present, it covers an area of about 1.36 million ha with the production of 2.68 million MT (NHB, 2017). During the last two decades, grape cultivation has gained popularity among fruit growers of north India. In recent past, it has been observed that non- availability of an adequate number of true to type, disease-free planting material has been the major constraint for the establishment of ideal vineyards (Jamwal et al., 2013). Grape is traditionally propagated through woody cuttings, suffered many limitations. Micropropagation offers another method for the rapid multiplication of many plant species. In vitro micropropagation has been standardized for several horticultural crops. However, its more widespread use is International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 8 Number 02 (2019) Journal homepage: http://www.ijcmas.com A study was carried out to establish efficient hardening strategy for in vitro raised plantlets of four grape genotypes. In vitro grown plantlets of Pusa Navrang, Hybrid 76-1 (Hur x Cardinal), Pearl of Csaba and Julesky Muscat were hardened in vitro using hardening medium consisting coco peat + vermiculite + perlite (2:1:1) ratio and two different types of hardening pots viz. glass jars with polypropylene cap (GJPP) and plastic pots with polyethylene cover (PPPC). The glass jar containing coco peat + vermiculite + perlite (2:1:1) was found the most effective strategy for hardening in vitro raised plantlets which gave the highest survival (85.97%) and earliest duration for acclimatization of plantlets (23.56 days). Plastic pot with the coco peat + vermiculite + perlite (2:1:1) (T 2 ) was found non-significant since it required a longer duration for acclimatization (27.93) and also giving lower survival rate (63.46%). Keywords Vitis vinifera, In vitro hardening, Acclimatization, Polyethylene Accepted: 15 January 2019 Available Online: 10 February 2019 Article Info