Comparative in vitro propagation of stress tolerant grape (Vitis spp.) rootstocks and assessment of clonal fidelity of plantlets

Micropropagation in nine Vitis rootstocks using nodal segments was studied. Optimum in vitro culture establishment was highest on Murashige and Skoog (1962) medium (MS) with 3.0 mgl⁻¹ BAP + 0.25 mgl⁻¹ NAA. Rootstock 110 R gave the earliest bud sprouting (4.03 days), whereas, 1616 C and 110 R gave the highest culture establishment (71.11 & 69.67%). The shoot proliferation was most efficient on MS medium + 4.0 mgl⁻¹ IBA + 0.5 mgl⁻¹ BAP. Dogridge showed the maximum multiplication rate/sub-culture (10.07), while 1613 had the minimum (5.07). Half-strength MS medium supplemented with 4.0 mgl⁻¹ IBA gave good rooting parameters, while halfstrength MS medium with 1.5 mgl⁻¹ IBA + 1.5 mgl⁻¹ NAA induced more number of roots. Dogridge and Salt Creek had the higher rooting (77.58 & 74.24%) compared to other genotypes. High ex vitro plantlet survival (82.75%) was noted in 1103 P in glass jars, while 1616 C plantlets took the shortest time (44.40 days) for transfer to glasshouse. Application of two marker (RAPD & ISSR) systems further confirmed the genetic stability of micropropagated plantlets. Based on the overall performance of rootstocks for in vitro multiplication they could be ranged as Dogridge > Salt Creek > V. parviflora > St. George >1616C > 1103P > 140Ru > 110R > 1613C.