Gill, M.I.S.Rehman, Haseeb ur2017-06-032017-06-032014http://krishikosh.egranth.ac.in/handle/1/5810016031In vitro propagation and shoot-tip grafting of Patharnakh (Pyrus pyrifolia (Burn F.) Nakai) pear was carried out in Tissue Culture Laboratory in Department of Fruit Science, Punjab Agricultural University, Ludhiana during 2011-13. Nodal explants from Patharnakh (forced and active) and Kainth (forced and active) were used for their in vitro propagation protocol development. The effect of various media {1/2 MS (M1), MS (M2) and WPM (M3)} and growth regulators (BAP, IBA and NAA) on establishment, proliferation and rooting of Patharnakh (forced and active) and Kainth (forced and active) was studied. Patharnakh scion derived from two sources, i.e. one derived from forced shoot tip (S2) and another from in vitro shoot tip (S1) having different lengths ( L1 = < 5mm, L2 = 5-10 mm and L3 = 10-15 mm) were used for shoot tip grafting on in vitro developed Kainth rootstock. Two grafting techniques viz, wedge (G1) and horizontal (G2) were used and shoot tip grafts obtained were allowed to grow in different media i.e. MS medium + 20 g/l sucrose (M1), liquid medium composed of MS solution + 20 g/l sucrose (M2), MS medium + 40 g/l sucrose (M3) and liquid medium composed of MS solution + 40 mg/l sucrose (M4). Observations on aseptic cultures (%) graft success (%), necrosis (%), vitrification (%) and vigour (1-3 point scale) were recorded. Besides this, pre-treatment of TDZ and 2, 4-D was given to scions before grafting by dip method for one minute. Observations regarding aseptic cultures (%), graft success (%), necrosis (%) and vitrification (%) were recorded. Necrotic culture (%) was found to be influenced by type of media and growth regulator fortification during establishment stage in both Patharnakh (forced and active) and Kainth (forced and active). Lowest necrotic culture percentage in Patharnakh (forced and active) was observed by using M2 medium fortified with BAP (1.0 mgl-1) and IBA (0.01mgl-1) whereas, M2 medium supplemented with BAP (1.5 mgl-1) and IBA (0.01 mgl-1) proved best by inducing least necrotic cultures in Kainth (forced and active). Maximum establishment (%) was obtained on M3`medium fortified with BAP (1.5 mgl-1) and IBA (0.01 mgl-1) i.e 96.10 per cent in case of Patharnakh (forced) and on M2 medium supplemented with BAP (1.5 mgl-1) and IBA (0.01 mgl-1) i.e 96.29 per cent in case of Patharnakh (active). Similarly, M2 containing BAP (1.5 mgl-1) and IBA (0.25 mgl-1) gave maximum explant establishment of 52.80 and 63.60 per cent respectively in Kainth (forced) and Kainth (active). Maximum proliferated cultures in Patharnakh (forced) and Patharnakh (active) were obtained using M3 medium fortified with BAP (2.5 mgl-1) i.e 85.67 per cent and BAP (5.0 mgl-1) i.e 79.47 per cent respectively. However, maximum proliferated cultures in Kainth (forced) and Kainth (active) were produced using M3 medium supplemented with BAP (3.0 mgl-1). Similarly the highest shoots per explant in Patharnakh (forced) and Kainth (active and forced) were obtained using M3 medium supplemented with BAP (2.5 mgl-1) and BAP (3.0 mgl-1) respectively. However, maximum shoots per explant (3.08) in Patharnakh (active) were produced in M2 medium supplemented with BAP (2.5 mgl-1). Longest shoots in Patharnakh (active) and Kainth (forced and active) were obtained in M3 medium containing BAP (0.0 mgl-1) i.e control. However, longest shoots (53.75 mm) in Patharnakh (forced) was obtained using M3 medium containing BAP (0.5 mgl-1). Rooting (%), roots per explant and root length was found to be influenced by type of medium and growth regulator fortification in both Patharnakh (forced and active) and Kainth (forced and active). Rooting (%) was maximum in Patharnakh (forced) i.e. 10.16 and Patharnakh (active) i.e. 9.16 using M1 medium fortified with IBA (1.0 mgl-1) while as maximum rooting (%) in Kainth (forced) i.e 13.34 and Kainth (active) i.e 14.08 was observed in M1 medium supplemented with IBA (0.1 mgl-1). Although no rooting was obtained in Patharnakh (forced and active) irrespective of media using NAA however, NAA (1.0 mgl-1) induced rooting (%) of 29.61 and 27.46 using M1 medium in Kainth (forced) and Kainth (active) respectively. Roots per micro-shoot were 2.38 and 2.60 respectively in Patharnakh (forced) and Patharnakh (active) using M1 medium supplemented with IBA (1.0mgl-1). Similarly in Kainth (forced) and Kainth (active), maximum roots per explant were obtained using M1 medium supplemented with IBA (1.0 mgl-1). NAA (1.0 mgl-1) induced highest number of roots per explant in Kainth (forced), i.e. 3.40 and Kainth (active), i.e. 3.60 using M1 and M2 medium respectively. In Patharnakh (forced and active), maximum root length were obtained using M3 medium supplemented with IBA (1.0 mgl-1). However, M3 supplemented with IBA (0.1 mgl-1) resulted in maximum root length (31.15 and 31.10 mm) in Kainth (forced) and Kainth (active), respectively. NAA (0.1 mgl-1) resulted in maximum root length (22.97 mm) in Kainth (forced) in M1 medium, whileas in Kainth (active), NAA (1.0 mgl-1) resulted in maximum root length of 23.22 mm using M3 medium. Aseptic culture, graft success, necrosis, vitrification and vigour were found to be influenced by scion origin, scion length, grafting technique and medium used during shoot tip grafting. Aseptic cultures were maximum (84.34 %) by employing S1, L2, G2 and M1. Graft success was maximum (33.71%) by using S1, L2, G1 and M2. However, necrosis was least (0.0%) in many treatment combinations. Vitrification was also found to be influenced by various treatment combinations with least vitrification (12.01 %) by employing S1, G1, L1 and M4. Maximum vigour (2.68) was found by using S1, G1, L2 and M2. Pre-treatment with growth regulators was found to have beneficial effects on graft success and other parameters. TDZ (0.5 mgl-1) + 2,4-D (5.0 mgl-1) resulted in maximum aseptic cultures (88.78%), whileas highest graft success (42.34 %) was obtained by giving pre-treatment of TDZ (0.5 mgl-1) + 2,4-D (7.5 mgl-1). However, least necrosis (1.65 %) resulted by treatment of TDZ (0.75 mgl-1) and minimum vitrification (4.11 %) was observed by treatment combination of TDZ (0.75 mgl-1) + 2, 4-D (7.5 mgl-1).engrafting, vegetative propagation, iba, scions, pears, biological development, auxins, planting, cultivation, concentratesThesis