In vitro micro propagation of “sand pear” Pyrus pyrifolia (Burm. f.) Nakai

Abstract

This study was undertaken to standardize protocols for in vitro explant establishment, shoot multiplication and in vitro rooting for Pyrus pyrifolia, growing in the Kashmir valley. The explant used was nodal cuttings of 2–3cm size with one or two axillary buds. The highest explant establishment (over 90%) was observed during spring while the lowest (60%) explant establishment frequency was observed during winter season. The shoots sprouted from the axillary buds were excised and subcultured on MS basal medium. The highest shoot multiplication rate (130 shoots from a single nodal cutting) was obtained on MS medium supplemented with BAP 2.2 mg·L^−1 and kinetin 1 mg·L^−1 after four weeks. The shoots were inoculated for rooting in root induction medium of half strength MS salts supplemented with plant growth regulators like IBA, IAA, NAA, and 2, 4-D. However, the best rooting response (8.50 roots per shoot) was obtained in combination of hormones (IBA+ NAA) 0.25 mg·L^−1 each. The rooted micro shoots were acclimatized under decreasing humidity regime (95% RH to 75% RH over a period of 5±1 weeks). The highest ex vitro plantlet survival percentage (56.50%) of Pyrus pyrifolia was observed on sand+ soil (1∶1 v/v).

Key words： Pyrus pyrifolia; micro propagation; shoot multiplication; nodal cuttings; Murashige and Skoog