Embryo culture of certain economically important Orchids

Abstract

The in vitro studies conducted in Cymbidium aloifolium Sw., Dendrobium nobile Lind and D. pierardii Roxb. revealed that, Vacin and Went medium was best for early (6.33 weeks) and highest germination (48.33%) in C. aloifolium, while Knudson C medium was best for D. nobile and D. pierardii with 100% germination. Nitsch medium was also equally effective as that of Knudson C in case of D. nobile. Coconut water increased leaf length (1.23 cm) and stem thickness (0.17 cm) in in vitro plantlets of D. pierardii. Banana pulp increased leaf number (4.0) and leaf length (1.37 cm) in D. nobile. Wheat and sago were better alternatives to agar as they promoted growth. Wheat malt increased shoot length in C. aloifolium (1.74 cm) and D.nobile (0.94 cm). It also promoted leaf length (1.30 and 1.13 cm) and stem thickness (0.23 and 0.17 cm,) in D. nobile and D. pierardii. Sago increased leaf number in C. aloifolium (3.85) and D.pierardii (3.65), shoot length (3.13 cm) in C. aloifolium,s leaf length (1.12 cm) and stem thickness (0.18 cm) in D. pierardii. Even in D. nobile it could replace agar with slight beneficial effects. BAP (1 ppm) had a growth promotive effect in D. nobile. In Dendrobium species 2,4-D (1 to 6 ppm) with BAP)1 ppm) induced callus. 2,4-D and BAP (1 ppm each) were found best for early induction of callus (65.63 days), higher callus intensity, better callus size (5.31 mm), weight (30.85 mg) and with very quality. But, 2,4-D (1 to 6 ppm) was inhibitory for C. aloifolium protocorms. Polyhouse with higher relative humidity (80.85%) was better t5han Green house for hardening of Dendrobium hybrid ‘Sonia’, since survival percentage was highest (66.25%), as compared with green house (56.88%).