Asymbiotic Seed Germination and Seedling Development in an Endangered and Commercially Important Orchid-Vanda coerulea Griff Ex. Lindl.
Simmi Aggarwal *
Department of Botany, Panjab University, Chandigarh-160014, India
Promila Pathak
Department of Botany, Panjab University, Chandigarh-160014, India
S.P. Vij
Department of Botany, Panjab University, Chandigarh-160014, India
*Author to whom correspondence should be addressed.
Abstract
The immature embryos of Vanda coerulea, obtained from undehisced green capsules (28 wap) were cultured on M medium and its supplementation with plant growth regulators (NAA, IBA, BAP; each used at 1.0 mg/l). Sixty percent seeds germinated within 4 weeks of inoculations in the basal medium; healthy seedlings were formed in 24 weeks. The frequency and onset of germination was, however, affected with the presence of growth regulators in the nutrient medium. Eighty to cent percent seeds germinated within 2-3 weeks, chlorophyllous protocorms obtained in 5 weeks differentiated leaf and root primordia in 9 and 12 weeks of culture respectively. The medium containing NAA proved optimal during germination and BAP induced rapid multiplication of the protocorms and favoured healthy seedling growth. The seedlings, thus, formed in 19 wk old cultures were subjected to in vitro hardening trials and finally transferred to community pots in the green house for further growth and development.
Keywords: Asymbiotic, Endangered orchid, Protocorms, Seed germination, Vanda coerulea