Effects of shoot tip removal, wounding manipulation, and plant growth regulators on shoot regeneration and plantlet development in Paphiopedilum species

Abstract

The micropropagation procedure of three endangered Paphiopedilum species (Paphiopedilum callosum, Paphiopedilum gratrixianum, and Paphiopedilum delenatii) by removing shoot apex and wounding method is reported in this study. The results showed that shoot regeneration of P. callosum, P. gratrixianum, and P. delenatii was at high frequency (5.61; 5.48; and 6.00 shoot/explant, respectively) when decapitated shoot apex was cultured on liquid Schenk and Hildebrandt (SH) medium added with thidiazuron (TDZ, 0.4–0.6 mg L−1). Multiple shoots were also induced in vitro shoots by wounding method, when cultured on medium containing TDZ (0.4–0.6 mg L−1) which were 4.48; 5.37; and 5.31 shoots/explant, respectively in each species. The shoots regenerated via both shoot apex decapitation and wounding method were well-developed to plantlets on SH medium supplement with 1.0 mg L−1 Naphthaleneacetic acid (NAA) after 90 days of culture. High-quality plants of P. callosum, P. gratrixianum, and P. delenatii. were observed when the plantlets were transferred onto peat moss with 100% survival rate after 24 months in greenhouse.