Paphiopedilum cloning in vitro

A mericloning protocol that enables shoot multiplication and rooting of Pap hiopedilum orchids in one step or in the same medium was developed by syste matically assessing and modifying the nutrient supplements employed earlier for shoot proliferation by Huang [Am. Orchid Soc. Bull. 57 (1988) 274]. Sh oots of aseptically established seedlings obtained from a commercial breede r were used as explants. The new combination of supplements to the MS [Phyi ol. Plant. 15 (1962) 473] based medium consists of MT [Proc. First Intl. Ci trus Symp. 3 (1969) 1155] vitamins, glycine and inositol; 13 muM BA (N-6-be nzyladenine); 1.6 muM NAA (alpha -naphthaleneacetic acid); 0.15 nim adenine sulfate . 2H(2)O; 1.23 mM NaH2PO4.H2O: 0.18 M sucrose; and 15% (v/v) cocon ut milk from very young fruits, The coconut milk can be substituted with 1 g l(-1) casein hydrolysate or 10 g l(-1) potato tuber sections. The investi gation also disclosed that TDZ (N-phenyl-N'-1,2,3-thiadiazol-5-yl urea) inh ibited shoot proliferation and rooting, and maltose depressed rooting. The protocol enables doubling the number of Paphiopedilum plants every 12 weeks . (C) 2001 Elsevier Science B.V. All rights reserved.