Plantlets from encapsulated shoot buds of Catalpa ovata G. Don

Abstract

Shoot buds isolated from in vitro shoot cultures of <em>Catalpa ovata</em> G. Don were encapsulated using 3% sodium alginate with sucrose (3%) and 50 mM calcium chloride. The morphogenic response of encapsulated buds was affected by such factors, like composition of the media and the presence of growth regulators. The highest frequency of plantlet germination from encapsulated buds (70% within 4 weeks) was obtained on Woody Plant medium (WP) (Lloyd and McCown 1980) containing indole-3-butyric acid (IBA) (1 mg/l). The process was substantially inhibited by cold-storage (4<sup>o</sup>C) of encapsulated buds. In this case, the frequency response ranged from 3% to 22% dependent on storage period (28 or 42 days) and the presence of the paraffin coat covering the alginate capsules. The plantlets developed from both unstored and stored encapsulated buds of <em>C. ovata</em> were transplanted to soil and grew in pots to phenotypically normal plants.