In vitro establishment of a highly effective method of castor bean (Ricinus communis L.) regeneration using shoot explants

An efficient plant regeneration protocol was established for castor bean (Ricinus communis L.), in which 0.3 mg L−1 thidiazuron (TDZ) induced shoot clusters and increased the number of adventitious shoots from hypocotyl tissue. Our results showed that treatment under dark conditions significantly promoted the average number of shoots per explant to 37.36±4.54 (with a 6-d treatment). Modified 1/2 Murashige and Skoog (MS) basal medium supplemented with 440 mg L−1 Ca2+, 0.2 mg L−1 gibberellic acid and 0.1 mg L−1 TDZ significantly increased shoot elongation rates and lowered vitrification rates. Furthermore, 1/2 MS media supplemented with 0.2 mg L−1 1-naphthaleneacetic acid induced a higher rooting rate compared with other culture conditions.