Optimizing in vitro micropropagation of Begonia rex using plant growth regulators

This research was conducted to optimize in vitro micropropagation of Begonia rex as an important ornamental pot plant. In vitro callogenesis and regeneration of three cultivars of B. rex (Jurassic, Silver dollar and Silver king) were carried out starting from leaf segments as explants. Eight Murashige and Skoog′s media consisted of four plant growth regulators, including α-naphthaleneacetic acid (NAA), ۶-benzyladenine (BA), ۳-Indole-۳-butyric acid (IBA), and Thidiazuron (TDZ). After four weeks, callogenesis and regeneration started. After eight weeks of proliferation, the explants were transferred to MS culture medium supplemented with ۰.۰۵ mg/l gibberellic acid. The highest direct regeneration percent occurred in the medium containing ۰.۵ mg/L BA + ۰.۲ mg/L TDZ. Callogenesis, regeneration and root formation occurred in all treatments. The highest number of leaves was observed in the culture medium supplemented with ۱ mg/L IBA + ۱ mg/L BA in the Jurassic cultivar. Medium fortified with ۰.۲ mg/L NAA + ۰.۲ mg/L BA and ۱ mg/L IBA + ۱ mg/L BA was selected as the best medium for increasing the fresh weight and proliferation of cv. Jurassic. The highest amounts of chlorophyll a and b were obtained in ۰.۵ mg/l BA + ۰.۲ mg/l TDZ and ۱ mg/l of IBA + ۱ mg/l of BA treatments in ‘Jurassic’ and ‘Silver dollar’ cultivars. The survival rate of transplanted plant lets was about ۱۰۰%. Generally, the combination of ۱ mg/l IBA with ۱ mg/l BA could be introduced as an effective and useful treatment in the micropropagation of studied three cultivars of Begonia rex.

Keywords:

Benzyladenine , Callus , Naphthaleneacetic acid , Organogenesis , Thidiazuron , اندام زایی , بنزیل آدنین , کالوس , تیدیازوزن , نفتالین استیک اسید