Leaf Culture Regeneration and Micropropagation of Rex Begonia

Rex Begonia is a native plant to the humid tropical and wetlands of India. The first Rex Begonia arrived in England in 1856, and a Belgian commercial horticulturist crossed it with several other Begonia species to produce some exciting hybrids. Rex Begonias do bloom, but are not grown for their blooms, which pale in comparison to their spectacular leaves. Rex Begonias can be multiplied by seeds or vegetated naturally by rhizomes or leaf cuttings. For modern agriculture, a method for large scale multiplied artificially by minicuttings through in vitro technology is needed. We report a Rex Begonia leaf culture and micropropagation protocol potentially for commercial production. Immature leaf cuttings were surface-sterilized using 25% Clorox with two drops of Tween-20 and then cultured in the embryonic competent cell induction medium [Murashige and Skoog (MS) medium supplemented with 1 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D)] for seven days. They were then transferred to regeneration medium [Murashige and Skoog (MS) medium supplemented with 1–4 mg/L 6-Benzylaminopurine (BA)] and cultured in a dark tissue culture room for four weeks for shoot initiation and development. Ninety percent of explants regenerated new shoots; an average of 8 shoots were formed in a ½ cm² explant. Elongated shoots were transferred to MS medium with 1 g/L activated charcoal for three weeks and 100% of the shoots formed functional roots, which resulted in a 100% survival rate when acclimatized in coco coir plugs.