Rapid and recurrent <i style="">in vitro </i>mass-multiplication of androgenic rice embryos

Abstract

<i style="">In vitro</i> mass multiplication of plantlets of androgenic origin was achieved in an <i style="">indica</i> rice var. IR72. The multiple shoots were developed profusely on MS medium containing 4 mg L^-1 Kn. When the shoots were cultured on MS supplemented with 6 mg L^-1 BAP, a large number of dormant embryos, pro-embryos and embryo-like structures were produced. Those multiple shoots and dormant embryos had no roots. The subcultured shoots and the dormant embryos on MS basal developed into healthy plantlets with prolific roots. Since 1998, these dormant embryos and the shoots are being sub-cultured at 45 d interval. Till date the multiple shoots and the dormant embryos are developing constantly depending upon the hormones used in the medium. The stock is being maintained by recurrent subculture using explants from the preceding culture. Such stock offers ample scope in genetic transformation of <i style="">indica </i>rice and multiplication of transgenic plantlets. The protocol also prospects efficient <i style="">in vitro</i> conservation through repeated subculture. It provides a novel source too for constant supply of embryos to produce synthetic seeds of androgenic origin in rice.