Effect of half-strength MS medium supplemented with plant growth regulators on in vitro response in ‘Bird of Paradise’ (Strelitzia reginae L.)

Abstract

Propagation of Bird of Paradise (Strelitzia reginae L.) from seeds is a slow and complicated process due to the hard endocarp that encloses the seed and hinders germination. A study was undertaken to optimize in vitro protocol for mass multiplication of ‘Bird of Paradise’ (Strelitzia reginae L.). The experiment consisted of four treatments with growth regulators, viz., GA3 @1mg L-1; GA3 @3mg L-1; GA3 @5mg L-1; and, GA3 @1mg L-1 + BA @1mg L-1 with various medium components (½ MS + Sucrose @1% + Gelrite 3g L-1 + Inositol 100mg L-1 + Thiamine-HCl @ 1mg L-1 + Biotin 2mg L-1; and, medium with ½ MS + Sucrose @1% + Gelrite 3g L-1 + Inositol 100mg L-1 + Thiamine- HCl @1mg L-1 + Biotin 2mg L-1 (Control). Results from the experiment showed the significant differences between the treatments. The maximum rate of contamination was found in control while, minimum was in GA3 @ 5 mg L-1 and GA3 @ 1mg L-1+ BA @ 1 mg L-1 treatments. Higher rate and percentage of culture response (zygotic embryos germinated) were recorded in GA3 @ 1 mg L-1. Growth parameters such as shoot length (cm), root length (cm) and number of leaves per plant were maximum in ½ MS+ Sucrose @ 1% + Gelrite 3 g L-1 + Inositol 100 mg L-1 + Thiamine- HCl @ 1 mg L-1 + Biotin 2 mg L-1 + GA3 @ 1 mg L-1+BA @ 1 mg L-1 treatments. On the basis of overall results, our study confirmed that the media composed of ½ MS+ Sucrose @ 1% + Gelrite 3g L-1 + Inositol 100mg L-1+ Thiamine-HCl @1mg L-1+ Biotin 2mg L-1+ GA3 @1mg L-1 accelerated the germination rate and the combination of GA3 @1mg L-1 + BA @1mg L-1 growth regulators showed the better growth performance in in vitro propagation of ‘Bird of Paradises’ (Strelitzia reginae L.).