Effect of N⁶-benzyladenine on in vitro shoot multiplication of Iris collettii Hook.f. and I. domestica (L.) Goldblatt & Mabb.

Iris collettii Hook.f. and I. domestica (L.) Goldblatt & Mabb. are perennial plants that have a high potential as new economic ornamental plants due to their beautiful flowers. However, these plants are typically propagated through seeds or bulbs which cannot achieve large volumes of plants to the floriculture industry. Thus, to prevent the problem of smuggling these plants from their natural habitat, an in vitro shoot multiplication method for both Iris species was developed. In vitro plantlets at the height of 5-6 cm were used as starting materials. Leaf bases at 1.5 cm in length were excised from starting materials and used as explants. At eighth weeks of culture on Murashige and Skoog (MS) agar medium augmented with 0 (control), 1, 2, and 4 mg L^-1 N⁶-benzyladenine (BA), leaf bases of I. collettii cultured on MS medium supplemented with 1 mg L^-1 BA showed the greatest shoot formation (3.13 shoots explant^-1 and 2.31 cm). Whereas I. domestica provided maximum new shoot numbers explant^-1 (5.60) from leaf bases culturing on MS medium augmented with 2 mg L^-1 BA. This study also found that the media containing BA resulted in shorter regenerated shoots of I. domestica when compared to the control. Root formation was not found in any treatments except I. domestica cultured on BA-free medium. These results could be used as basic information for optimizing complete in vitro propagation protocol and germplasm conservation method of both Iris species in further study.