Phenylacetic acid improves bud elongation and in vitro plant regeneration efficiency in Capsicum annuum L.

A highly efficient three-stage protocol or the regeneration of chilli peppe r (Capsicum annuum L.) from cotyledon explants was developed. This protocol used PAA in both the shoot-bud induction medium and the medium for elongat ion of the shoot buds. A superior medium for the induction of buds from the cotyledons was MS medium supplemented with BA (5 or 7 mg/l) + PAA (2 mg/l) . Buds were elongated during the second stage pn medium containing BA (2 or 5 mg/l) + PAA (2 mg/l). On this medium most: of the buds elongated, and th eir number also increased due to the formation of new buds; bud elongation was achieved in 100% of the cultures provided the buds were induced in the primary stage on a medium supplemented with BA + PAA. The shoots that elong ated in the second-stage rooted at 100% frequency on a medium supplemented with NAA (1 mg/l). The complete plantlets with well-developed root and shoo t systems were transferred to field conditions where they grew to maturity, flowered and fruited normally. While shoot-bud induction from the cultured cotyledons was also observed on media supplemented with BA (5 or 7 mg/l) a lone or in combination with IAA (0.2-2 mg/l), buds induced on these media w ere often distorted, with most not developing into normal shoots in the sec ond-stage subculturing; a rosette of buds was seen in the second stage subc ulturing. On the other hand,PAA in combination with BA in the primary induc tion medium and second-stage medium promoted normal development and the elo ngation of shoot buds.