In vitro plant regeneration of 4 Capsicum spp. genotypes using different explant types

Abstract

This study evaluates the effectiveness of in vitro regeneration of 4 genotypes of pepper (Capsicum spp.) that differ in origin and functional properties: California Wonder, (ATZ × Sono)F_1, Jalapeno, and SF-9. In order to investigate the effect of the initial explant type, photoperiod, and presence of 2.0 mg L^{-1} of glycine in the medium, organogenesis was induced on the MS medium with 2.0 g L^{-1} 2-(N-morpholine) ethanesulfonic acid, 1.7 mg L^{-1} AgNO_3, 0.4 mg L^{-1} indole-3-acetic acid (IAA), and 6.0 mg L^{-1} 6-benzyladenine. The effectiveness of organogenesis in the 3 genotypes representing C. annuum L. was similar and considerably lower for line SF9 derived from an interspecific hybrid (C. frutescens L. × C. annuum L.). The highest number of adventitious leaves was recorded in the decapitated seedlings exposed to continuous light. The lack of glycine in the medium favored direct organogenesis. A simultaneous formation of adventitious leaves with a stable number of chromosomes and mixoploid callus tissue was determined by flow cytometry. The successive stage of foliaged shoots and roots formation was most effective in the MS medium with 1.1 mg L^{-1} IAA. The use of these optimal conditions resulted in developing 42%-56% of properly formed diploid plantlets, successfully acclimatized in 86%-97%.