In vitro propagation and agronomic performance of regenerated chili pepper (Capsicum spp.) plants from commercially important genotypes

The application of modern biotechnology for improvement of chili pepper productivity requires an efficient in vitro plant regeneration protocol. In this study, a reliable protocol was developed for the in vitro regeneration of four types of chili, Capsicum annuum var. annuum (Jalapeño and Serrano), C. annuum var. glabriusculum/aviculare (Piquin), and C. chinense (Habanero) by direct organogenesis using three different explants (cotyledon, hypocotyls, and embryo) and three induction media. All evaluated culture media promoted the formation of adventitious shoots. When embryos or hypocotyls were used as explants, morphologically normal adventitious shoots developed, while culturing cotyledons resulted in nonelongating rosette-shaped shoots. The highest in vitro regeneration efficiency (14.6 shoots per explant) was achieved when Habanero chili hypocotyls were grown on Murashige and Skoog medium containing 1.7 μM indole-3-acetic acid and 22.2 μM N⁶-benzyladenine. This regeneration rate is higher than that obtained in previous reports. Regenerated plants were ready to be transferred to the greenhouse 13 wk after the explant culture. An evaluation carried out under greenhouse conditions showed differences in agronomic performance between in vitro regenerated plants and plants developed from seeds with the magnitude of the differences depending on the genotype being studied.