An efficient system for in vitro regeneration by organogenesis starting from internodal stem segments from seedlings of Mexican lime (Citrus aurantifolia Christm. Swing.) and mandarin (C. reticulata Blanco cv. Monica) was developed. The best results were obtained when the wounded edges of internodal stem segments cut longitudinally were placed downward on the surface of the culture medium. The optimal culture medium from both species was Murashige and Skoog with vitamins from B5 medium, 5% sucrose, 33.3 μm BA and 5.4 μm NAA. The best response was obtained when the segments were incubated at 25 ± 2 °C for 21 d in darkness, followed by 29 d on a 16/8-h light/dark cycle (fluorescent light, 54 μmol·m-2·s-1). The best regeneration system tested allowed the attainment of adventitious shoots from 96% and 88% of the explants in Mexican lime and mandarin, respectively. In Mexican lime an average of 7.8 well-differentiated shoots per explant was obtained, and in mandarin the yield was 5.1. Rooting of 70% of the shoots was achieved in culture medium with NAA (2.7–5.4 μm) or IBA (2.5–4.9 μm). Of the rooted plants, 85% adapted well to soil conditions. Chemical names used: 6-benzylaminopurine (BA), α-naphthaleneacetic acid (NAA), indole-3-butyric acid (IBA).
Eugenio Pérez-Molphe-Balch and Neftalí Ochoa-Alejo
Robert L. Jarret, Gloria E. Barboza, Fabiane Rabelo da Costa Batista, Terry Berke, Yu-Yu Chou, Amanda Hulse-Kemp, Neftali Ochoa-Alejo, Pasquale Tripodi, Aniko Veres, Carolina Carrizo Garcia, Gabor Csillery, Yung-Kuang Huang, Erzsebet Kiss, Zsofia Kovacs, Mihaly Kondrak, Magda Lisette Arce-Rodriguez, Marisel A. Scaldaferro and Antal Szoke
Pepper (Capsicum L.) is a major vegetable and spice crop worldwide. Global production of both fresh and dried fruit continues to increase steadily in terms of area harvested and yield. Various topics are addressed in this review, including recent additions to and clarification of Capsicum taxonomy, genetic resources of Capsicum, cytogenetic studies, the current status of our understanding of the mechanisms affecting the biosynthesis of capsaicinoids, the use of gene mutations to elucidate carotenoid biosynthetic pathways and their regulation, and recent advances in whole-genome sequencing and assembly.