The aim of this study was to determine the pungency level of different accessions of Habanero peppers. The high-performance liquid chromatography (HPLC) technique was used to evaluate the content of total capsaicinoids in the whole fruit, placenta, and pericarp of 18 accessions of Habanero pepper from the germplasm bank of the Capsicum chinense species maintained in the Scientific Research Center of Yucatan [Centro de Investigación Científica de Yucatán (CICY)]. Thirteen of these accessions belonged to the “orange type”, four to the “red type”, and one to the “yellow type”. During the study, the plants were cultivated and maintained under greenhouse conditions and the fruit was harvested only when it was completely ripe on the plant. The results show considerable intraspecific diversity for this characteristic as well as the existence of cultivars of this species that surpass the levels of pungency reported for Habanero peppers under the conditions evaluated.

Current protocols for Agave americana L. micropropagation have limited commercial application due to the low number of plants produced by explant. Indirect organogenesis could be an alternative, however is necessary to optimize plant growth regulators for plantlet number maximization. The objective of this work was to optimize 2,4-dicholorophenoxyacetic acid (2,4-D) and 6-benzyl adenine (BA) concentrations on the induction of A. americana embryogenic callus from apical meristem as explant for maximized the number of shoots per callus using a response surface experimental design. MS medium containing 30 g l-1 sucrose amended with 0.11,0.18, 0.45 or 2.26 μM 2,4-D, and 11.0, 22.0, 38.2 or 44.0 μM BA was used. Nine treatments with three repetitions was applied and number of shoots per callus were monitored after 4, 16, 20 and 36 weeks. In vitro rooting of shoot was done in MS medium added with indole butyric acid (IBA). A maximum number of plantlets per explant (74) was obtained with 2.26 μM of 2,4-D and 38.2 μM BA. In conclusion, the indirect organogenesis of A. americana L. could be an alternative for obtain plantlets for propagation commercial purposes.

The ontogenesis of direct high-frequency somatic embryogenesis of C. chinense induced from hypocotyl was characterized through a histological analysis of the different phases in the histodifferentiation process during the development of the somatic embryo. The anatomical analysis was carried out since the hypocotyl segments were placed in the culture medium until 45 days of culture. The somatic embryos were induced and maintained in Murashige and Skoog medium supplemented with 2,4-dichlorophenoxyacetic acid (9.5 μ m ). Samples of tissues and organs were taken every 24 h, fixed in formalin acetic alcohol, and embedded in plastic resin. They were cut into serial sections (5 μm) and stained with toluidine blue. The analysis revealed that the proembryogenic cells originated just from provascular hypocotyl cells. Provascular cells acquired the embryogenic competence 48 h after induction and an intense mitotic division was observed and embryogenic structures were generated first along the vascular strands, which subsequently evolved into somatic embryos. After 2 weeks, there were observed embryos at different stages of development (preglobular, globular, heart-shaped, torpedo-shaped, and cotyledonary). This is the first report dealing with the ontogenesis of the direct somatic embryogenesis of C. chinense , and it is the most complete histological characterization carried out on somatic embryogenesis in the Capsicum genus to date.

La producción de piña (Ananas comosus L.) por métodos convencionales está limitada principalmente por la falta de disponibilidad de retoños de alto rendimiento. Sin embargo, se ha demostrado que por medio de metodologías de propagación in vitro como la embriogénesis somática y organogénesis, es posible obtener plantas de alto rendimiento de una manera más eficiente y controlable. El objetivo de este estudio consistió en generar un protocolo eficiente de micropropagación de piña criolla (Ananas comosus L.) para la multiplicación y conservación in vitro de esta especie, el estudio se llevó a cabo en 2021. Se evaluó la respuesta morfogénica de la piña criolla a partir de diferentes explantes (meristemo apical y hoja), cultivados en medio de cultivo Murashige y Skoog (MS) suplementado con diversos reguladores de crecimiento: ácido naftalenacético (ANA) (0.5, 1 y 1.5 mg L-1), 6-bencilaminopurina (BAP) (1, 2 y 3 mg L-1) y ácido 2,4-diclorofenoxiacético (2,4-D) (1, 2 y 4.5 mg L-1), así como un tratamiento control libre de reguladores. Los resultados mostraron que de los explantes evaluados la mejor respuesta se observó en el meristemo apical, en el cuales se obtuvo la formación de brotes adventicios a los 60 días del tratamiento de inducción, cuando el medio de cultivo fue suplementado con BAP a una concentración de 2 mg L-1 obteniéndose ocho brotes/explante. El protocolo desarrollado es un estudio clave para la propagación masiva de piña criolla.

The effect of NaCI salinity on growth and development of somatic embryos of Habanero pepper was examined. Addition of 75 and 100 m m NaCI into the medium greatly increased the growth and development of somatic embryos and both of these concentrations favored the proliferation of somatic embryos. However, supplementation of 200 and 300 m m NaCI to the medium showed a negative effect on the growth and development of somatic embryos. Concentration increases of NaCl provoked a significant reduction of the embryos survival rate with the average lethal dose (46%) being registered in the treatment of 100 m m . Furthermore, a lower tolerance to salt stress (NaCl) was observed in deformed somatic embryos. Concentrations of 200 and 300 m m NaCl significantly delayed development in the surviving embryos in both treatments. These embryos remained at the globular stage throughout culture time. At 75 m m NaCl, most of the embryos were observed in the torpedo stage. However, the embryos exposed to 100 m m NaCl were observed mainly in globular and cotiledonar stages. It is quite likely that the transition from one intermediate stage of development to another occurs rapidly. With the exception of the concentration at 300 m m NaCl, salt stress stimulated embryonic germination, particularly at 100 m m NaCl. The content of proline in somatic embryos increased substantially in response to salinization. The results suggest that somatic embryos of C. chinense can tolerate concentrations of NaCl up to 100 m m without their development being affected. Moreover, they have sufficient cellular mechanisms to tolerate salinity at relatively higher levels.