Characterization of pro-embryogenic calli and somatic embryogenesis of Byrsonima intermedia A. Juss.

Abstract

Byrsonima intermedia A. Juss. is a species from the Brazilian Cerrado that produces edible fruits and, in common with other species from the Byrsonima genus, has pharmacological potential. Previous attempts to propagate the species through conventional methods showed difficulties. Thus, the purpose of this work was to characterize pro-embryogenic masses of Byrsonima intermedia callus, aiming for their in vitro propagation through somatic embryogenesis. Leaf segments from in vitro germinated seedlings were employed as explants for callus production. The calli were then subcultured and exposed to dyes to fulfill their embryogenic potential. Digitalizations of the cytological preparations were made in order to measure the area that was stained by both Aceto-Carmine and Evans-Blue, using image tool software. Somatic embryos were induced after treatments with 1-naphthaleneacetic acid (NAA). The percentages of double-colored areas (by Aceto-Carmine and Evans-Blue) were calculated and the data were analyzed by using the Skott-Knott test (P ≤ 0.05) and, the embryogenic callus, as well as the formation of somatic embryos were analyzed by using the Krsuskal-Wallis rank test (P ≤ 0.05). The results show that double coloration is effective at identifying cells showing embryogenic potential. Early callus subculture phases show a larger percentage of embryogenic area (83%). Somatic embryos were induced by using high auxin level.