Somatic embryogenesis of Byrsonima intermedia A. Juss.: induction and maturation via indirect approach

Abstract

Byrsonima, especially the species Byrsonima intermedia, is an endangered Brazilian plant that has been widely used as food and for its therapeutic characteristics. However, this species faces challenges with sexual propagation, and somatic embryogenesis has emerged as a viable alternative option for propagation. Therefore, this study aimed to establish a protocol for inducing somatic embryogenesis in B. intermedia. For the induction of callus from in vitro seedling leaves, different subcultures (three subcultures, 60 days each) and concentrations of different cytokinins (BAP, TDZ, Kin and ZEA) combined with varying NAA solutions were tested. Different concentrations of NAA were also analyzed in the induction of pro-embryogenic calli. For the induction of embryogenic calli and somatic embryos, the pro-embryogenic calli were subcultured on MS medium without adding growth regulators. The somatic embryos that originated were inoculated on a maturation medium containing different concentrations of gibberellic acid (GA3). The formation of secondary embryos was also analyzed using different concentrations (0, 2.88, and 8.66 µM) of GA3 and different types of lids (Conventional lid, Biossama® commercial lid and conventional lid with membranes). The results show that for the induction of somatic embryos, the use of kinetin with NAA presented the formation of somatic embryos in the second (4.76 µM CIN + 0.54 µM NAA) and third (5.17 µM CIN + 10.54 µM NAA) subcultures. The use of 28.87 µM GA3 favored the formation of seedlings. The Biossama lid and 2.88 µM GA3 showed higher formation of secondary embryos.