Encapsulation of lateral buds of Hancornia speciosa

Abstract

Hancornia speciosa Gomes gives a fruit of great potential for many regions in Brazil. However, the low germination percentage and the recalcitrance of its seeds are a limitation factor of the productivity, influencing conventional conservation and the availability of plant material. Thus, the use of a technique to produce in vitro explants encapsulated aims to regenerate and achieve a large scale production of H. speciosa seedlings, with an important supply to the micropropagation and germplasm conservation. The aim of this work was to establish the encapsulation protocol for lateral buds of H. speciosa. Shoots previously multiplied in vitro in WPM culture medium were used as the explant source. Lateral buds were immersed in WPM supplemented with 30 g L-1 sucrose, 0.4 g L-1 PVP and 2.5% sodium alginate, with or without 0.2 μM BAP. Thereafter, explants were individually recovered and dropped into calcium chloride solution (100 mM), where they stayed for 20 min, characterizing the complexation stage. Subsequently, capsules were immersed during 15 min in potassium nitrate solution (100 mM) for decomplexation before being transferred to bud regeneration conditions. The data recorded after 30 days of cultivation were relevant to the bud regeneration efficiency and the shoot regrowth. Higher survival rate (86%) was observed in WPM supplied with 0.2 μM BAP, there was also significant differences for the average length of shoots (7.4 cm) as well as for the average number of leaves per shoots (8.5). Results obtained in encapsulated lateral bud regeneration supports the conservation techniques like encapsulation-dehydration and encapsulation-vitrification.