Anatomía comparada de plantas de Dioscorea alata L. clon Caraqueño cultivadas en tres ambientes de crecimiento in vitro

The in vitro conservation of Dioscorea alata L. clone Caraqueno is fundamental to guarantee the propagation and distribution of healthy plantation material to the farmers and the establishment of one in vitro bank of this clone of great agronomic and commercial value in the Oriental Region of Cuba. With the purpose of evaluating the anatomical modifications that take place in yam plants under three in vitro culture conditions: conserved plants by slow growth, regenerated plants and in plants multiplication phase in MS 75% medium, was carried out an analysis of the foliar and caulinar anatomy from transversal cuts of the foliar sheet and of the stem, and longitudinal and transversal cuts of microtubers formed during the conservation process. Smaller thickness of the mesophyll and of the epidermis in the leaves of the conserved plants were showed and the conductive sheaves area of the stem were also smaller, due to the stress process during the in vitro conservation. However during the recovery of the conserved material through the regeneration and the in vitro multiplication were reestablished to their normal state these parameters. It was also evidenced that the microtubers formed in the in vitro conservation, have reserve parenchyma with abundant starch granules, thin cortical parenchyma and conductive sheaves little developed were determined. All this characteristics indicated the presence of meristematic activity. Key words: Anatomical characterization; In vitro conservation; In vitro tubers; Nodal cutting; Yam