Microcutting culture and morpho-physiological changes during acclimation in two Lycium chilense cytotypes.

Lycium chilense, a deciduous perennial shrub, is one of the endangered native species of Patagonia due to sheep overgrazing. Chances of recolonization by seeds are scarce due to the limited density of propagules in the soil and very specific requirements for germination. The objective was to develop an in vitro propagation protocol that would help to perform reestablishment of this species in degraded areas of the Patagonian steppe. Seeds came from two provenances with different somatic number due to differences in ploidy level. Defoliated microcuttings were planted in test tubes with different growing media and taken to a growth chamber. Rooting percentage did not differ between origins, but higher values were encountered for medium without hormones. Subcultures increased significantly rooting percentage and reduced time to rooting. The leaves from micropropagated plants were thinner, did not exhibit hairs, and had poorly developed palisade parenchyma and less epicuticular waxes. In vitro leaves had lower stomatal density and their stomata were less functional when compared to acclimated leaves. A repopulation program of Lycium chilense based on microcutting culture, specially using subcultures, is feasible.