The origin of new roots from cut seeds of Eugenia species

Studies on seed germination in Eugenia species after embryo fractionation have demonstrated that cotyledon cells have capacity for de-differentiation and consequent production of roots. However, there is no information about the origin of those new roots. Thus, the aim of this study was to characterize anatomically the cotyledon regions of seeds of five species of Eugenia to elucidate the tissue that originates such roots. Seeds were sectioned across the hillum region and immediately placed to germinate. As soon as the fractions of these cut seeds develop roots they were fixed and processed to the usual techniques for light microscopy. The adventitious roots originated only when the seed was fractioned, never occurring spontaneously in uninjured seeds. Adventitious roots were formed from perivascular parenchyma cells, located close to the injured region of the cotyledons. These cells divided periclinally and proliferated, giving rise to a root meristem. Therefore, new seedlings probably have a different genome than the mother plant, but they would be identical to the embryo that was a result of fertilization.

Automated summary

Studies have shown that cotyledon cells in Eugenia species have the ability to de-differentiate and produce roots, but the origin of these new roots has not been determined. Anatomical analysis of cotyledon regions in five species of Eugenia revealed that adventitious roots form from perivascular parenchyma cells located near the injured area of the cotyledons. These findings suggest that new seedlings may have a different genome from the mother plant, but they are identical to the fertilized embryo.