Morphological and physiological studies of the foliar embryos of Kalanchoe pinnata Pers

Abstract

One of the outstanding features of Kalanchoe pinnata Pers. is the formation of foliar embryos in the sinuses of the leaves. The embryos will erupt, under the proper conditions, forming a plant with typical roots, stems, and leaves. During development, the foliar embryos pass through three stages; a meristematic patch, a foliar embryo, and eruption. Embryogenesis was correlated with the development of the leaf sinus. The embryo was initiated from 3 to 4 tiers of cells adjacent to the leaf epidermis at the base of a sinus when the leaf was approximately 3 mm in length. Mitotic activity in these cells resulted in the formation of a meristematic patch of cells. When the leaf was approximately 12 mm long, the patch entered a quiescent phase during which the patch enlarged very slowly. In leaves 60 to 88 mm long, rapid foliar embryo development occurred. The patch bulged into the sinus. Two leaf primordia and an apical meristem were initiated on the exposed surface of the patch when the leaf was approximately 70 mm long. Shortly thereafter, two root primordia were initiated from the lower surface of the patch embedded in the parent leaf. The roots projected toward the lower epidermis of the parent leaf. ...