Morphogenic Investigations on Parasitic Angiosperms. IV. Morphogenesis in Decotylated Embryos of Cassytha filiformis L. Lauraceae

Abstract

Investigations on in vitro culture of embryos of Cassytha filiformis, from which varying fractions of cotyledons were surgically severed in 11 patterns, have demonstrated that the larger the portion of cotyledons severed, the more adversely affected the shoot morphogenesis. The retention, with the embryo axis, of either the radicular half of both cotyledons, or the radicular half of one cotyledon together with more than one-half of the other cotyledon, was necessary for the expression of shoot morphogenesis. The retention of only the plumular half of one or both cotyledons inhibited shoot morphogenesis. Data on chemical regulation of morphogenesis of totally decotylated embryos showed that only coconut milk promoted shoot development in the explants, although to a limited degree. There was no evidence of the formation of a primary root in any of the treatments.