Magalhaes 2012 (Article) Tillandsioideae

Seed morphoanatomy and its systematic relevance to Tillandsioideae (Bromeliaceae)

Author(s):—R.I. Magalhães & J.E.A. Mariath

Publication:—Plant Systematics and Evolution 298: 1881-1895. (2012)

Abstract:—The morphoanatomy of mature seeds of 14 species, representing Vriesea and Tillandsia genera, was investigated in light and scanning electron microscopy to establish structural patterns of the seed coat, endosperm and embryo, allowing the distinction between both genera and contributing to the systematic of Tillandsioideae. All species studied have basal plumose appendages in a para- chute-like arrangement. In Vriesea , the embryo occupies about 1/3 of the seed, and the rest is filled by the endo- sperm. In Tillandsia , the area occupied by the embryo within the seed varies according to the species analyzed. The reserves stored in the endosperm and in the embryo differ considerably: both between Vriesea and Tillandsia genera and among Tillandsia species. In the median region of the hypocotyl-radicle axis of Tillandsia embryo, there is a constriction zone that separates the root portion from the rest of the embryo. This feature was not observed in Vriesea species. Our results indicate that few morphoana- tomical features of the mature seed coat are good for use in phylogenetic analysis, without considering the ontogenetic study of these structures. On the other hand, characteristics of the embryo and endosperm are very informative. They are useful to separate Vriesea and Tillandsia and also to distinguish groups of species within Tillandsia genus

Keywords:—Embryo  Poales  Monocots  Tillandsia  Vriesea