IBONE   05434
INSTITUTO DE BOTANICA DEL NORDESTE
Unidad Ejecutora - UE
artículos
Título:
Embryology in Helosis cayennensis (Balanophoraceae): Structure of Female Flowers, Fruit, Endosperm and Embryo
Autor/es:
GONZALEZ, ANA MARÍA; GONZALEZ, ANA MARÍA; SATO, HECTOR ARNALDO; SATO, HECTOR ARNALDO; MARAZZI, BRIGITTE; MARAZZI, BRIGITTE
Revista:
Plants
Editorial:
MDPI AG
Referencias:
Lugar: Basel; Año: 2019 vol. 8 p. 1 - 19
Resumen:
Abstract: Helosis cayennensis (Balanophoraceae s.str.) is a holoparasite characterised by aberrantvegetative bodies and tiny, reduced unisexual flowers. Here, we analysed the development of femaleflowers to elucidate their morpho-anatomy and the historical controversy on embryo sac formation.We also studied the developmental origin of inflorescences and the ontogeny of fruits, embryo andendosperm and discussed in a phylogenetic framework. Inflorescences were analysed by optical,fluorescence and scanning electron microscopy. Inflorescences of H. cayennensis arise endogenously.Female flowers lack perianth organs, thus only consist of the ovary, two styles and stigmata. Ovulesare undifferentiated; two megaspore mother cells develop inside a nucellar complex. The femalegametophyte, named Helosis-type, is a bisporic four-celled embryo sac, provided with a typical eggapparatus and a uni-nucleated central cell. Fertilization was not observed, yet a few-celled embryoand cellular endosperm developed. In sum, results confirm that, among Santalales holoparasites,Helosis is intermediate in the reduction series of its floral organs. Although perianth absence bestsupports the Balanophoraceae s.str. clade, our literature survey on female flower developmental dataacross Balanophoraceae s.l. highlights the many gaps that need to be filled to really understand thesefeatures in the light of new phylogenetic relationships.