Systematic relevance of the pollen morphology for the Rondeletia complex (Cinchonoideae, Rubiaceae)
Por:
Torres-Montúfar A., Ramírez-Arriaga E., Martínez-Hernández E., Ochoterena H.
Publicada:
1 ene 2020
Resumen:
Seventeen morphologically related genera have been considered as the Rondeletia complex, traditionally in Rondeletieae. Molecular studies agree that this is a polyphyletic group and some genera have been transferred to Guettardeae. Nevertheless, no solid morphological characters support this hypothesis. Our aim is to explore pollen morphology to see if this source of characters has systematic value. Our study uses light and scanning electron microscopy for 30 species of both tribes representing 14 genera. The most important characters are polar outline, endoaperture type and nexine discontinuities. Our results do not permit diagnosis of tribes, but they show that the genera formerly included in the Rondeletia complex, but now placed in Guettardeae, have nexine discontinuities in polar areas: endofissures (Rogiera) or endocracks (Arachnothryx complex: Arachnothryx-Gonzalagunia-Javorkaea-Renistipula). Palynological data also confirm a close relationship of Rondeletia with Stevensia, corroborating their synonymy, and of Arachnothryx with Gonzalagunia-Javorkaea-Renistipula, providing evidence of their close relationship. We conclude that pollen is a useful source of characters for supporting main lineages, but further research is still necessary for other genera, including Blepharidium, Machaonia, Mazaea and additional Rondeletia spp.We thank the Programa de Posgrado en Ciencias Biologicas, Universidad Nacional Autónoma de México (UNAM) for a graduate scholarship. The first author would like to thank the Consejo Nacional de Ciencia y Tecnologia (CONACYT) for the Doctoral scholarship of the Programa Nacional de Posgrados de Calidad (grant 239869). We thank Margarita Reyes Salas for taking SEM photographs and Teresa M. González Cruz for preparing some of the acetolized pollen slides. In addition, special thanks to S.H. Ponce Wainer for revising and proofreading the first English version of this paper. All authors declare no conflict of interest in regard to the content of this manuscript. © 2020 The Linnean Society of London, Botanical Journal of the Linnean Society, 2020, 194, 290-307
Filiaciones:
Torres-Montúfar A.:
Herbario FES-Cuautitlán, Departamento de Ciencias Biológicas, Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de México (FESC-UNAM), Carretera Cuautitlán Teoloyucan 2.5, San Sebastián Xhala, Cuautitlán Izcalli, C.P. 54714, Mexico
Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, A.P. 70-367, México, Cd. Mx., C.P. 04510, Mexico
Ramírez-Arriaga E.:
Laboratorio de Palinología, Departamento de Paleontología, Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, Cd. Mx., C.P. 04510, Mexico
Martínez-Hernández E.:
Laboratorio de Palinología, Departamento de Paleontología, Instituto de Geología, Universidad Nacional Autónoma de México, Ciudad Universitaria, México, Cd. Mx., C.P. 04510, Mexico
Ochoterena H.:
Departamento de Botánica, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, A.P. 70-367, México, Cd. Mx., C.P. 04510, Mexico
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