Interploidy hybridization in sympatric zones: the formation of Epidendrum fulgens 3 E. puniceoluteum hybrids (Epidendroideae, Orchidaceae) Ana P. Moraes1,2, Mariana Chinaglia1, Clarisse Palma-Silva3 &Fabio Pinheiro4 1Laboratorio de Biossistematica e Evolucßao~ de Plantas, Departamento de Biologia Vegetal, Instituto de Biologia, Universidade Estadual de Campinas/UNICAMP, Campinas, Sao~ Paulo, Brasil 2Programa de Po´ s Graduac¸a˜ o em Evoluc¸a˜ o e Diversidade, Universidade Federal do ABC/UFABC, Santo Andre, Sao~ Paulo, Brasil 3Departamento de Ecologia, Instituto de Biologia, Universidade Estadual Paulista/UNESP, Rio Claro, Sao~ Paulo, Brasil 4Instituto de Botanica,^ Nucleo de Pesquisas do Orquidario do Estado, Sao~ Paulo, Brasil Keywords Abstract Epidendrum, GISH, hybrid zone, interploidy crossing, karyotype, orchids, plant speciation. Interspecific hybridization is a primary cause of extensive morphological and chromosomal variation and plays an important role in plant species diversifi- Correspondence cation. However, the role of interploidal hybridization in the formation of Ana P. Moraes, Programa de Po´ s Graduac¸a˜ o hybrid swarms is less clear. Epidendrum encompasses wide variation in chro- em Evoluc¸a˜ o e Diversidade, Universidade mosome number and lacks strong premating barriers, making the genus a Federal do ABC/UFABC, Avenida dos Estados, good model for clarifying the role of chromosomes in postzygotic barriers in 5001. Bairro Bangu, Santo Andre´ ,Sa˜ o Paulo, interploidal hybrids. In this sense, hybrids from the interploidal sympatric CEP 09210-580, Brasil. Tel: +55 11 4996 = = = = 7960; Fax: +55 11 4996 0090; zone between E. fulgens (2n 2x 24) and E. puniceoluteum (2n 4x 56) E-mail:
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