Clearly distinct chromosome numbers allied to monophyly provide some support for a circumscription of the Bombacoideae and distinction within the Malvaceae. The phylogenetic signal for chromosome number supports the idea of an ancient WGD and further neopolyploidy events as important evolutionary trends for the Bombacoideae.

Approximately 70% of the angiosperm species are polyploid, an important phenomenon in the evolution of those plants. But ploidy estimates have often been hindered because of the small size and large number of chromosomes in many tropical groups. Since polyploidy affects cell size, morphometric analyses of pollen grains and stomata have been used to infer ploidy level. Polyploidy is present in many species of the Cerrado, the Neotropical savanna region in Central Brazil, and has been linked to apomixis in some taxa. Eriotheca gracilipes and Eriotheca pubescens are common tree species in this region, and present cytotypes that form reproductive mosaics. Hexaploid individuals (2n = 6x = 276) are polyembryonic and apomictic, while tetraploid and diploid individuals (2n = 2x = 92, 2n = 4x = 184) are sexual and monoembryonic. We tested whether morphometric analysis can be used to estimate ploidy levels in E. gracilipes and E. pubescens individuals. Pollen material from diploid and hexaploid individuals of E. gracilipes, and tetraploid and hexaploid individuals of E. pubescens, were fixed in 50% FAA, and expanded leaves were dried in silica gel. Pollen grains and stomata of at least five individuals from each population were measured. The results demonstrate that all measures were significantly different among cytotypes. Individuals with higher levels of ploidy (hexaploid) all presented measurements that were higher than those with lower levels (diploid and tetraploid). There was no overlap between ploidy levels in each species at 95% confidence interval. Thus, the size of the pollen grains and stomata are effective parameters for analysis of ploidy levels in E. gracilipes and E. pubescens.

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Neotropical Entomology 36(3): 454-458 (2007) Formigas Urbanas e o Transporte de Bactérias Nosocomiais RESUMO -Muitas espécies de formigas de comportamento sinantrópico que tiveram sucesso na dispersão em áreas urbanas podem causar problemas em hospitais ao atuarem como vetoras, transportando bactérias. Neste estudo, foram encontradas bactérias em formigas coletadas no Hospital de Clínicas da Universidade Federal de Uberlândia, no campus e em residências próximas. As formigas coletadas foram identificadas como Tapinoma melanocephalum (Fabricius) e Camponotus vittatus (Forel) (Hymenoptera: Formicidae) e as cepas bacterianas encontradas pertenciam ao grupo dos estafilococos coagulase positivos, estafilococos coagulase negativos e bacilos gram negativos, tendo sido encontradas cepas resistentes a antimicrobianos. O estudo de bactérias encontradas nas formigas e no ambiente mostrou que algumas formigas carreavam bactérias não isoladas do mesmo ambiente e com níveis de resistência mais elevados, evidenciando o potencial transmissor desses insetos. PALAVRAS-CHAVE: Infecção hospitalar, Tapinoma melanocephalum, Camponotus vittatus, vetorABSTRACT -Many ant species displaying synanthropic behavior that have successfully dispersed in urban areas can cause problems in hospitals by acting as bacterial vectors. In this study, we encountered bacteria on ants collected at the Universidade Federal de Uberlândia hospital, in the campus and at households nearby. The ants were identified as Tapinoma melanocephalum (Fabricius) and Camponotus vittatus (Forel) (Hymenoptera: Formicidae) and the bacterial strains found here belong to the group of the coagulase-positive staphylococcus, coagulase-negative staphylococcus and gram negative bacilli, including antimicrobial drug-resistant strains. An investigation of the bacteria found in the ants and in the environment revealed that some ants carried non-isolated bacteria from the same environment and with high levels of resistance, evidencing the transmission potential of these insects.

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