Alessandra Selbach Schnadelbach

Phylogeny of Calliandra (Leguminosae: Mimosoideae) based on nuclear and plastid molecular markers

We reconstructed phylogenetic relationships in Leguminosae subfam. Mimosoideae tribe Ingeae using 135 sequences from the nuclear (ITS) and 119 from the plastid (trnL-F) genome, representing 23 of the 36 currently recognized genera in the tribe with newly generated sequences of Blanchetiodendron, Guinetia, Macrosamanea, Thailentadopsis and Viguieranthus and an extensive sampling of Calliandra. Only two of the five Neotropical generic alliances of Barneby & Grimes (1996) were supported as monophyletic. Calliandra is resolved as monophyletic with the inclusion of Guinetia. The five previously proposed sections within Calliandra were not supported by our study. Nevertheless, based on these results, a new infrageneric classifica- tion is proposed for Calliandra, and the African species of the genus are assigned to a new genus, Afrocalliandra. Three new sections are proposed for Calliandra: (1) sect. Tsugoideae based on C. ser. Tsugoideae, with four species from northwestern South America; (2) sect. Septentrionales, with six species distributed in dry areas from the United States to Mexico and (3) sect. Monticola, which consists of species restricted to the Espinhaco range of Brazil; these latter species form a clade with low levels of sequence variation, a potential indicator of the recent diversification of this group.

A molecular phylogeny of Raddia and its allies within the tribe Olyreae (Poaceae, Bambusoideae) based on noncoding plastid and nuclear spacers.

The plastid spacer trnD-trnT and the nuclear ribosomal internal transcribed spacer (ITS) were sequenced for 37 samples of herbaceous bamboos (Poaceae: Olyreae), including all Raddia species and allied genera, as well as two members of the woody bamboos (tribes Bambuseae and Arundinarieae), in order to examine their relationships. The sequences were analyzed using maximum parsimony and Bayesian inference. Both the individual and combined analyses of ITS and trnD-trnT supported Olyreae as a monophyletic group. All species of Raddia also formed a well-supported monophyletic group, and combined datasets allowed us to outline some relationships within this group. Individual analyses indicated incongruence regarding the sister group of Raddia, with ITS data weakly indicating Raddiella malmeana whereas trnD-trnT data supported Sucrea maculata in this position. However, the combined analysis supported Sucrea as sister to Raddia, although the monophyly of Sucrea is not well supported. Parodiolyra is paraphyletic to Raddiella in all analyses; Olyra is also paraphyletic, with species of Lithachne, Arberella and Cryptochloa nested within it. Eremitis and Pariana appeared as an isolated clade within Olyreae, and the position of the New Guinean Buergersiochloa remains uncertain within this tribe.

Species delimitation and phylogenetic analyses of some cosmopolitan species of Hypnea (Rhodophyta) reveal synonyms and misapplied names to H. cervicornis, including a new species from brazil

Hypnea has an intricate nomenclatural history due to a wide pantropical distribution and considerable morphological variation. Recent molecular studies have provided further clarification on the systematics of the genus; however, species of uncertain affinities remain due to flawed taxonomic identification. Detailed analyses coupled with literature review indicated a strong relationship among H. aspera, H. cervicornis, H. flexicaulis, and H. tenuis, suggesting a need for further taxonomic studies. Here, we analyzed sequences from two molecular markers (COI‐5P and rbcL) and performed several DNA‐based delimitation methods (mBGD, ABGD, SPN, PTP and GMYC). These molecular approaches were contrasted with morphological and phylogenetic evidence from type specimens and/or topotype collections of related species under a conservative approach. Our results demonstrate that H. aspera and H. flexicaulis represent heterotypic synonyms of H. cervicornis and indicate the existence of a misidentified Hypnea species, widely distributed on the Brazilian coast, described here as a new species: H. brasiliensis. Finally, inconsistencies observed among our results based on six different species delimitation methods evidence the need for adequate sampling and marker choice for different methods.

Phylogenetic relationships of Echinolaena and Ichnanthus within Panicoideae (Poaceae) reveal two new genera of tropical grasses.

Echinolaena and Ichnanthus are two tropical grass genera distributed mostly in the Americas, characterized by the presence of rachilla appendages in the shape of convex swellings, scars or wings at the base of the upper anthecium. However, recent studies have shown that rachilla appendages arose several times independently in several groups within Paniceae and Paspaleae (Panicoideae). Thus, this study aimed to assess the monophyly of Echinolaena and Ichnanthus and their relationship to other genera of Paniceae and Paspaleae, especially those including species with rachilla appendages. Parsimony and Bayesian analyses of the cpDNA regions ndhF, rpl16, trnH-(rps19)-psbA, trnL-trnF, trnS-(psbZ)-trnG, and the rDNA ITS region included 29 of the 39 known species of Echinolaena and Ichnanthus, 23 of which were sampled for the first time. The multiple loci analyses indicated that Echinolaena and Ichnanthus are polyphyletic in their current circumscriptions, with species in four distinct lineages within subtribe Paspalinae, each one characterized by a single type of rachilla appendage. Thus, Echinolaena and Ichnanthus are each circumscribed in a narrow sense, and the other two lineages excluded from them are proposed as the new genera Hildaea and Oedochloa, resulting in 15 new combinations and the restablishment of I. oplismenoides Munro ex Döll.

Diversidade genética de Xylella fastidiosa em regiões produtoras de citros na Bahia

O objetivo deste trabalho foi avaliar, por meio de marcadores SSR, a diversidade genetica de Xylella fastidiosa no Estado da Bahia. Foram estudadas duas das principais regioes produtoras de citros no Estado, o Litoral Norte e o Reconcavo Sul. Para fins comparativos, utilizaram-se dez amostras provenientes do Estado de Sao Paulo. Foram empregados os seguintes iniciadores: ASSR20, OSSR9, OSSR17, CSSR4, CSSR12 e CSSR20, dos quais os quatro ultimos permitiram identificar 22 loci polimorficos. As populacoes de X. fastidiosa presentes em citros no Estado da Bahia apresentam elevada diversidade genetica, com base nos marcadores SSR, com pools genicos distintos e agrupamento geografico. No Litoral Norte, as populacoes do isolado apresentam maior diversidade genetica do que as da regiao do Reconcavo Sul da Bahia.