We have analysed the genetic diversity of South and Central American (SCA) goats by partially sequencing the mitochondrial control region of 93 individuals with a wide geographical distribution. Nucleotide and haplotype diversities reached values of 0.020 +/- 0.00081 and 0.963 +/- 0.0012 respectively. We have also observed a rather weak phylogeographic structure, with almost 69% of genetic variation included in the within-breed variance component. The topology of a median-joining network analysis including 286 European, Iberian, Atlantic and SCA mitochondrial sequences was very complex, with most of the haplotypes forming part of independent small clusters. SCA sequences showed a scattered distribution throughout the network, and clustering with Spanish and Portuguese sequences occurred only occasionally, not allowing the distinguishing of a clear Iberian signature. Conversely, we found a prominent cluster including Canarian, Chilean, Argentinian and Bolivian mitochondrial haplotypes. This result was independently confirmed by constructing a Bayesian phylogenetic tree (posterior probability of 0.97). Sharing of mitochondrial haplotypes by SCA and Canarian goats suggests that goat populations from the Atlantic archipelagos, where Spanish and Portuguese ships en route to the New World used to stow food and supplies, participated in the foundation of SCA caprine breeds.

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This is the first study to isolate, identify and characterize Streptococcus iniae as the causative disease agent in two tilapia (Oreochromis aureus) populations. The populations were geographically isolated, of distinct origins, and did not share water sources. Affected fish showed various external (e.g., exophthalmia and cachexia, among others) and internal (e.g., granulomatous septicaemia and interstitial nephritis, among others) signs. All internal organ samples produced pure cultures, two of which (one from each farm, termed S-1 and S-2) were subjected to biochemical, PCR and 16S rRNA sequencing (99.5% similarity) analyses, confirming S. iniae identification. The two isolates presented genetic homogeneity regardless of technique (i.e., RAPD, REP-PCR and ERIC-PCR analyses). Pathogenic potentials were assessed through intraperitoneal injection challenges in rainbow trout (Oncorhynchus mykiss) and zebrafish (Danio rerio). Rainbow trout mortalities were respectively 40% and 70% at 10 and 10 CFU per fish with the S-1 isolate, while 100% mortality rates were recorded in zebrafish at 10 and 10 CFU per fish with the S-2 isolate. The obtained data clearly indicate a relationship between intensified aquaculture activities in Mexico and new disease appearances. Future studies should establish clinical significances for the tilapia industry.

The subtribe Otachyriinae was established, within tribe Paniceae, by Butzin in 1970, originally including 18 genera. Recent phylogenetic studies, based on molecular data, indicated that Otachyriinae belongs to tribe Paspaleae and is represented by the genera Anthaenantia, Hymenachne, Dallwatsonia, Otachyrium, species of Panicum sect. Laxa, Plagiantha, and Steinchisma. These taxa show a peculiar diversity in photosynthetic types, including C 4 species, C 3 -C 4 intermediates and C 3 species. The internal evolutionary relationships among members of Otachyriinae have not yet been explored in detail. With the aim of providing new evidence to understand phylogenetic relationships of taxa included in Otachyriinae, 21 new sequences of the ndhF gene from 34 species were generated and analyzed using Bayesian inference and maximum parsimony (MP). The evolution of photosynthetic pathway was studied employing MP, Markov chain Monte Carlo, and maximum likelihood methods. Our results confirm that subtribe Otachyriinae is monophyletic. Within the subtribe, Anthaenanthia is a monophyletic C 4 genus and is sister to the remaining species included in this treatment. Hymenachne and Panicum sect. Laxa, in its traditional concept, are polyphyletic; Dallwatsonia, P. auritum, and P. hemitomon are treated within Hymenachne, while three species of Panicum sect. Laxa are considered a new genus in the subtribe. The genus Otachyrium is paraphyletic, while all species of Steinchisma are recovered as a monophyletic group with high support. Finally, our data suggest that C 4 and C 3 -C 4 photosynthesis evolved just once each during the speciation of the subtribe from a C 3 ancestor.

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The cosmopolitan species Hymenophyllum tunbrigense was traditionally represented in southern South America by two allopatric varieties: H. tunbrigense var. tunbrigense in the Andean Patagonian forests of Argentina and Chile, and H. tunbrigense var. cordobense, an endemic taxon restricted to the mountain system of central and north-western Argentina. Given the diagnosable differences between these two taxa, and between these taxa and the European and African entity, based on morphological, anatomical, molecular, ecological and distributional evidence, we exclude H. tunbrigense for Southern Cone, propose to revalidate the name Hymenophyllum asperulum for the species present in the Magellanic and Valdivian forests and elevate H. tunbrigense var. cordobense to species rank. We consider these two taxa as endemic species, closely related to the widespread H. tunbrigense. We also cite Hymenophyllum cordobense for first time for the flora of Bolivia.

The structure of the synflorescence and the flowering units in Amaranthaceae are characterized. The synflorescence is polytelic. In the flowering unit we recognize the main florescence and the enrichment zone. The florescences may consist of: (1) Fully developed partial florescences bearing three or more flowers; (2) Partial florescences reduced to one or a few fertile flowers having prophylls with more or less modified axillary productions; or (3) No partial florescences but solitary flowers having prophylls with no axillary productions. We described the flowering unit in species with florescences bearing a solitary flower and the flowering unit in species with florescences bearing partial florescences. Hypothesized developmental processes are described, with a view to finding relationships among different models characterized in the family as well as defining characters for cladistic studies, which may be useful to depict all the variations observed.