La posición sistemática de Cubanthus y otras especies arbustivas endémicas de Euphorbia (Euphorbiaceae) en Cuba

Cubanthus (Euphorbiaceae) has traditionally been recognized as a small genus of three similar species restricted to Cuba and Hispaniola. In this study we used DNA sequence data from the nuclear ITS and chloroplast ndhF gene regions to investigate its systematic position and the position of four other shrubby Euphorbia species endemic to Cuba: E. cubensis, E. helenae, E. munizii, and E. podocarpifolia. The results demonstrate that all of these taxa belong to a well-supported Antillean clade nested within Euphorbia that also includes E. punicea and E. gymnonota. For that reason, we treat Cubanthus as a section of Euphorbia instead of a separate genus. Euphorbia sect. Adenorima is relegated to a synonym of sect. Cubanthus. New names are proposed for Cubanthus brittonii and Cubanthus linearifolius (Euphorbia millspaughii and E. scutiformis, respectively), and a new combination is made for Cubanthus umbelliformis (Euphorbia umbelliformis). Section Cubanthus belongs to clade C of Euphorbia and is part of a New World assemblage that includes members of sections Euphorbiastrum, Pteroneurae, Portulacastrum, Stachydium, and the former genus Pedilanthus. Based on both the molecular results and morphological differences, two subsections are proposed: subsect. Cubanthus and subsect. Moa. The molecular phylogeny supports the hypothesis that section Cubanthus radiated entirely within the Antilles and the nearby Bahamian archipelago.Cubanthus (Euphorbiaceae) ha sido tradicionalmente reconocido como un género de tres especies muy similares entre sí y endémicas de las islas de Cuba y La Española. En este estudio se emplearon datos de secuencias de ADN tanto nuclear (ITS) como del cloroplasto (ndhF) para investigar la posición sistemática de Cubanthus y de cuatro especies arbustivas de Euphorbia endémicas de Cuba: E. cubensis, E. helenae, E. munizii, y E. podocarpifolia. Los resultados muestran que todas las especies analizadas pertenecen a un clado Antillano anidado en Euphorbia, al cual también pertenecen E. punicea y E. gymnonota. Por tal razón, tratamos a Cubanthus como una sección de Euphorbia en lugar de un género distinto. Euphorbia sección Adenorima se relega como sinónimo de la sección Cubanthus. Se proponen nuevos nombres para Cubanthus brittonii y C. linearifolius (Euphorbia millspaughii y E. scutiformis, respectivamente) y una nueva combinación para Cubanthus umbelliformis (Euphorbia umbelliformis). La sección Cubanthus pertenece al clado C de Euphorbia y es parte de un grupo del Nuevo Mundo que incluye miembros de las secciones Euphorbiastrum, Pteroneurae, Portulacastrum, Stachydium y del anteriormente reconocido género Pedilanthus. Basado en los resultados moleculares y las diferencias morfológicas, se proponen dos subsecciones: subsección Cubanthus y subsección Moa. La filogenia molecular sustenta la hipótesis de que la sección Cubanthus surgió y se diversificó en Las Antillas y el Archipiélago de Las Bahamas

Expression of a rice chitinase gene in transgenic banana ('Gros Michel', AAA genome group) confers resistance to black leaf streak disease

Peer reviewe

Which Factors Determine Spatial Segregation in the South American Opossums (Didelphis aurita and D. albiventris)? An Ecological Niche Modelling and Geometric Morphometrics Approach

Didelphis albiventris and D. aurita are Neotropical marsupials that share a unique evolutionary history and both are largely distributed throughout South America, being primarily allopatric throughout their ranges. In the Araucaria moist forest of Southern Brazil these species are sympatric and they might potentially compete having similar ecology. For this reason, they are ideal biological models to address questions about ecological character displacement and how closely related species might share their geographic space. Little is known about how two morphologically similar species of marsupials may affect each other through competition, if by competitive exclusion and competitive release. We combined ecological niche modeling and geometric morphometrics to explore the possible effects of competition on their distributional ranges and skull morphology. Ecological niche modeling was used to predict their potential distribution and this method enabled us to identify a case of biotic exclusion where the habit generalist D. albiventris is excluded by the presence of the specialist D. aurita. The morphometric analyses show that a degree of shape discrimination occurs between the species, strengthened by allometric differences, which possibly allowed them to occupy marginally different feeding niches supplemented by behavioral shift in contact areas. Overlap in skull morphology is shown between sympatric and allopatric specimens and a significant, but weak, shift in shape occurs only in D. aurita in sympatric areas. This could be a residual evidence of a higher past competition between both species, when contact zones were possibly larger than today. Therefore, the specialist D. aurita acts a biotic barrier to D. albiventris when niche diversity is not available for coexistence. On the other hand, when there is niche diversification (e.g. habitat mosaic), both species are capable to coexist with a minimal competitive effect on the morphology of D. aurita

Habitat Associations of Juvenile Fish at Ningaloo Reef, Western Australia: The Importance of Coral and Algae

Habitat specificity plays a pivotal role in forming community patterns in coral reef fishes, yet considerable uncertainty remains as to the extent of this selectivity, particularly among newly settled recruits. Here we quantified habitat specificity of juvenile coral reef fish at three ecological levels; algal meadows vs. coral reefs, live vs. dead coral and among different coral morphologies. In total, 6979 individuals from 11 families and 56 species were censused along Ningaloo Reef, Western Australia. Juvenile fishes exhibited divergence in habitat use and specialization among species and at all study scales. Despite the close proximity of coral reef and algal meadows (10's of metres) 25 species were unique to coral reef habitats, and seven to algal meadows. Of the seven unique to algal meadows, several species are known to occupy coral reef habitat as adults, suggesting possible ontogenetic shifts in habitat use. Selectivity between live and dead coral was found to be species-specific. In particular, juvenile scarids were found predominantly on the skeletons of dead coral whereas many damsel and butterfly fishes were closely associated with live coral habitat. Among the coral dependent species, coral morphology played a key role in juvenile distribution. Corymbose corals supported a disproportionate number of coral species and individuals relative to their availability, whereas less complex shapes (i.e. massive & encrusting) were rarely used by juvenile fish. Habitat specialisation by juvenile species of ecological and fisheries importance, for a variety of habitat types, argues strongly for the careful conservation and management of multiple habitat types within marine parks, and indicates that the current emphasis on planning conservation using representative habitat areas is warranted. Furthermore, the close association of many juvenile fish with corals susceptible to climate change related disturbances suggests that identifying and protecting reefs resilient to this should be a conservation priority

Snake Bite in South Asia: A Review

Snake bite is one of the most neglected public health issues in poor rural communities living in the tropics. Because of serious misreporting, the true worldwide burden of snake bite is not known. South Asia is the world's most heavily affected region, due to its high population density, widespread agricultural activities, numerous venomous snake species and lack of functional snake bite control programs. Despite increasing knowledge of snake venoms' composition and mode of action, good understanding of clinical features of envenoming and sufficient production of antivenom by Indian manufacturers, snake bite management remains unsatisfactory in this region. Field diagnostic tests for snake species identification do not exist and treatment mainly relies on the administration of antivenoms that do not cover all of the important venomous snakes of the region. Care-givers need better training and supervision, and national guidelines should be fed by evidence-based data generated by well-designed research studies. Poorly informed rural populations often apply inappropriate first-aid measures and vital time is lost before the victim is transported to a treatment centre, where cost of treatment can constitute an additional hurdle. The deficiency of snake bite management in South Asia is multi-causal and requires joint collaborative efforts from researchers, antivenom manufacturers, policy makers, public health authorities and international funders

Genomics-assisted breeding in four major pulse crops of developing countries: present status and prospects

The global population is continuously increasing and is expected to reach nine billion by 2050. This huge population pressure will lead to severe shortage of food, natural resources and arable land. Such an alarming situation is most likely to arise in developing countries due to increase in the proportion of people suffering from protein and micronutrient malnutrition. Pulses being a primary and affordable source of proteins and minerals play a key role in alleviating the protein calorie malnutrition, micronutrient deficiencies and other undernourishment-related issues. Additionally, pulses are a vital source of livelihood generation for millions of resource-poor farmers practising agriculture in the semi-arid and sub-tropical regions. Limited success achieved through conventional breeding so far in most of the pulse crops will not be enough to feed the ever increasing population. In this context, genomics-assisted breeding (GAB) holds promise in enhancing the genetic gains. Though pulses have long been considered as orphan crops, recent advances in the area of pulse genomics are noteworthy, e.g. discovery of genome-wide genetic markers, high-throughput genotyping and sequencing platforms, high-density genetic linkage/QTL maps and, more importantly, the availability of whole-genome sequence. With genome sequence in hand, there is a great scope to apply genome-wide methods for trait mapping using association studies and to choose desirable genotypes via genomic selection. It is anticipated that GAB will speed up the progress of genetic improvement of pulses, leading to the rapid development of cultivars with higher yield, enhanced stress tolerance and wider adaptability