Breeding beans for resistance to terminal drought in the Lowland tropics

In the lowland regions of Latin America, a large proportion of beans are sown at the beginning of a dry season where a guaranteed terminal (end-of-season) drought will reduce yields. This study was undertaken to identify lines within two black bean recombinant inbred line (RIL) populations with resistance to terminal drought. The two RIL populations were developed from crosses between a drought resistant line, B98311 from Michigan, with TLP 19 and VAX 5, two lines from CIAT with improved disease resistance and adaptation to growing conditions in Latin America. The RIL populations were evaluated in experiments conducted in Zamorano, Honduras and Veracruz, Mexico under drought stress and well-watered (non-stress) treatments. Yields were reduced in each experiment by drought and the fungal pathogen, Macrophomina phaseolina. Drought stress, disease pressure and low yields contributed to high coefficients of variation (CV), which made it difficult to select superior lines. Selection was based on rank of geometric mean (GM) yield calculated from the yield in the stress and non-stress treatments. One RIL, L88-63 ranked first in GM yield at both locations. Subsequent testing in Honduras and Michigan confirmed the high yield potential and broad adaptation of L88-63. Breeding beans for drought resistance in lowland tropical environments should also include breeding for resistance to M. phaseolina. This revised version was published online in July 2006 with corrections to the Cover Date.     

Community patterns generated by human harvesting on Chilean shores: a review

1. The Chilean rocky coast has been exploited for food by coastal gatherers for at least 8500 years BP and probably was an important factor in how prehistoric people were able to colonize the South Americas Pacific Rim. The main species targeted in the past were the same as those today except that now the gatherers are resident and the fishing activity is more intense and persistent. 2. With many pertinent studies from around the world having been published on this topic, mostly conducted in Marine Reserves, this review tries to identify the main patterns that can help us recognize, in the Chilean intertidal, the degree of exploitation on wave exposed and wave protected rocky shore habitats. 3. Three clear patterns were identified depending on the trophic level adopted by the human gatherers in the food chain of the intertidal zone. First, when the humans act as herbivores, collecting the large laminarian Durvillaea antarctica, adult plants disappear from the accessible sites, especially the midlittoral, semi‐exposed and exposed habitats. 4. Second, when humans harvest the ecologically important herbivorous archeogastropoda Fissurella spp., this results in the red alga Mazzaella laminarioides covering almost 100% of the midlittoral rocks. Third, when humans become top predators by collecting the muricid carnivore Concholepas concholepas, then bivalves, mainly Perumytilus purpuratus, cover the rocks in multiple layers. 5. These patterns contribute to the evaluation of the state of conservation of the Chilean rocky intertidal shores, especially because the north and the south are beginning to be connected by a new coastal road. Thus it is necessary to evaluate urgently, on a large spatial scale, the state of conservation of these communities, in order to help select the appropriate places for establishing Marine Reserves. Copyright © 2001 John Wiley & Sons, Ltd.     

Milkfish seedling survival in raceways of freshwater recirculating systems

Wooden and concrete raceways in closed recirculating freshwater systems were tested for rearing milkfish (Chanos chanos) fry up to 2 to 3 cm total length. Artificially produced detritus and natural plankton were tested separately as food. Growth, health and survival were good for larvae supplied natural plankton, but poor for those reared on detritus.Precipitation, temperature and intensity of solar insolation had no adverse effects on the production of natural plankton cultivated in the outdoor closed systems. Fish growth was better in experiments in June–July than in August and September.The concrete raceways, 86 m³ at fixed water depth, could produce an estimated 405 000 viable seedlings of 2 to 3 cm length in a 10-month period. Average survival was 70%. Water flow in the raceways was 10 cm/s.     

Tetraploid bahiagrass hybrids: breeding technique,genetic variability and proportion of heterotic hybrids

Manipulating apomixis for fixing tetraploid bahiagrass (Paspalum notatum Flüggé) hybrids exhibiting superior agronomic characteristics would be a valuable tool for the genetic improvement of this species. The objectives were to create a second generation of hybrids by crossing sexual first-generation tetraploid hybrids (FGTH) and unrelated apomictic FGTH or ecotypes, determine the segregation for mode of reproduction, and estimate the resulting genetic variation and heterosis for several agronomic characteristics. The segregation for mode of reproduction was analyzed using mature embryo sac observations. Field measurements and visual ratings were used to evaluate the growth habit, production of inflorescences, cool-season growth and freeze resistance of hybrids. A ratio of 4.6:1 between sexual and apomictic hybrids was observed. Only 3% of the progeny was classified as highly apomictic. The low proportion of highly apomictic progeny restricts the feasibility of this breeding approach. Large genetic variation was observed among hybrids for growth habit, cool-season growth and freeze resistance. The proportion of hybrids exhibiting heterosis was high for plant height, cool-season growth, and freeze resistance. The tetraploid bahiagrass germplasm contains a large diversity for traits of agronomic importance that can be exploited for the genetic improvement of this species.     

Conservation of the purple gallinule (Porphyrio porphyrio L.) in Portugal: causes of decline, recovery and expansion

Historical data on the distribution and status of the purple gallinule (Porphyrio porphyrio) in Portugal were collected by bibliographic research, from museum catalogues and from questionnaires to wetland managers, ornithologists and birdwatchers. The population suffered severe decline and range contraction at the end of the 19th century and most of the 20th century, due mainly to habitat loss and degradation and excessive hunting. However, the population has begun to recover in the last decade mainly through direct protection of the species and of the remaining habitat, together with creation of artificial wetlands and a reintroduction programme, and probably also due to immigration from Spain. The population size has increased about 10-fold and the range has expanded to most of its former area. The estimated Portuguese breeding population in 2002 was 49-67 pairs. Densities varied between 0.05 and 7 individuals/ha in recently colonized areas and stable (saturated) areas, respectively. Although the population is recovering, its small size, high fragmentation and several natural and anthropogenic threats lead us to consider it still a species of major concern in Portugal.     

A review of some characteristics,socio-economic aspects and utilization of Zulu sheep: implications for conservation

Zulu sheep are Nguni sheep of Zululand and are adapted to the harsh conditions of KwaZulu-Natal. They are used by rural farmers for economic purposes. Their numbers are declining, indicating a potential extinction threat. Knowledge of their phenotypic and genotypic characteristics is essential for conservation planning. In this review, there is a focus on the utilization, socio-economic aspects, phenotypic and genotypic characteristics as well as a proposed breeding programme. A survey has shown that rural farmers in the areas of northern KwaZulu-Natal prefer to keep this breed for its adaptability, resistance to diseases and meat quality. Zulu sheep are small-framed multi-coloured animals. Mature males weigh up to 38 kg and females up to 32 kg. Based on four morphological traits and live weight, phenotypic diversity between three populations was estimated at 48%. A genetic diversity between these three populations was estimated at 22%. Live weight of Zulu sheep can be estimated using the heart girth and wither height measurements. Scrotum circumference of young rams (up to 22 months old) is reliable for estimating the live weight. Animals that were characterized in the studies were grazed extensively and no supplements were provided. There is therefore a potential of weight increase if these animals are reared in a semi-extensive environment. An open nucleus breeding scheme is thus recommended for a sustainable use and conservation of this breed. For more conclusive results, larger numbers of phenotypic and genetic characteristics, in larger numbers of Zulu sheep populations, should be investigated.     

Hepatic profile of Gallus gallus Linnaeus, 1758 experimentally infected by Plasmodium juxtanucleare Versiani & Gomes, 1941

One of the species that causes avian malaria is Plasmodium juxtanucleare. It is commonly found in poultry, especially when the birds receive food free of coccidiostats. Since industrial and organic poultry breeding is increasing in the world and few studies have been conducted examining the clinical parameters of both healthy and infected birds, this work evaluated whether the infection caused by P. juxtanucleare in Gallus gallus provokes alterations in the birds' hepatic profile. We analyzed the activity of ALT and AST and carried out histological analyses of liver sections of infected fowls by intracelomic inoculation with infected blood from a donor fowl with a parasite load of around 7%. The infected birds' parasite load was evaluated during 45 days by means of blood smears. There was a positive correlation between the increase in parasite load and higher ALT activity in the infected fowls, but there was no significant variation of the AST activity between the control and infected groups, possibly because of the non-specificity of this enzyme as an indicator of hepatic lesion. The results show that infection caused by P. juxtanucleare in G. gallus provokes hepatic alterations, indicated by the increase in the ALT enzyme activity and by the inflammatory infiltrates found in the liver sections of the infected fowls.     

Assessing the effects of a highway on a threatened species using Before–During–After and Before–During–After-Control–Impact designs

Due to the growing awareness of potential impacts of roads, managers demand well-designed studies about the implications of linear infrastructures on ecosystems. We illustrate the application of Before–During–After and Before–During–After-Control–Impact designs (BDA and BDACI) to assess effects of highway construction and operation using a population of great bustards (Otis tarda) as a model. Based on a time series of demographic and distribution data (1997–2009), we developed generalized additive models and classification trees to test the effect of road distance on bustard distribution, identify road-effect distances and explore the seasonality of these effects. Two control zones were selected to test the changes between construction phases on productivity, and population trends using TRIM models. From the start of the road construction, great bustards tended to avoid close proximity to the highway (ca. 560–750 m threshold distance). The exclusion band was narrower during the breeding season. In addition, family groups were less tolerant to highway operation disturbances, as shown by their higher distance effect (ca. 1300 m). Population trends did not differ between impact and control zones during the construction. However, once the highway was in operation, bustard numbers declined gradually up to 50% in the impact zone, remained stable in the closest control zone, and increased in the zone located at the greatest distance from the highway. The effects on density of family groups were less evident. Our approach provides information relevant to great bustard conservation and suggests methods for obtaining information of interest to road managers, that could be applied to linear infrastructures with others species.