Improved Soybean Production after Inoculation with Bradyrhizobium japonicum

Fruit firmness testing of strawberries was carried out with five methods. Four instruments, Instron, Texture Analyser, penetrometer PNR10 (SUR Berlin) and Bareiss HHP-2001-Fff, were tested. In addition "Eisenhuth's method" was tried, which involves putting the fruits into a cylinder, placing a load on the top and measuring the compression. Eisenhuth's method was found to be cheap, time-saving and easy to use, and is a promising method for firmness testing of strawberries. Bareiss is a small instrument, which was found to be easy and quick to use, and gave reliable results. The results were easily transmitted to a personal computer. Instron and Texture Analyser are good and advanced instruments with reliable results, but they are expensive, complicated and time-consuming. The PNR10 is quite easy to use but time-consuming, and the results showed large variations. Relatively large natural variability in strawberry firmness was found; therefore, the sample size should be at least 25 fruits. Strawberry fruit firmness was tested in 18 cultivars by two methods. Considerable cultivar differences were found and the ranking of the cultivars was different by the two methods. Large variations in fruit firmness and in soluble solids between individual fruits within samples were observed, especially for cv. 'Korona'. The correlations between firmness and soluble solids content were not significant. Small fruits tended to be firmer than large ones. Ripe fruits were softer than pink ones, but the difference was reduced during storage. The fruits were softer when the internal fruit temperature was 20°;C than at lower temperatures. Fruit colour measured by a Minolta Colorimeter showed smaller variations than in firmness and soluble solids. Only low correlations between colour and other fruit characteristics were found.     

Factors associated with long-term changes in distribution of black-tailed prairie dogs in northwestern Mexico

The area occupied by colonies of the black-tailed prairie dog (Cynomys ludovicianus; BTPD henceforth) in northwestern Mexico was dramatically reduced between 1988 and 2005. We conducted a quantitative assessment of the distributional changes of these BTPD colonies during the periods 1988–2000 and 2000–2005 focusing on the potential roles of plant biomass, landscape configuration, habitat loss, and habitat suitability. We used remote sensing and GIS tools to characterize habitat and landscape conditions at areas of extinction and persistence at the beginning of each period. Based on this information, we contrasted areas of extinction and persistence within single BTPD colonies, and used logistic regression to model extinction of entire colonies. The greatest levels of reduction, fragmentation and extinction of colonies occurred between 1988 and 2000. The trend of reduction continued between 2000 and 2005 because the largest colony became smaller and fragmented, driving the area down, however, the rest of the towns showed a marginal increase. During the first period, extinction of entire colonies was higher in smaller colonies occupying low-biomass areas. Both extinction models and raw data indicate that colony area lost to agriculture and urbanization was relatively low for both periods. Because the period exhibiting the highest colony area loss coincided with a severe period of drought (1994–1995), we hypothesized that an unusually high food shortage could be the driving force behind this generalized reduction in colonies. Our results suggest that BTPD populations are sensitive to size and isolation effects mainly in the context of severe drought. Because changes in precipitation have profound impacts on plant productivity and composition in arid ecosystems, BTPD populations at the southernmost edge of their geographic range are especially vulnerable to drought and desertification processes, and therefore to climate disruption.     

Loss of viability and vigour in the course of short-term storage of Pityrocarpa moniliformis seeds cannot be attributed to reserve degradation

New Forests - The quality of forest seeds may be maintained in the course of storage for their use in the restoration of degraded areas and the conservation of genetic resources. In this sense,...     

The CIDA-QUEST large-scale survey of Orion OB1: evidence for rapid disk dissipation in a dispersed stellar population

We are conducting a large-scale, multiepoch, optical photometric survey [Centro de Investigaciones de Astronomia-Quasar Equatorial Survey Team (CIDA-QUEST)] covering about 120 square degrees to identify the young low-mass stars in the Orion OB1 association. We present results for an area of 34 square degrees. Using photometric variability as our main selection criterion, as well as follow-up spectroscopy, we confirmed 168 previously unidentified pre-main sequence stars that are about 0.6 to 0.9 times the mass of the sun (Mo), with ages of about 1 million to 3 million years (Ori OB1b) and about 3 million to 10 million years (Ori OB1a). The low-mass stars are spatially coincident with the high-mass (at least 3 Mo) members of the associations. Indicators of disk accretion such as Halpha emission and near-infrared emission from dusty disks fall sharply from Ori OB1b to Ori OB1a, indicating that the time scale for disk dissipation and possibly the onset of planet formation is a few million years.     

Quantile regression for modelling the impact of climate in cork growth quantiles in Portugal

The annual growth and the thickness of cork are known to be highly variable between trees located in the same geographical location. Researching how climate variables affect different trees within the same site is a step forward for the management of cork production since current knowledge focusses only on the average tree response. Quantile regression methodology was applied for the first time to a large data set containing measurements of cork growth, sampled in 35 stands across the cork oak distribution area in Portugal. This methodology proved to be useful for testing the hypothesis raised: does climate affect differently the annual cork growth, and ultimately cork thickness of individual trees located in the same stand? Estimating the amount of cork produced by one stand that has the required thickness for the production of natural cork stoppers is essential to support cork oak management. However, no model, before this work, had been developed to provide managers with this information. A downward parabolic relationship between annual cork growth and annual precipitation was determined for all quantiles, with optimum annual average precipitation value ranging from 1103 to 1007 mm. April to August monthly temperatures, spring average temperature or summer average temperature, showed a negative relationship with annual cork growth, in particular for lower quantiles. Maximum annual temperature was shown to negatively affect annual cork thickness, in particular for the trees under the 6th quantile. The ratio between annual precipitation and average temperature, that define the Lang index (LI), showed a downward parabolic relationship with annual cork growth. Best cork growth conditions are found for Lang index values around 60, corresponding for the transition between semi-arid climate and humid climate. The application of the final model developed for estimating cork thickness of an eight years’ cork growth period allowed the prediction and mapping of the percentage of cork suitable for natural cork stopper production. It showed that higher values are expected in the Southern and Central coastal regions and along the Tagus River basin. The Northern coastal and mountain regions, characterised by Lang index values higher to 60 (humid climates), present lower estimated values for the percentage of cork suitable for natural cork stopper production. The estimated values are expected to be reduced under climate change scenarios in the Southern and Central coastal regions.

     

Antigenic characterization of Anaplasma marginale isolates from different regions of Brazil

Antigenic characterization of A. marginale isolates has contributed to identifying the presence of common and restricts epitopes of major surface proteins (MSPs). The data may improve vaccine development to protect against A. marginale isolates from different regions. Brazilian A. marginale isolates were characterized antigenically by Western blot with monoclonal antibodies (MAbs) against MSPs and rabbit anti-MSP-4 from Florida strain. Six A. marginale isolates from MS, MG (AUFV1), SP, PR-L1, PR-HV, RS and Florida strain were tested with ANA22B1 to MSP-1a, AMR36A6 to MSP-1b, ANAF19E2 to MSP-2, AMG75C1 and AMG76B2 to MSP-3 and ANAF16C1 to MSP-5. ANA22B1 recognized MSP-1a epitope in all A. marginale isolates, and reacted with polypeptides of different size ranging 46-105kDa. MSP2 was not detected in MS and SP isolates by ANAF19E2, and only PR-L1 and MG (AUFV1) isolates reacted with MAbs which recognize MSP3 epitope. MSP4 and MSP5 were detected in all A. marginale isolates analyzed. The results revealed conservation of MSP-1a and MSP-5 epitopes among all Brazilian isolates, and showed antigenic variability to MSP-1b, MSP-2 and MSP-3 proteins, agreeing with recent data about the genetic diversity found in the polimorphic multigene family responsible for these proteins.     

High seroprevalence of caseous lymphadenitis in Brazilian goat herds revealed by Corynebacterium pseudotuberculosis secreted proteins-based ELISA

We conducted a seroepidemiological survey to determine the prevalence of caseous lymphadenitis (CLA) in goat herds in Minas Gerais state, Brazil. Serum samples were collected from goats (n = 676) from 108 rural properties in 2001, covering most of the sub-regions of this ca. 586,500 square kilometer state. Antibodies against Corynebacterium pseudotuberculosis secreted proteins were detected by an indirect enzyme-linked immunosorbent assay (ELISA). Most of the animals (78.9%) tested positive for CLA; 98% of flocks presented at least one seropositive animal. Goats managed under an extensive production system had a significantly higher seroprevalence of CLA than those in intensive and semi-intensive operations. The age distribution of the animals in the flocks affected the prevalence of this disease; however, goat breed did not. We found seropositivity against C. pseudotuberculosis to be highly prevalent in these Brazilian goat herds; consequently, appropriate management practices for the control of CLA should be implemented.     

Threonine incorporation in tissues of growing broiler chickens using L-[15N] threonine

Most amino acid requirement trials appear for whole-body responses, but there is little information concerning amino acid incorporation in individual tissues, which may vary according to the age. L-[¹⁵N] threonine was used to evaluate its incorporation rate and distribution among broiler tissues in different ages. Seventy-two male broiler chickens were distributed into three different phases: starter (4 to 9 days old), grower (18 to 23 days old) and finisher phase (32 to 37 days old). L-[¹⁵N] threonine was added on balanced diets, and birds were fed for five days in each phase. Enriched samples of breast muscle, feathers, liver, jejunum and plasma were collected at 0, 6, 12, 24, 48, 72, 96 and 120 hr after fed birds with the tracer in each phase. In the tissues were analysed dry matter, nitrogen and stable nitrogen. The ¹⁵N isotope abundance according to the time was fitted into exponential or linear equations using a same intercept. The ratio of the steepness or slope coefficients was determined to compare the L-[¹⁵N] threonine incorporation according to the age. In addition, L-[¹⁵N] threonine mass balances were performed to assess the L-[¹⁵N] threonine distribution among the evaluated tissues. Except for feathers, the L-[¹⁵N] threonine incorporation rate decreased with ageing. Taking into account the L-[¹⁵N] threonine distribution in the tissues, only in the jejunum was not observed an increase as the broiler grew. The L-[¹⁵N] incorporation varied in each tissue and according to the age of the broiler chickens. These outcomes could be useful to comprehend changes in amino acid requirements tissue-specific according to age.