Species hybridization in Trifolium

This investigation confirms the existence of a high degree of incompatibility between species of Trifolium. Two techniques were developed in an attempt to overcome the barriers to hybridization. The first deals with the use of grafting as a screening technique for compatible genotypes, and the second is an embryo culture method for salvaging hybrid embryos which would otherwise abort. The value of these methods is discussed, and the results are compared with those from hybridizations of non-grafted material and of seed set without artificial embryo culture. Hybrids were obtained from three species combinations at different levels of ploidy.     

Comparing genetic diversity in agroforestry systems with natural forest: a case study of the important timber tree Vitex fischeri in central Kenya

It is possible that current tree domestication practices undertaken by farmers reduce the genetic base of tree resources on farms, raising concerns regarding the productivity, sustainability and conservation value of agroforestry ecosystems. Here, we assessed possible changes in genetic variation during domestication in the important and heavily utilised timber species, Vitex fischeri Gürke (syn. Vitex keniensis), by comparing geographically proximate forest and farm material in central Kenya. Employing RAPD analysis, a total of 104 polymorphic markers revealed by five arbitrary primers were scored in a total of 65 individuals, 32 from forest and 33 from farmland. Despite concerns of possible genetic erosion, forest and farm stands did not differ significantly in levels of genetic variation, with H values of 0.278 and 0.269, respectively. However, Mantel tests did reveal greater geographically related associative genetic structure among individuals in farm rather than forest material, with r _M values of 0.217 and 0.114, respectively. A more detailed analysis of structure suggested this could be due to local variation in origin of some on-farm trees. Implications of data for the genetic management of V. fischeri stands during farmer-led tree domestication activities are discussed. At present, there appears little reason to reject on-farm V. fischeri as a source of germplasm for future on-farm planting or for conservation purposes, although this situation may change and will require monitoring.     

Global parasite and Rattus rodent invasions: The consequences for rodent‐borne diseases

We summarize the current knowledge on parasitism‐related invasion processes of the globally invasive Rattus lineages, originating from Asia, and how these invasions have impacted the local epidemiology of rodent‐borne diseases. Parasites play an important role in the invasion processes and successes of their hosts through multiple biological mechanisms such as “parasite release,” “immunocompetence advantage,” “biotic resistance” and “novel weapon.” Parasites may also greatly increase the impact of invasions by spillover of parasites and other pathogens, introduced with invasive hosts, into new hosts, potentially leading to novel emerging diseases. Another potential impact is the ability of the invader to amplify local parasites by spillback. In both cases, local fauna and humans may be exposed to new health risks, which may decrease biodiversity and potentially cause increases in human morbidity and mortality. Here we review the current knowledge on these processes and propose some research priorities.     

A Quantitative Assay Using Mycelial Fragments to Assess Virulence of Mycosphaerella fijiensis

ABSTRACT We describe a method to evaluate the virulence of Mycosphaerella fijiensis, the causal agent of black leaf streak disease (BLSD) of banana and plantain. The method is based on the delivery of weighed slurries of fragmented mycelia by camel's hair brush to 5-by-5-cm areas on the abaxial surface of banana leaf blades. Reliable BLSD development was attained in an environmental growth chamber with stringent lighting and humidity controls. By localizing inoculum onto small areas of large leaves, we achieved a dramatic increase in the number of strains that can be tested on each leaf and plant, which is critical for comparing the virulence of numerous strains concurrently. Image analysis software was used to measure the percentage of each inoculated leaf section showing BLSD symptoms over time. We demonstrated that the level of disease of four isolates was correlated with the weight of the mycelium applied and relatively insensitive to the degree of fragmentation of hyphae. This is the first report demonstrating that weighed mycelial inoculum, combined with image analysis software to measure disease severity, can be used to quantitatively assess the virulence of M. fijiensis under rigorously controlled environmental conditions.     

The use of medetomidine-based sedation protocols to perform urohydropropulsion and cystoscopy in the dog

Voiding urohydropropulsion and cystoscopy are routine procedures performed in the dog for diagnostic and therapeutic purposes. These procedures are typically performed under general anesthesia. The purpose of this study was to describe the use of medetomidine-based sedation protocols to perform voiding urohydropropulsion and cystoscopy in cardiovascularly healthy, non-diabetic dogs without evidence of urinary obstruction, renal disease, or hepatic disease. Results of this study revealed significantly shorter procedure times and decreased cost in sedated dogs, with diagnostic and therapeutic outcomes equivalent to those of patients that underwent general anesthesia. Based on the results of this retrospective study, the authors recommend medetomidine-based sedation protocols for voiding urohydropropulsion and cystoscopy in appropriately selected patients.     

Clinical findings related to intramammary infections in meat-producing ewes

The aim of this study was to investigate the relationship between clinical findings and bacterial isolation in milk samples of meat-producing ewes. The study was conducted in 17 commercial flocks and 550 udder halves from suckling Santa Ines ewes. Initially, the clinical examination of the mammary glands and teats was performed by visual inspection and palpation of the teats and udder halves; then a scoring system was devised for all the findings. After that, the strip cup test and the California mastitis test (CMT) were performed. Then, milk samples for somatic cell counts (SCCs) and bacteriological analyses were collected. Staphylococci bacteria were the main etiological agent isolated in the present study. Upon investigation of the correlations between bacterial isolation and the clinical findings, only the presence of teat injury, pendulous udder, and alterations in the palpation of the teat were associated with bacterial isolation. A significant correlation between bacteriologically positive milk samples and CMT and SCC was also found. Thus, some clinical findings appeared as a risk factor for bacteriologically positive milk samples and can be used as a tool in mastitis control programs. However, a complete and extensive diagnosis, an appropriate therapy, and an efficient mastitis control program will require the combination of clinical examination, microbiological tests, and SCC.     

First report of Porcine teschovirus (PTV), Porcine sapelovirus (PSV) and Enterovirus G (EV-G) in pig herds of Brazil

Porcine teschovirus (PTV), Porcine sapelovirus (PSV) and Enterovirus G (EV-G) have been associated with enteric, respiratory, reproductive and neurological disorders. Although Brazil is the world’s fourth largest producer and exporter of pork, no information on the occurrence of PTV, PSV and EV-G infections is available for Brazilian pig herds. This study aimed to investigate the occurrence of Porcine enteric picornavirus infections in pig farms located in three distinct geographical regions of Brazil. Forty randomly selected diarrhoeic and normal consistency faeces of suckling (n?=?22) and nursery (n?=?18) pigs from farms located in 21 distinct cities of the Southern, Southeast, and Midwest regions of Brazil were evaluated by nested-RT-PCR assays. Suckling piglets presented the expected amplicon size for PTV (158 bp) and EV-G (313 bp) in single and mixed infections in 40.9 % (9/22) of the faecal samples. PSV amplicon (212 bp) was not detected in this age group. For nursery pigs, Porcine enteric picornaviruses amplicons were present in 77.8 % (14/18) of the faecal samples. PTV and EV-G were detected in single and mixed infections, while PSV was detected only in two samples in co-infection with PTV and EV-G in this age group. The Brazilian regions evaluated presented at least two of the tested viruses. Sequencing analysis revealed high similarities to the related viruses (95.3 to 99.2 % for PTV, 94.2 to 98.5 % for PSV and 86 to 100 % for EV-G). For the first time PTV, PSV and EV-G have been molecularly detected and characterised in pig faecal samples in Brazil.     

Spillover effects of a Mediterranean marine protected area on the European spiny lobster Palinurus elephas (Fabricius, 1787) resource

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