Frequency of a mutant allele of cytochrome b conferring resistance to Ool fungicides in the Czech population of Ramularia collo-cygni

Journal of Plant Diseases and Protection - Ramularia collo-cygni (RCC) is a fungal pathogen infecting both spring and winter barley and causing Ramularia leaf spot (RLS). Fungicides based on...     

Gene Identification and Reaction of Rice Varieties to Korean and Philippine Races of Xanthomonas oryzae. pv. Oryzae

Bacterial blight （BB） caused by Xanthomonas oryzae pv. Oryzae （Xoo） is one of the most serious diseases of rice. Ten races of the bacterium have been identified in the Philippines. Each race has specific virulence to varieties with different resistance genes, showing a gene-for-gene relationship in the host-pathogen interaction （Lee et al., 2003）. So far, twenty-nine major genes have been identified （Lee et al., 1999）. Due to emergence of the new races and genetic vulnerability of resistant varieties, the spreading of bacterial blight disease occurrence is increasing now in all areas of Korea. This study was carried out to find the gene identification and reaction of rice varieties to Korean and Philippine races ofXanthomonas oryzae, pv. oryzae.     

Landscape patterns and diversity of meadow plants and flower-visitors in a mountain landscape

Context

Wild flowering plants and their wild insect visitors are of great importance for pollination. Montane meadows are biodiversity hotspots for flowering plants and pollinators, but they are contracting due to tree invasion.

Objectives

This study quantified flowering plants and their flower-visitor species in montane meadows in the western Cascade Range of Oregon. Species diversity in small, isolated meadows was expected to be lower and nested relative to large meadows. Alternatively, landform features may influence richness and spatial turnover.

Methods

Flowering plants and their visitors were sampled in summers of 2011–2017 in twelve montane meadows with varying soil moisture. All flowering plants and all flower-visitors were recorded during five to seven 15 min watches in ten 3?×?3 m plots in each meadow and year.

Results

A total of 178 flowering plant species, 688 flower-visitor species and 137,916 interactions were identified. Richness of flower-visitors was related to meadow patch size, but neither plant nor flower-visitor richness was related to isolation measured as meadow area within 1000 m. Species in small meadows were not nested subsets of those in large meadows. Species replacement accounted for more than 78% of dissimilarity between meadows and was positively related to differences in soil moisture.

Conclusions

Although larger meadows contained more species, landform features have influenced meadow configuration, persistence, and soil moisture, contributing to high plant and insect species diversity. Hence, conservation and restoration of a variety of meadow types may promote landscape diversity of wild plants and pollinators.

     

THE NUTRITIVE VALUE OF WEEPING LOVEGRASS DURING THE SPRING SEASON

A continuous digestibility trial, lasting 50 days with subperiods of 5 days each, was made with the spring regrowth of Eragrostis curvula grown in the semi-arid region of Argentina. Five sheep were used to measure the digestibility of DM, organic-matter, cell-wall contents and N. DM yield was estimated simultaneously. The fall in digestibility of all fractions examined was described by quadratic equations. Cell-wall digestibility explained 91% of the variation in organic-matter digestibility. The rate of decrease in crude-protein digestibility increased with time and was particularly noticeable after about 40 days of growth. Digestible DM yield increased at a decreasing rate as maturity advanced, but digestible crude-protein content decreased linearly throughout the trial. It is concluded that the optimum stage of maturity for weeping lovegrass utilization depends upon the performance required from the animals that are to utilize it.     

A disease and production index (DPI) for selection of cacao (Theobroma cacao) clones highly productive and tolerant to pod rot diseases

Frosty pod rot (FPR) (Moniliophthora roreri), along with black pod rot (Phytophthora species) and witches’ broom disease (Moniliophthora perniciosa) constitute the main phytosanitary problems limiting cacao (Theobroma cacao) production causing severe yield losses. One of the main sought after methods of pod rot management is the selection of tolerant cacao genotypes. Typically, the selection is carried out through the quantification of the percentage of diseased pods (PDP). However, PDP does not consider the relative productivity, or production potential (PT) of the genotype. Production potential can vary among cacao genotypes. Consequently, genotypes with similar PT can have similar or vastly different disease tolerance levels as measured by PDP. The disease and production index (DPI) was developed to integrate a genotype's tolerance to M. roreri and other diseases as measured by PDP, with its PT. Here, we evaluated the number of healthy pods, number of diseased pods, and weight of fresh seed for 29 clones grown in replicated five-tree plots over 4 years. The data obtained was used to calculate PDP and DPI for each clone for three different disease combinations: frosty pod rot alone, pod rots other than frosty pod rot, and the combination of all pod rots. Multivariate analysis verified that DPI discriminated between clones based on productivity and disease tolerance. Surprisingly, there was a close ranking of clones between resistance to FPR and resistance to all other pod rots. The DPI can be used in breeding programmes focused on the selection of high yielding disease-tolerant cacao genotypes.     

An online operational alert system for the early detection of shrimp epidemics at the regional level based on real-time production

Diseases are among the greatest threats affecting the sustainability of shrimp aquaculture. In Ecuador, diseases of cultured shrimp have been quickly transmitted from one region to another. Therefore, an early detection system of impending epidemics could serve as an important management tool for the aquaculture sector. We developed a system for the early detection of shrimp epidemics for the largest shrimp zone of Ecuador based on production surveillance. The system, called Epidemiological Alert System and Aquaculture Management (SAEMA), uses a geographical information system (GIS) with an imaginary grid cartography (12,860 ha per grid) dividing the study area. A production and management index is calculated with the harvest data of each pond. A standardized deviation around the historical averages and an alert level is calculated per grid and month. Normal conditions of production and therefore the absence of disease are depicted in green and yellow. While, orange and red colours express a disease warning manifested through suboptimal production levels. As a result, a map of the study area with grid divisions is displayed, with a specific alert colour for each grid where information is available. SAEMA was developed as a Web application (http://www.saema.espol.edu.ec) that enables producers to record data via a worksheet format using any web browser. Instantaneously, the applications perform a calculation of the alert index and provide feedback to the alert levels displayed in an interactive map. A feedback process was initiated in May 2006 with 19 participating shrimp farms. The objective of this research is to develop a platform for an early detection of shrimp epidemics on a regional scale. The detection of an epidemic, expressed as suboptimal production in a specific region, can provide producers from other zones and government authorities to engage in time preventive and control measures in order to reduce the spread of diseases.     

Multidrug and multispecies resistance in sheep flocks from São Paulo state, Brazil

The economic importance of sheep production is increasing worldwide simultaneously with the emergence of parasitic resistance. This study aimed to survey the current situation of management practices and parasite resistance in sheep flocks in S?o Paulo state, Brazil. A questionnaire was given to 35 sheep farmers to obtain information related to flock management practices. Of these flocks, 30 were submitted to the fecal egg count reduction test (FECRT) with at least one of the five following anthelmintics: albendazole, closantel, ivermectin, levamisole, and moxidectin, for comparison against an untreated control group. In the survey, the median number animals per flock was 301, mainly of the Santa Ines breed (in 75.8% of the flocks) and crossbred animals (in 54.5% of the flocks). The predominant farming system was semi-intensive (82.9%), using rotational grazing (80%). Selective treatment was based on FAMACHA grade (47.1%) and in clinical signs (41.2%). The most often applied anthelmintics were macrocyclic lactones (42.9-54.2% in the last three applications). Considering the anthelmintics employed in this study, 10.7% of the farms' flocks were resistant to three, 35.7% to four, and 53.6% to all five anthelmintics. The main helminth genera observed before and after treatments were Haemonchus sp. (75.8%) and Trichostrongylus sp. (19.1%), but all observed genera (Cooperia sp., Oesophagostomum sp., and Strongyloides sp.) were detected by the FECRT. Considering efficacy values less than or equal to 90% in the FECRT as resistant, 100% of flocks were resistant to albendazole and ivermectin, 96.6% to moxidectin, 92.9% to closantel, and 53.6% to levamisole. It is thus possible to conclude that multidrug resistance is widespread in sheep flocks in S?o Paulo state, Brazil, and this involves all prevalent helminth genera.     

Detection of zoonotic intestinal parasites in public parks of Spain. Potential epidemiological role of microsporidia

Several studies have demonstrated that the soil of public parks presents an important source of infection which has a significant impact on public health. Children are the main group affected by accidentally ingestion of contaminated soil. This study was performed in order to identify the presence of zoonotic parasites in dog and cat faecal and soil samples from public parks of Madrid, Spain. Six hundred twenty-five and seventy-nine soil and faecal samples (presumably from dogs and cats) respectively were collected from 67 parks. Intestinal parasites were identified in 27 parks (40.3%), which were contamined with Giardia sp. (19.4%), microsporidia (19.4%), Toxocara spp. (16.4%), Cryptosporidium sp. (6%), Entamoeba histolytica (3%) and Ancylostomidae (3%). Combinations of two or more intestinal parasites were found in 11 parks, and it was common to find Giardia and microsporidia together in samples. Intestinal parasites were detected in 18% (112/625) of soil samples. The most frequent parasite species found in the examined soil samples were Toxocara spp. (16.4%), followed by Giardia sp. (4.5%) and Strongyloides sp. larvae (3%). The zoonotic parasites found in the 79 faecal samples were Giardia sp. (17.7%), Cryptosporidium sp. (9%), E. histolytica (2.5%), Trichuris vulpis (1.3%), Toxascaris leonina (1.3%) and microsporidia spores (28%). Microsporidia characterization by amplification of DNA confirmed 10 samples as positive, eight for E. bieneusi and two for E. hellem by PCR. The role of those parasites in the environment are discussed.