Comparison of Resistance to Tomato Leaf Curl Virus (India) and Tomato Yellow Leaf Curl Virus (Israel) among Lycopersicon Wild Species, Breeding Lines and Hybrids

The objective of this study was to screen wild and domesticated tomatoes for resistance to Tomato yellow leaf curl virus, Israel (TYLCV-Is) and Tomato leaf curl virus from Bangalore isolate 4, India (ToLCV-[Ban4]) to find sources of resistance to both viruses. A total of 34 tomato genotypes resistant/tolerant to TYLCV-Is were screened for resistance to ToLCV-[Ban4] under glasshouse and field conditions at the University of Agricultural Sciences, Bangalore, India. Resistance was assessed by criteria like disease incidence, symptom severity and squash-blot hybridization. All the tomato genotypes inoculated with ToLCV-[Ban4] by the whitefly vector Bemisia tabaci (Gennadius) produced disease symptoms. In some plants of the lines 902 and 910, however, the virus was not detected by hybridization. The tomato genotypes susceptible to ToLCV-[Ban4] by whitefly-mediated inoculation were also found susceptible to the virus under field conditions. However, there were substantial differences between genotypes in disease incidence, spread, symptom severity and crop yield. Despite early disease incidence, many genotypes produced substantially higher yields than the local hybrid, Avinash-2. Sixteen tomato genotypes from India resistant/tolerant to ToLCV-[Ban4] were also tested for TYLCV-Is resistance at the Hebrew University of Jerusalem, Rehovot, Israel. Accessions of wild species, Lycopersicon hirsutum LA 1777 and PI 390659 were the best sources of resistance to both viruses. Lines 902 and 910, which were, resistant to TYLCV-Is were only tolerant to ToLCV-[Ban4] and accession Lycopersicon peruvianum CMV Sel. INRA, resistant to ToLCV-[Ban4], was only tolerant to TYLCV-Is. Implications of using the resistant lines in breeding programme is discussed.     

Human disturbance in Western Gull Larus occidentalis livens colonies and possible amplification by intraspecific predation

Indirect evidence is presented that human disturbances are having a profound effect on reproductive efforts of Larus occidentalis livens at several colonies in the Gulf of California. Breeding adults that lose their eggs or chicks apparently practise conspecific predation whether or not humans are present, thus increasing effects of human intrusions. These combined effects could lead to a severe decline in numbers or even pose a threat to the survival of this endemic population, if human disturbance is widespread. Attempts to assess breeding success throughout the Gulf seem warranted and, if necessary, some action to regulate human contact may be essential.     

Investigation of a possible chain of Streptococcus suis infection in a pig breeding community using PCR-based genotyping

Streptococcus (S.) suis plays an important role in pig breeding causing invasive diseases such as meningitis and polyarthritis. Herd problems with Streptococcus suis are common in many pig farms and are frequently characterised by disease outbreaks. In this context, it is often important to identify chains of infection, e.g. between a farrow-to-wean and a grower farm. In the following case report a possible chain of infection among the different farms of a farrow-to-finish system was investigated. In two grower units herd problems with S. suis were present; the mortality was higher than 5 %. It appeared likely, that the streptococci causing these problems were transmitted from a single farrow-to-wean unit to the two different grower farms. In the respective farms swabs were taken from different healthy animals and, in the case of the grower farms, also from the infected animals. Genotypic profiling of strains by a multiplex-PCR and AFLP typing method revealed that two different S. suis pathotypes were responsible for the herd problems. Both pathotypes could not be detected in the farrow-to-wean farm.Thus, a chain of infection originating from the farrow-to-wean farm appeared unlikely. The multiplex PCR was in this case sufficient to elucidate the described problem.     

Fragment size is associated with post-operative complications following elective arthroscopy of the tibiotarsal joint of horses

The objective of this retrospective study was to determine the occurrence of joint-related complications after elective arthroscopy of the tibiotarsal joint (TTJ) in 329 horses, and the association with specific clinical parameters. Data were collected from medical records of horses undergoing elective tibiotarsal joint arthroscopy for fragment removal. Exact conditional univariate regression was used to determine significant risk factors for joint-related post-operative complications.Of 485 joints, 2 (0.4%) developed surgical site infection, 4 (0.8%) developed septic arthritis, 1 (0.2%) developed synovial fistula. There was a significantly increased odds of having septic arthritis as height and length of the distal intermediate ridge of the tibia (DIRT) lesion increased. The median height and length of the DIRT fragments in affected cases was 13.5 mm and 18.0 mm, respectively. For each unit (1 mm) increase in height, there was a 42% increase in the risk of septic arthritis occurrence (P = 0.0042), and a 15% increase for each unit increase in length (P = 0.035). Horses were significantly less likely to develop septic arthritis when suture smaller than USP 0 was used.Horses with larger osteochondritis dissecans lesions of the DIRT region have an increased risk of developing septic arthritis following fragment removal.     

Conferring resistance to pre-harvest sprouting in durum wheat by a QTL identified in <Emphasis Type="Italic">Triticum spelta</Emphasis>

Pre-harvest sprouting (PHS) causes significant yield loss and degrade the end-use quality of wheat, especially in regions with prolonged wet weather during the harvesting season. Unfortunately, the gene pool of Triticum durum (tetraploid durum wheat) has narrow genetic base for PHS resistance. Therefore, finding out new genetic resources from other wheat species to develop PHS resistance in durum wheat is of importance. A major PHS resistance QTL, Qphs.sicau-3B.1, was mapped on chromosome 3BL in a recombinant inbred line population derived from ‘CSCR6’ (Triticum spelta), a PHS resistant hexaploid wheat and ‘Lang’, a PHS susceptible Australian hexaploid wheat cultivar. This QTL, Qphs.sicau-3B.1, is positioned between DArT marker wPt-3107 and wPt-6785. Two SCAR markers (Ph3B.1 and Ph3B.2) were developed to track this major QTL and were used to assay a BC₂F₈ tetraploid population derived from a cross between the durum wheat ‘Bellaroi’ (PHS susceptible) and ‘CSCR6’ (PHS resistant). Phenotypic assay and marker-assisted selection revealed five stable tetraploid lines were highly PHS resistant. This study has successfully established that PHS-resistance QTL from hexaploid wheat could be efficiently introgressed into tetraploid durum wheat. This tetraploid wheat germplasm could be useful in developing PHS resistant durum cultivars with higher yield and good end-use quality.     

Dietary Esterified Astaxanthin Concentration Effect on Dermal Coloration and Chromatophore Physiology in Spinecheek Anemonefish,Premnas biaculeatus

Anemonefishes dominate the marine ornamental aquaculture production and coloration plays an important role in market price of the product. This study examined the effect of dietary esterified astaxanthin concentration and duration on skin coloration in spinecheek anemonefish, Premnas biaculeatus. The chromatophore physiology parameters examined were color, density, and diameter of carotenoid granules. Juveniles of 30 days post hatch (d.p.h.) were fed diets consisting of 23, 214, or 2350 ppm esterified astaxanthin for 115 d and the fish were sampled at 45, 120, and 145 d.p.h. Hue was significantly reduced with increasing time and astaxanthin concentration. Saturation fluctuated over time while luminosity was only affected by time. Carotenoid granule density was similar across the treatments: approximately 0.3 granules/µm². Significant difference in carotenoid granule size was detected, with larger diameters at the higher astaxanthin treatment. Carotenoid granules showed significantly lower hues, higher saturation, and lower luminosity values for the higher astaxanthin concentration diets. This is indicative of higher concentration of carotenoids in the granules. Diets explicitly imparted different coloration in P. biaculeatus and the manifested color differences in the fish are result of increased carotenoid granule size and increased carotenoid concentration within granules. Astaxanthin concentration of 214 ppm imparts adequate coloration for high market value.     

Isolation and differentiation of bovine mammary gland progenitor cell populations

OBJECTIVE: To isolate bovine mammary gland cells with stem cell characteristics. SAMPLE POPULATION: Monolayers of bovine mammary gland cells. PROCEDURE: Mammary gland cell populations were separated by use of selected media supplements. Phenotypic characteristics were examined via light and transmission electron microscopy. Cellular expression of casein and connexin 43 was identified immunohistochemically. A scrape-loading and dye transfer assay was used to examine the mammary gland cell populations for homogenous gap junctional intercellular communication (GJIC). RESULTS: Subpopulations of mammary gland cells grown in vitro are classified on the basis of their distinct morphologic features and ability to communicate via gap junctions. Ultrastructurally, 2 morphologically distinct cell types were classified as type I and II cells. Type I cells were small light undiffertiated cells and large light undifferentiated cells that were deficient in functional gap junctions (as is characteristic of stem cells). Type II cells included large light differentiated cells and terminally differentiated cells; GJIC was functional in type II cells. Type II cells had cytoplasmic expression of connexin 43, whereas, type I cells did not. All cells expressed casein. CONCLUSIONS AND CLINICAL RELEVANCE: Subpopulations of bovine mammary gland cells with stem cell characteristics were identified. Phenotypic differences are observed among type I bovine mammary gland cells with stem cell characteristics. Gap junctional intercellular communication may be necessary for the differentiation of stem cells. Characterization of bovine mammary gland stem cells and their progeny may provide a new tool with which to study mammary gland health.