Bioassays on the role of tomato,potato and sweet pepper as sources of <Emphasis Type="Italic">Tomato chlorosis virus</Emphasis> transmitted by <Emphasis Type="Italic">Bemisia tabaci</Emphasis> MEAM1

Shot hole disease of stone fruits caused by Thyrostroma carpophilum has become a major threat to stone fruit industry of Jammu and Kashmir, India because of the failure in its management with fungicides. To understand the diversity in shot hole pathogen, a combination of conventional (morphological, cultural and pathological) and molecular (ISSR and ITS markers) approaches were employed to discern variability in 25 isolates of T. carpophilum isolated from peach, plum, apricot, almond and cherry leaves collected from Srinagar, Ganderbal, and Baramulla districts of Jammu and Kashmir, India. The studies revealed a high level of variability among the pathogen. Based on the morpho-cultural and pathological studies, the isolates were grouped into different categories based on colony growth, texture, margin and colour besides change in media colour, incubation period, leaf area infected, etc. Using ISSR markers, a high level of polymorphism in different isolates of T. carpophilum was observed which indicated that these markers are suitable for studying the genetic diversity in this pathogen. Based on dendrogram, the isolates were grouped irrespective of their geographical origin or host species. Phylogenetic analysis of the 25 sequences based on ITS region showed maximum similarity with T. carpophilum (Syn. Wilsonomyces carpophilus) sequences retrieved from NCBI and grouped them in a single clade which proved it as a powerful tool for authentic identification. The pathogen was highly variable based on morpho-cultural, pathological and molecular (ISSR) characterisation.     

Folic Acid,Iron, and Zinc Contents in Chosen Food Products Prepared with Fortified Flours

In 2002, Brazil issued a regulation requiring that corn and wheat flours be fortified by the addition of folic acid and iron. The aim of the present work was to evaluate the levels of folic acid, iron, and zinc in macaroni, pizza, and bread prepared with fortified flour. The methodologies used for the mineral (FAAS) and vitamin (HPLC) determinations were validated and considered adequate. For macaroni, the folic acid content range was 50.0–182.4 μg/100 g. The iron and zinc levels were 1.6–5.4 mg/100 g and 0.7–1.0 mg/100 g, respectively. The pizza and bread samples contained 14.8–271.3 μg/100 g and 47.4–481.4 μg/100 g of folic acid, respectively. The iron and zinc levels were 2.6–7.3 mg/100 g and 0.4–0.9 mg/100 g, respectively, for pizza, and 3.0–12.4 mg/100 g and 0.4–0.8 mg/100 g for bread. The results indicated that the distribution of folic acid and iron in the majority of the samples tested was heterogeneous. This study could be of use to governmental authorities in their food fortification evaluation programs. Moreover, the average iron contents observed in the products could result in problems with zinc absorption, and it is important to consider that iron can induce oxidative stress in cells.     

Partial characterization of a bipartite begomovirus infecting yellow passion flower in Brazil

During the spring of 2001, approximately 10 000 yellow passion flower plants, from two orchards in the county of Livramento de Nossa Senhora, Bahia State, Brazil, exhibited intense yellow mosaic symptoms and drastic reduction of the leaf lamina and plant development. A large population of whiteflies ( Bemisia tabaci ) was also found colonizing the plants. All field samples collected tested positive for Passion fruit woodiness virus in DAS-ELISA. Five out of 20 passion flower plants inoculated with adult whiteflies collected from diseased plants in the field developed symptoms 20–30 days after inoculation. Two of these plants gave a positive reaction in TAS-ELISA using antiserum against a begomovirus. Degenerated PCR primers amplified viral DNA fragments from the DNA-A and DNA-B components of a begomovirus infecting these plants. The fragment corresponding to the core region of the coat protein (DNA-A) was cloned and sequenced. A phylogenetic analysis placed this begomovirus isolated from passion flower in the same clade of the New World begomoviruses as several other species from Brazil. Based on the symptoms induced by this virus alone, the disease was tentatively named passion flower little leaf mosaic.     

Pfaffia mosaic virus: a new potyvirus found infecting Pfaffia glomerata in Brazil

In Brazil plants of Pfaffia glomerata with mosaic symptoms were found to be infected with a previously undescribed potyvirus, Pfaffia mosaic virus (PfMV). Virus particles were long and flexuous, c.  10 × 700–800 nm, and cylindrical inclusions typical of potyviruses were present in cells of infected tissue. Partial host-range studies revealed that in addition to P. glomerata , PfMV infected only Chenopodium amaranticolor and Chenopodium quinoa . It was efficiently transmitted by the aphids Aphis gossypii and Myzus persicae . Polyclonal antiserum produced against the PfMV coat protein (CP) reacted with Potato virus Y (PVY), but not with four other potyviruses in PTA-ELISA. The similarity of the nucleotide sequence of the PfMV coat-protein gene ( CP ) varied from 7 to 76% when compared with other members of the family Potyviridae . Similarity of the 3' NTR sequence varied from 4 to 23%. In both cases the highest similarity was with PVY. These data indicate that PfMV is a new species in the genus Potyvirus .     

The dynamics of heavy metals through litterfall and decomposition in a red mangrove forest

The cycling of Zn, Mn and Fe through production, decomposition, and export of litter was studied at the Itacurussá Experimental Forest, a red mangrove forest in Southeast Brazil. The total litterfall was 8.69 t ha-1 yr-1. The heaf litter represented 56% to 100% of the total litterfall. The metal concentrations in the fallen leaves were: Mn = 230 ± 50 g g-1; Fe = 116 ± 44 g g-1 and Zn = 5.5 ± 1.0 g g-1 (n = 15). The average transfer rates of heavy metals from canopy to sediment through leaf fall were: 1.39 kg ha-1 yr-1 for Mn, 0.70 kg ha-1 yr-1 for Fe, and 0.03 kg ha-1 yr-1 for Zn. These rates represent 4.5%, 4.0%, and 57.0% of the total forest biomass reservoir for Zn, Fe and Mn, respectively. There was no accumulation of the metals in the first 10 days of decomposition, and since the residence time of leaves in the sediments was less than 6 days, litter exported from the forest had relatively low metal concentrations. Since 7% of the leaf fall (0.42 t ha-1 yr-1) is exported to the sea, we estimated an average export of heavy metals throught leaf detritus as: Mn = 0.097 kg ha-1 yr-1, Fe = 0.049 kg ha-1 yr-1 and Zn = 0.002 kg ha-1 yr-1. The export of metals through leaf fall represents less than 0.01% of the total sediment reservoir. We conclude that mangrove ecosystems are probably efficient biogeochemical barriers to the transport of metal contaminants in tropical coastal areas.     

Serum C-reactive protein concentrations in dogs with multicentric lymphoma undergoing chemotherapy

OBJECTIVE: To determine whether serum C-reactive protein (CRP) concentration is high in dogs with multicentric lymphoma, whether CRP concentration changes in response to chemotherapy, and whether CRP concentration can be used as a marker for relapse in dogs with multicentric lymphoma. DESIGN: Cohort study. ANIMALS: 20 dogs with multicentric lymphoma and 8 healthy control dogs undergoing chemotherapy with cyclophosphamide, vincristine, and prednisone (CVP) or with vincristine, cyclophosphamide, methotrexate, and L-asparaginase (VCMA) and 20 other healthy dogs. PROCEDURES: Serum CRP concentration was measured weekly during the first month of chemotherapy and then at 3-week intervals until relapse in dogs with multicentric lymphoma, weekly for 16 weeks in healthy dogs undergoing chemotherapy, and once in the healthy dogs not undergoing chemotherapy. RESULTS: For both groups of dogs with lymphoma, mean serum CRP concentration during week 1 (prior to treatment) was significantly higher than mean concentrations following induction of chemotherapy and at the time of relapse. Mean serum CRP concentration in the healthy dogs undergoing chemotherapy was not significantly different at any time from mean concentration for the healthy dogs not undergoing chemotherapy. No significant differences were observed between dogs treated with CVP and dogs treated with VCMA. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that serum CRP concentration is high in dogs with multicentric lymphoma but that serum CRP concentration is not a useful marker for relapse and that chemotherapy itself does not affect serum CRP concentration.     

Production of beef cattle grazing on Brachiaria brizantha (Marandu grass)—Arachis pintoi (forage peanut cv. Belomonte) mixtures exceeded that on grass monocultures fertilized with 120 kg N/ha

Mixed grass/legume pastures are an alternative to grass monocultures for increased beef cattle production in tropical climates. The objective of this study was to evaluate the productivity of beef cattle grazing either a mixed pasture of Brachiaria brizantha cv. Marandu grass and Arachis pintoi (forage peanut) cv. Belomonte or a Marandu monoculture, under rotational stocking. Five trials were conducted over a period of nine years in north-eastern Brazil where the sward structure (forage, grass and legume mass) and animal performance were compared for a mixed Marandu grass/forage peanut pasture, and a Marandu grass monoculture with 120 kg N ha⁻¹ y⁻¹. Stocking rate was adjusted to maintain forage allowance at 4% body weight/day. A block design was used with four replicates, and warm and cool seasons within each trial were considered, using repeated measurements over time. In the warm season, the forage mass in the mixed pastures was 17% greater than in the monoculture (p = .049), and the stocking rate, average daily gain and liveweight gain per ha were 16.4%, 20.0% and 28.7% greater (p = .004, p < .001 and p < .001 respectively). The average daily gain showed a positive linear relationship with the legume proportion in the sward (p < .001). The mixed forage peanut/Marandu pasture sustained significantly greater beef cattle production (789 kg ha⁻¹ y⁻¹) compared to the N-fertilized grass monoculture (655 kg ha⁻¹ y⁻¹). Appropriately managed, mixed pastures of forage peanut/Brachiaria pastures are sustainable and have high potential for use in the humid tropics.     

Improved plating media for the detection of Salmonella species with typical and atypical hydrogen sulfide production.

The Salmonella detection ability of 2 surfactant-supplemental media, xylose-lysine-tergitol (Nia-proof) 4 (XLT4) and Miller-Mallinson (MM) agar, was compared against that of several commonly used plating media. XLT4 and MM appeared to be the most efficient in detecting Salmonella in meat products and food animal environments. MM was superior to XLT4 in detecting those increasingly more prevalent strains of Salmonella possessing weak to ultraweak H2S production characteristics.     

FOLIAR SPRAY OF POTASSIUM SILICATE ON THE CONTROL OF ANGULAR LEAF SPOT ON BEANS

This study aimed to determine if potassium silicate (KSi) sprays could reduce the intensity of angular leaf spot. In field experiment 1, bean plants were sprayed with KSi (pH 10.5) at rates of 8, 20, 40, and 60 g L^?1. In field experiment 2, with the same treatments, the pH of the KSi solutions was 5.5. In experiment 3, the treatments were KSi (40 g L^?1, pH 5.5), potassium hydroxide (KOH) (6.5 g L^?1, pH 5.5), tebuconazole (0.5 L ha^?1), and control. In experiment 4, the treatments were the same as in experiment 3, but the pH of the KSi and KOH solutions was 10.5. Plants sprayed with water served as a control treatment for all field experiments. Plants were artificially inoculated with Pseudocercopora griseola before products application. For experiments 3 and 4, the treatment with KOH was included to equalize the amount of potassium (K) with the treatment corresponding to the application of KSi. Disease severity was evaluated using a scale with values ranging from 0.2 to 30.4% at 85 days after seedling emergence. Plant defoliation, Si, and K concentration in the plant tissues, and yield were also determined. There was no relationship between KSi rates and Si concentration in leaf tissues, but Si concentration increased by 58 and 57%, respectively, as the KSi rates increased from 0 to 60 g L^?1 regardless of the pH. The K concentration in leaf tissues did not change among the treatments. Disease severity decreased by 42 and 30%, respectively, at the highest KSi rate with pH 5.5 and pH 10.5 over the control. Disease severity levels were similar between the KSi and KOH treatments, but they were significantly higher compared to the tebuconazole. Plant defoliation at the highest KSi rate with pH 5.5 and 10.5 was 17 and 33%, respectively, less than the control. Plant defoliation decreased with the application of KSi with pH 5.5 and 10.5 in 29 and 34%, respectively, compared to the control. Yield increased by 30 and 43%, respectively, as the KSi rates increased from 0 to 60 g L^?1with pH 5.5 and 10.5. No statistical difference in yield was detected between the KSi and KOH treatments regardless of the pH used, but both were different from tebuconazole. Significant differences in yield were found only between tebuconazole and the control. Results from this study suggest that foliar application of KSi and KOH has the potential to reduce angular leaf spot severity. The KSi did not offer any advantage over the KOH spray, suggesting a lack of a direct effect of Si accumulated in the leaf tissue on disease control.     

Genetics and genomics of uniformity and resilience in livestock and aquaculture species: A review

Genetic control of residual variance offers opportunities to increase uniformity and resilience of livestock and aquaculture species. Improving uniformity and resilience of animals will improve health and welfare of animals and lead to more homogenous products. Our aims in this review were to summarize the current models and methods to study genetic control of residual variance, genetic parameters and genomic results for residual variance and discuss future research directions. Typically, the genetic coefficient of variation is high (median = 0.27; range 0–0.86) and the heritability of residual variance is low (median = 0.01; range 0–0.10). Higher heritabilities can be achieved when increasing the number of records per animal. Divergent selection experiments have supported the feasibility of selecting for high or low residual variance. Genomic studies have revealed associations in regions related to stress, including those from the heat shock protein family. Although the number of studies is growing, genetic control of residual variance is still poorly understood, but big data and genomics offer great opportunities.