The inheritance of flower colour and vegetative characters in Rubus coreanus

Summary Dominant genes An ₁ for pink flower colour and Br ₁ and Br ₂ controlling branching of the canes in Rubus coreanus are described. In an F₁ progeny and in first backcrosses to red raspberry, some seedlings inherited the ability of R. coreanus to form up to three accessory buds per node. Polygenic systems controlling spine number and spine size are described, number and size being positively correlated. It is postulated that the greater size of spines of h (glabrous-caned) plants is due to linkage of a block of size-controlling genes with the H locus. The greater number of spines of H (hairy-caned) plants is attributed to a pleiotropic effect of the H allele. A new type of dwarf, cauli-flower, which occurred in the F₁ and some first backcross progenies, is described.     

Prevalence and risk factors for agents causing diarrhea (Coronavirus,Rotavirus, Cryptosporidium spp., Eimeria spp., and nematodes helminthes) according to age in dairy calves from Brazil

The present study attempted to verify the prevalence of and risk factors for diarrhea-causing agents in dairy calves from Brazil. Additionally, ages with a higher risk of occurrence for each agent were verified by means of the receiver operating characteristic (ROC) curve. The collections were performed on 39 farms, belonging to 29 municipalities located in eight states of Brazil. It was possible to conclude that the prevalence of Coronavirus, Rotavirus, Cryptosporidium spp., Eimeria spp., and nematodes was 7.20% (95% CI 4.54–9.78), 6.37% (95% CI 3.85–8.89), 51.52% (95% CI 45.26–55.57), 3.46% (95% CI 2.24–4.67), and 3.46% (95% CI 2.24–4.67), respectively. Ages with higher probabilities of occurrence of these diseases in calves were <?10, >?8, >?6, >?37, and >?36 days, respectively. Diarrhea occurred more significantly (P?<?0.0001) in animals less than 21 days old and mainly on those receiving milk through automatic feeders (P?<?0.001). Cryptosporidium spp. were a risk factor for the occurrence of Rotavirus, and vice versa (P?=?0.0039) and presented a positive correlation with Coronavirus (P?=?0.0089). Calves that drink water from rivers, streams, and ponds had a higher chance of being infected by Eimeria spp. (P?<?0.0001), as well as developing infection by nematodes (P?<?0.0001). The results found in this study highlight the importance of studying the agents of diarrhea together, once they act as coinfection where the losses triggered for the owners will involve some of these agents simultaneously.

     

Food ingestion and digestibility of five unicellular algae by 1-day-old Strombus gigas larvae

This work presents food ingestion and digestibility analysis carried out by means of epifluorescence microscopy of 1‐day‐old Strombus gigas (Linnaeus, 1758) larvae fed five different algal cells: Tetraselmis suecica, T. tetrathele, Chlorella keslleri, Chlorella sp. and Chaetoceros cerastoporum. Absolute ingestion and digestion indices (AII and ADI) were used to compare larval feeding behaviour. Differences in efficiency of ingestion and digestion were observed, according to the diet: the highest AII and ADI were observed with T. suecica and T. tetrathele (>90% and 85–88% respectively). With C. cerastoporum and Chlorella sp. these indices were zero. We confirm the use of Tetraselmis as a suitable diet for S. gigas hatchery. On the contrary, Chlorella sp. and C. cerastoporum are not recommended during the early larval stage, due to their non‐ingestion and digestion.     

A direct multiplex loop-mediated isothermal amplification method to detect three CITES-listed shark species

1. Species identification of sharks under catch or trade regulations is important for law enforcement and species conservation. Rapid detection of Convention on the International Trade in Endangered Species (CITES)-listed species is needed for on-site screening.
2. Species-specific primers were designed to target three mitochondrial genes (ND2, COI, and CytB) in both the simplex and multiplex loop-mediated isothermal amplification (LAMP) assay for the pelagic thresher shark (Alopias pelagicus), the bigeye thresher shark (Alopias superciliosus), and the scalloped hammerhead shark (Sphyrna lewini), respectively. Another primer set designed to target S. lewini was used for detection-limit testing of the LAMP assay.
3. The refined direct multiplex LAMP was used to detect the three CITES-listed shark species and omitted the lengthy DNA extraction process. A homogenizer was used to release the DNA from the shark tissues, and a simplex or multiplex LAMP reaction was conducted for 30 min in an incubator at 65°C using species-specific primer sets.
4. Positive LAMP reactions showed a colour change from pink to yellow, whereas negative reactions showed no colour change. Multiplex LAMP assays were performed using 84 samples, which successfully identified the target and non-target species and provided a fast (<1 h), simple, and reliable method to distinguish three CITES-listed shark species from the other non-target species, for either fresh or dry fin products.
5. Results of this study and the method developed will play a critical role in assisting fishery agencies and customs officials in identifying the illegal catch and trade of CITES-listed shark species.

     

Morphological changes,peptidase activity,and effects of exogenous enzymes in the early ontogeny of Nile tilapia,Oreochromis niloticus

Aquaculture International - During the early ontogeny, the transition from endogenous (yolk protein) to exogenous feeding (artificial diets) represents a critical period linked to the...     

Nitrogen fixation by nodulated soybean under tropical field conditions estimated by the 15N isotope dilution technique

The contribution of biological N₂ fixation to the N nutrition of nodulated soybean was estimated using the ¹⁵N isotope dilution technique and a non-nodulating soybean isoline as a non-fixing control plant. The plants were grown in the field in concrete cylinders (60 cm dia) and harvested at seven stages of plant growth. Labelled N was added to the soil either as labelled organic matter before planting or in seven small additions (2kg N ha^?1) of (NH₄)₂SO₄ during the growing period.There was good agreement between isotope dilution estimates of nitrogen fixation for the two labelling methods. Acetylene reduction assays on intact root systems greatly underestimated N₂ fixing activity. The difference in total N between nodulated and non-nodulated plants generally gave higher estimates compared with the isotope technique. The data indicate that this was because nodulated plants recovered more N from the soil than the non-nodulated plants. After 92 days of growth, the soybean derived approximately 250kg N ha^?1 from biological N₂ fixation.     

The 15N-isotope dilution technique applied to the estimation of biological nitrogen fixation associated with Paspalum notatum cv. batatais in the field

The contribution of associated biological nitrogen fixation to the nitrogen nutrition of Paspaulum notatum cv. batatais was estimated using the ¹⁵N-isotope dilution technique. The plants were grown in the field in concrete cylinders (60 cm dia) filled with soil, to which were added small quantities of ¹⁵N-labelled fertilizer at frequent intervals over 12 months. The pensacola cultivar of P. notatum was used as a non-N₂-fixing control plant. This was justified by the observation that nitrogenase (intact core C₂H₂ reduction) activity associated with the pensacola cultivar was consistently much lower than that of the batatais cultivar.At the first harvest, no evidence for N₂ fixation associated with the batatais cultivar was obtained, probably because of slow establishment of the N₂-fixing association. However, at the subsequent three harvests the batatais cultivar exhibited a lower ¹⁵N-enrichment and yielded more N than the pensacola cultivar. These data together suggested that 8–25% of the N in the batatais cultivar originated from N₂ fixation.The grass Paspalum maritimum was also included in the experiment and exhibited low nitrogenase activity similar to that of the pensacola cultivar of P. notatum. However, the total N and ¹⁵N data of these two grasses were not in good agreement indicating that it is important for the use of the isotope dilution technique that control plants are of very similar physiology and growth habit.     

Impact of anthropogenic activity on the Hg concentrations in the Piracicaba river basin (São Paulo State, Brazil)

A sampling and analysis program has been completed between 1995 and 1998 in order to determine mercury concentrations in water, sediments, soils and fish in the Piracicaba river basin, one of the most populated and industrialized regions in Brazil. In sediment, the average Hg concentrations varied between 33 ± 17 ng g^?1 and 106 ± 78 ng g^?1, in samples collected during the rainy and dry season, respectively. The same averages were also found for soil samples (35 ± 14 and 109 ± 61 ng g^?1). In water, the total Hg concentration varied between < 1.1 and 24.0 ng L^?1. In piscivore fish, up to 943 μ g Hg kg^?1 was found. Our results show that all compartments undergo Hg contamination, in view of the levels found in pristine environments. Water contamination seems to be due mainly to diffuse processes of soil erosion and suspension of river bed sediment during the rainy season. Also untreated wastewaters generated by industrial activities and from domestic sewage appear to be potential non-point sources in the most industrialized and populated part of the basin. On the other hand, atmospheric transport of mercury originating from the Campinas Metropolitan Region could be another source of mercury contamination, especially in the basin headwaters.     

Molecular characterization of Mycoplasma gallisepticum isolates from Jordan

Two groups of Mycoplasma gallisepticum (MG) isolates (n = 24) from Jordan were analyzed by molecular methods and compared with other Middle Eastern isolates, related international isolates, and reference strains. The first group (n = 19) was isolated from July 2004 to January 2005 (isolation period A), and the newer group (n = 5) from June 2007 to April 2008 (isolation period B). The groups of isolates are from chicken flocks from northern Jordan, but are not from the same farms. None of the flocks were vaccinated for MG. Random amplified polymorphic DNA analysis, targeted sequencing of the partial MG cytadhesin 2 (mgc2), and the MG 16S-23S rRNA intergenic spacer region (IGSR) divided the Jordanian isolates into two groups. All of the 19 isolates from time period A, in addition to two isolates from time period B, were indistinguishable from the F strain. Three of five isolates from time period B were characterized as wild types and were indistinguishable from each other. The wild-type field strain was readily distinguished from the F strain. It was 91% and 96.4% similar to the F strain based on Clustal-W alignments of sequences of mgc2 and IGSR, respectively. Sequence similarity of mgc2 gene of the Jordan wild-type strain to isolates from Israel and Egypt ranged from 96.5% to 100%, whereas for IGSR it was 99.4%-100%. We theorize that the F-strain live MG vaccine, commonly used in Jordan prior to 2007, was transmitted to nonvaccinated poultry in the region and was a predominant genotype during time period A.