Genotyping of Giardia intestinalis from domestic and wild animals in Japan using glutamete dehydrogenase gene sequencing

To determine the genotypes of Giardia intestinalis from domestic and wild animals in Japan, Giardia isolates obtained from feces of 24 dogs kept in households and breeding kennels, three companion cats, five dairy calves and three wild monkeys, Macaca fuscata, were genotyped using the 177 bp sequence of the glutamete dehydrogenase gene (gdh). The genotypes were assemblages A, C, D or A/D for dog isolates, Assemblage F for cat isolates, assemblages A or E for calf isolates and assemblage B for monkey isolates. This is the first report on the genotypes of Giardia isolates from cats, calves and wild monkeys in Japan.     

Accumulation of lipofuscin in broiler chicken with wooden breast

Lipofuscin is one of the indicators of oxidative stress. To elucidate the role of oxidative stress in the development of wooden breast, this study investigates lipofuscin accumulation in various parts of wooden breast muscles. Sampling was performed using 46-day-old broiler chickens housed at a commercial Japanese poultry slaughterhouse. Fourteen wooden breast fillets and 13 normal breast fillets were collected in the deboning line. The samples used to measure shear force, 2-thiobarbituric acid reactive substance (TBARS), and for histological analysis were taken from the six portions of breast muscle fillets. In muscles affected by wooden breast, vacuolated muscle fibers were observed, and connective tissues appearing like perimysium were expanded with fibrosis. TBARS value and accumulation of lipofuscin were significantly higher in the wooden breast than in the normal breasts. A lot of lipofuscin granules were localized in the cytoplasm of collapsed muscle fibers of the wooden breast. The cranial portion of the wooden breast showed the highest shear force. The cranial position had a large amount of connective tissue and lipofuscin granules. The results of the present study strongly suggest that high oxidative stress, especially with a significant accumulation of lipofuscin, is associated with the development of wooden breasts.     

Airborne basidiospores as an inoculum source of <Emphasis Type="Italic">Typhula variabilis</Emphasis> and the effect of hilling on the incidence of Typhula winter rot of carrots

Typhula winter rot on overwintering carrots caused by Typhula variabilis is a newly confirmed disease, and no practical control measure is yet available. To develop a control method, here we researched the infection period of T. variabilis and the time that winter rot appeared on carrots. Using spore traps, we found that basidiospore rain occurred from September to November before snowfall in Memuro, Hokkaido. In addition, carrot leaves collected in autumn had already been infected by T. variabilis. These epidemiological investigations revealed that the pathogen releases basidiospores to infect carrot leaves before snow cover, resulting in root decay under snow. An effective control method was then developed to avoid direct contact of basidiospores of T. variabilis with plant tops by covering the plants with soil in autumn. Thus, the percentage of rotted roots was reduced to about half.     

Agropyron elongatum HMW-glutenins have a potential to improve wheat end-product quality through targeted chromosome introgression

After screening of 177 disomic addition lines (DALs) of wheat (Triticum aestivum) containing a pair of chromosomes from different alien species, we found that the chromosome 1E addition line of Agropyron elongatum, that is known to be a potential genetic resource for drought and salinity tolerance, showed potential for improvement of bread-making quality of wheat. This was indicated by increased SDS sedimentation, specific sedimentation, mixograph peak time and SE-HPLC analysis of polymeric proteins. This addition line spontaneously gave rise to a substitution line for chromosome 1D in subsequent generations that showed weak dough strength. Analysis of the x-type HMW-glutenin subunit sequence of Ag. elongatum from DAL1E indicated that it closely resembled the x-type sequence of the A and B genomes of wheat, and the y-type was intermediate between x- and y-type HMW-glutenin subunit genes. From these observations, it was inferred that 1E-encoded seed storage proteins have considerable potential for improvement of wheat end-product quality if transferred to specific chromosomes such as 1A of Chinese Spring (CS) wheat, which has a negative overall effect on bread-making quality.     

Identification of introgression lines of Oryza glaberrima Steud. with high mineral content in grains

Mineral concentrations in cereals are crucial for human health, especially for people who consume cereals as a subsistence diet. Although rice (Oryza sativa L.) is one of most important staple crops in the world, starch constitutes a large portion of its grains, and mineral concentrations are lower than in other staple crops. One solution is the improvement of mineral concentrations in rice grains through biofortification, and this approach requires investigation of genetic resources that confer high mineral concentrations to rice grains. In the present study, we performed 2 years of field experiments, in 2012 and 2013, and determined sodium (Na), magnesium (Mg), phosphorus (P), potassium (K), calcium (Ca), boron (B), manganese (Mn), iron (Fe), copper (Cu), zinc (Zn) and molybdenum (Mo) concentrations in the rice grains of 40 introgression lines derived from a cross between a japonica cultivar, Taichung 65 (T65), and African rice, Oryza glaberrima Steud. Substantial variation in mineral concentrations was observed among the 40 introgression lines. We selected several elite lines that had significantly higher concentrations of minerals, including Fe, Cu, Zn, Mo, Mg, P and Ca than the cultivated rice T65. These lines could be novel potential materials for breeding programs for biofortification and provide us with positional information for the candidate loci in the O. glaberrima genome responsible for high mineral concentrations in rice grains.     

Development of photoperiod-sensitive cytoplasmic male sterile (PCMS) wheat lines showing high male sterility under long-day conditions and high seed fertility under short-day conditions

A “two-line system” using photoperiod-sensitive cytoplasmic male sterility (PCMS) caused by Aegilops crassa cytoplasm under long-day photoperiods (≧15 h) has been proposed as a means of producing hybrid varieties in common wheat (Triticum aestivum). The PCMS line is maintained by self-pollination under short-day conditions, and hybrid seeds can be produced through outcrossing of the PCMS line with a pollinator line under long-day conditions. Our previous studies revealed that PCMS lines showing complete male sterility under long-day conditions are necessary for practical hybrid wheat breeding, especially to obtain high hybrid purity in F₁ seeds. Furthermore, practical PCMS lines should have high seed fertility under short-day conditions, which is associated with female fertility. Wheat cv. Norin 26 with Ae. crassa cytoplasm exhibits high seed fertility under short-day conditions, and cv. Fujimikomugi with Ae. crassa cytoplasm shows high male sterility under long-day conditions. Here we developed practical PCMS lines derived from the F₁ generation of Norin 26 and Fujimikomugi (with Ae. crassa cytoplasm) that were then backcrossed to elite wheat lines.     

Dietary Bacillus subtilis C-3102 Supplementation Enhances the Exclusion of Salmonella enterica from Chickens

Among the reported probiotic Bacillus strains, B. subtilis C-3102 has the unique potential to improve feed uptake under stress conditions in the broilers, piglets, and cows. In this study, we sought to evaluate the protective effect of feed additive probiotic Bacillus subtilis C-3102 against Salmonella enterica infection of specific pathogen-free (SPF) chicks in floor pens in two experiments. In the experiment-1, the chicks in the control group (n=32) were fed a basal diet and those in the C-3102 group (n=32) were fed a basal diet supplemented with 1×10⁶ CFU/g of feed for 28 days. On day 7 post-challenge with S. enterica, there was no significant change in the body weight between both the groups throughout the test period, whereas detection rates of S. enterica in the C-3102 group were significantly lower in the cecum and liver on days 21 and 14 post-challenge, respectively. In the experiment-2, minimum dosage of C-3102 cells required to protect Salmonella infection was evaluated using 3 dosages. Chicks were divided into four groups, fed with different dosages of C-3102 (1×10⁶, 5×10⁵, 3×10⁵, and 0 CFU/g of feed), and challenged with S. enterica (2.8×10⁸ CFU/chicken). S. enterica infection was completed within 7 days post- challenge and was almost excluded from the liver and spleen on day 21 post- challenge in the control group. Average values showed a trend for higher infection rates in the control group >3×10⁵>5×10⁵>1×10⁶ CFU/g on days 14 and 21 post-challenge. These results suggest that B. subtilis C-3102 supplementation has the potential to reduce S. enterica infection rates and/or to accelerate the exclusion of S. enterica from the chicks.