Phylogenetic analysis of Myanmar indigenous chickens using mitochondrial D-loop sequence reveals their characteristics as a genetic resource

Myanmar indigenous chickens play important roles in food, entertainment, and farm business for the people of Myanmar. In this study, complete mitochondrial D-loop sequences (1232 bp) were analyzed using 176 chickens, including three indigenous breeds, two fighting cock populations, and three indigenous populations to elucidate genetic diversity and accomplish a phylogenetic analysis of Myanmar indigenous chickens. The average haplotype and nucleotide diversities were 0.948 ± 0.009 and 0.00814 ± 0.00024, respectively, exhibiting high genetic diversity of Myanmar indigenous chickens. Sixty-four haplotypes were classified as seven haplogroups, with the majority being haplogroup F. The breeds and populations except Inbinwa had multiple maternal haplogroups, suggesting that they experienced no recent purifying selection and bottleneck events. All breeds and populations examined shared haplogroup F. When 232 sequences belonging to haplogroup F (79 from Myanmar and 153 deposited sequences from other Asian countries/region) were analyzed together, the highest genetic diversity was observed in Myanmar indigenous chickens. Furthermore, Myanmar indigenous chickens and red junglefowls were observed in the center of the star-like median-joining network of 37 F-haplotypes, suggesting that Myanmar is one of the origins of haplogroup F. These findings revealed the unique genetic characteristic of Myanmar indigenous chickens as important genetic resources.     

三叶木通生物学特性研究

在人工栽培条件下，研究了三叶木通的生物学特性。结果表明，三叶木通一年内可萌发三次新梢，春梢和夏梢的生长期分别为１１０，１３０天左右，当年能进行花芽分化；秋梢因寒害多为枯尖死亡。其花期为３０天左右。     

Host selection of small cedar longicorn beetle, <Emphasis Type="Italic">Callidiellum rufipenne</Emphasis> (Coleoptera:Cerambycidae), on Japanese cedar, <Emphasis Type="Italic">Cryptomeria japonica</Emphasis>, in terms of bark water content of host trees

We caught the adults of a secondary wood-boring insect, Callidiellum rufipenne (Motschulsky), on Japanese cedar, Cryptomeria japonica D. Don., trees and logs with manipulated bark water contents to clarify the mechanism of host selection by C. rufipenne. More C. rufipenne were trapped when the bark water content range was ca. 120–200%. Fewer C. rufipenne were trapped at higher and lower bark water contents. These findings indicate that C. rufipenne adults do not simply select weakened or dying trees. Bark water content is one of important factors for C. rufipenne choosing their host for oviposition.     

Establishment and growth of coniferous seedlings in an altered forest floor after long-term exclusion of deer

We evaluated differences between the forest floors and the establishment and growth of coniferous seedlings in fenced (13 years) and unfenced plots on Mt Ohdaigahara where the sika deer (Cervus nippon) population density is high. Large coniferous seedlings (height > 0.05 m) were less abundant in the unfenced plot, as a result of deer browsing. Small coniferous seedlings (height < 0.05 m), however, were more abundant in the unfenced plot, where most seedlings of Abies homolepis were found on bare ground and those of Picea jezoensis var. hondoensis were found on buttresses and fallen logs. The large area of bare ground in the unfenced plot was caused by deer browsing. Deer therefore have an indirect effect on the emergence and growth of small coniferous seedlings by modifying the forest floor.     

Intramammary infusion of an Enterococcus faecium SF68 preparation promoted the involution of drying off Holstein cows partly related to neutrophil‐associated matrix metalloproteinase 9

A problem for dairy cows following milk stasis is to cope with a high risk of intramammary infection and there is a need to initiate an extensive renewal of secretory modules in mammary glands so that milk production in next lactation may be optimized. We recently reported that ultrasonicated Enterococcus faecium SF68 (SF68) is compatible with cow mammary glands and an enhancer of innate immunity during the immediate post‐milk stasis period. The current study further examines the concomitant effect of ultrasonicated SF68 on mammary tissue remodeling. Four Holstein cows each received intramammary infusions of regular antibiotic dry‐cow formula (positive control) and two different doses of SF68 in different quarters. Analyses of individual quarter secretion samples showed faster neutrophil infiltration, earlier modifications in protein composition, including caseins and lactoferrins, as well as more prompt elevation of the specific unit of 92‐kDa matrix metalloproteinase 9 (MMP9) in SF68‐infused quarters compared to the positive controls. Intramammary infusion of ultrasonicated SF68 seems able to accelerate the regression of mammary synthetic capacity and potentiate the breakdown of glandular extracellular matrix, indicating a more efficient mammary gland involution. Correlation analyses imply that the ability of ultrasonicated SF68 to induce faster neutrophil chemotaxis and the associated MMP9 release is partly responsible.     

油茶炭疽病的研究

油茶炭疽病引起落花、落蕾、落果及落叶。病落果率约为全年总落果率的60%,根据标准株平均统计,病落蕾率占总落蕾率的26—45%。通过菌种形态比较与接种试验,肯定病原与茶叶上云纹叶枯病菌系同一种为 Colletotrichum camelliae Massee。其无性世代发生在寄主各部位,呈现不同征状,有性世代仅出现在连续阴雨一个月以上的枝梢及花蕾的病斑上。分生孢子具有抗旱及抗低温能力,但不能忍受冰冻温度。初次侵染来源为枝干的溃疡斑及病蕾蕾痕,经春雨浸湿大量产生,通过雨中风力广泛传布。干燥气流在传病上不起作用。夏、秋晨间露水滴溅也可使病菌孢子扩散侵染。根据湘西怀化县长期观察试验,象鼻虫在传病上并不是重要因素。各地区温差影响发病迟早,湿差影响严重度,雨天日数决定落蕾、落果的数量与时期。品种抗病性差异除形态特征外(气孔数量、角质层厚薄等),可能与表皮细胞层次与缀密度以及细胞的内含成份有关,果形及色泽与抗病性差异无实质关系。小果型品种(湖南珍珠于、苦槠子,江西宜春中子)的抗病性可能由上述的特性决定。     

Effect of fructo‐oligosaccharides on nutrient digestibility and digesta retention time in adult guinea pigs

A previous study suggested that addition of fructo‐oligosaccharides (FOS) to the diet improved nitrogen (N) utilization and decreased acid detergent fiber (ADF) digestibility in guinea pigs. The present study was conducted to clarify the relationship between ADF digestibility and gastrointestinal mean retention time (MRT) in guinea pigs under FOS supplementation. Adult male guinea pigs were fed a commercial diet (50 g/day) with either 5% glucose (glucose group) or 5% FOS (FOS group) for 12 days in individual metabolism cages. Unlike the glucose group, N utilization improved, but ADF digestibility significantly (P < 0.05) decreased in the FOS group. MRT of solid digesta also significantly (P < 0.05) decreased in the FOS group compared with that in the glucose group. We concluded that reduction of MRT of solid digesta containing FOS decreased ADF digestibility in guinea pigs.     

Population density and range use of sika deer,Cervus nippon, on Mt. Ohdaigahara, central Japan

We investigated the population density and range use of sika deer,Cervus nippon, on Mt. Ohdaigahara, central Japan, from July 1996 to July 1997. The deer population density estimated by the block count was high at 17.5–30.9 deer/km². Although the deer remained this area from spring to fall, they moved out in winter, probably because of deep snow. A spotlight count showed that the deer prefer the eastern area as spring-summer range, where the forest consists of coniferous trees over a floor cover ofSasa nipponica, andS. nipponica grassland. The deer also use dense coniferous forest for cover, especially in summer and fall. Part of this study was presented at the 108th Annual Meeting of the Japanese Forestry Society (1997). This study was financially supported by the Environment Agency, Japan.     

Roles of water quality and disinfectant application on inactivation of fish pathogenic Streptococcus agalactiae with povidone iodine,quaternary ammonium compounds and glutaraldehyde

Streptococcosis is an important bacterial disease in Nile tilapia causing severe economic losses to tilapia aquaculture worldwide. The effects of water quality (low‐ [LS] and high‐level [HS] soiling, to mimic clean or dirty surface conditions and temperatures) and disinfectant application (diluted concentrations and exposure time) were characterized on the inactivation of Streptococcus agalactiae isolated from diseased tilapia. Five isolates were tested against three commercial disinfectant products with the main ingredients being povidone iodine (Anidine 100?; AD), benzalkonium chloride (Better BKC 80%?; BKC 80), and a mixture of quaternary ammonium compounds and glutaraldehyde (Chloraldehyde?; CR). CR demonstrated highest efficacy to S. agalactiae inactivation, followed by BKC 80 and AD, respectively. Higher‐level soiling, low temperature, diluted concentrations and short exposure time all decreased the disinfectant efficacy. CR and BKC 80 provided more than 5‐log inactivation at 1‐min exposure at 20°C under HS conditions, and also with ten‐fold‐diluted concentrations at 60‐min exposure time at 30°C. However, AD required 10‐min exposure to effectively remove bacteria under LS conditions at 30°C. The results could facilitate aquaculture management planning that leads to operating cost reductions and improvements in biosecurity.     

Evaluation of Seed Vigor Tests for Predicting Seedling Establishment at Low Temperature in Rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.)

This study was carried out to develop an evaluation method to predict rice seedling establishment (SE) under low-temperature conditions. Two Korean-bred japonica cultivars, Shindongjin and Hopum were used in the experiment. Fresh seeds were treated with an accelerated aging (AA) at 40°C and 100% RH for 1-15 days. The SEs of the fresh and AA seeds were evaluated in nursery beds at 17°C, and their correlation coefficients with seed vigor values measured by 9 test methods including standard germination test (SGT), cool germination test (CLT), cold germination test (CDT), seedling growth rate test (SGRT), ascorbate peroxidase (APX), peroxidase (POX), superoxide dismutase (SOD), catalase (CAT), and α ‐amylase (AMY) activities. The percentage of SE decreased slowly from 75 to 0% with an increasing of AA period from 0 to 15 days. The result of nine vigor tests showed different correlations with the SE. SGT, CLT, SGRT, and POX were significantly correlated with the SE. In the correlation analysis with only short-term aging seeds (1-7 days), the SE was very highly correlated with SGT, CLT, CDT, SGRT, POX, and CAT. These results suggest that seed vigor values measured by several methods including SGT and POX could be used as a reference value to secure SE at low temperatures in nursery bed rice seedling culture.