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1.
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.  相似文献   
2.
ABSTRACT:   Experimental insemination was performed using artificially produced low-motility sperm. A mathematical model was applied to the results of the insemination in order to clarify the relationship between sperm motility, the density of sperm and the fertilization rate of eggs. In the model, the probability of fertilization by individual spermatozoa was a function of sperm density in the insemination solution. The results showed that the probability of fertilization clearly decreased with increased sperm density, and the maximum possible fertilizing rate by increasing the sperm density was constrained by the proportion of motile sperm (% motility). The model was also applied to the results of insemination tests of cryopreserved sperm in order to evaluate the fertilizing capacity of cryopreserved sperm. It was proven that cryopreserved sperm needed a higher density to obtain the maximum fertilization rate compared with fresh sperm, and it was anticipated that the ratio of the motile inseminated cryopreserved sperm should be more than 5.0% to achieve an egg fertilization rate greater than 90%.  相似文献   
3.
A total of 448 samples in five natural populations of wild rice (Oryza rufipogon) were collected in Cambodia. They were examined using 12 SSR and two chloroplast markers to evaluate the degree of variation among populations and the genetic structure within populations. In the two annual populations, the number of plants with homozygous alleles at all 12 SSR loci were high (66.3% and 79.5%), suggesting that these plants propagate mainly through self-pollination. In the three perennial populations, no individuals had all homozygous genotypes, but redundant genotypes resulted from clonal propagation were observed. Percentages of the redundant genotypes were highly varied (3.6%, 29.2% and 86.0%). This may be due to the different stable levels of environmental conditions. As for chloroplast genome, most of the wild plants showed the same chloroplast types as most Indica-type cultivars have. However, plants with different chloroplast types were maintained, even in the same population. In tropical Asian countries, many wild rice populations were observed under similar ecological conditions examined in this study. Therefore, the present results concerning population structure will be important to further elucidate genetic features of wild rice, and will also give strong clues to utilize and conserve wild natural genetic resources.  相似文献   
4.
In vitro fermentation and in vivo feeding experiments were conducted to characterize the effects of soybean (Glycine max) husk on the fecal fermentation metabolites and microbiota of dogs. An in vitro fermentation study using feces from three Toy Poodle dogs (6.5 ± 3.5 months in age and 2.9 ± 0.4 kg in body weight) revealed that the fecal inoculum was able to ferment soybean husk (supplemented at 0.01 g/mL culture) and increased levels of short chain fatty acids (SCFA) and Bifidobacterium, irrespective of pre‐digestion of the husk by pepsin and pancreatin. In a feeding experiment, four Shiba dogs (7–48 months in age and 7.5 ± 1.7 kg in body weight) fed a commercial diet supplemented with 5.6% soybean husk showed an increase in SCFA, such as acetate and butyrate, and lactate, and a decrease in indole and skatole in the feces compared to those fed a 5.6% cellulose diet. Real‐time PCR assay showed that soybean husk supplementation stimulated the growth of lactobacilli, Clostridium cluster IV including Faecalibacterium prausnitzii, Clostridium cluster XIVa, Bacteroides‐Prevotella‐Porphyromonas group but inhibited the growth of Clostridium cluster XI. Both in vitro and in vivo experiments indicated that soybean husk supplementation improves gastrointestinal health through optimization of beneficial organic acid production and increase of beneficial bacteria. Therefore, soybean husk is suggested to be applicable as a functional fiber in the formulation of canine diets.  相似文献   
5.
Abstract

The toxicity and efficacy of the acute rodenticide zinc phosphide (Zn3P2) was evaluated in the laboratory against the lesser bandicoot rat (Bandicota bengalensis), from Rangoon, Burma. The acute LD50 and LD95 doses of orally-administered zinc phosphide for B. bengalensis were found to be 25.0 mg/kg and 113.0 mg/kg of body weight respectively. When caged bandicoots were given a choice between plain and poison baits, the optimum rodenticidal concentrations in the bait was found to be 2.5%. Symptoms of poisoning appear from 32 minutes to 3 hours after feeding starts, giving individual animals time to consume from 10 to over 27 LD50 doses of 25% zinc phosphide before feeding stops. Death occurred in a minimum of 4 to 5 hours following either oral dosing or free choice feeding. There appears to be aversion to the poison at higher concentrations in food baits. The relative merits of zinc phosphide and pyriminyl as rodenticides against the lesser bandicoot in Rangoon will have to be determined in a series of comparative field trials.  相似文献   
6.

In the last 40 years, the rice-cropping system has considerably changed in the Ayeyarwady Delta. The large archive of satellite imagery provides a history of how land and water resource managements have changed in the face of growing populations, resource demand, and climate change. This study aimed to assess the decadal changes in the rice-cropping system in the Ayeyarwady Delta by using the large archive of satellite imagery for the last 40 years (1981???2020). The long-term NDVI dataset provided various information on rice cultivation. Signal processing techniques were used to detect on the historical changes in the rice-cropping system, and the impact of climate change was assessed by using trend analysis. Until the 1980s, single-cropping of summer rice was dominant in the Delta. To enhance the grain yield of rice, the irrigation facilities were introduced in 1992 under an initiative of the Myanmar government. As a result, the annual cropping intensities increased from 1.087?±?0.390 in the 1980s to 1.422?±?0.499 in the 2010s. The information on historical change in the rice-cropping system would be useful to consider the practical and cost-effective utilization of remaining land and water resources. Moreover, the trend analysis of NDVI time-series showed negative trends in coastal areas. This indicates that the rice production in coastal areas has been constrained by the saline intrusion. The salt-affected areas are expected to expand under future climate change scenarios. Government support is highly required for sustainable rice production in the Delta.

  相似文献   
7.
Journal of Crop Science and Biotechnology - Fatty acids (FAs) are important desirable compounds in oil crops. Here, we evaluated the amounts of 14 FAs in sesame grains using gas chromatography mass...  相似文献   
8.
Wheat yellow dwarf disease (BYD), caused by different species of barley/cereal yellow dwarf viruses (B/CYDVs), is one of the most serious cereal diseases in China and the Czech Republic. Because genetic diversity of the virus directly influences disease epidemiology, the molecular diversity and population structure of 24 Chinese isolates and 16 the Czech Republic isolates of BYDV-PAV from different regions in two countries were analyzed by sequencing their coat protein (CP) and readthrough protein (RTP) domain (RTD) genes and comparing the sequences with six CP and 16 RTP sequences of BYDV-PAV isolates from the NCBI database based on nucleotide identity position, phylogenetic analysis and nucleotide diversity. Nucleotide identities between the Chinese and the Czech Republic isolates for the CP were 76.6–99.4%, 73.9–89.1% for RTD (ORF5), respectively. The Chinese and the other country isolates showed 74.7–99.2% nucleotide identity for RTP (ORF3+ORF5). Phylogenetic analysis of CP sequences showed that 20 Chinese isolates clustered in the same clade, but the other four Chinese isolates clustered in another clade with the isolates from the Czech Republic and other counties. The population of BYDV-PAV in China had greater nucleotide variability and was more divergent than that in the Czech Republic. Geographical and ecological factors but not hosts might contribute to the population differences in the two countries.  相似文献   
9.
Paddy and Water Environment - Summer rice cannot be grown near the coast of the Ayeyarwady Delta, Myanmar, because of the high salinity in river water during the dry season. This means that saline...  相似文献   
10.
Topology and formation of triple-stranded H-DNA   总被引:39,自引:0,他引:39  
Repeating copolymers of (dT-dC)n.(dA-dG)n sequences (TC.AGn) can assume a hinged DNA structure (H-DNA) which is composed of triple-stranded and single-stranded regions. A model for the formation of H-DNA is proposed, based on two-dimensional gel electrophoretic analysis of DNA's with different lengths of (TC.AG)n copolymers. In this model, H-DNA formation is initiated at a small denaturation bubble in the interior of the copolymer, which allows the duplexes on either side to rotate slightly and to fold back, in order to make the first base triplet. This nucleation establishes which of several nonequivalent H-DNA conformations is to be assumed by any DNA molecule, thereby trapping each molecule in one of several metastable conformers that are not freely interconvertible. Subsequently, the acceptor region spools up single-stranded polypyrimidines as they are released by progressive denaturation of the donor region; both the spooling and the denaturation result in relaxation of negative supercoils in the rest of the DNA molecule. From the model, it can be predicted that the levels of supercoiling of the DNA determine which half of the (dT-dC)n repeat is to become the donated third strand.  相似文献   
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