Evaluation of genetic variation among wild rice populations in Cambodia     

Chhourn Orn  Rieko Shishido  Masahiro Akimoto  Ryo Ishikawa  Than Myint Htun  Ken-Ichi Nonomura  Yohei Koide  Men Sarom  Seng Vang  Sakhan Sophany  Ouk Makara  Takashige Ishii 《Breeding Science》2015,65(5):430-437

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   

Factors affecting oat haploid production following oat × maize hybridization     

P. K. Sidhu    N. K. Howes    T. Aung    P. K. Zwer    P. A. Davies 《Plant Breeding》2006,125(3):243-247

Doubled haploids (DHs) are becoming increasingly important in crop breeding programmes but methods for producing oat DHs remain inefficient. In this study haploid and DH oat plants were produced using the oat × maize hybridization method. Factors influencing the rate of caryopsis and haploid embryo production including genotype, post‐pollination plant growth regulator application and temperature were investigated. The four growth regulators tested showed significant differences in their capacity to induce caryopsis formation with dicamba producing the highest numbers of caryopses, followed by picloram, 2,4‐dichlorophenoxyacetic acid (2,4‐D) and gibberellic acid (GA₃). No significant differences were observed between these growth regulators for their effect on embryo production. The concentration of dicamba was also important and was found to influence caryopsis but not embryo production, with 50 and 100 mg/l dicamba producing significantly more caryopses than 25 or 5 mg/l. Temperature had a significant impact on both caryopsis and embryo production with the magnitude and direction of response depending on genotype. Rates of haploid embryo production observed were between 0.8% and 6.7% of the pollinated florets. The proportion of haploids, which survived and were successfully doubled with colchicine following transfer to soil was between 72% and 81%.  相似文献   

Interfering with regular meiotic behaviour in Avena sativa as a method of incorporating the gene for mildew resistance from A. barbata     

Hugh Thomas  W. Powell  T. Aung 《Euphytica》1980,29(3):635-640

Summary The regular meiotic behaviour of the cultivated oat Avena sativa (2n=6x=42) is genetically controlled. The factors which control the diploid-like meiotic behaviour also restrict the amount of pairing that occurs between alien chromosomes and their homoeologues in A.sativa, and hence increases the difficulties of introducing desirable variation from wild species into the cultivated oat. A genotype of the diploid species A.longiglumis which interferes with the regular meiotic behaviour of A. sativa can be used to induce pairing between alien chromosomes and their corresponding chromosomes in A. sativa. Using this procedure the dominant gene conferring mildew resistance has been transferred from the tetraploid weed species A. barbata into the cultivated oat.  相似文献   

The transfer of the gene for mildew resistance from Avena barbata (4x) into the cultivated oat A. sativa by an induced translocation     

Taing Aung  Hugh Thomas  I. T. Jones 《Euphytica》1977,26(3):623-632

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Volatile emissions of navel oranges as predictors of freeze damage     

Obenland DM  Aung LH  Bridges DL  Mackey BE 《Journal of agricultural and food chemistry》2003,51(11):3367-3371

Volatile emissions of navel orange (Citrus sinensis L. Osbeck cv. Washington) fruit were evaluated as a means for predicting and gauging freeze damage. The fruits were subjected to -5 or -7 degrees C treatments in a laboratory freezer for various time periods of 2-9.5 h and stored at 23 degrees C for 1, 2, or 7 days, after which time the emission of volatiles from the fruit was measured. Following the final day of volatile measurements the fruits were stored at 5 degrees C for an additional 2-3 weeks and then evaluated for fruit quality characteristics. Peel injury in the form of brown lesions, drying of the juice vesicles, a decline in acidity, and a loss of flavor were observed to occur as a result of freezing. Corresponding to the loss in fruit quality were large increases in the emissions of ethanol, ethyl butanoate, methyl hexanoate, and ethyl octanoate. With the exception of methyl hexanoate, for which volatile emissions decreased during storage for 7 days at 23 degrees C, all of the other volatiles were relatively unchanged in amount by storage. Treatment at -7 degrees C caused greater injury, quality loss, and more volatile emanation than did freezing at -5 degrees C. The measurement of volatile emissions appears to be a useful approach to identify freeze-damaged navel oranges.  相似文献   

Proteus mirabilis infection in quail in burma     

Aung Myint 《Tropical animal health and production》1987,19(2):75-76

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Iron biofortification of rice using different transgenic approaches   总被引：1，自引：0，他引：1  

Hiroshi Masuda  May Sann Aung  Naoko K Nishizawa 《Rice》2013,6(1):40

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Effect of soybean husk supplementation on the fecal fermentation metabolites and microbiota of dogs          下载免费PDF全文

Htun Myint  Yu Iwahashi  Satoshi Koike  Yasuo Kobayashi 《Animal Science Journal》2017,88(11):1730-1736

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   

Sulphur supply impairs spread of Verticillium dahliae in tomato     

Katharina Bollig  Andr�� Specht  San Shwe Myint  Marc Zahn  Walter J. Horst 《European journal of plant pathology / European Foundation for Plant Pathology》2013,135(1):81-96

Vascular wilt caused by the soil-borne fungus Verticillium dahliae is a major yield and quality-limiting disease across a broad spectrum of crop plants worldwide. Sulphur-enhanced plant defence mechanisms provide an opportunity to effectively and environmentally safely constrain the wilt disease levels in planta. To evaluate the influence of sulphur nutrition on the protective potential of these mechanisms, two near-isogenic tomato genotypes differing in fungal susceptibility, were treated with low or supra-optimal sulphur supply. Microscopic analysis revealed a significant sulphur-induced decrease in the amount of infected vascular cells in both genotypes. However, plant shoot and severely pathogen-affected root growth did not display this distinct alleviating influence of sulphur nutrition. Rates of leaf photosynthesis were impeded by Verticillium dahliae infection in both genotypes especially under low sulphur nutrition. However, assimilate transport rates in the phloem sap were enhanced by fungal infection more in the resistant genotype and under high sulphur nutrition suggesting a stronger sink for assimilates in infected plant tissues possibly involved in sugar-induced defence. A SYBR Green-based absolute quantitative Real-Time assay using a species-specific primer was developed which sensitively reflected sulphur nutrition-dependent changes in fungal colonization patterns. High sulphur nutrition significantly reduced fungal spread in the stem in both tomato genotypes. Concentrations of selected sulphur-containing metabolites revealed an increase of the major anti-oxidative redox buffer glutathione under high sulphur nutrition in response to fungal colonization. Our study demonstrates the existence of sulphur nutrition-enhanced resistance of tomato against Verticillium dahliae mediated by sulphur-containing defence compounds.  相似文献   

Postharvest conditioning temperatures and fruit maturity on flavedo soluble sugars of coastal and desert lemons     

L. H. Aung  J. F. Jenner  D. C. Fouse  L. G. Houck 《The Journal of Horticultural Science and Biotechnology》2013,88(3):288-292

Summary

The content and changes in flavedo soluble sugars of Citrus limon (L.) Burm. F. of different maturity derived from coastal and desert climatic regions to two postharvest conditioning temperatures of 158C and 108C were determined. Conditioning caused significant changes of flavedo soluble sugars in lemons of the two geographic areas. Raffinose level increased with duration of conditioning in both desert and coastal lemons and was slightly higher at 108C than at 158C conditioning. The flavedo sucrose content of green coastal lemons was greater than silver or yellow lemons and increased significantly in silver and yellow lemons after conditioning for 3 d at 158Cor108C, but declined significantly in all maturity classes to a low level with conditioning of more than 3 d. In contrast, the flavedo sucrose content of green and yellow desert lemons was 2.8–fold and 1.7–fold greater, respectively, than comparable coastal lemon flavedo, with the green lemon flavedo showing a significant gradual decrease with increasing duration of conditioning at 158C and 108C, but not in yellow lemon flavedo. The flavedo glucose and fructose contents of desert lemons remained relatively unchanged with conditioning at 158C and 108C, but their contents in yellow, silver and green coastal lemon flavedo increased after prolonged conditioning. The flavedo fructose content of yellow coastal lemons was significantly greater than green lemons, but there was no difference in flavedo fructose content of green and yellow desert lemons. The observed alteration of flavedo soluble sugars associated with conditioning provided an insight of cellular response to temperature, and emphasized the importance of climatic origin on lemon flavedo sugar composition.  相似文献