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ABSTRACT: Genetic variation of the fungal parasite Pythium porphyrae ,causative organism of red rot disease of Porphyra , isolatedfrom Asan, Mokpo, Pusan and Wando in Korea, and from Aichi, Fukuokaand Miyagi in Japan was investigated by random amplified polymorphicDNA (RAPD) cluster analysis. The total 67 RAPD markers were generatedfrom 38 isolates by RAPD-polymerase chain reaction (PCR) using arbitraryprimers consisting of 10 nucleotide sequences and 33 of them indicatedpolymorphisms. The dissimilarity coefficients calculated from theRAPD banding patterns ranged from 0.0010 to 0.6983. The dendrogramgenerated by the unweighted pair-group method using arithmetic averagesshowed that the 38 isolates were classified into three clusters(Groups 1, 2 and 3). Group 1 consisting of two isolates from Miyagiwas separated from all other isolates by a genetic distance of 0.6983.Groups 2 and 3 containing the majority of the isolates were branchedon genetic distance of 0.3957. These two clusters subdivided intofour and three subclusters, respectively, which were apparentlyassociated with geographic origins of the isolates. Interestingly,the isolates from Asan of Korea were close to Japanese isolatesrather than Korean isolates on genetic diversity. In addition, thegenetic distances of intra-isolates from Japan were higher thanthose from Korea. 相似文献
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FAJRI ANUGROHO MAKOTO KITOU FUJIO NAGUMO KAZUTOSHI KINJO YOSHIHIRO TOKASHIKI 《Weed Biology and Management》2009,9(1):63-71
Hairy vetch ( Vicia villosa ), as a winter cover crop, can be used to suppress weeds in subtropical regions, as well as temperate regions. Information on the potential biomass growth of hairy vetch for weed control and nutrient accumulation is not available in subtropical regions. Hairy vetch was sown in November 2004, and October, November, and December 2005. The wide-ranging cultivation period of hairy vetch indicated that it could be used in various cropping systems. It showed a higher biomass and nutrient accumulation when grown in subtropical Okinawa, Japan. Moreover, the biomass, and fixed carbon and magnesium (Mg) uptake in the above-ground parts of hairy vetch were found to be the highest in late May, with the highest nitrogen (N), potassium, and calcium uptake in mid-April and phosphorus (P) uptake in late March. Meanwhile, in the underground parts of the plant, they were highest in early May, except for the P and Mg uptake, which were highest in mid-April. According to the sowing date, the biomass and nutrient uptake of hairy vetch that was harvested in February were higher when sown in October. Similarly, when harvested in March, the biomass and nutrient uptake were higher when sown in October or November. In April, they were higher when sown in November or December. Hairy vetch has the potential to effectively suppress weeds in the winter and the spring seasons related to its sufficient biomass during the growing seasons. However, both the sowing and harvesting times of hairy vetch should be considered with reference to the cropping system; the subsequent crop will be sown to meet the N requirement. 相似文献
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Two of the many benefits of including legume cover crops in a fallow cropping system are weed suppression and increased soil organic N. This study was conducted in order to examine the effect of hairy vetch (Vicia villosa) on weed growth and soil N through a fallow period in subtropical Okinawa, Japan. Together with an untreated control plot, hairy vetch was grown from November 2007 to April 2008 and subsequently incorporated into the soil. The weeds were allowed to develop uncontrolled for 2 months until the time when a cash crop would be planted. In the period after the incorporation of hairy vetch, the weed biomass in the hairy vetch (HV)+ plot was more than threefold greater than that in the HV? plot. Hairy vetch had a high tendency to uptake N in April before the incorporation of hairy vetch; the N uptake by the weeds was lower in the HV+ plot than in the HV? plot. After the incorporation of hairy vetch, the N uptake by the weeds in the HV+ plot was two‐to‐six times higher than that by the weeds in the HV? plot. The C/N ratios of hairy vetch and the weeds in the HV+ plot were lower than those of the weeds in the HV? plot. More than half of the hairy vetch residue and N in the residue had decomposed by 28 days after incorporation. The content of both the NH4‐N and NO3‐N in the HV+ soil was higher than that in the HV? soil. Moreover, the amount of NO3‐N increased during the growing period of hairy vetch and decreased after the incorporation of hairy vetch. The fallow soil into which hairy vetch had been incorporated displayed a greater weed biomass and resulted in a higher inorganic N content than the soil that had not supported hairy vetch. 相似文献
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土壤微生物种群类型,对土壤质量和作物生长具有重要影响,研究寡糖对土壤微生物种群的影响特征,有助于正确、高效及安全使用寡糖。本研究利用人工气候室进行土壤培养,土壤施加50mg·L−1的壳寡糖（CSOS）和纤维寡糖（COS）溶液,以清水（CK）为对照处理,培养6d后取样,利用高通量测序技术,分析土壤微生物群落结构组成及多样性分布特征。结果表明：壳寡糖（CSOS）和纤维寡糖（COS）处理均显著改变细菌、真菌的群落结构,提高细菌的物种观测数。变形菌门（Proteobacteria）、酸杆菌门（Acidobacteria）、放线菌门（Actinobacteria）、绿弯菌门（Chloroflexi）、芽单胞菌门（Gemmatimonadetes）和拟杆菌门（Bacteroidetes）为优势细菌门,子囊菌门（Ascomycota）、担子菌门（Basidiomycota）和被孢霉门（Mortierellomycota）为优势真菌门。通过组间群落组成比较分析可知,壳寡糖（CSOS）和纤维寡糖（COS）处理均不同程度降低酸杆菌门（Acidobacteria）的相对丰度,增加变形菌门（Proteobacteria）、放线菌门（Actinobacteria）、芽单胞菌门（Gemmatimonadetes）、壶菌门（Chytridiomycota）以及有益菌属溶杆菌属（Lysobacter）、硝化螺旋菌属（Nitrospira）、Haliangium、芽球菌属（Blastococcus）和链霉菌属（Streptomyces）的相对丰度,但与纤维寡糖（COS）相比,壳寡糖（CSOS）处理微生物群落组成的变化幅度更大。此外,壳寡糖（CSOS）和纤维寡糖（COS）处理在调节土壤微生物群落结构上存在一定差异。其中,壳寡糖（CSOS）处理有益菌属Talaromyces的相对丰度增加195%,纤维寡糖（COS）处理有益菌属假单胞菌属（Pseudomonas）的相对丰度增加215%。综上,壳寡糖和纤维寡糖处理均能优化土壤微生物群落的结构组成,其调控差异性有助于理解不同寡糖的调控机制,推动寡糖的应用与推广。 相似文献
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MINORU FUNAKI JUNJI YAMAMOTO MAKOTO NISHIZAWA TAKASHI YAMAGISHI 《Fisheries Science》2002,68(5):1151-1154
The isolated mantle of scallop ( Patinopecten yessoensis ) was shown to adsorb minerals (Zn, Ca, Mg, Fe, Cu, Ni and Co) to more than 1% upon treatment with mineral solution. The amounts of adsorbed Zn, Ca and Mg were 44.3, 47.4 and 15.5 mg/g dry weight, when the mantle was treated with 5% ZnSO4 , CaCl2 and MgSO4 solutions at room temperature, respectively. The amounts of adsorbed Zn, Ca and Mg were dependent on the concentration of mineral solution used. This is the first report showing that the isolated mantle adsorbs nutritionally important minerals such as Ca, Mg and Fe. This finding may lead to the development of new mineral-enriched food supplements. 相似文献
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Tomo TAKAGI Ryuichi ANDO Atsushi OHGUSHI Tomonori NAKANISHI Hazizul HUSSAIN-YUSUF Ryoji ONODERA Hiroyuki SATO D. Michael DENBOW Mitsuhiro FURUSE 《Animal Science Journal》2003,74(2):101-104
It has been demonstrated that L-pipecolic acid (L-PA), a major metabolic intermediate of L-lysine (L-Lys) in the brain, is involved in the functioning of the γ-aminobutyric acid-ergic system. Previous study has shown that intracerebroventricular injection of L-PA suppressed feeding and induced sleep-like behavior in neonatal chicks. The present study examines whether the action of L-PA was induced by gavage in both chicks and mice. Oral administration of L-PA significantly inhibited food intake at 2 h after treatment in neonatal chicks, although no significant effect of L-Lys was detected. In mice, oral L-PA suppressed food intake compared to the control after 2 h of treatment. It was concluded that L-PA was effective for suppression of food intake after oral administration in both avian and mammalian species. 相似文献
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Shiori IKUSHIMA Masaki ANDO Makoto ASANO Masatsugu SUZUKI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2021,83(2):349
Monitoring the mortality of wildlife provides basic demographic information to support management plan preparation. The utility of mortality records for conservation measures was investigated in the Japanese serow, focusing on temporal trends and spatial distribution. Using the mortality records of Japanese serow from 2006 to 2018 in Gifu prefecture, cause-specific mortality was categorized into five groups (disease, accident, vehicle collision, parapoxvirus infection, and unknown), and the sex ratios were examined. A state space model was used to analyze the time series for the monthly mortalities, and kernel estimation was used for the spatial distribution of the parapoxvirus infection. Land cover type around the detection point was also reported. Disease, accident, and vehicle collision mortality were similar, and 30% of mortality was of anthropogenic origin. The number of mortality records for males was higher, and the larger home range of males could account for this. The state space model showed moderate increases in monthly mortalities over time and a seasonal variation with the highest level in spring and lowest in winter. Land cover analysis demonstrated a temporal increase in the proportion of human settlement areas, suggesting the change of the Japanese serow habitat. The proximity of Japanese serow to human settlements contributed to increase in mortality records. The point pattern analysis indicated spatial clustering for parapoxvirus infection in the area where an epidemic had occurred in the past. Several measures are recommended; however, mortality records can help develop improved conservation plan. 相似文献