Changes in petiole hydraulic properties and leaf water flow in birch and oak saplings in a CO2-enriched atmosphere     

Eguchi N  Morii N  Ueda T  Funada R  Takagi K  Hiura T  Sasa K  Koike T 《Tree physiology》2008,28(2):287-295

Water relations in woody species are intimately related to xylem hydraulic properties. High CO(2) concentrations ([CO(2)]) generally decrease transpiration and stomatal conductance (g(s)), but there is little information about the effect of atmospheric [CO(2)] on xylem hydraulic properties. To determine the relationship between water flow and hydraulic structure at high [CO(2)], we investigated responses of sun and shade leaves of 4-year-old saplings of diffuse-porous Betula maximowicziana Regel and ring-porous Quercus mongolica Fisch. ex Ledeb. ssp. crispula (Blume) Menitsky grown on fertile brown forest soil or infertile volcanic ash soil and exposed to 500 micromol CO(2) mol(-1) for 3 years. Regardless of species and soil type, elevated [CO(2)] consistently decreased water flow (i.e., g(s) and leaf-specific hydraulic conductivity) and total vessel area of the petiole in sun leaves; however, it had no effect on these parameters in shade leaves, perhaps because g(s) of shade leaves was already low. Changes in water flow at elevated [CO(2)] were associated with changes in petiole hydraulic properties.  相似文献   

Factors controlling soil microbial respiration during the growing season in a mature larch plantation in Northern Japan     

Laiye Qu  Satoshi Kitaoka  Takayoshi Koike 《Journal of Soils and Sediments》2018,18(3):661-668

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Application of single‐step genomic best linear unbiased prediction with a multiple‐lactation random regression test‐day model for Japanese Holsteins          下载免费PDF全文

Toshimi Baba  Yusaku Gotoh  Satoshi Yamaguchi  Satoshi Nakagawa  Hayato Abe  Yutaka Masuda  Takayoshi Kawahara 《Animal Science Journal》2017,88(8):1226-1231

This study aimed to evaluate a validation reliability of single‐step genomic best linear unbiased prediction (ssGBLUP) with a multiple‐lactation random regression test‐day model and investigate an effect of adding genotyped cows on the reliability. Two data sets for test‐day records from the first three lactations were used: full data from February 1975 to December 2015 (60 850 534 records from 2 853 810 cows) and reduced data cut off in 2011 (53 091 066 records from 2 502 307 cows). We used marker genotypes of 4480 bulls and 608 cows. Genomic enhanced breeding values (GEBV) of 305‐day milk yield in all the lactations were estimated for at least 535 young bulls using two marker data sets: bull genotypes only and both bulls and cows genotypes. The realized reliability (R²) from linear regression analysis was used as an indicator of validation reliability. Using only genotyped bulls, R² was ranged from 0.41 to 0.46 and it was always higher than parent averages. The very similar R² were observed when genotyped cows were added. An application of ssGBLUP to a multiple‐lactation random regression model is feasible and adding a limited number of genotyped cows has no significant effect on reliability of GEBV for genotyped bulls.  相似文献   

Responses of community structure,diversity, and abundance of understory plants and insect assemblages to thinning in plantations   总被引：1，自引：0，他引：1  

Hisatomo Taki  Takenari Inoue  Hiroshi Tanaka  Hiroshi Makihara  Masahiro Sueyoshi  Masahiro Isono  Kimiko Okabe 《Forest Ecology and Management》2010

Identifying effective management operations for plantations is important for conservation of biodiversity in a plantation-dominated landscape. We tested whether pre-commercial thinning influenced community structures and could be an effective strategy for increasing diversity and abundance of plants and animals in plantations. We designated thinned and unthinned study stands in Japanese cedar (Cryptomeria japonica) plantations and compared the communities of understory vegetation, bees, butterflies, hoverflies, and longhorn beetles 1 and 3 years after thinning. The analyses of vegetation showed that pre-commercial thinning affected community structure, but species richness and vegetation abundance were not significantly affected. Thinning affected insect community structure, and both species richness and abundance of all insect groups increased 1 year after thinning. However, 3 years after thinning, significant differences only remained in the species richness of bees and the abundance of bees, butterflies, and hoverflies. These results suggest that pre-commercial thinning in plantation stands influences the community structure of understory vegetation and can be an effective way to increase the diversity and abundance of some insect groups in the short term. However, the results also suggest that the duration of the operational effects of pre-commercial thinning varies among insect groups; thus, the variable effects of pre-commercial thinning should be carefully considered in the conservation-based management of plantation stands.  相似文献   

Evaluation of the juice brix of wild sugarcanes (Saccharum spontaneum) indigenous to Japan     

Takeo Sakaigaichi  Yoshifumi Terajima  Makoto Matsuoka  Takayoshi Terauchi  Taiichiro Hattori  Shoko Ishikawa 《Plant Production Science》2016,19(2):323-329

Modern sugarcane cultivars are derived from the interspecific crossing between Saccharum officinarum and wild sugarcane, Saccharum spontaneum. The introgression of valuable characteristics from wild sugarcane is recognized as extremely important, but this process typically requires long-term effort over multiple generations of backcrosses owing to the low sugar content of the initial interspecific hybrids. In this study, we aimed to identify Japanese wild sugarcanes with high juice brix in order to promote effective interspecific crossing of sugarcane. Sixty-four accessions from the Nansei Islands and 70 accessions from the Honshu were evaluated for juice brix. Wild sugarcanes with high juice brix were demonstrated to exist among wild sugarcanes indigenous to the Honshu. A significant difference was observed between the median juice brix values of wild sugarcanes of the Nansei Islands and those of the Honshu. The relationship between juice brix and stem traits was then examined in 20 wild sugarcanes, 10 each from the Nansei Islands and the Honshu. The reproducibility of juice brix value in both experiments was confirmed. In contrast to juice brix, stem traits, such as length, diameter, and volume, were typically smaller in wild sugarcanes from the Honshu. Moreover, a negative correlation was observed between the index of stem volume and juice brix. In this study, we identified outstanding wild sugarcanes with high juice brix. Using germplasms from the identified wild sugarcanes in interspecific crossing could contribute to the increases in both yield and sugar content.  相似文献   

Inheritance mode of male sterility in bunching onion (<Emphasis Type="Italic">Allium fistulosum</Emphasis> L.) accessions     

Ken-ichiro Yamashita  Hikaru Tsukazaki  Akio Kojima  Takayoshi Ohara  Tadayuki Wako 《Euphytica》2010,173(3):357-367

Cytoplasmic male sterility (CMS) is an indispensable trait for F₁ hybrid seed production in bunching onion (Allium fistulosum L.). Expansion of the cytoplasmic diversity of F₁ hybrid cultivars by introduction of various CMS resources has great potential to eliminate vulnerability to cytoplasm type-specific diseases. This study aimed to evaluate appearance frequency of male sterile plants in several bunching onion accessions and to identify CMS resources. In eight (‘Nogiwa Aigara’, ‘Bansei Hanegi’, ‘Amarume’, ‘Kimnung’, ‘Zhangqiu’, ‘INT/CHN/1990/GOTOU’, ‘Natsunegi’ and ‘Guangzhou’) of 135 accessions collected from Japan, China, Mongolia, Korea and Taiwan, male sterile plants appeared with varied frequencies from 1.7% (‘Nogiwa Aigara’ and ‘Bansei Hanegi’) to 24.5% (‘Zhangqiu’). The inheritance mode of Zhangqiu- and Guangzhou-derived male sterility was confirmed to be CMS by sib-crossings and interbreed crossings. Microscopic examination of microsporogenesis in the CMS plants revealed that microspore protoplasm rapidly degenerated without mitotic division after the release of microspores from tetrads. The CMS germplasm described here would be useful for the development of “A” lines to be used in F₁ hybrid seed production of bunching onion. Male fertility in ‘Nogiwa Aigara’, ‘Bansei Hanegi’, ‘Kimnung’, ‘INT/CHN/1990/GOTOU’ and ‘Natsunegi’ was verified to be controlled by a single fertility restoration locus.  相似文献   

四种虎凤蝶翅面斑纹特征及鳞片的超微结构   总被引：2，自引：0，他引：2  

洪健  叶恭银  胡萃 《浙江大学学报(农业与生命科学版)》1998,(Z1)

比较了中华虎凤蝶、太白虎凤蝶、乌苏里虎凤蝶和日本虎凤蝶成虫翅面斑纹特征及鳞片超微结构。前翅外缘黄色斑,后翅外缘半月斑、亚外缘红色斑、亚外缘黑色斑、中室黑带及前翅外缘形状和后翅尾突长度等特征在种间有明显差别,是种鉴定的重要依据。鳞片按其形状和结构可分为４种类型,后翅外缘处的青色鳞片具金属光泽,为结构色,其余各色鳞片的结构相同,为色素色。四种虎凤蝶的鳞片超微结构无明显差异。  相似文献   

Development of novel clubroot resistant rapeseed lines (Brassica napus L.) effective against Japanese field isolates by marker assisted selection     

Mitsuyo Kawasaki  Takayoshi Ohara  Masahiko Ishida  Yoshihito Takahata  Katsunori Hatakeyama 《Breeding Science》2021,71(5):528

Clubroot is an important disease infectible to cruciferous plants and a major threat to rapeseed production in Japan. However, no clubroot resistant rapeseed cultivars have been released. We surveyed pathotype variation of six isolates collected from rapeseed fields and found they were classified as pathotype groups 2 and 4 using Japanese F₁ Chinese cabbage cultivars. We produced the resynthesized clubroot resistant Brassica napus harboring two resistant loci, Crr1 and Crr2, by interspecific crossing and developed resistant rapeseed lines for southern and northern regions by marker-assisted selection and backcrossing. We improved the DNA marker for erucic acid content to remove linkage drag between Crr1 and high erucic acid content and successfully selected lines with clubroot resistance and zero erucic acid for northern regions. A novel line, ‘Tohoku No. 106’, suitable for southern regions showed stable resistance against all six isolates and high performance in infested fields. We conclude that Crr1 and Crr2 are important genes for CR rapeseed breeding and marker-assisted selection is effective in improving clubroot resistance.  相似文献   

Importance of basic cultivation techniques to increase irrigated rice yields in Tanzania     

Nobuhito Sekiya  Motonori Tomitaka  Nobuaki Oizumi  Adam Gabriel Pyuza  Richard James Shayo  Anne Niediwe Assenga  Takayoshi Iemoto  Kenji Ishido  Yasunori Saiki  Kenji Tamura  Takahiro Nakamura 《Paddy and Water Environment》2017,15(4):847-859

The productivity of irrigated rice is low in Tanzania. We hypothesized that this is caused by the absence of a packaged application of basic cultivation techniques. A baseline survey of 31 rice irrigation schemes across the country revealed that a large proportion of fields were cultivated without a technical package. Thus, a package was introduced to each of the 31 schemes through a farmer-to-farmer (FTF) extension approach. First, selected key farmers (KFs) were trained with the basic cultivation techniques at agricultural training institutes. Second, the KFs transferred their knowledge to intermediate farmers (IFs) by working together at a demo-field established in each scheme. Third, the KFs and IFs exhibited the rice performance to other farmers (OFs). The paddy yield across the 31 schemes greatly increased from the pre-training level of 2.4 t ha^?1 to 3.6 t ha^?1after the FTF extension. However, the farmer interviews in the four selected schemes suggested that the technical package was not adopted by all farmers owing to the time-consuming nature of the FTF extension. It was inferred from our study that the low productivity of irrigated rice is caused by the absence of basic cultivation techniques in Tanzania. However, the post-training yield remained relatively low compared with high-yields (4.3–8.4 t ha^?1) recorded in cultivar selection trials and high-performing schemes in the county. This “yield gap” could be partly ascribed to the insufficient technical diffusion and the technique-dependent adoption among OFs.  相似文献   

The Afferent Venous Vessels to the Liver and the Intrahepatic Portal Distribution in the Fowl     

Takayoshi  Miyaki 《Anatomia, histologia, embryologia》1978,7(2):129-139

The afferent veins to the liver of 325 adult fowls belonging to ten breeds were investigated by celluloid and neoprene latex casts, and venography. The author elucidates macroscopically the basic pattern of the hepatic portal vein. The right and left portal veins ramify the main branches to the liver, therefore, the intrahepatic distribution is divided into the two portal territories varying in relative size, but this change relates to the development of the medial branch from the right portal vein and the presence of the hepatic fissure.  相似文献