Effects of elevated CO2 concentration on growth, annual ring structure and photosynthesis in Larix kaempferi seedlings   总被引：2，自引：0，他引：2  

Yazaki K  Ishida S  Kawagishi T  Fukatsu E  Maruyama Y  Kitao M  Tobita H  Koike T  Funada R 《Tree physiology》2004,24(9):951-959

We evaluated the effects of elevated carbon dioxide concentration ([CO2]) and two nutrient regimes on stem growth rate, annual ring structure and temporal variations in photosynthetic characteristics of seedlings of Japanese larch (Larix kaempferi (Lamb.) Carr.). Seedlings were grown in phytotron chambers in an ambient (360 ppm) or an elevated (720 ppm) [CO2] in two nutrient regimes for one growing season. Elevated [CO2] reduced stem height and increased stem basal diameter compared with ambient [CO2]. The effect of elevated [CO2] on growth tended to be greater at high-nutrient supply than at low-nutrient supply. Elevated [CO2] had no significant effect on ring width or the number of tracheids per radial file. There was no obvious difference in cell wall thickness or the relative area of the cell wall between seedlings grown in ambient or elevated [CO2]. Although growth in elevated [CO2] resulted in a slight increase in cell diameter, the increase had a relatively minor effect on the relative area of the cell wall. Net assimilation rate increased in response to elevated [CO2]; however, the increase in whole-crown photosynthetic rate (Total Agrowth) in seedlings in the elevated [CO2] treatment was minimal because of the smaller specific needle area and acclimation of the photosynthetic characteristics of the needles to the growth [CO2]. In conclusion, we observed no obvious enhancement in the capacity for carbon fixation in Japanese larch seedlings grown in the presence of elevated [CO2] that might be attributable to changes in stem growth. However, elevated [CO2] caused changes in the temporal pattern of stem growth and in some anatomical features of the tracheids.  相似文献   

Effects of residual trees on tree height of 18- and 19-year-old Cryptomeria japonica planted in group selection openings     

Kenichi Yamashita  Nobuya Mizoue  Satoshi Ito  Akio Inoue  Hideaki Kaga 《Journal of Forest Research》2006,11(4):227-234

This study examined the effects of residual trees on the height of 18- and 19-year-old Cryptomeria japonica planted in group selection openings of about 0.1 ha at Yufuin in Oita Prefecture in southern Japan. We first developed a general model expressing variation in the height for all of the planted trees within the openings from indices of both between-cohort competition (the effects of residual trees) and within-cohort competition (among the even-aged planted trees). The between-cohort competition index was calculated both with and without taking into account the direction that residual trees were positioned from subject trees. The two models suggested that residual trees located near the northern edge of the opening were not effective competitors for light for the planted trees within the opening. In addition, our results indicated that both between-cohort competition and within-cohort competition are important for explaining tree height in closed stands within group selection openings. Using the general model, we then estimated the potential loss of height growth for locally dominant trees within the openings that could be attributed only to the influence of residual trees. These results indicated that in addition to the effect of opening size, both the degree of crowding and the direction of residual trees from the planted trees are important factors affecting the height of individual trees planted in group selection openings.  相似文献   

Genetic and environmental variances on growth and reproductive traits of silver crucian carp Carassius langsdorfii using communal and separate rearing systems     

Worawut Koedprang  Kenichi Ohara and  Nobuhiko Taniguchi 《Fisheries Science》2000,66(6):1092-1099

SUMMARY: Five clonal lines of silver crucian carp Carassius langsdorfii were produced from natural maternal fish to estimate the variance and heritability of total length, bodyweight and gonadosomatic index (GSI). The larvae on the 10th day after hatching were reared together in a common rearing system with five duplicate systems. Another system was prepared using a separate system with two replications in each family. Estimation of variance and heritability were done in the first, third, fifth and 10th month for total length and bodyweight. Microsatellite DNA markers were used to identify the clonal lines in each communal rearing tank. Average heritabilities in the first month were 0.105 for total length (ranging from 0.21 to 0.03) and 0.127 for bodyweight (ranging from 0.22 to 0.06) then decreased in the third, fifth and 10th month. In contrast, intermediate levels of heritability from separate systems were observed. Likewise, relative heritability of GSI in the 10th month presented a high level in both rearing systems. Those heritabilities indicated that growth, total length, bodyweight and reproductive performances of silver crucian carp were affected by genetic influence. The results suggest that clonal lines of silver crucian carp are suitable as experimental animals for evaluations of environmental change and various pollutants through quantitative traits such as growth, reproductive and other physiological traits.  相似文献   

Production and properties of Japanese oriented strand board I: effect of strand length and orientation on strength properties of sugi oriented strand board     

Shigehiko Suzuki  Kenichi Takeda 《Journal of Wood Science》2000,46(4):289-295

Oriented strand boards (OSB) were made using sugi wood strand with different lengths at different free fall distance conditions. Strand alignment and mechanical properties of sugi OSB were evaluated. Results obtained can be summarized as follows. The alignment angle distribution was greatly affected by both free fall distance and strand length. It was found that the standard deviation of the angles can be a measure for predicting the distribution when employing the von Mises distribution function with concentration parameter. The Monte Carlo simulation showed an agreement between the theoretical considerations and the experimental results on the strand alignment. The mechanical properties as affected by both strand length and layer structure were determined. Bending properties could be equal in both directions at 25% face layer ratio. Young's modulus obtained by the in-plane vibration method showed almost linear relation to the face layer ratio. No significant differences or only a slight difference was observed for the internal bond strength, plate-shear modulus, and nail resistance properties. Further studies are necessary.  相似文献   

Hydraulic function contributes to the variation in shoot morphology within the crown in Quercus crispula     

Yoshimura K 《Tree physiology》2011,31(7):774-781

Hydraulic and light environments have variation within the crown in well-grown trees. Shoot morphology and shoot hydraulics were compared between the upper and lower crown or among branching patterns in well-grown Quercus crispula Blume. Shoots in the upper crown had longer and thicker axes and lower water potential than did shoots in the lower crown. Hydraulic conductance from the soil to the shoot did not differ between the upper crown and the lower crown. Shoots in the upper crown are exposed to hydraulic stress, and shoots in the lower crown are under shade stress. Shoot morphology and shoot hydraulic traits (i.e., higher Huber value and higher hydraulic conductivity) in the upper crown affected the hydraulic conductance of shoots. Shoots in the lower crown showed larger light-receiving leaf area per leaf biomass investment, which is an adaptive morphology under shaded environments. Shoot morphology and shoot hydraulics were not correlated to branching pattern significantly, but shoots with higher branching intensity in the upper crown represented trends for higher hydraulic conductivity. These results reveal that shoot morphological and physiological characteristics in the upper crown reduce hydraulic stress, and those in the lower crown reduce shade stress. I conclude that vertical position within a crown affects both morphological and physiological acclimation for light acquisition and hydraulic conductance, and that hydraulic architecture is associated with crown architecture.  相似文献   

Tolerance of Japanese larch to drought is modified by nitrogen and water regimes during cultivation of container seedlings     

Kitao  Mitsutoshi  Agathokleous  Evgenios  Harayama  Hisanori  Kitaoka  Satoshi  Uemura  Akira  Yazaki  Kenichi  Tobita  Hiroyuki 《European Journal of Forest Research》2022,141(4):699-712

Improving drought tolerance of container seedlings of Japanese larch is of high importance to afforestation. We hypothesized that adequate nitrogen (N) and limited water supply would increase the tolerance of container seedlings to water-deficit stress, circumventing photoinhibition, by means of (i) enhanced photosynthetic capacity with higher leaf N and (ii) decreased water loss from leaves with lower biomass allocation into aboveground parts. Container seedlings of Japanese larch were grown under the treatment combinations of adequate (+?N: 300 mg N container^?1) or limited (??N: 150 mg N container^?1) N and adequate (+?W: daily irrigation) or limited (??W: twice-a-week irrigation) water. Then, seedlings were subjected to a progressive drought treatment. Higher leaf N was observed in container seedlings grown under?+?N and???W. During progressive drought, lower stomatal conductance and net photosynthetic rate were observed in leaves with higher leaf N at a given predawn leaf water potential. Furthermore, the maximum efficiency of PSII photochemistry (F_v/F_m) was lower in leaves with higher leaf N, suggesting that higher leaf N might impair intrinsic tolerance to drought at the leaf level contrary to expectations. Conversely,???N and???W seedlings with lower shoot biomass delayed soil drying as a whole-plant response via a reduction in leaf transpiration, leading to delayed photoinhibition as indicated by a decline in F_v/F_m. To circumvent stress at the initial stage of water deficit, lower leaf N via limited N regime and smaller shoot biomass driven by limited N and water regimes would be important.

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Serological properties and intrinsic antibiotic resistance of soybean bradyrhizobia isolated from Thailand     

Tadashi Yokoyama  Shotaro Ando  Kenichi Tsuchiya 《Soil Science and Plant Nutrition》2013,59(2):505-515

A group of Bradyrhizobium strains isolated from soybean plants in Thailand did not correspond to any known DNA homology groups of Bradyrhizobium japonicum and Bradyrhizobium elkanii reported by Hollis et al. (J. Gen. Microbiol., 123, 215–222, 1981). To clarify the phenotypic characteristics of the group, serological properties and intrinsic antibiotic resistance (IAR) profile of 94 Thai strains were compared with those of USDA and Japanese strains. Indirect ELISA tests for each Thai strain were performed agaiIl.st polyclonal antisera prepared against 15 USDA standard serotype strains of B. japonicum and B. elkanii. Among the 94 Thai strains tested, 36 which were previously identified as B. elkanii, with the exception of one strain, were strongly responsive to an antiserum prepared against USDA 31. The remaining 58 strains, with the exception of two strains, showed multiple cross reactions which were peculiar to the Thai strains. These serological reaction patterns did not correspond to any known serogroups labeled as B. japonicum and B. elkanii. In the IAR test, the taxonomically unknown Thai soybean bradyrhizobia exhibited a high level of resistance to neomycin (50 µg/mL), polymyxin (50 µg/mL), nalidixic acid (15 µg/mL), and kanamycin (15 µg/mL). Kanamycin could thus be useful in combination with neomycine and nalidixic acid for distinguishing between the unknown Thai strains and strains of B. japonicum and B. elkanii. Our results demonstrated that the unknown Thai strains were serologically and IAR-phenotypically remote from both B. japonicum and B. elkanii.  相似文献   

Extraordinary high aluminium tolerance of the acidophilic thermophilic alga,Cyanidium caldarium     

Etsuro Yoshimura  Seiji Nagasaka  Yoshiyuki Sato  Kenichi Satake  Satoshi Mori 《Soil Science and Plant Nutrition》2013,59(3):721-724

A strain of an acidophilic, thermophilic alga, Cyanidium caldarium, was cultured in a medium containing various metal ions (A1, Cd, Cr, Cu, Mn, Ni, Zn). Among these metals, the alga tolerates especially high levels of AI: it can grow in a medium containing 200 mM AI, although the growth rate was reduced to 58%. The cellular Al concentration was kept at a considerably lower level as compared to the medium Al concentration. This may account for the Al tolerance of the alga. Treatment of the algal cells with carbonylcyanide m-chlorophenylhydrazone in the presence of Al increased the cellular Al concentration. It was suggested that energy-coupled Al exclusion mechanisms can operate in the alga.  相似文献   

Expression and regulation of Foxa2 in the rat uterus during early pregnancy     

Kazuki YAMAGAMI  Nobuhiko YAMAUCHI  Kaiyu KUBOTA  Sho NISHIMURA  Vishwajit Sur CHOWDHURY  Kenichi YAMANAKA  Masashi TAKAHASHI  Shoji TABATA  Masa-aki HATTORI 《The Journal of reproduction and development》2014,60(6):468-475

The forkhead box a (Foxa) protein family has been found to play important roles in mammals. Recently, the expression of Foxa2 was reported in the mouse uterus, and it was reported to be involved in regulation of implantation. However, the regulation of Foxa2 expression in the uterus is still poorly understood. Therefore, the present study was conducted to investigate the expressional profiles of Foxa2 in the rat uterus during the estrus cycle and pregnancy. Furthermore, the effect of steroid hormones and Hedgehog protein on the expression of Foxa2 was analyzed in vivo and in vitro. In this study, the level of expression of Foxa2 was low in the rat uterus during the different stages of the estrus cycle. However, the expression increased transiently during early pregnancy at 3.5 days post coitus (dpc) and decreased at 5.5 dpc. In ovariectomized rats, P4 treatment had no effect on the expression of Foxa2 compared with the expression in control animals. Moreover, the expression of Foxa2 in cultured epithelial cells was not increased by P4 treatment in vitro. However, Foxa2 expression was significantly decreased in the rat uterus after 24 h of E2 treatment. Treatment of cells with a recombinant Hedgehog protein significantly increased the expression of Foxa2. These results suggest that the expression of Foxa2 may transiently increase just before the implantation and it may be regulated by E2 and Hedgehog protein.  相似文献   

Pathogenic and genetic variability of Ralstonia solanacearum strains from the Philippines     

Joselito E. Villa  Mitsuo Horita  Mitsuro Hyakumachi  Kenichi Tsuchiya 《Plant pathology》2021,70(3):544-554

In the Philippines, bacterial wilt caused by Ralstonia solanacearum is one of the most important diseases affecting vegetables and banana. In this study, 89 strains of R. solanacearum isolated from various hosts were screened for their biovar, phylotype, pathogenicity, and genetic diversity. Foreign strains were included for comparison with these Philippine strains. Results of the biochemical and multiplex-PCR tests divided the Philippine strains into five biovars (1, 2, 3, 4, and N2) and three phylotypes (I, II, and IV). Three potato strains belonged to biovar N2/phylotype IV. Pathogenicity tests divided the strains into five pathogenicity types based on their virulence in tomato, potato, eggplant, sweet pepper, and tobacco. Strains classified as biovar N2 were weakly pathogenic to potato (pathogenicity type III) and almost all strains isolated from banana were not pathogenic to the test plants except potato (pathogenicity type V). The results of AFLP analysis divided the strains into four clusters. Cluster 1 was composed of strains isolated from solanaceous crops, ginger (Zingiber officinale), and Morus sp. from the Philippines and other Asian countries. Cluster 2 grouped the potato strains (biovar N2) from the Philippines and Japan and blood disease bacterium strains from Indonesia. Cluster 3 contained the local and foreign strains isolated from potato (biovar 2) and banana (biovar 1). Cluster 4 consisted only of the tomato strain from the USA.  相似文献