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171.
Hideaki Shibata Rieko Urakawa Hiroto Toda Yoshiyuki Inagaki Ryunosuke Tateno Keisuke Koba Asami Nakanishi Karibu Fukuzawa Ayaka Yamasaki 《Journal of Forest Research》2011,16(5):374-385
Net nitrogen transformation was investigated under different climate conditions by soil transplantation and in situ incubation
of forest surface soils using the resin-core method. Selected conditions were considered to reflect those of the natural climate
gradient in the Japanese archipelago. Study sites were established in natural forests in northern Hokkaido (Uryu), northern
Kanto (Kusaki), central Kinki (Kamigamo), and southern Kyushu (Takakuma), representing the northernmost to the southernmost
island regions of Japan. Field experiments comparing soils incubated at “native” and “transplanted” sites were conducted from
June 2008 to May 2009. Net production, accumulation, and leaching of soil ammonium (NH4
+) and nitrate (NO3
−) were measured at each of the sites during the growing season (June–October), the dormant season (November–May), and throughout
the year. Net nitrate production was highest in Kusaki soil, especially during the growing season, whereas net ammonium production
was highest in Uryu soil, the coldest site, especially during the dormant season. Net nitrate production increased significantly
in soils transplanted to a warmer climate during the growing season. However, net ammonium production increased in soils transplanted
to colder climates during the dormant season. These findings indicate that, with the exception of the infertile soil samples
from Kamigamo, the range of natural climates in Japan has a significant effect on nitrogen availability in surface soil. In
addition, the original characteristics of the nitrogen cycle of the surface soil from each native site were retained, even
when marked changes in soil temperature (approximately 8°C) occurred after transplantation. 相似文献
172.
Kodama H Nakamura H Kashima M Iwasaki T Togase H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2011,73(10):1319-1325
A microbial culture was prepared by co-cultivation of Lactobacillus paracasei, Pichia membranifaciens and Saccharomyces cereviciae for 48 hr at 30°C in rice bran extract medium, supplemented with dextrose. Oral administration of the resulting non-viable heat-inactivated microbial culture to common carp, Cyprinus carpio L., delivered in feed for four weeks, induced effective protection against experimental atypical Aeromonas salmonicida infection which causes "ulcer disease". After challenge of the carp by immersion, fish mortality and development of skin lesions such as hemorrhages and ulcers were significantly suppressed in carp treated with mixed microbial culture adsorbed on dry pellets relative to carp treated with medium or without extract. Atypical A. salmonicida was re-isolated from ulcerative lesions in parts of dead and surviving fish, but Aeromonas hydrophila and Flavobacterium sp. were also isolated from these fish, verifying microbial population changes during the progression of skin lesions. Among interleukin-1β (IL-1β), tumor necrosis factor-α, as well as CXC-α and CXC-β chemokines, gene expression of IL-1β was up regulated in the spleen and head kidney three weeks after administration of the mixed microbial culture. These results clearly show that this mixed microbial culture, delivered in feed, is effective in preventing A. salmonicida disease in carp. 相似文献
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Phenol-formaldehyde resin-bonded particleboard (PF board) and isocyanate resin-bonded particleboard (MDI board) were soaked in water at 40, 70 and 100 °C, and the relationships between soaking conditions and nail joint properties were analyzed. The soaking time to reach the lower limit of nail-head pull-through (NHPT) of the PF board was 2 h at 100 °C, while it took 168 h at 70 °C. The soaking time to reach the lower limit of lateral nail resistance (LNR) of the PF board was 24 h at 100 °C, but it did not take 168 h at 70 °C to reach it. The lower limits of NHPT and LNR for the MDI board were higher than those for the PF board. For the PF board, there was a high correlation between modulus of rupture, internal bond strength and nail joint properties. Based on the results of water soaking and outdoor exposure, it was shown that thickness change has a significant effect on NHPT and LNR, and that the reduction in NHPT and LNR results from the collapse of bonding points owing to swelling of the board. 相似文献
176.
Shotarou Nukui Satomi Kitamura Tomoyo Hioki Hideaki Ootsuka Kazumitsu Miyoshi Takao Satou Yuka Takatori Tomo Oomiya Keiichi Okazaki 《Breeding Science》2011,61(4):327-337
Fertile plants undergoing male gametogenesis can be treated with nitrous oxide (N2O) gas to obtain 2n male gametes. N2O treatment is also expected to restore the fertility of interspecific hybrids through meiotic restitution or mitotic amphidiploidization. However, this technique has few applications to date, and it is un-known how N2O treatment restores fertility in sterile hybrids. To establish optimal N2O treatment conditions and determine its cytological mechanism of action, we treated various sized floral buds with N2O gas at different anther developmental stages from fertile and sterile hybrid lilies. N2O treatment using the optimal 1–4 mm floral buds induced mitotic polyploidization of male archesporial cells to produce 2n pollen in fertile hybrid lilies. In sterile hybrid lilies, N2O treatment doubled the chromosome number in male archesporial cells followed by homologous chromosome pairing and normal meiosis in pollen mother cells (PMC), resulting in restoration of pollen fertility. Backcrossing the resultant fertile pollen to Lilium × formolongi produced many triploid BC1 plants. Thus N2O treatment at the archesporial cell proliferating stage effectively overcame pollen sterility in hybrid lilies, resulting in fertile, 2n pollen grains that could produce progeny. The procedure presented here will promote interspecific or interploidy hybridization of lilies. 相似文献
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