Anthracnose of Madagascar periwinkle caused by species belonging to the Colletotrichum gloeosporioides species complex     

Keisuke Tomioka  Junji Nishikawa  Jouji Moriwaki  Toyozo Sato 《Journal of General Plant Pathology》2013,79(5):374-377

Severe blight of stems was found on Madagascar periwinkle (Catharanthus roseus) in Shizuoka and Okinawa prefectures, Japan, in July 2003 and September 2004, respectively. Similar fungi were isolated from the diseased plants. The isolated fungi caused the disease after inoculation and subsequently were reisolated from diseased tissues. The fungi were identified as species closely related to C. siamense or C. tropicale according to sequences of the β-tubulin-2 gene, indicating that they belong to the Colletotrichum gloeosporioides species complex. This is the first report specifying the genetic relationships of the pathogens of Madagascar periwinkle anthracnose in the complex.  相似文献   

Decadal changes in the rice-cropping system in the Ayeyarwady Delta using a large archive of satellite imagery from 1981 to 2020     

Sakai  Toru  Omori  Keisuke  Oo  Aung Naing  Ma  Swe Swe  Zaw  Yan Naung 《Paddy and Water Environment》2021,19(2):295-306

In the last 40 years, the rice-cropping system has considerably changed in the Ayeyarwady Delta. The large archive of satellite imagery provides a history of how land and water resource managements have changed in the face of growing populations, resource demand, and climate change. This study aimed to assess the decadal changes in the rice-cropping system in the Ayeyarwady Delta by using the large archive of satellite imagery for the last 40 years (1981???2020). The long-term NDVI dataset provided various information on rice cultivation. Signal processing techniques were used to detect on the historical changes in the rice-cropping system, and the impact of climate change was assessed by using trend analysis. Until the 1980s, single-cropping of summer rice was dominant in the Delta. To enhance the grain yield of rice, the irrigation facilities were introduced in 1992 under an initiative of the Myanmar government. As a result, the annual cropping intensities increased from 1.087?±?0.390 in the 1980s to 1.422?±?0.499 in the 2010s. The information on historical change in the rice-cropping system would be useful to consider the practical and cost-effective utilization of remaining land and water resources. Moreover, the trend analysis of NDVI time-series showed negative trends in coastal areas. This indicates that the rice production in coastal areas has been constrained by the saline intrusion. The salt-affected areas are expected to expand under future climate change scenarios. Government support is highly required for sustainable rice production in the Delta.

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Sulfonylurea-resistant biotypes of Monochoria vaginalis generate higher ultraweak photon emissions than the susceptible ones     

Hidehiro Inagaki  Toshiyuki Imaizumi  Guang-Xi Wang  Tohru Tominaga  Kimihiko Kato  Hiroyuki Iyozumi  Hideki Nukui 《Pesticide biochemistry and physiology》2009,95(3):117-120

All living organisms spontaneously generate ultraweak photon emissions, which originate from biochemical reactions in cells. Current research uses the ultraweak photon emission from organisms as a novel indicator in nondestructive analyses of an organisms living state. This study indicates that ultraweak photon emissions from Monochoria vaginalis are different between resistant biotypes (R) to sulfonylurea (SU) and susceptible biotypes (S). In SU-R biotypes, distinct increases in photon emissions were observed, but there was little increase in SU-S biotypes. In addition, photon emissions from the resistant biotypes of M. vaginalis were suppressed by treatment with P450 inhibitors. This suggests that cytochrome P450 monooxygenase, which plays a crucial role in the metabolic detoxification of SUs, could be associated with the generation of ultraweak photon emissions. Ultraweak photon emissions have a potential use in a novel diagnosis system as an indicator in a nondestructive testing of weeds resistant to SUs.  相似文献   

QTL analysis of panicle morphology response to irrigation regime in aerobic rice culture     

Yoichiro Kato  Keisuke Nemoto  Junko Yamagishi   《Field Crops Research》2009,114(2):295-303

In water-efficient rice production, grain yield is often constrained by panicle size. The objective of this study was to genetically dissect the response of panicle morphology to irrigation regimes in aerobic rice culture. We grew ‘Akihikari’ (a lowland japonica cultivar) × ‘IRAT109’ (an upland japonica cultivar) backcross inbred lines in aerobic soils with full or limited irrigation for 2 years, and examined 4 panicle traits—number of florets per panicle (FPP), number of primary branches per panicle (BPP), number of florets per primary branch (FPB), and frequency of pre-flowering floret abortion (%FA)—and grain yield. QTLs for BPP were detected in both the irrigation regimes but QTLs for FPB and %FA were detected mostly only in either of the irrigation regimes. The QTL for FPP on chromosome 2 (RM3421–RM213) coincided with that for yield under full irrigation, showing that this QTL is related to sink capacity and yield potential in aerobic rice culture. On the other hand, the QTL for FPB on chromosome 1 (RM3148–RM243) coincided with that for yield under limited irrigation, when water deficit was moderate. The QTL for root axis length at vegetative stage, previously identified in the same mapping population, was located near this region. This study unravelled the complicated genetic control on panicle morphology in aerobic rice culture, and suggested the positive roles of the dehydration avoidance mechanism by vigorous root growth on panicle size and yield under dry soil conditions.  相似文献   

Effects of topography on the construction and efficiency of earthen weirs for rice irrigation in Northeast Thailand     

Keisuke Hoshikawa  Shintaro Kobayashi 《Paddy and Water Environment》2009,7(1):17-25

Farmers in some parts of the Indochina Peninsula have been using earthen weirs to supply water to their rice fields, and the use of such weirs is especially prevalent in Northeast Thailand. Although now a typical rain-fed rice cultivation area, a significant percentage of rice fields in Northeast Thailand used earthen weirs before the extensive expansion of rain-fed rice fields that occurred in the early 20th century. In this study, we clarified some of the historical changes associated with the construction and use of earthen weirs and their effects on rice production. In particular, we investigated some of the topographic effects, such as terrain, catchment size, and slope grade, on water delivery. In addition, water delivery methods, construction periods, and the discontinued use of earthen weirs were examined with respect to regional influences and topography. Earthen weirs were found to be most suitable in areas that exhibited complementarity between the riverbed slope and the water catchment. The type of earthen weir was dependent on the magnitude of the riverbed slope. Earthen weirs have been constructed continuously on steeper upstream slopes of rivers for more than a century, while weir construction on lower riverbeds with larger catchments appears to be more recent.

Keisuke HoshikawaEmail:

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Genome editing of Nf1, Pten,and Trp53 in neonatal mice induces glioblastomas positive for oligodendrocyte lineage transcription factor 2     

Hiromi Yamamoto  Keisuke Yamamura  Haruka Nagasaki  Takamasa Suzuki  Fumiko Ninomiya  Kenji Matsubara  Naomoto Harada  Shuichi Ohkubo 《Journal of toxicologic pathology》2021,34(4):359

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Identification of a bacterium isolated from galls on carrot and weeds     

Hideshi Kawarazaki  Masao Goto  Kotaro Kato  Toshio Kijima  Hiroshi Kawada  Keisuke Yamamoto  Yuichi Takikawa 《Journal of General Plant Pathology》2009,75(3):235-240

In 2004, bacterial galls were found on the roots of carrots in Shizuoka Prefecture, Japan. Galls were about 0.1–2 cm in diameter, light brown in color and had rough surfaces. In 2005, similar galls were found on the roots of three weeds: henbit (Lamium amplexicaule L.), Persian speedwell (Veronica persica Poir.) and leaf mustard (Brassica juncea L.). A bacterium that forms white, rough colonies was isolated from the carrot and weeds galls. The bacterial isolates had properties identical with Rhizobacter dauci Goto and Kuwata. Phylogenetic analysis based on 16S rDNA sequences showed that the carrot isolate had the highest homology (similarity of 100%) with that of the type strain of R. dauci. Rep-PCR genomic fingerprinting using BOX A1R primer showed that the carrot and weeds isolates were nearly identical. Pathogenicity of the isolates was confirmed by inoculating the roots of carrots and the weeds. After 2–5 weeks, they formed galls on the roots of the original host species and on other plant species tested. The galls were indistinguishable from those formed naturally, and the inoculated bacterium was reisolated. Thus, the causal bacterium of carrot and weeds gall was identified as R. dauci, and the bacterium was found to have a wider host range than previously known. These weed hosts may serve as inoculum sources for carrot bacterial gall disease.  相似文献   

Marigold Leaf Spot Caused by Alternaria tagetica New to Japan     

Keisuke TOMIOKA  Toyozo SATO  Hiroki KOGANEZAWA 《Journal of General Plant Pathology》2000,66(4):294-298

In October 1998, a disease causing mainly foliar necrotic lesions was found on African marigold (Tagetes erecta) and French marigold (T. patula) grown in Miyagi Prefecture, Japan. Similar lesions also developed on stems and flowers, resulting in early blight of the affected organs. Plants with numerous lesions withered rapidly. A mitosporic fungus isolated repeatedly from the diseased plants was identified as Alternaria tagetica and demonstrated to cause the disease. The disease, as well as the fungus, is new to Japan. We propose the name “hanten-by?”, which means leaf spot in Japanese, for this disease. Received 5 April 2000/ Accepted in revised form 31 May 2000  相似文献   

室温条件下保存的小鼠桑椹胚的生存性     

安铁洙  朴善花  李青龙 《中国兽医学报》2000,20(5):511-514

为了开发哺乳动物胚胎的室温保存液 ,在室温 ( 2 0℃ )条件下 ,用磷酸缓冲型 PB1、HEPES缓冲型 M2及重碳酸缓冲型 m KRB等 3种溶液及其修正液 ,保存小鼠桑椹胚 4 8h或 72 h,然后经体外培养 ,观察其发育至扩大囊胚的能力。结果 ,用 M2液保存的小鼠桑椹胚获得比较高的囊胚率 ;从 M2液中除去 Na H2 PO4、Na HCO3及葡萄糖 3种成分保存的小鼠桑椹胚 ,发育至扩大囊胚的能力显著提高 ;从溶液中除去丙酮酸钠和乳酸钠 ,或者添加 EDTA和谷氨酰胺 ,对保存后的桑椹胚发育至扩大囊胚能力无显著影响 ;而在保存液中添加犊牛血清后 ,小鼠胚胎的发育能力反而下降。结果表明 ,在室温条件下 ,不含 Na H2 PO4、Na HCO3及葡萄糖 3种成分的 M2液 ,对保存小鼠桑椹胚非常有效  相似文献   

Effects of β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin in β‐carotene‐deficient Japanese Black cows          下载免费PDF全文

Yoshitaka Nishijima  Saya Taniguchi  Shuntaro Ikeda  Kenichi Yoshitani  Takashi Hamano  Hiroshi Tani  Masahiko Fujita  Kenji Murakami  Keisuke Kogusa  Kenji Sato  Miki Sugimoto  Shinichi Kume 《Animal Science Journal》2017,88(4):653-658

Data from 18 β‐carotene‐deficient Japanese Black cows were collected to clarify the effects of feeding β‐carotene‐enriched dry carrots on β‐carotene status and colostral immunoglobulin (Ig) in cows. Cows were assigned to control or carrot groups from 3 weeks before the expected calving date to parturition, and supplemental β‐carotene from dry carrots was 138 mg/day in the carrot group. Plasma β‐carotene concentrations in the control and carrot groups at parturition were 95 and 120 μg/dL, and feeding dry carrots slightly improved plasma β‐carotene at parturition. Feeding dry carrots increased colostral IgA concentrations in cows and tended to increase colostral IgG₁, but colostral IgM, IgG₂, β‐carotene and vitamin A were not affected by the treatment. Feeding dry carrots had no effects on plasma IgG₁, IgA and IgM concentrations in cows, but plasma IgG₁ concentrations decreased rapidly from 3 weeks before the expected calving date to parturition. These results indicate that feeding β‐carotene‐enriched dry carrots is effective to enhance colostral IgA and IgG₁ concentrations in β‐carotene‐deficient cows.  相似文献