著者

Toshiyuki Takai Patrick Lumanglas Daisuke Fujita Kazuhiro Sasaki Njato Michael Rakotoarisoa Yasuhiro Tsujimoto Nobuya Kobayashi Eliza Vie Simon

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

pp.21045, (Released:2021-11-17)

被引用文献数

1

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The heading date is an important trait for determining regional and climatic adaptability in rice. To expand the adaptability of the indica rice cultivar ‘IR64’, we pyramided multiple early or late heading quantitative trait locus (QTLs) in the ‘IR64’ genetic background by crossing previously developed near-isogenic lines (NILs) with a single QTL for early or late heading. The effects of pyramiding QTLs were observed in three different climatic zones of the Philippines, Madagascar, and Japan. The early heading pyramiding lines (PYLs) headed 6.2 to 12.8 days earlier than ‘IR64’ while the late heading PYLs headed 18.8 to 27.1 days later than ‘IR64’. The PYLs tended to produce low grain yield compared to ‘IR64’. The low yield was not improved by combining SPIKE, which is a QTL that increases the number of spikelets per panicle. Conversely, ‘IR64-PYL(7+10)’ carrying Hd5 and Hd1 headed earlier, produced more tillers, and more panicles per m2 than ‘IR64’, and mitigated the yield decrease in early heading. These results suggest that the effects of pyramided QTLs on heading date were consistent across various environments and PYLs could be used to enhance the adaptation of ‘IR64’ in other rice growing environments.

著者

Md. Mostofa Kamal Cuong Dinh Nguyen Sachiyo Sanada-Morimura Shao-Hui Zheng Daisuke Fujita

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

vol.73, no.5, pp.450-456, 2023 (Released:2023-12-21)

参考文献数

25

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The development of resistant rice (Oryza sativa L.) varieties is a key strategy for the eco-friendly control of brown planthopper (BPH: Nilaparvata lugens Stål). However, BPH outbreaks occur frequently owing to the evolution of virulent strains in the field and the rapid breakdown of monogenic resistance to BPH. Therefore, to enhance BPH resistance and gauge the effectiveness of gene pyramiding against strongly virulent BPH, we developed pyramided lines (PYLs) in the genetic background of ‘IR64’ carrying BPH resistance genes. We developed six IR64-PYLs (BPH3 + BPH17, BPH32 + BPH17, BPH32 + BPH20, BPH3 + BPH17-ptb, BPH20 + BPH3, and BPH17-ptb + BPH32) through marker-assisted selection. To assess the resistance of the IR64-PYLs, we conducted antibiosis test, honeydew test, and modified seedbox screening test (MSST) using strongly virulent BPH populations. The level of BPH resistance increased in all six IR64-PYLs compared to both ‘IR64’ and the corresponding NILs in MSST. Among them, IR64-BPH3 + BPH17 and IR64-BPH32 + BPH17 exhibited the highest resistance to BPH. However, the resistance level of most IR64-PYLs was not significantly higher than that of the corresponding NILs in antibiosis test. Thus, these PYLs could serve as a valuable resource for breeding programs aimed at improving resistance to virulent strains of BPH and enhancing their durability.

著者

Ha Thi Le Nguyen Shizuka Suetsugu Yuna Nakamura Zita Demeter Shao-Hui Zheng Daisuke Fujita

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

vol.73, no.4, pp.365-372, 2023 (Released:2023-10-03)

参考文献数

34

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A large vascular bundle number (VBN) in the panicle neck in rice (Oryza sativa L.) is related to the ability to transport assimilates from stem and leaf to reproductive organs during seed maturation. Several quantitative trait loci (QTLs) for VBN have been identified by using segregating populations derived from a cross between indica and japonica rice cultivars. However, the detailed location, effect, and interaction of QTLs for VBN were not understood well. Here, to elucidate the genetic basis of VBN, we identified three stable QTLs for VBN—qVBN5, qVBN6 and qVBN11—by using 71 recombinant inbred lines derived from a cross between indica ‘IR24’ and japonica ‘Asominori’. We confirmed their positions and characterized their effects by using chromosome segment substitution lines (CSSLs) with an ‘IR24’ genetic background. qVBN6 had the most substantial effect on VBN, followed by qVBN11 and qVBN5. We developed pyramided lines carrying two QTLs for VBN to estimate their interaction. The combination of qVBN6 and qVBN11 accumulated VBN negatively in the pyramided lines owing to the independent actions of each QTL. The QTLs detected for VBN will enhance our understanding of genetic mechanisms of VBN and can be used in rice breeding.

著者

Saw Bo Day Shar Cuong Dinh Nguyen Sachiyo Sanada-Morimura Hideshi Yasui Shao-Hui Zheng Daisuke Fujita

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

vol.73, no.4, pp.382-392, 2023 (Released:2023-10-03)

参考文献数

56

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The brown planthopper (BPH: Nilaparvata lugens Stål) is one of the most destructive insects in rice production. The use of host plant resistance has potential to reduce damage caused by BPH. The heat tolerance japonica rice ‘Sagabiyori’, with superior grain quality and high soluble starch in the stem, is highly susceptible to damage by BPH. Here, to enhance its BPH resistance, we developed seven near-isogenic lines (NILs) carrying BPH2, BPH17-ptb, BPH32, BPH3, BPH17, BPH20, and BPH21 through marker-assisted selection and evaluated resistance to two BPH populations. Most lines were more resistant to the Hadano-1966 BPH population than Sagabiyori but were less effective against the highly virulent Koshi-2013 population. Nevertheless, in antixenosis tests, Koshi-2013 settled less on all NILs than on Sagabiyori. In addition, adult mortality and the percentage of fresh weight loss of lines carrying BPH17 and BPH3 indicated that these lines have higher resistance to Koshi-2013 than Sagabiyori. Current study revealed that BPH resistance of Sagabiyori became stronger by transferring BPH3 and BPH17 genes. Thus, BPH3 and BPH17 might be valuable for breeding programs to enhance BPH resistance of high grain quality rice varieties with heat tolerance.

著者

Md. Mostofa Kamal Cuong Dinh Nguyen Sachiyo Sanada-Morimura Shao-Hui Zheng Daisuke Fujita

出版者

Japanese Society of Breeding

雑誌

Breeding Science (ISSN:13447610)

巻号頁・発行日

vol.73, no.3, pp.278-289, 2023 (Released:2023-07-27)

参考文献数

55

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The brown planthopper (BPH), Nilaparvata lugens Stål, is an insect pest that severely damages rice (Oryza sativa L.) in Asia, causing huge yield loss. Use of resistant variety is a cost-effective and eco-friendly strategy for maintaining BPH populations below the economic injury level. However, current BPH populations have been changed to virulence against resistant varieties. In this study, to estimate effective combinations among eight BPH resistance genes (BPH32, BPH17-ptb, BPH20, BPH17, BPH3, BPH25, BPH26 and qBPH6), eight near-isogenic lines with the genetic background of an Indica Group rice variety ‘IR64’ (IR64-NIL) were developed using marker-assisted selection. The genome recoveries of these NILs ranged from 89.3% to 98.8% and agronomic traits of them were similar to those of ‘IR64’. In modified seed box screening test, resistance level of IR64-NILs was higher than that of ‘IR64’. In antibiosis test, high adult mortalities of BPH (from 56.0% to 97.0%) were observed among NILs, in comparison with that of ‘IR64’. Among IR64-NILs, the line carrying BPH17 showed the highest resistance level at all tests. Thus, these IR64-NILs with multiple BPH resistance genes could be valuable breeding lines for enhancing resistance levels by gene pyramiding and multiline variety.

著者

Daisuke Fujita Kenichi Kobara Hiroshi Osaka Susumu Watanabe Teppei Sintani Takuya Sugimura Kenji Makino Tim Cleminson Tunayoshi Morikawa

出版者

The Society of Physical Therapy Science

雑誌

Journal of Physical Therapy Science (ISSN:09155287)

巻号頁・発行日

vol.24, no.8, pp.667-670, 2012 (Released:2012-11-07)

参考文献数

22

被引用文献数

2 1

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[Purpose] The purpose of this study was to measure the effect of structural components on walking ability by conducting tests using subjects who used combined rollator-wheelchairs and walking aids in their daily lives. [Subjects] Ten residents living in a health care facility for the elderly who required walking aids participated in this study. [Methods] We measured maximum walking speed (MWS), step length, cadence and conducted the shuttle stamina walk test (SSTw), and the timed up-and-go test (TUG) under three conditions (rollator with forearm support, rollator with handgrip and cart). [Results] There were significant differences among the conditions with forearm support providing the best results in terms of MWS, step length, cadence, SSTw and TUG, showing in improved walking abilities of walking speed, endurance and dynamic balance. [Conclusion] These results show that therapists should advocate using rollators with forearm support as a safe method of expanding the range of walking activities for elderly who use walking aids or rollator-wheelchairs in their daily lives.

著者

Youichi Seto Yukiko Moriyama Daisuke Fujita Mieko Komatsu

出版者

JAPANESE ASSOCIATION OF BENTHOLOGY

雑誌

BENTHOS RESEARCH (ISSN:02894548)

巻号頁・発行日

vol.55, no.2, pp.85-93, 2000-12-31 (Released:2011-11-11)

参考文献数

17

被引用文献数

2 4

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Abstract: Sexual and asexual reproduction of the fissiparous asteroid Coscinasterias acutispina(Stimpson)was studied in two populations(Kurosaki and Uozu)in Toyama Bay, Sea of Japan, during April 1998-March 1999(Kurosaki)and April 1998-October 1999(Uozu). A total of 96% and 87% of all starfish collected at Kurosaki and Uozu, respectively, showed signs of asexual reproduction by fission. Monthly changes in the ratio of regenerated arm length to maximum arm length revealed that starfish in these populations split most frequently in summer. There was a marked difference in the development of gonads between the two populations. In the Kurosaki population, monthly changes of gonad indices and histological observations on gonads indicated a distinct annual cycle, with a winter spawning season in both males and females. In the Uozu population, gonad indices remained low, and no starfish with mature gonads were observed during the study. An unbalanced sex ratio was observed in both populations; the Uozu population was composed entirely of males. The absence of mature gonads and the extremely biased sex ratio suggest that larval recruitment was low or absent in the Uozu population.