著者

Jun-ichiro Masuda Yukio Ozaki Michikazu Hiramatsu Kaori Sakai Junghee Kim Hiroshi Okubo

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-082, (Released:2017-07-04)

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Effects of photoperiod and temperature on rhizome enlargement (dormancy induction) and accompanied dormancy depth were investigated in this study. Nine-day-old seedlings were transplanted from 26 July at 1 week intervals, and they were grown under a natural photoperiod for 5 weeks in an unheated greenhouse in Fukuoka Prefecture, Japan. Although subterranean stems elongated in the plants grown until 30 August or 6 September, enlarged rhizomes were formed in those grown until 13 September or 20 September. It was revealed from these results that the lotus recognizes a natural photoperiod after 6 September as a short day. When 9 treatments of day length combinations (LD0+SD8–LD8+SD0) were applied to the seedlings, the plants grown under short day after long day treatment of 0 (LD0+SD8), 1 (LD1+SD7), 2 (LD2+SD6), 3 (LD3+SD5), 4 (LD4+SD4), 5 (LD5+SD3), 6 (LD6+SD2), or 7 (LD7+SD1) weeks formed enlarged rhizomes from the fifth, fifth, sixth, seventh, eighth, tenth, twelfth, and fourteenth internodes, respectively. Although photoperiodic treatment in the first week was different between LD0+SD8 and LD1+SD7 treatments, subterranean stems began to enlarge from the same internode (fifth internode) in both treatments. This indicates that photoperiod treatments for the first week do not affect morphology of subterranean stems. Seven treatments of day length combinations (LD2+SD0+LD6–LD2+SD6+LD0) were applied to seedlings after long day treatment for 2 weeks. Enlarged subterranean stems were observed in the plants grown under short day for 6 weeks (LD2+SD6+LD0), but not in those under long day for 6 weeks (LD2+SD0+LD6). On the other hand, subterranean stems elongated again after rhizome enlargement under a subsequent long day following 1 (LD2+SD1+LD5), 2 (LD2+SD2+LD4), 3 (LD2+SD3+LD3), or 4 (LD2+SD4+LD2) weeks of short day. This clarified that morphogenesis in subterranean stems is completely dependent on photoperiod. Further, it is expected that such growth resumption may be attributed to a weak dormant state in the enlarged rhizome. The enlarged rhizomes were exposed to natural low temperatures to examine environmental factors for deepening dormancy. Rhizomes sprouted in all treatments irrespective of exposure to low temperatures when they were transferred to ideal conditions. Rapid growth in leaves and subterranean stems was particularly observed by exposure to low temperature. It was suggested that low temperature is an environmental factor for releasing dormancy, but not for deepening dormancy. It is proposed from these results that subterranean stem growth is completely dependent on photoperiod, and that enlarged rhizomes show weak dormancy.

著者

Yukio Ozaki Yoko Takeuchi Miyuki Iwato Satomi Sakazono Hiroshi Okubo

出版者

園芸学会

雑誌

Journal of the Japanese Society for Horticultural Science (ISSN:18823351)

巻号頁・発行日

pp.CH-073, (Released:2014-07-18)

被引用文献数

1 4

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The origin of a spontaneous triploid asparagus plant from crosses of 2x × 2x was investigated by SSR and flow cytometric analyses. One hundred and twenty-four progeny were obtained from crosses between a diploid female ‘Gold Schatz’ and a diploid male ‘Hokkai 100’. SSR analysis proved that two and one genes were transmitted from the maternal and paternal parents, respectively, at each SSR locus of one progeny, 07M-61, whereas one gene each was from the female and male parents in the other diploid progeny. Triploidy of 07M-61 was confirmed by flow cytometric analysis. It was suggested that the triploid plant was derived from fertilization between an unreduced egg and reduced sperm nuclei, given its SSR genotypes. It was also suggested that the unreduced maternal gamete was derived from first division restitution (FDR) or second division restitution (SDR) with chiasma occurrence during meiosis. There were no noticeable morphological differences between the triploid and diploid progeny.