著者

Ayaka Matsuta Takahiro Mayuzumi Hajime Katano Masanori Hatashita Keiichi Takagi Yoriko Hayashi Tomoko Abe Koji Murai Yusuke Kazama

出版者

Japan Mendel Society, International Society of Cytology

雑誌

CYTOLOGIA (ISSN:00114545)

巻号頁・発行日

vol.86, no.4, pp.317-322, 2021-12-25 (Released:2021-12-24)

参考文献数

43

被引用文献数

1

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A high-LET heavy-ion beam has a severe effect on survival and effectively induces chromosomal rearrangements. In this study, the effect of high-LET heavy-ion irradiation on mutation induction in the M1 generation was investigated in an inbred line of Torenia fournieri, which is a widely used horticultural plant. Dry seeds of the inbred line ‘Zairai murasaki’ were irradiated with a C-ion beam (LET: 50 keV µm−1) or Ar-ion beams (LETs: 184 keV µm−1 or 290 keV µm−1) at different doses, and then sown on 1/2 MS plates. After determining the survival rates from each irradiation condition, appropriate doses of each beam were roughly determined to produce a survival rate of 90%: 300, 75, and 50 Gy for the C-ion beam with a LET of 50 keV µm−1, Ar-ion beam with a LET of 184 keV µm−1, and Ar-ion beam with a LET of 290 keV µm−1, respectively. In the screening of branches with aberrant flowers, one and two aberrant plants were isolated from 16 and 30 M1 plants after irradiation with LETs of 184 keV µm−1 and 290 keV µm−1, respectively. However, no aberrant plants were identified in M1 plants after irradiation with a LET of 50 keV µm−1. We concluded that high-LET heavy-ion beam irradiation is effective in inducing mutations even in the M1 generation of inbred ornamental plants. This technique could be widely used for breeding ornamental plants that can be propagated vegetatively.

著者

Tomonari Hirano Yuka Matsuyama Anna Hanada Yoriko Hayashi Tomoko Abe Hisato Kunitake

出版者

Japan Mendel Society, International Society of Cytology

雑誌

CYTOLOGIA (ISSN:00114545)

巻号頁・発行日

vol.86, no.4, pp.311-315, 2021-12-25 (Released:2021-12-24)

参考文献数

23

被引用文献数

2

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Heavy-ion beams have been applied as effective mutagens to various plant materials. Pollen has been used as material for mutant induction and genetic analysis. However, our knowledge of the DNA damage response of plant male gametes remains limited. In the present study, we irradiated Cyrtanthus mackenii pollen with an argon ion beam, which induced complex DNA damage, and investigated the DNA damage response of male gametes during pollen tube growth. Male gametes derived from the irradiated pollen grains were isolated from pollen tubes after 12 and 24 h of culture and subjected to cell cycle analysis. After 12 h of culture, the irradiated generative cells were frequently arrested at metaphase during pollen mitosis II (PMII), and the proportion of metaphase cells increased with increasing absorbed dose. These results suggest that the genomic lesions induced by the argon ion beam caused spindle assembly checkpoint (SAC)-dependent arrest. After 24 h of culture, the irradiated male gametes completed PMII, albeit forming sperm cells with abnormalities in chromosome separation, and chromosomal bridges were often formed between these cells. Moreover, phosphorylated H2AX foci, an indicator of DNA double-strand breaks, were detected in the irradiated male gametes after 24 h of culture, regardless of passing through the SAC. Taken together, these results indicate that male gametes activate functions to cope with radiation-induced complex DNA damage during pollen tube growth.

著者

Yoichi Sato Tomonari Hirano Yoriko Hayashi Nobuhisa Fukunishi Tomoko Abe Shigeyuki Kawano

出版者

Japan Mendel Society, International Society of Cytology

雑誌

CYTOLOGIA (ISSN:00114545)

巻号頁・発行日

vol.86, no.4, pp.291-295, 2021-12-25 (Released:2021-12-24)

参考文献数

29

被引用文献数

3

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In Undaria pinnatifida, an effective method for mutant screening in sporophytes has not been established. The present study developed a novel mutant screening method for Undaria sporophyte by combining gametophyte mutagenesis with heavy-ion beam and land-based tank culture system. When we irradiated gametophytes and sporophytes with carbon- and argon-ion beams, survival rates of the female gametophytes and the sporophytes decreased with increasing dose. However, those of the male gametophyte did not decrease after both of the irradiations. Mutant screening during the sporophyte development was performed by using a land-based tank culture system. High-growth plants were selected in the first mutant (M1) population derived from the irradiated materials. We successfully obtained mutant candidates with higher growth than the wild type in the M2 generation obtained from brother-sister inbreeding of selected M1 plants. Four high-growth mutant candidate lines were selected from M2 populations of 48 lines. The mutant candidates were derived from 3 lines of the gametophyte irradiation and 1 line of the sporophyte irradiation, suggesting that the materials for the irradiation are applicable for mutant induction. The mutant screening method and the selected mutant candidates would advance the breeding and molecular biology in U. pinnatifida.