CAJ | 학술논문

细胞质雄性不育在高等植物中普遍存在，是杂种优势利用的重要工具，为推动植物杂种优势的利用发挥了重要作用。文章以本课题组前期新选的玉米细胞质雄性不育系A1、A2及保持系18(红)为材料，利用石蜡切片技术对不育材料小孢子发育过程进行细胞学观察，采用高效液相色谱法(HPLC)对不同发育时期的叶片及不同发育时期的雄穗DNA进行甲基化分析，从细胞学和表观遗传学角度了解不育系A1、A2的败育机制。结果表明：不育材料A1、A2小孢子发生败育的主要时期为四分体时期至单核小孢子中期。在不育系A2中还存在另一种败育方式，即在花粉母细胞时期表现出败育特征。甲基化分析结果表明，保持系18(红)的叶片DNA甲基化水平从苗期到拔节期迅速上升，而不育系A1、A2叶片DNA甲基化水平基本保持不变；保持系雄穗DNA甲基化水平表现为从花粉母细胞时期到双核期逐渐升高，而不育材料A1、A2从花粉母细胞时期到双核期的雄穗DNA甲基化水平表现为先上升后下降的趋势，达到最高峰的时期均出现在小孢子发育的四分体时期。从小孢子发育的细胞学观察结果可以发现，小孢子败育的主要时期往往具有较高的甲基化水平，推测DNA甲基化水平变化可能与不育材料A1、A2的花粉败育有关。
세포질웅성불육재고등식물중보편존재，시잡충우세이용적중요공구，위추동식물잡충우세적이용발휘료중요작용。문장이본과제조전기신선적옥미세포질웅성불육계A1、A2급보지계18(홍)위재료，이용석사절편기술대불육재료소포자발육과정진행세포학관찰，채용고효액상색보법(HPLC)대불동발육시기적협편급불동발육시기적웅수DNA진행갑기화분석，종세포학화표관유전학각도료해불육계A1、A2적패육궤제。결과표명：불육재료A1、A2소포자발생패육적주요시기위사분체시기지단핵소포자중기。재불육계A2중환존재령일충패육방식，즉재화분모세포시기표현출패육특정。갑기화분석결과표명，보지계18(홍)적협편DNA갑기화수평종묘기도발절기신속상승，이불육계A1、A2협편DNA갑기화수평기본보지불변；보지계웅수DNA갑기화수평표현위종화분모세포시기도쌍핵기축점승고，이불육재료A1、A2종화분모세포시기도쌍핵기적웅수DNA갑기화수평표현위선상승후하강적추세，체도최고봉적시기균출현재소포자발육적사분체시기。종소포자발육적세포학관찰결과가이발현，소포자패육적주요시기왕왕구유교고적갑기화수평，추측DNA갑기화수평변화가능여불육재료A1、A2적화분패육유관。
Cytoplasmic male sterility (CMS) is a widespread phenomenon in higher plants and has been applied in the commercial production of hybrid seeds. Two CMS lines A1 and A2 of maize were obtained previously by a trans-genic experiment. In this study, we conducted cytological observation of developmental microspores with CMS line A1, A2 and their maintainer line (18 red) using paraffin section technology. We also analyzed DNA methylation levels at different developmental stages using high performance liquid chromatography (HPLC). Our results showed that the pollen abortion of A1 and A2 mainly happened from the tetrad stage to the middle of mononuclear stage. Another abortive phenomenon found in CMS line A2 occurred at the pollen mother cell stage. The DNA methylation level of leaf increased rapidly from the seedling stage to the shooting stage in 18 red, while it remained constant in A1 and A2. For the tassel, the DNA methylation levels in 18 red increased gradually during the anther development, while a peak of DNA methylation level occurred in A1 and A2 at the tetrad stage, corresponding to the abortion period of micro-spore. This result suggested that the level of DNA methylation in the tassels is associated with the pollen abor-tion characteristics in CMS lines. In summary, our results implied a connection between pollen abortion and epige-netic regulation in maize CMS.