芜菁小孢子培养及其胚状体离体发育过程
Turnips（Brassica rapa L.）Microspore Culture and Embryoid Development in Vitro

为提高芜菁小孢子培养的产胚率，以新疆柯坪县当地农家品种‘阿恰芜菁’为供试材料，通过DAPI染色进行荧光显微观察芜菁花蕾长度与小孢子发育时期的对应关系，了解其对胚诱导的影响，并利用倒置显微镜技术观察了解小孢子培养过程中胚状体离体发育过程。结果表明：花蕾长度为1.5~2.0 mm时，仅有6.45%的小孢子处于单核靠边期，培养未得到胚状体；当花蕾长度为2.0~2.5 mm时，56.55%的小孢子属于单核靠边期，此时产胚率最高，每蕾达8.32个；当花蕾长度为2.5~3.0 mm时，单核靠边期的小孢子降至36.15%，此时可以得到胚状体，但每蕾仅有0.72个。可见，大部分处于单核靠边期至双核早期的小孢子最适合芜菁的小孢子培养。芜菁小孢子培养过程中胚状体的发育过程为：热激处理→膨大→均等分裂或不均等分裂→小细胞团→球形幼胚→心形胚→鱼雷形胚→子叶期胚→胚再生植株，且在此过程中胚胎发育存在不同步性。
To improve the percentage of microspore embryogenesis,‘Arqia turnip’ collected from Keping county in Xinjiang was as material. Based on DAPI staining fluorescence microscopic observation,the correspondence between bud length and microspore development period was explored,and discuss the effects of embryo induction. Using the inverted microscope technology observe the whole process that cultivate microspore embryo in vitro. The results showed that when the length of flower bud was 1.5-2.0 mm,only 6.45% microspores were in the late uninucleate stage,and no embryoid was obtained. When flower bud was 2.0-2.5 mm length,56.55% microspores were in the late uninucleate stage and 8.32 embryos per bud were obtained. When flower bud was 2.5-3.0 mm,the ratio of late-uninucleate-stage microspores dropped to 36.15% and 0.72 embryos per bud were obtained. Obviously,most of the microspores at the stage fromlate mononuclear stage to early binuclear stage were cultivated easily. The embryo development process of turnip cultivated after hot shock treatment experienced the stage of cell expansion,equal or asymmetric division,cell cluster,globular embryo,hear-shape embryo,torpedo-shape embryo,cotyledon embryo and embryo regeneration plant in sequence,and the asynchronism of embryonic development was observed.