萝卜小孢子不同发育时期的细胞学和花器官形态特征观察

通过醋酸洋红染色和DAPI荧光染色对萝卜小孢子的发育过程进行了细胞学观察，两种染色方法中，后者较前者能更清楚和全面地显示细胞的结构。通过对4份萝卜材料不同发育时期花蕾的细胞学和形态学的观察发现，小孢子的发育时期与花器官形态特征之间存在密切的关系。各材料小孢子不同发育时期的花蕾纵径、花蕾横径、花蕾纵横比、花药长、花药宽、花瓣长和瓣药比均存在明显差异。不同萝卜材料处于单核靠边期的花器官各形态指标也存在明显差异，其中花蕾纵径、花蕾纵横比、花瓣长和瓣药比适合于作为不同材料花蕾取样适期的鉴定指标，各指标的适宜尺度：花蕾纵径在2.991～3.510 mm之间，花蕾纵横比在 1.412～1.480之间，花瓣长在1.889～2.561 mm之间，瓣药比在0.923～1.057之间。此外，适合小孢子培养的花蕾的外观特征为花药被萼片包裹紧密，花瓣和花药等长或接近等长，花蕾饱满，花药浅黄色至黄色。

Morphological Characteristics of Flower Organ and Cytological Observation of Microspore in Different Development Stage in Radish (Raphmnus Sativus L.)

The developmental stage of microspores was observed by two different methods acetic magenta staining and DAPI staining.It was found that the nucleolus in microspore display more clearly by DAPI staining than acetic magenta staining.The relationship between microspore developmental stage and morphological characteristics of flower buds and anthers was studied by both of cytological and morphological methods on four different radish genotypes.There were significant differences in longitudinal diameter and transverse diameter of flower buds，the ratio between longitudinal diameter and transverse diameter of flower buds，anther length，anther width，petal length，the ratio of petal length and anther length，during the developmental stages of the microspore in all four different radish genotypes.At the late-single nucleus stage，significant difference existed in all the above-mentioned index of different varieties.It indicated that the longitudinal diameter of buds，the ratio of the longitudinal diameter and the transverse diameter of flower buds，petal length and the ratio of the petal length and the anther length were suitable for the determination of sampling time for microspore culture.The appropriate longitudinal diameter of buds ranged 2.991-3.510 mm and the ratio of the longitudinal diameter and the transverse diameter of flower bud ranged 1.412-1.480，the petal length ranged 1.889-2.561 mm，the ratio between petal length and anther length ranged 0.923-1.057.In addition，it is necessary that the anthers should be covered by the sepal，the length of sepal was equal or close to the anther lenghth，and the flower bud was full，the anther showed from light yellow to yellow.