月季‘云粉’花粉母细胞减数分裂的初步研究

Observation on Pollen Mother Cell Meiosis of New Rose Cultivar,Rosa ‘Yunfen'

【目的】本文探讨了切花月季自育品种‘云粉’作父本时结籽率差异显著且较低的原因。【方法】以改良的制片法对‘云粉’的花粉母细胞减数分裂各个时期进行了观察。【结果】观察‘云粉’花粉母细胞减数分裂的最佳时期是当花药由淡绿色转变为淡黄色、花蕾横径为1.03~1.07 cm、纵径为2.9~3.4 cm大小时;在同一花药中,花粉母细胞的减数分裂并不同步,可以观察到不同时期的分裂相。花粉母细胞在减数第1次分裂过程中存在单价体、三价体、染色体桥等异常现象,减数第2次分裂末期观察到三分体和二分体。【结论】‘云粉’因花粉母细胞减数分裂过程存在异常分裂现象,从而产生2n雄配子,在一定程度上降低了其作父本时的结籽率。

[ Objective]Rosa ＇ Yunfen＇ was a plant breeders＇ right owned new cut rose cultivar. The rose hip and achene setting rates were very low and differred significantly among crossing combinations when R. ＇ Yunfen＇ was used as the paternal parents in hybridization breeding. [ Method ] To find the reason, pollen mother cell meiosis of R. ＇ Yunfen＇ was observed and the meiotic phases in different periods of the division were recorded in this study. [ Result ] The optimal time for observation of meiosis was when the bud was about 1.03 - 1.07 cm wide and 2.9 - 3.4 cm long. At that stage, the anther colour turned from light green to yellowish green. The meiotic behaviors of pollen mother cells were non-synchronic and several meiosis phases could be observed in the same anther. Abnormal phenomina of meiosis such as univalent, trivalent and chromosome-bridge could be observed in the first division of meiosis. Then, triad and dyad were produced in the second division of meiosis of R. ＇ Yunfen＇ , by which 2n pollens were formed. [ Conclusion] The abnormal division of PMCs of R. ＇ Yunfen＇ might be a reason for the low hip and aehene setting rate when used as paternal parent in breeding.