甜瓜小孢子发育时期与花器形态的关系

Correlation between microspore development period and floral organ morphology of Cucumis melo L.

【目的】研究各发育时期甜瓜小孢子的细胞学特征及其与花器外观形态的关系,以期能根据花器的外观形态确定小孢子的发育阶段,为花药、小孢子培养研究提供细胞学依据。【方法】采集不同蕾长的饱满雄花花蕾,形态学观察后分别进行DAPI和醋酸洋红染色,观察小孢子发育的细胞学特征,以确定花粉的发育时期,分析各发育时期甜瓜小孢子的细胞学特征与花器外观形态的关系。【结果】2种染色方法以醋酸洋红染液染色效果较佳;甜瓜小孢子发育经历四分体时期、单核早中期、单核靠边期和双核期,每个时期形态特征明显;甜瓜小孢子发育时期与花蕾的大小、花药颜色密切相关。甜瓜花蕾纵径在2.9~3.5mm、横径在2.7~3.2mm,且花瓣微露,花药呈黄色时,绝大多数的小孢子发育至单核靠边期。【结论】可以根据甜瓜花蕾的形态、大小和花药发育情况判断小孢子的发育时期,从而确定小孢子最佳培养时期对应的选蕾标准。

【Objective】The cytology characteristics of melon microspore and morphology of flower organ were observed in different development periods for determining the relationship between microspore development and buds morphology,which would provide evidence for culturing of anther and microspore.【Method】Full male flower buds with different lengths were collected and DAPI and carmine acetate staining methods were used in cytological observation of melon microspore development to confirm the pollen development periods after morphological observation.The relationship between cytological characteristics of different development periods of melon microspore and morphology of flower organ was also analyzed.【Result】Carmine acetate dyeing had better dyeing effects.The development of melon microspore was divided to four stages:tetrad,early-or mid-uninucleate,late-uninucleate,and binucleate,and each stage had obvious characteristics.The microspore development period of melon was closely related with bud size and anther color.The buds were 2.9-3.5mm in height and 2.7-3.2mm in diameter.The petals were calyx slightly and the anthers were yellow.Most microspores could develop to the stage of late-uninucleate.【Conclusion】The development period of melon microspore could be determined by the form,size and an-ther development condition of buds,and it is helpful to obtain the standard of bud selection at the best development stage of microspore.