‘马哈利’樱桃雌雄蕊发育解剖学研究

An anatomical study on pistils and stamens in Prunus mahaleb

【目的】了解‘马哈利’樱桃的生殖生物学特性,以及探讨其结实率低的原因。【方法】用常规石蜡切片技术,对‘马哈利’樱桃(Prunus mahaleb Linn)的雌雄蕊发育过程进行观察研究,为科学利用这种优良砧木育种材料提供参考。【结果】(1)‘马哈利’樱桃的花药4室;花药壁由外向内分别为表皮、药室内壁、中层和绒毡层;绒毡层为腺质绒毡层;小孢子母细胞减数分裂为同时型;4个小孢子初期为四面体型排列;成熟花粉为3-细胞型,扫描电镜下可见3个萌发沟,外壁有横纹。‘马哈利’授粉结实率低的一个重要原因就是由于其雄配子体的液泡化衰败导致花粉的败育。(2)‘马哈利’樱桃其胚珠具双珠被,为厚珠心;雌配子体发育早期,在单室子房内可以看到2个倒生胚珠。后期,其中一个退化,另一个发育为种子;胚囊的发育类型为蓼型。丝状器缺乏也可能是导致‘马哈利’受精不良,结实率低的原因。(3)从‘马哈利’雌雄蕊的发育进程来看,可知其雄蕊发育早于雌蕊,花粉具有早熟性。【结论】阐明了优良育种资源‘马哈利’樱桃的生殖生物学特性,并且揭示了其授粉结实率低的解剖学研究。

【Objective】 The objectives of the study were to explore the reproductive biological characteristics and investigate the reason of low fruit set rate of Prunus mahaleb Linn.【Method】 The development of pistils and stamens were studied by using the method of paraffin section.【Results】 The results showed that:(1) The anther had four chambers. The wall of anther consisted of epidermis, endothecium, middle layer and tapetum from out to inside, and the tapetum cell was glandular. The meiosis of microspore mother cell was simultaneous type, and the tetrads were tetrahedral. Mature pollen was 3-cellular type. The mature pollen grains were observed using scanning electronic microscope(SEM). There were three germinal furrows in the exine of pollen with horizontal stripes. One important reason of the low fruit set rate was the vacuolization of male gametophyte.(2) P. mahaleb had crassinucellate ovule with two integuments. During the early period of gametophyte, there were two anatropous ovules which attached to the placenta on the inner wall of its unilocular ovary. In late period, one of them degraded while the another developed into a seed. The monosporic embryo sac was polygonum type. Lack of filiform apparatus might cause poor pollination and poor bearing.(3) The development of stamens were earlier than that of pistils, so the stamens were precocious. 【Conclusion】 The research results provided scientific basis for exploring the reproductive biological characteristics of the excellent breeding resource P. mahaleb and the reason of low fruit set rate.