【摘要】 【目的】为了观察‘新高’梨花粉母细胞减数分裂及花粉发育过程,探讨‘新高’梨花粉败育的细胞学基础,【方法】以雄性不育的‘新高’和可育的‘丰水’梨为试材,采用常规压片法观察花粉母细胞减数分裂和花粉发育过程。【结果】结果表明,‘新高’梨花粉母细胞减数分裂过程中,染色体能正常配对形成二价体,经过2次分裂后产生四分体,随后释放出小孢子。然而在小孢子发育早期,小孢子发育缓慢;在中期,细胞质收缩,细胞壁加厚不明显,出现小孢子粘连;到小孢子发育晚期,大量小孢子出现粘连降解,或小孢子细胞壁破损,细胞质、细胞核降解消失。【结论】‘新高’梨花粉母细胞的减数分裂正常,其花粉败育发生在小孢子中出现液泡到单核晚期。更多还原

【Abstract】 【Objective】 The study is to observe the morphological changes of pollen mother cell meiosis and pollen development process of male-sterile ’Niitaka’ and male-fertile ’Housui’(Pyrus pyrifolia Nakai),and to examine the cytological basis of pollen abortion【Method】using conventional tableting method.【Result】 The meiosis of pollen mother cell in ’Niitaka’ pear was normal,chromosome showed normally bivalent pairing,and tetrad formed via two divisions,then released microspores.However,at the early stage of microspore development,microspore developed slowly compared with the normal.At the middle stage,cytoplasm shrink and cell wall thickening were not obvious and some of the microspores became adhered to each other.At the late stage,more microspores were observed to adhere and disintegrate,or microspore wall damaged,cytoplasm and nucleus disintegrated.【Conclusion】 It was suggested that pollen abortion in ’Niitaka’ pear occurs between microspore vacuolization and mononuclear late stage,while its pollen mother cell meiosis is normal.更多还原