摘要： 对棉属3个种间杂种TM-1×石系亚1号、TM-1×辣根棉和TM-1×瑟伯氏棉花粉母细胞的减数分裂进行了观察。结果表明，3个杂种多数花粉母细胞中期Ⅰ的染色体构型为13Ⅱ+13Ⅰ。二价体联会成环状、棒状或V型。TM-1×辣根棉杂种的二价体联会较紧密。杂种除正常的染色体组AA和DD联会外，还发生AD联会及出现多价体。中期Ⅰ单价体大部分分散于赤道板两侧，并较早移向两级。个别二价体也不排列在赤道板上。二价体向两极移动时常形成染色体“桥”，使这些染色体移动速度减慢，导致细胞分裂不同步。此外，在第一次分裂和第二次分裂中都能看到落后染色体、远离大多数染色体的零星染色体、孤立的染色体群等现象。后期Ⅱ的花粉母细胞可形成较多的核仁。在四分孢子期，3个种间杂种既产生四分体，也形成二、三、五、六乃至十分体。TM-1×石系亚1号、×辣根棉、×瑟伯氏棉杂种的四分体数分别为70.2%、63.1%和35.1%.

关键词: 减数分裂, 种间杂种, 花粉母细胞, 棉属

Abstract: Meiosis of pollen mother cells(PMCs) of three interspecific hybrids of Gossypium,TM-1 (Texas Marker 1,G. hirsutum) ×Shixiya 1 (G. arboreum), TM-1 ×G. armourianum,TM-1 ×G. thurberi, were observed. The Chromosome configuration of most of PMCs at metaphase Ⅰin these hybrids was 13 Ⅱ+ 13 Ⅰ. Bivalents synapsized into ring, rod, or V-shape.The synapsis of bivalents in the hybrid TM-1 ×G. armourianum was better than the other two hybrids. Hybrids produced anomalous synapsis of AD chromosomes and multivalents as well as normal synapsis of AA and DD chromosomes. Most of univalents scattered on the two sides of the equatorial plate and moved earlier to poles. One or two bivalents were not on the equatorial plate. The chromosome bridges were frequently formed when bivalents moved towards the poles,which slowed down the moving speed of chromosomes and resulted in nonsynchronization of cell divisions. In addition, lagging chromosomes, scattered chromosomes far from most of chromosomes, and lone small chromosome groups were found during the first and second divisions. PMCs yielded more nucleoli at telophase Ⅱ. At tetraspore stage, these three hybrids produced not only tetrads but also polyads (2-10 microspores). Tetrad percentages were 70. 2,63.1, and 35. 1 respectively in TM-1 ×Shixiya 1, TM-1 ×G. armourianum, and. TM-1 ×G.thurberi.

Key words: Meiosis, Interspecific hybrid, Pollen mother cell, Gossypium spp

中图分类号: 

• S562.01