小麦与高冰草不对称体细胞杂种F_5代部分株系的花粉母细胞染色体观察分析

STUDIES ON CHROMOSOMES OF POLLEN MOTHER CELLS IN PARTS OF F_5 PLANTS DERIVED FROM ASYMMETRIC SOMATIC HYBRID BETWEEN TRITICUM AESTIVUM AND AGROPYRON ELONGATUM

普通小麦 (TriticumaestivumL .)济南 177原生质体 (受体 )和经紫外线照射的高冰草 (Agropy ronelongatum)原生质体 (供体 )用PEG法诱导融合 ,形成外形偏向小麦的不对称体细胞杂种及后代 .经过田间繁育 ,现已到F5代 .在对F1至F4 代杂种植株完成各项分析的基础上 ,对F5代不同株系 (Ⅱ 2 ,8 1,Ⅱ Ⅰ 8)的花粉母细胞染色体进行观察和分析 ,结果表明 :杂种花粉母细胞在减数分裂时基本正常 ,88%以上的细胞染色体数目在 2 0 - 2 1对之间 ,并且绝大多数染色体可以正常配对形成二价体 .少数细胞存在小染色体 ,数目多为 1- 2个 ,且大部分以配对形式存在 .由此可见 ,杂种在遗传上基本是稳定的 ,且杂种的表型及遗传在较短的世代就基本稳定 .但个别杂种花粉母细胞中也存在减数分裂异常现象 ,如不均等分离、落后染色体、染色体桥、多着丝粒体、易位环及多价体等 .

Hybrid plants were obtained from protoplast fusion between Triticum aestivum L.(cv. Jinan 177) and Agropyron elongatum . Through the breeding in the field, we now have the F 5 plant. On foundation of the analysis of F 1 F 4 hybrid plants, we have analysed the pollen mother cell (PMC) chromosomes in parts of F 5 plants (Ⅱ 2,8 1,Ⅱ Ⅰ 8), and the result indicated that the meiotic pairing of these plants at MⅠwas almost normal. Numbers of the chromosome pairs distributed between 20-21 in more than 88% cells. One or two micro chromosomes were found in few cells, and most of them occurred in pairs. Thus we can see that the hybrid was fundamentally stability. But some abnormal phenomena were also observed in few cells, such as unequal separation, lagging chromosomes, translocation rings, chromosome bridges, multi constrictions and multivalent chromosomes, etc.