【作者】 李造哲；

【导师】 云锦凤；

【作者基本信息】 内蒙古农业大学 ， 草业科学， 2001， 博士

【摘要】 采用形态学、细胞学、同工酶电泳、RAPD 等方法或技术，对披碱草和野大麦杂交后代的遗传特性及育性进行了研究，主要结果如下：（1）披碱草和野大麦杂种F1代的外部形态特征偏向亲本披碱草，正、反交对F1代植株颜色有明显影响。BC1代外部形态明显偏向轮回亲本野大麦，不同株系有较大变异。第一颖形状可作为鉴别杂种真伪的重要特征之一。（2）杂种F1代的生长天数、分孽能力、抗旱及耐盐性为双亲的中间型，产草量表现出较强的杂种优势，正反交对F1代生育期、分蘖能力、再生速度有影响。BC1代的生物学及农艺特性明显偏向轮回亲本野大麦，不同株系间有较大的变异。（3）杂种F1代减数分裂不规则，单价体的普遍存在是造成杂种不育的重要原因。BC1代染色体发生了数目上的变异，变异范围为28—35。BC1代减数分裂单价体频率较F1有所降低，二价体频率有所增高，有些株系的环状二价体占绝对优势。（4）杂种 F1代POD和EST同工酶谱为双亲的互补型或有杂种特征带。BC1代POD和EST同工酶谱明显地受轮回亲本野大麦的影响。（5）RAPD 能客观真实地检测出亲本及杂交后代间的遗传差异，该技术可用于禾草远缘杂种鉴定及回交后代目标性状植株检测的遗传标记。（6）杂种F1代高度不育，BC1代育性有不同程度的提高，有些株系花粉可育率达 73％，自然结实率达 14.6％，表明回交是克服杂种不育的有效方法。更多还原

【Abstract】 The genetic characters and fertility of the hybrids between Elyrnus dahuricus and Horde urn brevisubulaturn were studied by means of morphology, cytology, isozyme electrophoresis and RAPD. The results were as follows: (1) The morphological characteristics of hybrid F1 between E. dahuricus and H. brevisubulatum tended toward recurrent parent H. brevisubulaturn, and there were significant differences among backcross 1 (BC1) lines. The lepicena shape can be used as one of the important characteristics to identify hybrids.(2)The growing days,tiller ability, drought resistance and salt tolerance of the hybrid F1 were in the middle of the parents, the heterosis of F1 yield was stronger, there were significant differences in phenological period, tiller ability and regeneration rate between E. dahuricusX H. brevisubulaturn F1 and H. brevisubulaturn X E. dahuricus F1.The biological and agronomic characters of BC1 tended toward recurrent parent H. brevisubulaturn and there were significant differences among BC1 lines. (3) The meiosis of hybrid F1 was irregular and univalents existed universally, which was the main reason why hybrid F1 is infertile. The BC1 varied in chromosome number ranged from 28 to 35, the univalent frequency in meiosis of BC1 decreased and the bivalent frequency increased compared with that of F1, the ring bivalents in some BC1 lines were absolutely dominant. (4) The zymogram of POD and EST of hybrid F1 were the mutual suplementary isozymes of the parents or had hybrid bands. The zymogram of POD and EST of BC1 were affected obviously by recurrent parent H. brevisubulaturn. (5) The genetic differences among parents and their hybrids can be tested objectively by RAPD, which can be used as genetic marker to identify hybrid and to determine the plants with object characteristics. (6) Hybrid F1 is highly infertile, the fertilities of BC1 were enhanced in different degree, the pollen fertility rate of some BC1 lines reached to 73%, seed set reached to 14.6%, which showed that backcross is an effective ways to restore fertility to wide- cross hybrid F1.更多还原