作　　者： ; ; ; ; ;

机构地区： 安徽科技学院植物科学学院

出　　处： 《作物学报》 2008年第7期1206-1212,共7页

摘　　要： 苏丹草(S. sudanense)与高粱(S. bicolor)均为禾本科高粱属植物, 两者的杂种优势明显, 杂交种品质好, 抗逆性强, 在水产、畜禽养殖及资源利用与环境保护上有着广阔的开发利用前景, 但两者是否属于同一个种至今存在争议。本文采用去壁低渗-火焰干燥法, 分析了 2 份苏丹草、2 份高粱及其 3 个杂种 F1 有丝分裂核型, 观察了 3 个杂种F1 减数分裂染色体行为和 2 个杂种 F2 体细胞染色体数目。结果表明, 苏丹草、高粱及其杂种 F1 均为 1A 核型, 但核型公式不完全相同, 苏丹草 Sa 为 2n=18m+2sm(sat), 高粱 3042A 和 3042A×Sa F1 为 2n=20m, 其余材料均为2n=20m(sat)。苏丹草、高粱及其杂种 F1 3 者在 10 条染色体的绝对长臂、绝对短臂、绝对全长、臂比和相对全长上差异均不显著(P>0.05), 说明苏丹草与高粱在染色体长度上的变化不明显。杂种 F1花粉母细胞减数分裂, 终变期和中期 I 染色体核型和数目清晰可见(2n=2x=20), 配对行为规则; 棒状和环状二价体的频率因组合不同而异, Tx623A×S722 F1、3042A×Sa F1 和 Tx623A×Sa F1 棒状二价体频率分别为 4.887、5.710 和 5.126, 环状二价体频率分别为 5.113、 4.290 和 4.874; 在后期 I, 配对的染色体能够正常分离。杂种 F2 体细胞染色体数目为 20(2n=20)。因此, 苏丹草与高粱的亲缘关系非常近。 Sudangrass （Sorghum sudanense） and sorghum （S. bicolor） are two members of the genus Sorghum （Gramineae）. Their hybrids have exhibited favorable forage yields and overall improved quality and disease resistance. They are widely used in aquaculture, production of livestock food and environmental protection, but some disagreements exist as to whether they actually belong to the same species. The Karyotypes of two sudangrass varieties, two sorghum varieties, three sorghum-sudangrass F1 hybrids were analyzed by the method of cell wall degradation and hypotonic treatment for chromosome preparations, and the meiosis behavior of three F1 hybrids and the chromosome numbers of two F2 hybrids were observed. The result showed that the karyotypic types of sorghum and sudangrass were 1A, and the karyotype formula was 2n=18m＋2sm （sat） for Sa, 2n=20m for 3042A and 3042A×Sa F1, and 2n=20m（sat） for the others. The difference of chromosomes among three groups （i.e. sudangrass, sorghum, and sorghum-sudangrass hybrid F1） were not significant in terms of absolute long arm, absolute short arm, absolute total length, arm ratio （l/s）, relative total length （P〉0.05）; the change of chromosome length was not obvious in sorghum and sudangrass. The paired chromosome configuration of sorghum-sudangrass hybrid F1 in pollen mother cells at diakinesis and metaphaseIwas 2n=2x=20（10II） and the chromosome pairing behavior was regular, but the frequencies of rod bivalent of Tx623A×S722 F1, 3042A×Sa F1, and Tx623A×Sa F1 were 4.887, 5.710, and 5.126, respectively; those of ring bivalent were 5.113, 4.290, and 4.874, respectively. At anaphase I, the paired chromosomes of sorghum-sudangrass hybrid F1 could separate from each other. The chromosome numbers of F2 hybrid were 20 （2n=20）. Therefore, the sudangrass/sorghum relationship is sufficiently close.

关 键 词： 苏丹草 高粱 杂交种 染色体 细胞遗传学

领　　域： [农业科学] [农业科学]