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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。
S. sudanense and S. bicolor are both of the genus Saccharomyces, which have obvious heterosis, high quality hybrids and strong resistance to stress. In aquaculture, livestock breeding and resource utilization and environment Protection has a broad prospect of development and utilization, but whether the two belong to the same species is still controversial. In this paper, the mitotic karyotypes of two Sudan grass, two sorghum and three hybrids F1 were analyzed by wall-down osmosis-flame drying method. The chromosomes of meiosis of three F1 hybrids and chromosomes of two hybrid F2 somatic cells number. The results showed that the sudan grass, sorghum and their hybrid F1 were 1A karyotype, but the karyotype formulas were not exactly the same. Sudan grass Sa was 2n = 18m + 2sm (sat), sorghum 3042A and 3042A × Sa F1 were 2n = 20m, The rest of the material is 2n = 20m (sat). Sudan grass, sorghum and their F1 hybrids had no significant difference in the absolute long arm, absolute short arm, absolute full length, arm ratio and relative full length of 10 chromosomes (P> 0.05) Chromosome length changes are not obvious. Hybrid F1 pollen mother cells meiosis, the final and mid-term I chromosome karyotype and the number of visible (2n = 2x = 20), the rules of pairing; rod and the ring of bivalent body frequency varies depending on the combination of Tx623A × S722 F1,3042A × Sa F1 and Tx623A × Sa F1 The rod-like bivalence frequencies were 4.887, 5.710 and 5.126, respectively. The frequencies of the cyclic bivalents were 5.113, 4.290 and 4.874, respectively. At the later stage, the paired chromosomes could be separated normally . The number of hybrid F2 somatic chromosomes is 20 (2n = 20). Therefore, Sudan grass and sorghum are very close.