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亚比棉异源四倍体是山西农业大学棉花育种组于上个世纪80年代用A染色体组亚洲棉(Gossypium.arboreum)(迁西小黑籽)与G染色体组野生棉比克氏棉(G.bickii)杂交成异源二倍体后,又经过加倍而获得的。亚比棉异源四倍体不仅育性得到恢复、结铃正常,而且成功地将比克氏棉的优异性状——种子腺体延缓形成转育到亚比棉中。这为实现棉花综合利用和提高抗虫性创育了新的育种材料。在随后的多年中,山西农业大学棉花育种组对亚比棉异源四倍体进行了广泛的细胞形态学研究,对其核型做了分析。然而,仅依据形态学和普通的核型图像,还不能确定该异源四倍体棉种中比克氏棉G染色体(亚)组在核型中的表现。该文以比克氏棉gDNA为探针,亚比棉异源四倍体根尖体细胞染色体为靶细胞染色体,封阻材料为亚洲棉(迁西小黑籽),进行亚比棉基因组原位杂交(Genomeinsituhybridization,GISH)及核型分析。从获得的图像中可以清晰地发现有52条染色体,其中有/无杂交信号的各一半,这直观地证实了人工复合亚比棉杂交种确为异源四倍体,而且是双二倍体。A亚组与G亚组染色体长度存在交替排列。亚比棉异源四倍体基于GISH图像的核型公式为:2n=4x=52=46m(4sat)+6sm(4sat)。A亚组和G亚组染色体上各有2对随体。G亚组染色体中至少有5对双重显色明显的染色体,意味着可能有A亚组染色体的交换,而A亚组染色体中只观察到或多或少的探针红色荧光信号,由于分辨率不够而难于定量分析。进一步以45SrDNA为探针,以鲑鱼精DNA作为封阻DNA,对亚比棉异源四倍体进行45SrDNA-FISH,实验表明,亚比棉异源四倍体有14个NOR(核仁组织区)信号,说明亚比棉异源四倍体有14个随体,即7对随体。比克氏棉对亚洲棉的GISH结果显示,在有亚洲棉DNA封阻的条件下,亚洲棉靶细胞染色体无任何杂交信号,说明比克氏棉与亚洲棉染色体之间不存在较大的同源或相似序列。
Alloploid tetraploid cotton is the cotton breeding group of Shanxi Agricultural University in the 1980s with the A genome of cotton (Gossypium.arboreum) (Qianxi black seed) and the G genome of wild cotton than Kirschner wire G.bickii) after hybridization into allotering diploids, but also after doubled. Alloploid tetraploid not only restored fertility, normal bolting, but also succeeded in the excellent trait of Beech’s cotton seed gland delay the formation of the transfer into the cotton. This created a new breeding material for the realization of comprehensive utilization of cotton and improvement of insect resistance. In the ensuing years, the cotton breeding group of Shanxi Agricultural University extensively studied the morphology of allotetraploid tetraploids, and analyzed their karyotypes. However, based on morphological and common karyotype images, it is not yet possible to determine the karyotype behavior of the G (subscript) subgroup of Bükks cotton in this allotetraploid cotton. In this paper, the gDNA of Becker’s cotton was used as a probe. The chromosomes of allotetraploid apical somatic cells of Asiatic cotton were taken as target cell chromosomes. The blocking material was Asiatic cotton (Qianxi black seed) Genomeinsituhybridization (GISH) and karyotype analysis. From the obtained image, we can clearly find that there are 52 chromosomes, with and without hybridized signal half, which visually confirmed that artificial hybrids were indeed allotetraploid tetraploid hybrids, but also double diploid . A subgroup and G subgroup chromosome length exist alternately. The karyotype formula based on the GISH image of allotetraploid tetraploidy of cotton is: 2n = 4x = 52 = 46m (4sat) + 6sm (4sat). There are 2 pairs of satellites on the A and G subgroups. At least 5 pairs of clearly dyed chromosomes in the G subgroup indicate that there may be exchange of chromosomes in the A subgroup whereas more or less probe red fluorescence signals are observed in the A subgroup, Not enough but difficult to quantitative analysis. Furthermore, 45S rDNA-FISH was performed using 45S rDNA as a probe and salmon sperm DNA as a blocking DNA. The results showed that there were 14 NORs (nucleolar organizer regions ) Signal, indicating that there are 14 satellite satellites in allotopic tetraploid, that is, 7 pairs of satellite. GISH results of Beech’s cotton on Asian cotton showed that there was no hybridization signal on chromosomes of target cotton from Asian cotton under the condition of blocking DNA of Asian cotton, indicating that there is no significant difference between Barker’s cotton and Asian cotton chromosomes Source or similar sequence.