Analysis of 45S rDNA Loci of Natural Tetraploid and Corresponding Diploid in Citrus by FISH
Aiming to study the origin of natural tetraploids from citrus seedlings, three diploid female Font parents of different embryony number types (monoembryony, polyembryony, the mixture monoembryony and polyembryony) and their natural tetraploid progenies were used for 45S rDNA loci analysis by FISH (Fluorescence in situ hybridization). Diploid female parents were C. limon ( Femminello), C. grandis ( Shatianyou)and C. sinensis ( Hongjiangcheng). The number of 45 S rDNA loci of the diploid and tetraploid of Femminello was three and four respectively. Three 45S rDNA loci of diploid were detected all on centromeric region, while two loci of tetraploid located on telomeric region of short arm and other two were on centromeric region, which indicated that formation of natural tetraploids of Femminello should be relative to sexual hybridization with foreign genome. The diploid of Shatianyou had four 45S rDNA sites, and natural tetraploids of Shatianyou had eight or six sites. The signal location and intensity of tetraploids of Shatianyou were complicated in different individuals. These signal information suggested that these tetraploids were possibly autotetraploid or allotetraploid. The number of 45S rDNA sites of diploid of Hongjiangcheng was three, and its tetraploid had six sites. According to similar signal character, tetraploids of Hongjiangcheng should be from chromosome doubling of nucellar cells. In conclusion, natural citrus tetraploids could be from sexual hybridization with recombination of foreign genome when female is a monoembryony or the mixture of monoembryony and polyembryony. While female parent is polyembryonic, natural tetraploids maybe come from chromosome doubling of nucellar cells.
Citrus Tetraploid 45S rDNA Fluorescence ire situ hybridization (FISH)
S. Q. Xiang W. X. Wang X. L. Li D. Jiang X. Wei Q. He G. L. Liang
College of Horticulture and Landscape Architecture, Southwest University, Chongqing 400716,P. R. Chi Citrus Research Institute, Chinese Academy of Agricultural Sciences, Chongqing 400712, P. R. China
国际会议
11th International Citrus Congress(第11届国际柑橘大会)
武汉
英文
164-167
2008-10-01（万方平台首次上网日期，不代表论文的发表时间）