甘薯栽培种及其近缘野生种的DAPI核型及rDNA-FISH分析

rDNA-FISH Analysis and DAPI-karyotype of Ipomoea batatas cv.and Ipomoea hederacea Jacq.

利用DAPI显带和rDNA-FISH技术对栽培种甘薯(‘徐薯18’)(Ipomoea batatas cv.Xushu No.18)及2种不同产地近缘野生种(Ipomoea hederacea Jacq.)进行了细胞遗传学研究。DAPI核型分析表明,‘徐薯18’核型公式为2n=6x=90=72m+18sm(18SAT),随体位于第1、3、6染色体上;美国近缘野生种核型公式为2n=2x=30=30m(4SAT),香港近缘野生种核型公式为2n=2x=30=20m+10sm(4SAT),随体均位于第6、12染色体上。rD-NA-FISH结果显示,栽培种甘薯基因组中含有3对5SrDNA位点,分别位于着丝粒区、亚着丝粒区和染色体端部;美国近缘野生种基因组中含有2对5SrDNA位点,香港近缘野生种基因组中含有1对5SrDNA位点,均位于随体部位;两种不同地域来源的近缘野生种基因组中均含有2对45SrDNA位点,分别位于第6和第12染色体上。

Ipomoea batatas cv. Xushu 18 and its two wild relatives I. hederacea Jacq. from American and Hong Kong in China were studied by DAPI banding and rDNA-fluorescence in situ hybridization. The DA PI banding showed the karyotype of I. batatas and I. hederacea Jacq. from American and Hong Kong in China are 2n=6x=90=72m＋18sm（18SAT） with satellites on chromosome 1,3 and 6;2n=2x=30=30m （4SAT） ;2n=2x=30=2Om＋lOsm（4SAT）, both with satellite on chromosome 6 and 12, respectively. The FISH data indicated that three pairs of 5S rDNA signals,located on centromere,pericentromere and the re- lomere of chromosome r and 12 were detected on some 6 of 1. hederacea J and 12 of that from Am rant from the sweet pot espeetively of I. batatas; both I. hederacea Jacq. acq. from Hong Kong,2 erican. Taking all the da ato,and there were sore Two pairs of 45S rDNA signals, located on chromosome 6 ;While 1 pairs of 5S rDNA signals presented on chromo- pairs of 5S rDNA signals occurred on the chromosome 6 ta obtained in the study,both I. hederacea Jacq. were dis e differentiations in the chromosomes of the I. hederacea