【摘要】 为探讨柑橘天然四倍体来源,以5SrDNA作为探针,运用荧光原位杂交技术比较柑橘属3个生物型的天然四倍体及其相应的二倍体的5SrDNA位点.结果表明,红江橙二倍体和化州橙二倍体的5SrDNA位点为2个,其天然四倍体均有4个位点;资阳香橙二倍体有1个5SrDNA位点,其天然四倍体有2个位点.供试天然四倍体柑橘的5SrDNA位点数目为二倍体的加倍,而在染色体上的位置与相应二倍体处于相同序号染色体的相同位置,只是信号亮度存在差异.5SrDNA位点数目和倍性有密切联系,随着倍性的增加有成倍增加的趋势,推测这些天然四倍体基因组的形成极有可能由二倍体直接加倍而来.更多还原

【Abstract】 In order to study the origin of the natural tetraploids in Citrus,the 5S rDNA was used as a probe and we compared the 5SrDNA sites among 3natural tetraploids belonging to Citrus L.and their corresponding diploids by the technique of fluorescence in situ hybridization(FISH).The results showed that 2sites were found in diploid of C.sinensis(Hongjiangcheng)and C.sinensis(Huazhoucheng)while 4sites in theirs tetraploids.Moreover,1site was detected in the diploid of C.junos Sieb.ex Tanaka while 2sites in its tetraploids.The number of the natural tetraploid citrus were twice as their corresponding diploids and the location of the natural tetraploid citrus in the chromosome were the same as their corresponding diploids though their signal intensity were different.Those 5SrDNA sites imply that the natural tetraploids in this study are likely to be doubled directly from their corresponding diploids.更多还原