甜樱桃DFR基因内含子2和内含子3的多态性

【目的】研究70个甜樱桃品种DFR基因多态性与果皮颜色的相关性。【方法】通过DNA序列分析，以不同果皮颜色的10个甜樱桃品种（Prunus avium L.）为材料，检测DFR基因的多态性。根据多态性出现的位点设计特异引物，通过PCR扩增检测70个甜樱桃品种DFR基因的多态性。【结果】获得甜樱桃DFR基因约1 kb的片段，测序结果用BLAST分析发现，其核苷酸序列与樱桃李（Prunus cerasifera）的核苷酸相似性为80 %，预测的氨基酸序列与已知的甜樱桃（P. avium）DFR氨基酸序列相似性达99 %。该片段由3个外显子和3个内含子组成，2个多态性位点分别在内含子2和内含子3上。在黄色、黄底红晕和红色果皮3个组的70个甜樱桃品种中发现3个单倍型，共5种单倍型组合。通过SAS 9.0软件分析发现，所检测到的DFR基因的等位基因频率在黄底红晕果皮品种组和红色品种果皮组中的分布无显著差异。【结论】本研究在甜樱桃DFR基因座上得到2个差异位点，分别在内含子2和内含子3内，其优势基因频率依次为：0.864和0.679；但未发现DFR基因内含子2和内含子3的多态性与果皮颜色之间存在直接关系。

Polymorphism of DFR Gene Intron 2 and Intron 3 in Sweet Cherry

【Objective】 The relationship between polymorphism of DFR gene and pericarp colors was studied in 70 sweet cherry varieties.【Method】 DNA sequences analysis was applied to detect the polymorphism of DFR gene in 10 sweet cherry varieties(Prunus avium L.) of different colors in pericarp.Special primers were designed to amplify the polymorphic DNA fragments.70 sweet cherry varieties(P.avium L.) were used to test DFR gene polymorphism.【Result】 The DNA sequences of partial DFR gene about 1 kb were obtained from sweet cherry(P.avium).The identity of these DNA sequences was 80% with DFR gene of peach(Prunus persica).The identity of predicted amino acid sequences was 99% with the amino acid sequence of DFR in sweet cherry.This partial DFR gene contained 3 extrons and 3 introns.Two polymorphic loci were detected in intron 2 and intron 3.Three haplotypes and five haplotype combinations were found among 70 sweet cherry varieties which are composed of yellow pericarp group,yellow with a pink blush pericarp group and red pericarp group.There was no significant difference in the DFR gene frequencies between yellow with a pink blush pericarp group and dark red pericarp group.【Conclusion】 Two polymorphism loci were detected in intron 2 and intron 3 of DFR gene.Preponderatn alleles frequencies of 70 sweet cherry varieties was 0.864 in intron 2 and 0.679 in intron 3,respectively.There is no direct relationship between pericarp colors and polymorphisms DFR gene in intron 2 and intron 3.