莲品种DNA指纹图谱的构建

为了克服单纯依据形态特性鉴定品种的局限性, 我们开展了莲品种DNA指纹图谱构建研究, 旨在对其品种的快速准确鉴定及专利权保护等起一定作用。本研究以圆明园保存的72个莲品种为实验材料, 用来自不同地点的1,409份野生莲(Nelumbo nucifera)和58份美洲黄莲(N. lutea)群体样本作遗传背景参照。从104对核微卫星引物(nSSR)中筛选出15对, 从17对叶绿体微卫星(cpSSR)引物中筛选出2对, 共17对引物作为72个莲品种DNA指纹鉴定的条码。15对nSSR引物共检测到94个等位基因(平均6.27个), 其中11个属于美洲黄莲, 65个属于野生莲, 18个不能区分; 多态信息含量(PIC)介于0.3899-0.8023之间 (平均0.5748)。2对cpSSR引物共检测到13个单倍型, 其中9个属于野生莲, 4个属于美洲黄莲。全部17对引物标记结果显示, 共有19个品种含有美洲黄莲遗传组分, 其中8个母系来源于美洲黄莲; 有36个品种(涉及12对引物)具有至少1个特有基因型; 最少8对引物组合可完全区分开68个品种。有2组共4个品种组内全部17对引物均不能区分。本研究通过核心引物组合法使68个莲品种获得特异性DNA指纹。推荐13对nSSR和2对cpSSR共15对引物作为莲品种鉴定的核心条码, 并建议将形态特征与DNA指纹相结合作为莲品种的鉴定标准。

Identification of lotus cultivars using DNA fingerprinting

DNA fingerprinting is a fast and accurate method for cultivar identification, which can overcome the limitation of morphological traits. We used DNA fingerprinting to identify 72 lotus (Nelumbo) cultivars collected from the Resources Garden of the Yuanmingyuan Park in Beijing. We used 1,409 samples of N. nucifera and 58 samples of N. lutea as a genetic background reference. Fifteen out of 104 pairs of nucleus microsatellite primers (nSSR) and 2 out of 17 pairs of chloroplast microsatellite primers (cpSSR), for a total of 17 pairs of fluorescent primers, were selected as the barcode for fingerprint identification of the 72 lotus cultivars. For the 15 nSSR primers, 94 alleles were examined (with an average of 6.27). Out of the 94 alleles, 11 belong to N. lutea, 65 belong to N. nucifera, and the remaining 18 alleles could not be identified. The polymorphism information content (PIC) range between 0.3899 and 0.8023, with an average value of 0.5748. For the two pairs of cpSSR primers, 13 haplotypes were examined. Among them, 9 haplotypes belong to N. nucifera and 4 haplotypes belong to N. lutea. Results of identification of all 17 pairs of primer markers showed that 19 cultivars included genes from N. lutea, and 8 cultivars had female parents from N. lutea. There were 36 cultivars (using 12 pairs of primers) which had at least one unique genotype. With a minimum of 8 pairs of primers, 68 cultivars could be distinguished. Among the 72 cultivars, four cultivars in two groups could not be distinguished based on the whole set of 17 primers. Using the core primer combination method, we developed specific DNA fingerprints for each of the 68 lotus cultivars. Based on the above results, we recommended 15 pairs of primers including 13 pairs of nSSR and 2 pairs of cpSSR as the core barcode for lotus cultivar identification.