基于ISSR标记的四照花栽培品种指纹图谱构建及亲缘关系分析

四照花观赏价值极高,其栽培品种繁多且难以区分。为了快速有效地鉴定四照花栽培品种,本研究利用ISSR标记,建立了44个四照花主要栽培品种及其亲本的指纹图谱,并分析了其亲缘关系,为四照花的推广应用提供依据。利用优化的ISSR-PCR体系,从100条ISSR引物中筛选出7条,对44个四照花样本的基因组DNA进行PCR扩增。通过2条引物UBC834和UBC847的扩增,建立了品种特异性指纹码,可将44个样本中的42个加以区分。7条ISSR引物共获得91条扩增带,其中多态性条带90条,多态性比例为98.9%,平均每个引物扩增出13个位点;在遗传距离为0.60处,可以将44个样本分为3类:第1类包括大花四照花原种、所有大花四照花栽培品种和以大花四照花为母本的杂交品种37号(C.‘Rutban’)和38号(C.‘Celestial Shadow’);第2类为所有日本四照花和中国四照花及其两者的栽培品种、以日本四照花为亲本的杂交品种36(C./Ruth Ellen/‘Rutlan’)、39(C.‘Rutcan’Constellation)、40(C.‘KN4-43’Starlight),和未知品种41号;第3类,未知样本42号单独聚为一类,但在遗传距离为0.62处与第1类聚到一起,推测其可能是源于大花四照花的品种。本研究基于ISSR标记构建的指纹图谱可有效用于四照花栽培品种鉴定,并揭示其亲缘关系。

Construction of Fingerprinting and Analysis of Genetic Relationship for Cultivars of Cornus based on ISSR Markers

The ornamental value of Cornus is very high and there are many cultivars but difficult to distinguish.In order to identify cultivars of Cornus quickly and effectively,fingerprints of 44 main cultivars and their parents were established based on ISSR marker.Also,the genetic relation was analyzed.These results could provide supports for the extensive application of Cornus.Based on optimization ISSR-PCR system,7 of 100 ISSR primers were screened for PCR amplification of genomic DNAs of 44 Cornus samples.Specific fingerprint code for 42/44 Cornus samples was established based on amplification loci primed by UBC834 and UBC847.Meantime,91 loci were amplified by 7 screened primers,showing an average of 13 loci per primer.Moreover,90/91 loci were polymorphic,the percentage of polymorphic loci was up to 98.9%.Based on cluster tree and the genetic distance,44 samples were divided into three groups at a genetic distance of 0.60.The first category consists C.florida,all the cultivated varie ties selected from C.florida and the hybrids C.’Rutban’and C.’Celestial Shadow’with C.florida as the female parent.The second category includes C.kousa and C.kousa subsp.chinensis and cultivated varieties originated from them,the hybrids C./Ruth Ellen/’Rutlan’,C.’Rutcan’Constellation,C.’KN4-43’Starlight with C.kousa as male parent,as well as unknown sample 41.The third category only has unknown sample 42 which grouped with the first category at a genetic distance of 0.62.It is inferred that No.42 would originate from C.florida.ISSR marker is an effective method to construct specific fingerprint to identify Cornus cultivars and to reveal their genetic relationship.