3种分子标记在分析茶树种质资源遗传多样性上的比较

Comparative Analysis of Three Molecular Markers on Germplasm Resources Genetic Diversity in Tea Plant

本研究的目的是比较EST-SSR、SRAP和SCoT标记在茶树资源研究中的可应用性,为茶树分子标记的选择与优化提供依据。本研究用6份有代表性的茶树资源,从中筛选出扩增条带清晰、多态性高的EST-SSR标记40对、SRAP标记40对、SCoT标记38个,对50份茶树材料的遗传多样性进行分析,重点比较了这3种分子标记的多态性条带比率(PPB)、多态性信息含量(PIC)、位点平均信息量(Ib_(av))、有效多元比率(EMR)、引物解析强度(Rp)、标记指数(MI)等方面的差异。40对EST-SSR引物共检测到320个等位位点,平均为8.00个,引物PPB、PIC、EMR、Ib_(av)、Rp、MI值分别为94.06%、0.85、7.53、0.56、4.48、4.22。40对SRAP引物共检测到336个等位位点,平均为8.40个,引物PPB、PIC、EMR、Ib_(av)、Rp、MI值分别为89.88%、0.77、7.55、0.61、5.11、4.61。38个SCoT引物共检测到439个等位位点,平均为11.55个,引物PPB、PIC、EMR、Ib_(av)、Rp、MI值分别为90.66%、0.79、10.47、0.58、6.71、6.07。3种标记体系检测到的平均等位位点、EMR、Rp和MI值都表现为SCoT最高,其次为SRAP,再次为EST-SSR,而EST-SSR的PPB和PIC值最高,其次为SCoT,再次为SRAP。SCoT具有较高的标记效率,而EST-SSR标记具有丰富的位点多态信息。

By comparing the applicability of EST-SSRs,SRAPs,and SCoTs in tea germplasm resources,the present study aimed to provide the basic data for selection and optimization of molecular markers of tea plant.We selected 40 pairs of clear and highly polymorphic EST-SSR,SRAP,and 38 SCoT marker primers from 6representative tea materials in order to assess the genetic diversity of 50 tea materials.Differences between the three kinds of markers in terms of the percentage of polymorphic bands（PPB）,polymorphism information content（PIC）,average band informativeness（Ib（av））,effective multiplex ratio（EMR）,resolving power（Rp）,and marker index（MI） were compared among these materials.Total 320（8.00 per primer） alleles were identified by 40 pairs of EST-SSR primers,and the PPB,PIC,EMR,Ib（av）,Rp,MI were 94.06%,0.85,7.53,0.56,4.48,4.22 respectively.Meanwhile,336（8.40 per primer） alleles were amplified by 40 pairs of SRAP,with the PPB,PIC,EMR,Ib（av）,Rp,MI of 89.88%,0.77,7.55,0.61,5.11,4.61 respectively.In addition,439（11.55 per primer） alleles were detected by38 SCoT primer,with the PPB,PIC,EMR,Ib（av）,Rp,MI of 90.66%,0.79,10.47,0.58,6.71,6.07 respectively.The average number of amplified allele per locus,EMR,Rp and MI showed similar trends among the three types of markers,with the highest values obtained by SCoT,followed by SRAP and EST-SSR.Nevertheless,the values of PPB and PIC showed different trends,with the highest values yielded by EST-SSR,followed by SCoT and SRAP.