Ma Jian-Qiang, Yao Ming-Zhe, Ma Chun-Lei, Wang Xin-Chao, Jin Ji-Qiang, Wang Xue-Min, Chen Liang
Key Laboratory of Tea Plant Biology and Resources Utilization, Ministry of Agriculture, National Center for Tea Improvement, Tea Research Institute of the Chinese Academy of Agricultural Sciences (TRICAAS), Hangzhou, Zhejiang Province, China.
PLoS One. 2014 Mar 27;9(3):e93131. doi: 10.1371/journal.pone.0093131. eCollection 2014.
Catechins are the most important bioactive compounds in tea, and have been demonstrated to possess a wide variety of pharmacological activities. To characterize quantitative trait loci (QTLs) for catechins content in the tender shoots of tea plant, we constructed a moderately saturated genetic map using 406 simple sequence repeat (SSR) markers, based on a pseudo-testcross population of 183 individuals derived from an intraspecific cross of two Camellia sinensis varieties with diverse catechins composition. The map consisted of fifteen linkage groups (LGs), corresponding to the haploid chromosome number of tea plant (2n = 2x = 30). The total map length was 1,143.5 cM, with an average locus spacing of 2.9 cM. A total of 25 QTLs associated with catechins content were identified over two measurement years. Of these, nine stable QTLs were validated across years, and clustered into four main chromosome regions on LG03, LG11, LG12 and LG15. The population variability explained by each QTL was predominantly at moderate-to-high levels and ranged from 2.4% to 71.0%, with an average of 17.7%. The total number of QTL for each trait varied from four to eight, while the total population variability explained by all QTLs for a trait ranged between 38.4% and 79.7%. This is the first report on the identification of QTL for catechins content in tea plant. The results of this study provide a foundation for further cloning and functional characterization of catechin QTLs for utilization in improvement of tea plant.
儿茶素是茶叶中最重要的生物活性化合物,已被证明具有多种药理活性。为了鉴定茶树嫩梢中儿茶素含量的数量性状位点(QTL),我们基于两个儿茶素组成不同的茶树品种种内杂交产生的183个个体的拟测交群体,利用406个简单序列重复(SSR)标记构建了一个中等饱和度的遗传图谱。该图谱由15个连锁群(LG)组成,与茶树的单倍体染色体数(2n = 2x = 30)相对应。图谱总长度为1143.5 cM,平均位点间距为2.9 cM。在两个测量年份共鉴定出25个与儿茶素含量相关的QTL。其中,9个稳定的QTL在多年间得到验证,并聚集在LG03、LG11、LG12和LG15的四个主要染色体区域。每个QTL解释的群体变异主要处于中高水平,范围从2.4%到71.0%,平均为17.7%。每个性状的QTL总数从4个到8个不等,而一个性状的所有QTL解释的总群体变异在38.4%到79.7%之间。这是关于鉴定茶树儿茶素含量QTL的首次报道。本研究结果为进一步克隆和功能鉴定儿茶素QTL以用于茶树改良奠定了基础。