Assunção Ana G L, Pieper Bjorn, Vromans Jaap, Lindhout Pim, Aarts Mark G M, Schat Henk
Institute of Ecological Sciences, Earth and Life Sciences, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands.
New Phytol. 2006;170(1):21-32. doi: 10.1111/j.1469-8137.2005.01631.x.
Zinc (Zn) hyperaccumulation seems to be a constitutive species-level trait in Thlaspi caerulescens. When compared under conditions of equal Zn availability, considerable variation in the degree of hyperaccumulation is observed among accessions originating from different soil types. This variation offers an excellent opportunity for further dissection of the genetics of this trait. A T. caerulescens intraspecific cross was made between a plant from a nonmetallicolous accession [Lellingen (LE)], characterized by relatively high Zn accumulation, and a plant from a calamine accession [La Calamine (LC)], characterized by relatively low Zn accumulation. Zinc accumulation in roots and shoots segregated in the F3 population. This population was used to construct an LE/LC amplified fragment length polymorphism (AFLP)-based genetic linkage map and to map quantitative trait loci (QTL) for Zn accumulation. Two QTL were identified for root Zn accumulation, with the trait-enhancing alleles being derived from each of the parents, and explaining 21.7 and 16.6% of the phenotypic variation observed in the mapping population. Future development of more markers, based on Arabidopsis orthologous genes localized in the QTL regions, will allow fine-mapping and map-based cloning of the genes underlying the QTL.
锌（Zn）超积累似乎是天蓝遏蓝菜的一种物种水平的固有特性。在锌有效性相同的条件下进行比较时，发现来自不同土壤类型的天蓝遏蓝菜种质在超积累程度上存在显著差异。这种差异为进一步剖析该特性的遗传机制提供了绝佳机会。以锌积累量相对较高的非金属矿区种质[莱林根（LE）]的植株与锌积累量相对较低的炉甘石矿区种质[拉卡勒米讷（LC）]的植株进行了天蓝遏蓝菜种内杂交。在F3群体中，根和地上部的锌积累出现了分离。利用该群体构建了基于莱林根/拉卡勒米讷扩增片段长度多态性（AFLP）的遗传连锁图谱，并对锌积累的数量性状位点（QTL）进行定位。鉴定出两个控制根锌积累的QTL，增强该性状的等位基因分别来自双亲，分别解释了定位群体中观察到的表型变异的21.7%和16.6%。基于位于QTL区域的拟南芥直系同源基因开发更多标记，将有助于对QTL underlying基因进行精细定位和图位克隆。
