Contreras Roberto, Figueiras Ana M, Gallego F Javier, Benavente Elena, Manzaneda Antonio J, Benito César
Departamento de Genética, Facultad de Biología, Universidad Complutense de Madrid, Madrid, Spain.
Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingenieros Agrónomos, Universidad Politécnica de Madrid, Madrid, Spain.
AoB Plants. 2017 Nov 7;9(6):plx060. doi: 10.1093/aobpla/plx060. eCollection 2017 Nov.
Aluminium (Al) toxicity is the main abiotic stress limiting plant productivity in acidic soils that are widely distributed among arable lands. Plant species differ in the level of Al resistance showing intraspecific and interspecific variation in many crop species. However, the origin of Al-tolerance is not well known. Three annual species, difficult to distinguish phenotypically and that were until recently misinterpreted as a single complex species under , have been recently separated into three distinct species: the diploids (2 = 10) and (2 = 20), and (2 = 30), the allotetraploid derived from the two diploid species. The aims of this work were to know the origin of Al-tolerance in acidic soil conditions within these three species and to develop new DNA markers for species discrimination. Two multiplex SSR-PCRs allowed to genotype a group of 94 accessions for 17 pentanucleotide microsatellite (SSRs) loci. The variability for 139 inter-microsatellite (ISSRs) markers was also examined. The genetic relationships obtained using those neutral molecular markers (SSRs and ISSRs) support that all Al-tolerant allotetraploid accessions of have a common origin that is related with both geographic location and acidic soils. The possibility that the adaptation to acidic soils caused the isolation of the tolerant populations from the others is discussed. We finally describe a new, easy, DNA barcoding method based in the upstream-intron 1 region of the gene, a tool that is 100 % effective to distinguish among these three species.
铝（Al）毒性是限制酸性土壤中植物生产力的主要非生物胁迫，酸性土壤广泛分布于耕地中。植物物种在耐铝水平上存在差异，许多作物物种在种内和种间都表现出这种差异。然而，耐铝性的起源尚不清楚。有三个一年生物种，在表型上难以区分，直到最近还被误作一个复合物种，最近已被分为三个不同的物种：二倍体（2n = 10）和（2n = 20），以及（2n = 30），即由这两个二倍体物种衍生而来的异源四倍体。这项工作的目的是了解这三个物种在酸性土壤条件下耐铝性的起源，并开发用于物种鉴别的新DNA标记。通过两次多重SSR-PCR对94份材料的17个五核苷酸微卫星（SSR）位点进行了基因分型。还检测了139个微卫星间（ISSR）标记的变异性。利用这些中性分子标记（SSR和ISSR）获得的遗传关系表明，所有耐铝的异源四倍体材料都有一个共同的起源，这与地理位置和酸性土壤都有关。文中讨论了适应酸性土壤导致耐铝种群与其他种群隔离的可能性。我们最终描述了一种基于基因上游内含子1区域的新型、简便的DNA条形码方法，该方法能100%有效地区分这三个物种。
