Institute of Plant Genetics, Polish Academy of Sciences, Strzeszyńska 34, 60-479, Poznań, Poland.
J Appl Genet. 2019 Nov;60(3-4):269-281. doi: 10.1007/s13353-019-00508-9. Epub 2019 Aug 13.
White lupin (Lupinus albus L.) is a legume grain crop cultivated since ancient Greece and Egypt. Modern white lupin cultivars are appreciated as a source of protein with positive nutraceutical impact. However, white lupins produce anti-nutritional compounds, quinolizidine alkaloids, which provide bitter taste and have a negative influence on human health. During domestication of this species, several recessive alleles at unlinked loci controlling low alkaloid content were selected. One of these loci, pauper, was exploited worldwide providing numerous low-alkaloid cultivars. However, molecular tracking of pauper has been hampered due to the lack of diagnostic markers. In the present study, the synteny-based approach was harnessed to target pauper locus. Single-nucleotide polymorphisms flanking pauper locus on white lupin linkage map as well as candidate gene sequences elucidated from the narrow-leafed lupin (L. angustifolius L.) chromosome segment syntenic to the pauper linkage group region were transformed to PCR-based molecular markers. These markers were analyzed both in the mapping population and world germplasm collection. From fourteen markers screened, eleven were localized at a distance below 1.5 cM from this locus, including five co-segregating with pauper. The linkage of these markers was confirmed by high LOD values (up to 58.4). Validation performed in the set of 127 bitter and 23 sweet accessions evidenced high applicability of one marker, LAGI01_35805_F1_R1, for pauper locus selection, highlighted by the low ratio of false-positive scores (2.5%). LAGI01_35805 represents a homolog of L. angustifolius acyltransferase-like (LaAT) gene which might hypothetically participate in the alkaloid biosynthesis process in lupins.
白 Lupinus albus L. 是一种豆类粮食作物，自古希腊和埃及就开始种植。现代白 Lupinus 品种因其具有积极的营养保健作用而被视为蛋白质的来源。然而，白 Lupinus 会产生抗营养化合物——喹诺里西啶生物碱，这些化合物会带来苦味，并对人类健康产生负面影响。在该物种的驯化过程中，选择了几个位于非连锁基因座上的隐性等位基因来控制低生物碱含量。其中一个基因座 pauper 被全世界利用，培育出了许多低生物碱的品种。然而，由于缺乏诊断标记， pauper 的分子追踪一直受到阻碍。在本研究中，利用基于同源性的方法来确定 pauper 基因座。从小叶 Lupinus angustifolius L. 染色体片段与 pauper 连锁群区域同源的白 Lupinus 连锁图谱上 pauper 基因座侧翼的单核苷酸多态性以及候选基因序列被转化为基于 PCR 的分子标记。这些标记在作图群体和世界种质资源库中进行了分析。在筛选的 14 个标记中，有 11 个标记的位置距离该基因座不到 1.5 cM，其中 5 个标记与 pauper 共分离。这些标记的连锁通过高达 58.4 的高 LOD 值得到了证实。在 127 个苦味和 23 个甜味品系的验证中，一个标记 LAGI01_35805_F1_R1 的适用性很高，用于 pauper 基因座的选择，其假阳性评分比例较低（2.5%）。LAGI01_35805 代表了小扁豆酰基转移酶样（LaAT）基因的同源物，该基因可能在 Lupinus 生物碱生物合成过程中具有潜在的作用。
