Chadwick Martin, Swann Jonathan R, Gawthrop Frances, Michelmore Richard, Scaglione Davide, Jose-Truco Maria, Wagstaff Carol
Department of Food and Nutritional Sciences, University of Reading, Harry Nursten Building, Whiteknights, Reading RG6 6DZ, UK.
Faculty of Medicine, University of Southampton, University Road, Southampton SO17 1BJ, UK.
Food Chem (Oxf). 2024 Aug 23;9:100215. doi: 10.1016/j.fochms.2024.100215. eCollection 2024 Dec 30.
Lettuce is the most highly consumed raw leafy vegetable crop eaten worldwide, making it nutritionally important in spite of its comparatively low nutrient density in relation to other vegetables. However, the perception of bitterness caused by high levels of sesquiterpenoid lactones and comparatively low levels of sweet tasting sugars limits palatability. To assess variation in nutritional and taste-related metabolites we assessed 104 members of a cv. Salinas x (accession UC96US23) mapping population. Plants were grown in three distinct environments, and untargeted NMR and HPLC were used as a rapid chemotyping method, from which 63 unique Quantitative Trait Loci (QTL) were identified. We were able to identify putative regulatory candidate genes underlying the QTL for fructose on linkage group 9, which accounted for up to 36 % of our population variation, and which was stable across all three growing environments; and for 15-p-hydroxyyphenylacetyllactucin-8-sulfate on linkage group 5 which has previously been identified for its low bitterness, while retaining anti-herbivory field effects. We also identified a candidate gene for flavonoid 3',5'- hydroxylase underlying a polyphenol QTL on linkage group 5, and two further candidate genes in sugar biosynthesis on linkage groups 2 and 5. Collectively these candidate genes and their associated markers can inform a route for plant breeders to improve the palatability and nutritional value of lettuce in their breeding programmes.
生菜是全球食用量最高的生食叶菜作物，尽管其相对于其他蔬菜的营养密度较低，但在营养方面仍具有重要意义。然而，高水平的倍半萜内酯和相对较低水平的甜味糖所导致的苦味感限制了其适口性。为了评估营养和口味相关代谢物的变异情况，我们对一个cv. Salinas x（种质UC96US23）作图群体的104个成员进行了评估。植株在三种不同环境中生长，非靶向核磁共振（NMR）和高效液相色谱（HPLC）被用作快速化学分型方法，从中鉴定出63个独特的数量性状位点（QTL）。我们能够鉴定出第9连锁群上果糖QTL潜在的调控候选基因，该基因在我们的群体变异中占比高达36%，并且在所有三种生长环境中都很稳定；还鉴定出了第5连锁群上的15 - 对羟基苯乙酰莴苣素 - 8 - 硫酸盐的候选基因，该基因此前已因其低苦味而被鉴定出来，同时保留了抗食草动物的田间效应。我们还在第5连锁群上的一个多酚QTL中鉴定出了类黄酮3',5'-羟化酶的一个候选基因，以及在第2和第5连锁群上糖生物合成中的另外两个候选基因。这些候选基因及其相关标记共同为植物育种者在其育种计划中改善生菜的适口性和营养价值提供了一条途径。
