Department of Bio-Industrial and Bioresource, Sejong University, Neungdong-ro 209, Gwangjin-gu, Seoul 05006, Korea.
Graduate School of Agricultural & Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
Genes (Basel). 2021 Jun 21;12(6):947. doi: 10.3390/genes12060947.
Lettuce plants tend to undergo floral initiation by elongation of flower stalks (bolting) under high-temperature and long-day conditions, which is a serious problem for summer lettuce production. Our objective was to generate a high-density genetic map using SNPs obtained from genotyping-by-sequencing (GBS) analysis of F5 recombinant inbred lines (RILs) and to map QTLs involved in stem growth and flowering time in lettuce. A set of 127 intra-specific RIL mapping populations derived from a cross between two varieties, green and red leaf lettuce, were used to identify QTLs related to the number of days from sowing to bolting (DTB), to flowering of the first flower (DTF), to seed-setting of the first flower (DTS), and the total number of leaves (LN), plant height (PH), and total number of branches of main inflorescence (BN) for two consecutive years. Of the 15 QTLs detected, one that controls DTB, DTF, DTS, LN, and PH detected on LG 7, and another QTL that controls DTF, DTS, and PH detected on LG 1. Analysis of the genomic sequence corresponding to the QTL detected on LG 7 led to the identification of 22 putative candidate genes. A consistent QTL related to bolting and flowering time, and corresponding candidate genes has been reported. This study will be valuable in revealing the genetic basis of stem growth and flowering time in lettuce.
生菜植株在高温和长日照条件下，往往通过花茎伸长（抽薹）来进行花的起始，这是夏季生菜生产的一个严重问题。我们的目的是利用来自 F5 重组自交系（RIL）的测序基因型分析（GBS）获得的 SNP 生成高密度遗传图谱，并对生菜茎生长和开花时间相关的 QTL 进行作图。一组 127 个来自两个品种（绿色和红色叶生菜）杂交的同型 RIL 作图群体，用于鉴定与从播种到抽薹的天数（DTB）、第一朵花的开花时间（DTF）、第一朵花的结实时间（DTS）、总叶数（LN）、株高（PH）和主花序的总分枝数（BN）相关的 QTL，连续两年进行分析。在检测到的 15 个 QTL 中，有一个控制 DTB、DTF、DTS、LN 和 PH 的 QTL，位于 LG 7 上，另一个控制 DTF、DTS 和 PH 的 QTL，位于 LG 1 上。对 LG 7 上检测到的 QTL 对应的基因组序列进行分析，鉴定出 22 个可能的候选基因。已经报道了一个与抽薹和开花时间相关的一致的 QTL 及其相应的候选基因。这项研究对于揭示生菜茎生长和开花时间的遗传基础将是有价值的。
