QTL Analysis of Stem Elongation and Flowering Time in Lettuce Using Genotyping-by-Sequencing

Abstract

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.

Development and application of Single Primer Enrichment Technology (SPET) SNP assay for population genomics analysis and candidate gene discovery in lettuce

“…The strongest signals found for bolting time at 164.43 Mb on chromosome 7 confirmed previous evidence. Indeed, several studies consistently supported the importance of chromosome 7 for lettuce flowering control (Kwon et al, 2013;Sthapit Kandel et al, 2020;Lee et al, 2021;Rosental et al, 2021). Despite the exact comparisons of the candidate region not always being possible, owing to the different marker system used (Han et al, 2021), our study supports whole-genome resequencing data findings (Wei et al, 2021), which detected a strong association at 164.5 Mbp in correspondence to PHYTOCHROME C involved in delaying of flowering.…”

Fucose as a potential therapeutic molecule against the immune-mediated inflammation in IgA nepharopathy: An unrevealed link

“…Short Time-Series Expression Miner (STEM) analysis was performed to cluster the hub genes with the same time trend in clusters and controls in data1; P < 0.05 was considered statistically significant clustering ( 21 ). The significantly clustered genes showed a gradual upregulation or downregulation trend.…”

GA signaling protein LsRGL1 interacts with the abscisic acid signaling-related gene LsWRKY70 to affect the bolting of leaf lettuce

“…Leaf lettuce ( Lactuca sativa L.), an annual vegetable crop in the Asteraceae family, is the most-eaten leafy vegetable globally and is highly valued due to its edible and medicinal properties [ 1 ]. Leaf lettuce is mainly cultivated in greenhouses or open fields, and during the process of cultivation is prone to high-temperature bolting (premature production of flowering stems) [ 2 , 3 ]. High temperatures accelerate bolting and cause bitter leaves, reducing quality and production, thus resulting in limited leaf lettuce sales [ 4 , 5 ].…”