Genome-wide association mapping reveals loci for shelf life and developmental rate of lettuce

Innovative breeding technologies in lettuce for improved post-harvest quality

“…A large-effect QTL on chromosome 4 explaining 40–75 % of the phenotypic variation for the decay of fresh-cut lettuce stored in MAP has been verified in two independent intraspecific mapping populations, over multiple growing seasons ( Hayes et al, 2014 ). Recently, this QTL has been verified in a genome wide association study, in which significant marker-trait associations were identified for shelf life at the same locus ( Sthapit Kandel et al, 2020 ). Single nucleotide polymorphism (SNP) alleles at the QTL site were identified which can reliably predict the rate of deterioration for a range of lettuce cultivar types ( Simko et al, 2018 ).…”

“…US96UC23 RIL population Zhang et al, 2007 Identification of three QTL for shelf life from five field trials L. sativa cvs. “Salinas 88” x “La Brillante” RIL population Hayes et al, 2014 Significant marker-trait associations identified for shelf life and developmental rate Diversity panel of cultivars, advanced breeding lines, individuals from RIL populations and plant introductions Sthapit Kandel et al, 2020 Discolouration Identified six QTL for discolouration traits in fresh-cut lettuce in two geographic locations L. sativa cvs. “Saladin” x “Iceberg” RIL population Atkinson et al, 2013 Nutrition QTL for antioxidant and chlorophyll content detected at two different stages of maturity and several production cycles L. sativa cvs.…”

“…Those which have been applied to post-harvest quality improvement of lettuce (in the public domain) are highlighted in blue, those which have been applied in lettuce, but not for post-harvest quality traits are in light blue and those which have not been exploited in lettuce are in red. Numbers indicate key references; [1] Landry et al, 1987 , [2] https://cgngenis.wur.nl , [3] Stoffel et al, 2012 , [4] Simko, 2016 , [5] Reyes-Chin-Wo et al, 2017 , [6] Zhang et al, 2017 , [7] Damerum et al, 2015 , [8] see Table 2 ,[9] Sthapit Kandel et al, 2020 , [10] Ripoll et al, 2019 , [11] Jeuken and Lindhout, 2004 , [12] Michelmore et al, 1991 , [13] Damerum, 2017 , [14] Su et al, 2020 , [15] Wagstaff et al, 2010 , [16] Zhang et al, 2018a , [17] Simko et al, 2018 , [18] Zhang et al, 2009b (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article). …”

A Composite Analysis of Flowering Time Regulation in Lettuce

“…Physical coordinates of the markers flanking significant QTLs were reported in seven studies (Niroula, 2017;Mamo et al, 2019;Sandoya et al, 2020;Seki et al, 2020;Sthapit Kandel et al, 2020;Niroula et al, unpublished;You et al, unpublished). DNA variant detector array probe sequences of the lettuce expression sequence tag (EST)-based single nucleotide polymorphism (SNP) markers used in four studies (Hartman et al, 2013b;Jenni et al, 2013;Kwon et al, 2013;Niroula, 2017) were blasted against version 8 of the reference genome (Reyes-Chin-Wo et al, 2017; NCBI: GCA_002870075.2) to determine their physical locations.…”

“…Multiple mapping populations have been developed and studied across the globe to investigate the genetic regulation of various agronomic traits of this internationally enjoyed vegetable (Silva et al, 1999;Hartman et al, 2013a,b;Truco et al, 2013). Sequencing of diverse accessions of wild and cultivated lettuce has enabled genome-wide association studies (GWAS) of commercially valuable traits (Kwon et al, 2013;Sthapit Kandel et al, 2020). Functional analyses of putative flowering time genes in lettuce have unveiled some of the molecular mechanisms underlying flowering time regulations.…”