Linkage mapping and QTL analysis of flowering time in faba bean

Abstract

Flowering time marks the transition from vegetative to reproductive growth and is key for optimal yield in any crop. The molecular mechanisms controlling this trait have been extensively studied in model plants such as Arabidopsis thaliana and rice. While knowledge on the molecular regulation of this trait is rapidly increasing in sequenced galegoid legume crops, understanding in faba bean remains limited. Here we exploited translational genomics from model legume crops to identify and fine map QTLs linked to flowering time in faba bean. Among the 31 candidate genes relevant for flowering control in A. thaliana and Cicer arietinum assayed, 25 could be mapped in a segregating faba bean RIL population. While most of the genes showed conserved synteny among related legume species, none of them co-localized with the 9 significant QTL regions identified. The FT gene, previously implicated in the control of flowering time in numerous members of the temperate legume clade, mapped close to the most relevant stable and conserved QTL in chromosome V. Interestingly, QTL analysis suggests an important role of epigenetic modifications in faba bean flowering control. The new QTLs and candidate genes assayed here provide a robust framework for further genetic studies and will contribute to the elucidation of the molecular mechanisms controlling this trait.

Genetic analysis of global faba bean diversity, agronomic traits and selection signatures

“…Interestingly, the region did not only have a large effect on the trait but is also highly conserved in multiple legumes, including Lotus japonicus (Gondo et al 2007 ), Medicago truncatula (Pierre et al 2008 ), chickpea (Cobos et al 2009 ), narrow-leafed lupin (Nelson et al 2006 ), and alfalfa (Robins et al 2007 ). The region on chromosome 5 from approximately 489 Mb to 602 Mb (comprising 244 genes) contains four of the peak markers identified for flowering time in this study, the QTL for flowering time identified from a bi-parental cross by Catt et al 2017 , as well as the peak markers identified in Cruz-Izquierdo et al ( 2012 ) and Aguilar-Benitez et al ( 2021 ). The region is syntenic to the region of Medicago truncatula chromosome 7 that harbors five flowering time genes and the spring1 locus (Yeoh et al 2013 ; Supplementary Fig.…”

Genetic Augmentation of Legume Crops Using Genomic Resources and Genotyping Platforms for Nutritional Food Security

“…In common bean, AM has been used for the identification of QTLs/gene(s) linked with iron, zinc, and protein contents [ 56 ]. Similarly, QTL mapping and the identification of marker–trait association have been carried out in faba bean for flowering time [ 57 ]. The marker–trait association has been identified for various traits in different legume crops, such as QTL for winter hardiness and leaf area in lentil [ 58 ], QTLs for number of branches and pods in soybean [ 59 ], QTL for resistance to ascochyta blight and early flowering in chickpea [ 60 ], and QTL for the determinacy gene ( Dt1 ) for determinant growth habit in pigeonpea [ 61 ].…”

Mechanisms of Vernalization-Induced Flowering in Legumes

“…In faba bean Vicia faba , the candidate gene mapping and the quantitative trait loci (QTL) analysis revealed the cluster of FT loci close to the most conserved flowering time QTL on chromosome 5 in a region syntenic with a section of Medicago chromosome 7 containing FTa and FTc genes [ 58 ]. However, the authors failed to map individual FT genes within this region due to high sequence conservation [ 58 ].…”