Study and QTL mapping of reproductive and morphological traits implicated in the autofertility of faba bean

Abstract

Autofertility describes the ability of faba bean flowers to self-fertilize thereby ensuring the productivity of this crop in the absence of pollinators or mechanical disturbance. In the legume crop faba bean (Vicia faba L.), lack of autofertility in a context of insufficient pollination can lead to a severe decrease in grain yield. Here we performed the first QTL analysis aimed at identifying the genomic regions controlling autofertility in this crop. We combined pod and seed setting scores from a recombinant inbred population (RIL) segregating for autofertility in different environments and years with measurements of morphological floral traits and pollen production and viability. This approach revealed 19 QTLs co-localizing in six genomic regions. Extensive co-localization was evident for various floral features whose QTLs clustered in chrs. I, II and V, while other QTLs in chrs. III, IV and VI revealed co-localization of flower characteristics and pod and seed set data. The percentage of phenotypic variation explained by the QTLs ranged from 8.9 for style length to 25.7 for stigma angle. In the three QTLs explaining the highest phenotypic variation (R2 > 20), the marker alleles derived from the autofertile line Vf27. We further inspected positional candidates identified by these QTLs which represent a valuable resource for further validation. Our results advance the understanding of autofertility in faba bean and will aid the identification of responsible genes for genomic-assisted breeding in this crop.

Association mapping of plant structure and yield traits in faba bean (Vicia faba L.)

“…In addition to association analysis, many more QTL analyses have been performed for morphological traits using biparental mapping populations in faba bean. [30][31][32][33][34] The first attempt was performed by Ramsay et al 30 34 detected 19 QTLs related to reproductive and morphological traits in the Vf6 Â Vf27 RIL population using their previous linkage map. 32 Most recently, Meng-wei et al 33 carried out a QTL mapping study and identified 98 QTLs for 14 agronomic traits using an integrated genetic linkage map with 6895 SNPs (3324.48 cM).…”

“…In three studies by Sallam and co‐workers, 27–29 156 SNP markers generated from a legume model ( Medicago truncatula ) were used for association mapping in 189 faba bean accessions, and putative QTLs were detected for frost tolerance, some morphological, physiological, and yield traits. In addition to association analysis, many more QTL analyses have been performed for morphological traits using biparental mapping populations in faba bean 30–34 . The first attempt was performed by Ramsay et al 30 using 23 markers [morphological, random amplified polymorphic DNAs (RAPDs), AFLPs, and isozymes] to map morphological and biochemical traits in a backcross F 2 (BCF 2 ) population.…”

“…Recently, Aguilar‐Benitez et al 32 identified 12 QTLs for flowering time through a comprehensive linkage analysis in a recombinant inbred line (RIL; Vf6 × Vf27) population of 124 individuals using a previous map including gene markers related to flowering, RAPDs, expressed sequence tag (EST), and SNP markers. Another study conducted by Aguilar‐Benitez et al 34 detected 19 QTLs related to reproductive and morphological traits in the Vf6 × Vf27 RIL population using their previous linkage map 32 . Most recently, Meng‐wei et al 33 carried out a QTL mapping study and identified 98 QTLs for 14 agronomic traits using an integrated genetic linkage map with 6895 SNPs (3324.48 cM).…”

Pollen production, pollen viability and autofertility in faba bean (Vicia fabaL.) and their relationship with realized paternal success

“…Previous studies used different parameters to describe autofertility, e.g. flowers per node, pods per node, pods per flower or seeds per pod, sometimes using all flowers of a plant (Lord and Heslop-Harrison 1984;Torres et al 1993;Aguilar-Benitez et al 2022), sometimes standardizing the number of flowers (Kambal et al 1976;Link 1990;Chen 2009;Gasim et al 2011;Puspitasari 2017) to account for the highly variable flower number in the faba bean species (50 to 300 per plant, Rowlands 1960).…”

“…For instance, those genotypes which produce a higher number of pollen grains per flower might realize higher success rates as pollen donors to cross-fertilized seeds. In faba bean, pollen number per flower has been estimated before with reported results that varied strongly (Kambal et al1976; Carré et al 1994; Suso et al 2008; Chen 2009; Bailes 2018; Aguilar-Benitez et al 2022). A four-fold variation in pollen production has been found between 30 faba bean inbred lines by Bailes et al (2018) and it has been shown that F1 hybrids produced more pollen grains per flower than their parental lines (Kambal et al 1976; Chen 2009).…”