Genetic linkage map and mapping of the locus of biological nitrogen fixation inefficiency in cowpea

Sirando Lima Seido,Carlos Antonio Fernandes Santos

doi:10.4025/actasciagron.v41i1.42603

Sirando Lima Seido, Carlos Antonio Fernandes Santos

Open Access

https://doi.org/10.4025/actasciagron.v41i1.42603

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Abstract

The objectives of the present study were to construct a cowpea genetic map using the F2 population resulting from the cross IC-1 x BRS Marataoã, based on single nucleotide polymorphism (SNP) markers, and to map the cpi gene, with additional reference to introgression with the consensus map of species, aiming to identify markers for assisted selection to develop more efficient cultivars for BNF. The parents and 89 F2 plants were genotyped with 51,128 SNP markers, of which 910 polymorphic markers were used to construct the map. The results revealed 11 linkage groups, with an average of 82 markers per chromosome and average distance of 1.26 cM between markers. Recombination analysis of the SNPs indicated that markers 2_12850 and 2_00188, located in linkage group 11, flanked the cpi gene at a distance of 6.7 cM and 5.64 cM, respectively. The introgression of linkage group 11 with the cowpea reference map revealed short distances (from zero to 0.6 cM) for these markers, indicating a strong association with the cpi gene. The constructed map and cpi mapping provide basic information that can assist the genetic breeding of more efficient cowpea plants for BNF by marker-assisted selection.

Highlights

Cowpea (Vigna unguiculata (L.) Walp.) is an autogamous diploid species (2n = 2x = 22) with a genome size estimated at 620 Mb (Arumuganathan & Earle, 1991)
This legume species can fix N 2 because of the species symbiotic relation with rhizobia (Leite et al, 2009). This economically important characteristic for cowpea provides nitrogen and mineral accumulation by the symbiotic association with N 2-fixing bacteria, depending on the macro- and microsymbiont interactions and environmental conditions (Mohammadi, Sohrabi, Heidari, Khalesro, & Majidi, 2012; Belane, Pule-Meulenberg, Makhubedu, & Dakora, 2014). Both parties of the association are susceptible to genetic variation, little information is available on the host plant (Bladergroen & Spaink, 1998; Shamseldin, 2013)
Non-nodulation is controlled by the host plant through the release of phenolic compounds incompatible with the nodulation promoter regions, which are responsible for the induction of transcription of the bacterial genes essential to nodulation (Geurts, Fedorova, & Bisseling, 2005; Madsen et al, 2010; Okazaki et al, 2016)

Summary

Introduction

This legume species can fix N 2 because of the species symbiotic relation with rhizobia (Leite et al, 2009) This economically important characteristic for cowpea provides nitrogen and mineral accumulation by the symbiotic association with N 2-fixing bacteria, depending on the macro- and microsymbiont interactions and environmental conditions (Mohammadi, Sohrabi, Heidari, Khalesro, & Majidi, 2012; Belane, Pule-Meulenberg, Makhubedu, & Dakora, 2014). Both parties of the association are susceptible to genetic variation, little information is available on the host plant (Bladergroen & Spaink, 1998; Shamseldin, 2013). Non-nodulating plants have been observed in several legume species and are usually determined by recessive alleles (Nigan, Nambiar, Dwivedi, Gibbons, & Dart, 1982; Vest & Caldwell, 1972; Ceccatto, Gomes, Sarries, Moon, & Tsai, 1988; Novák, 2003)

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