Molecular marker analysis of F1 progenies and their parents for carotenoids inheritance in African cassava (Manihot esculenta Crantz)

Njoku, DN; Gracen, VE; Offei, SK; Asante, IK; Danquah, Eric Yirenkyi; Egesi, CN; Okogbenin, Emmanuel

doi:10.5897/ajb2013.12244

“…Several mapping studies using either bulk segregant analysis or quantitative trait loci (QTL) mapping of S1 or F1 populations have been reported separately for dry matter and carotenoid content (Balyejusa Kizito et al, 2007 ; Marín Colorado et al, 2009 ; Welsch et al, 2010 ; Morillo et al, 2013 ; Njoku et al, 2014 ). The mapping resolution from single-cross experimental populations is expected to be limited due to the use of sparse genetic maps and the limited number of recombination events observed (Hamblin et al, 2011 ).…”

Section: Core Ideasmentioning

confidence: 99%

Genome‐Wide Association Mapping of Correlated Traits in Cassava: Dry Matter and Total Carotenoid Content

Rabbi

¹

,

Udoh

²

,

Wolfe

³

et al. 2017

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Cassava is a starchy root crop cultivated in the tropics for fresh consumption and commercial processing. Primary selection objectives in cassava breeding include dry matter content and micronutrient density, particularly provitamin A carotenoids. These traits are negatively correlated in the African germplasm. This study aimed at identifying genetic markers associated with these traits and uncovering whether linkage and/or pleiotropy were responsible for observed negative correlation. A genome-wide association mapping using 672 clones genotyped at 72,279 single nucleotide polymorphism (SNP) loci was performed. Root yellowness was used indirectly to assess variation in carotenoid content. Two major loci for root yellowness were identified on chromosome 1 at positions 24.1 and 30.5 Mbp. A single locus for dry matter content that colocated with the 24.1 Mbp peak for carotenoids was identified. Haplotypes at these loci explained 70 and 37% of the phenotypic variability for root yellowness and dry matter content, respectively. Evidence of megabasescale linkage disequilibrium (LD) around the major loci of the two traits and detection of the major dry matter locus in independent analysis for the white-and yellow-root subpopulations suggests that physical linkage rather that pleiotropy is more likely to be the cause of the negative correlation between the target traits. Moreover, candidate genes for carotenoid (phytoene synthase) and starch biosynthesis (UDP-glucose pyrophosphorylase and sucrose synthase) occurred in the vicinity of the identified locus at 24.1 Mbp. These findings elucidate the genetic architecture of carotenoids and dry matter in cassava and provide an opportunity to accelerate breeding of these traits.

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“…Molecular markers ranging from microsatellite (SSR) to single nucleotide polymorphisms (SNP), identifying regions in the genome responsible for carotenoids content have been reported as well [34,[66][67][68][69][70]. It would be expected that some of the QTLs identified in these studies are related to the PSY gene.…”

Section: Inheritance Of Carotenoids Content In Cassava Rootsmentioning

confidence: 99%

Carotenoids in Cassava Roots

Ceballos¹,

Davrieux²,

Talsma³

et al. 2017

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Vitamin A deficiency (VAD) is a preventable tragedy that affects millions of people, particularly in sub-Saharan Africa. A large proportion of these people rely on diets based on cassava as a source of calories. During the last two decades, significant efforts have been made to identify sources of germplasm with high pro-vitamin A carotenoids (pVAC) and then use them to develop cultivars with a nutritional goal of 15 μg g −1 of β-carotene (fresh weight basis) and good agronomic performance. The protocols for sampling roots and quantifying carotenoids have been improved. Recently, NIR predictions began to be used. Retention of carotenoids after different root processing methods has been measured. Bioavailability studies suggest high conversion rates. Genetic modification has also been achieved with mixed results. Carotenogenesis genes have been characterized and their activity in roots measured.

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“…Several mapping studies using either Bulk Segregant Analysis (BSA) or Quantitative Trait Loci (QTL) mapping of S1 or F1 populations have been reported separately for dry matter and carotenoid content (Balyejusa Kizito et al, 2007; Marín Colorado et al, 2009; Welsch et al, 2010; Morillo C et al, 2013; Njoku et al, 2014). The mapping resolution from single-cross experimental populations is expected to be limited due to the use of sparse genetic maps and the limited number of recombination events observed (Hamblin et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Genome-wide association mapping of correlated traits in cassava: dry matter and total carotenoid content

Rabbi

¹

,

Udoh

²

,

Wolfe

³

et al. 2017

Preprint

View full text Add to dashboard Cite

Cassava is a starchy root crop cultivated in the tropics for fresh consumption and commercial processing. Primary selection objectives in cassava breeding include dry matter content and micronutrient density, particularly provitamin A carotenoids. These traits are negatively correlated in the African germplasm. This study aimed at identifying genetic markers associated with these traits and uncovering whether linkage and/or pleiotropy were responsible for observed negative correlation. A genome-wide association mapping using 672 clones genotyped at 72,279 single nucleotide polymorphism (SNP) loci was performed. Root yellowness was used indirectly to assess variation in carotenoid content. Two major loci for root yellowness were identified on chromosome 1 at positions 24.1 and 30.5 Mbp. A single locus for dry matter content that colocated with the 24.1 Mbp peak for carotenoids was identified. Haplotypes at these loci explained 70 and 37% of the phenotypic variability for root yellowness and dry matter content, respectively. Evidence of megabasescale linkage disequilibrium (LD) around the major loci of the two traits and detection of the major dry matter locus in independent analysis for the white-and yellow-root subpopulations suggests that physical linkage rather that pleiotropy is more likely to be the cause of the negative correlation between the target traits. Moreover, candidate genes for carotenoid (phytoene synthase) and starch biosynthesis (UDP-glucose pyrophosphorylase and sucrose synthase) occurred in the vicinity of the identified locus at 24.1 Mbp. These findings elucidate the genetic architecture of carotenoids and dry matter in cassava and provide an opportunity to accelerate breeding of these traits.

show abstract

Molecular marker analysis of F1 progenies and their parents for carotenoids inheritance in African cassava (Manihot esculenta Crantz)

Abstract: Molec parents Njoku, D. N Cassava ge between th progenies association a total of 1 genotype c Three SSR carotene ge with the p appeared li marker did for 20% bet could prob sufficiently

Cited by 5 publications

References 14 publications

Genome‐Wide Association Mapping of Correlated Traits in Cassava: Dry Matter and Total Carotenoid Content

Genome‐Wide Association Mapping of Correlated Traits in Cassava: Dry Matter and Total Carotenoid Content

Carotenoids in Cassava Roots

Genome-wide association mapping of correlated traits in cassava: dry matter and total carotenoid content

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