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Doctoral thesis2023Open access

Nutritional profiling, SNP-based genomic tools development for population genetic analysis and genotype-by-environment interaction in noug (Guizotia abyssinica (L.f.) Cass.)

Tsehay, Sewalem

Abstract

Noug (Guizotia abyssinica) is an economically important oilseed crop and has its primary center of origin and diversity in Ethiopia. It is mainly cultivated in Ethiopia and India. Noug is a self-incompatible dicotyledonous annual herbaceous semi-domesticated crop. The nutritional content of diverse germplasm of noug seed was evaluated for total lipid, fatty acids, protein and 12 macro and micro-mineral elements using standard bioanalytical techniques. Noug seed contains 33–49% lipid with rich linoleic acid, an essential polyunsaturated omega-6 fatty acid (72–79%) and consequently low in oleic acid (5–9%). The total protein content of noug seeds ranged from 25 to 28%. Significant differences in mineral element contents were revealed across experimental locations with potassium (K) being the highest 9254 (µg g-1 ) in concentration. Meeting the demands of the world´s growing population in the presence of climate change demands intensive crop breeding. Breeding oilseed crops is part of the race to meet consumers' rising demands. However, before an intensive breeding program is initiated, we have to lay the foundation with prebreeding. Genomic tools facilitate our deep insights into crop genetic diversity, population structure, genotyping, and marker-assisted selection, which are valuable for breeding and conservation programs. This research developed novel DNA markers for noug based on transcriptome sequencing. For this, 959 single nucleotide polymorphisms (SNPs) were identified from 628 transcripts of two noug genotypes. Thereafter, kompetitive allele-specific PCR (KASP) markers were developed based on these SNPs and utilized in genotyping noug accessions. The genotypic data were utilized for population genetic analyses. The SNP loci had an average of 0.24 polymorphic information content (PIC) and about 50% of the loci showed significant deviation from Hardy-Weinberg equilibrium. The markers revealed a high genetic variation within accessions. The developed genomic resources proved useful for population genetic diversity analysis. Breeding noug involves improving its oil content, quality, and productivity, as well as adaptability to diverse environments. This research also evaluated the magnitude of the effect of genotype-by-environment interaction and stability of noug nutritional value traits including oil content, linoleic, oleic, palmitic and stearic acids, and the results provided useful insights, which could facilitate the development of superior cultivars through breeding.

Keywords

Genetic diversity; Genotype-by-environment interaction; Genotyping; Guizotia abyssinica; KASP markers; Lipids; Minerals; Noug; Oilseeds; Population structure; Protein; SNPs

Published in

Acta Universitatis Agriculturae Sueciae
2023, number: 2023:100
ISBN: 978-91-8046-252-5, eISBN: 978-91-8046-253-2
Publisher: Swedish University of Agricultural Sciences

    UKÄ Subject classification

    Genetics and Breeding

    Publication identifier

    DOI: https://doi.org/10.54612/a.3sj19brqcf

    Permanent link to this page (URI)

    https://res.slu.se/id/publ/126726