Genetic Diversity and Population Structure in Ethiopian Mustard (Brassica carinata A. Braun) as Revealed by Single Nucleotide Polymorphism Markers

Misteru Tesfaye; Tileye Feyissa; Teklehaimanot Hailesilassie; Selvaraju Kanagarajan; Li-Hua Zhu

doi:10.3390/genes14091757

Genetic Diversity and Population Structure in Ethiopian Mustard (Brassica carinata A. Braun) as Revealed by Single Nucleotide Polymorphism Markers

Genes (Basel). 2023 Sep 3;14(9):1757. doi: 10.3390/genes14091757.

Authors

Misteru Tesfaye^{1

2}, Tileye Feyissa², Teklehaimanot Hailesilassie², Selvaraju Kanagarajan¹, Li-Hua Zhu¹

Affiliations

¹ Department of Plant Breeding, Swedish University of Agricultural Sciences, P.O. Box 190, 234 22 Lomma, Sweden.
² Institute of Biotechnology, Addis Ababa University, Addis Ababa P.O. Box 1176, Ethiopia.

Abstract

Ethiopian mustard (Brassica carinata A. Braun) is currently one of the potential oilseeds dedicated to the production for biofuel and other bio-industrial applications. The crop is assumed to be native to Ethiopia where a number of diversified B. carinata germplasms are found and conserved ex situ. However, there is very limited information on the genetic diversity and population structure of the species. This study aimed to investigate the genetic diversity and population structure of B. carinata genotypes of different origins using high-throughput single nucleotide polymorphism (SNP) markers. We used Brassica 90K Illumina Infinium^TM SNP array for genotyping 90 B. carinata genotypes, and a total of 11,499 informative SNP markers were used for investigating the population structure and genetic diversity. The structure analysis, principal coordinate analysis (PcoA) and neighbor-joining tree analysis clustered the 90 B. carinata genotypes into two distinct subpopulations (Pop1 and Pop2). The majority of accessions (65%) were clustered in Pop1, mainly obtained from Oromia and South West Ethiopian People (SWEP) regions. Pop2 constituted dominantly of breeding lines and varieties, implying target selection contributed to the formation of distinct populations. Analysis of molecular variance (AMOVA) revealed a higher genetic variation (93%) within populations than between populations (7%), with low genetic differentiation (PhiPT = 0.07) and poor correlation between genetic and geographical distance (R = 0.02). This implies the presence of gene flow (Nm > 1) and weak geographical structure of accessions. Genetic diversity indices showed the presence of moderate genetic diversity in B. carinata populations with an average genetic diversity value (H_E = 0.31) and polymorphism information content (PIC = 0.26). The findings of this study provide important and relevant information for future breeding and conservation efforts of B. carinata.

Keywords: Brassica carinata; genetic diversity; population structure; single nucleotide polymorphism marker.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Genetic Variation* / genetics
Genotype
Humans
Mustard Plant / genetics
Plant Breeding
Polymorphism, Single Nucleotide* / genetics

Grants and funding

This work was financially supported by Swedish International Development Cooperation Agency (SIDA) and the Research and Training Grant awarded to the Addis Ababa University and the Swedish University of Agricultural Sciences (AAU-SLU, Biotech; https://sida.aau.edu.et/index.php/biotechnology-phd-program/; accessed on 25 September 2021).