Assessment of genetic diversity amongst Ugandan sesame (Sesamum indicum L.) landraces based on agromorphological traits and genetic markers
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Sesame (Sesamum indicum L.) is one of the most important ancient oilseed crops grown throughout the tropical and subtropical regions of the world. In Uganda, most of the cultivated sesame varieties are local landraces which are frequently traded between farmers. Although these traditional landraces are an important source of genetic diversity, knowledge of their genetic diversity is still limited.
Agromorphological traits and a set of published and newly developed microsatellite markers were analyzed on a collection of 121 accessions of Ugandan sesame landraces. CpSSR analysis revealed four haplotypes, whereby haplotype B was present in 96% of the individuals. The analysis of nSSR markers from 6 non-coding regions revealed a mean PIC value of 0.56 whereas the PIC value of eight selected EST-derived SSRs was 0.26. Accession-wise, the expected heterozygosity (He) varied from 0 to 0.396. AMOVA revealed that the majority of the variance occurred among the individuals accounting for 75% of the total variation, only 6% was attributed to differences among the districts, pointing towards a high gene flow (Nm = 4.476). These results are supported by the PCoA analysis as well as the NJ tree both of which revealed no clustering of the accessions according to their geographic origin. Also the statistical analysis of 10 agromorphological traits indicated no clear pattern related to the geographic origin. Such a poor grouping, indicative of considerable gene flow across geographic domains, could be explained either by a high outcrossing rate, and/or through extensive seed trading.
Keywordsgenetic diversity landraces molecular marker Sesamum indicum L. SSR
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- Arriel NHC, Di Mauro AO, Arriel EF, Unêda-Trevisoli SH, Costa MM, Bárbaro IM, Muniz FRS. 2007. Genetic divergence in sesame based on morphological and agronomic traits. Crop Breed. Appl. Biotechnol. 253–261Google Scholar
- Bhattacharyya U, Pandey SK, Dasgupta T. 2014. Identification of EST-SSRs and FDM in sesame (Sesamum indicum L.) through data mining. Sch. J. Agric. Sci. 4: 60–69Google Scholar
- Gebremichael DE, Parzies HK. 2011. Genetic variability among landraces of sesame in Ethiopia. Afr. Crop Sci. J. 19Google Scholar
- Hayward A, Tollenaere R, Dalton-Morgan J, Batley J. 2015. Molecular Marker Applications in Plants, in: J Batley, Ed., Plant Genotyping, Methods in Molecular Biology. Springer New York, pp. 13–27Google Scholar
- IPGRI, NBPGR. 2004. Descriptors for Sesame (Sesamum spp.). International Plant Genetic Resources InstituteGoogle Scholar
- R Core Team. 2015. R: A Language and Environment for Statistical Computing. R Foundation for Statistical Computing, Vienna, AustriaGoogle Scholar
- Weising K, Nybom H, Pfenninger M, Wolff K, Kahl G. 2005 DNA Fingerprinting in Plants: Principles, Methods, and Applications. CRC press.Google Scholar
- Yermanos DM. 1980. Sesame, In: Hybridization of Crop Plants. American Society of Agronomy, Crop Science Society of America, Madison, WI, pp 549–563Google Scholar
- Zhang Y, Wang L, Xin H, Li D, Ma C, Ding X, Hong W, Zhang X. 2013. Construction of a high-density genetic map for sesame based on large-scale marker development by specific length amplified fragment (SLAF) sequencing. BMC Plant Biol. 13: 141–141, doi:10.1186/1471-2229-13-141CrossRefPubMedPubMedCentralGoogle Scholar