Eastern Africa, where sorghum is a significant arable crop, is arid and areas are at risk of desertification. Consequently, many valuable landraces of sorghum are at risk for genetic erosion. Genetic diversity plays a vital role in the success of any breeding programme. This study aimed to investigate the genetic diversity and genetic relationships in germplasm accessions among east African countries using morpho-agronomical and simple sequence repeat (SSR) markers in order to (i) understand the extent of genetic variation in different countries, and (ii) quantify the genetic structure and how the diversity is distributed among and within countries. The extent of regional patterns of phenotypic diversity was assessed in 1013 accessions using 13 qualitative and five quantitative traits. A total of 1108 sorghum accessions from Sudan, Kenya, Uganda, Ethiopia, Eritrea, Rwanda, and Burundi were assessed using 39 SSR markers. Results on qualitative and quantitative traits data showed that there was a high level of morpho-agronomical diversity among accessions studied. Analysis of variance revealed highly significant differences between accessions pooled over countries and between countries. Based on SSR data, Sudan had the highest genetic diversity and Rwanda the lowest. Levels of genetic diversity differed significantly, with most of the diversity being partitioned more within than between countries. Results suggested that despite sorghumâs predominantly autogamous mating system, countries clustered totally separately with almost no integration and therefore emphasized the role of farmersâ practices in the preservation of landrace identity and the favouring of genetic diversity. The morpho-agronomical and molecular marker data showed a high level of variation among accessions, and indicated that sorghum populations studied were a mixture of a large number of different genotypes. Therefore, future germplasm collection should take all levels of variation into consideration.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-07162013-152120 |
| Date | 16 July 2013 |
| Creators | Salih, Shadia Abdallah |
| Contributors | Dr D Kiambi, Prof MT Labuschagne, Prof L Herselman |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-07162013-152120/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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