Ethiopian Sorghum Landraces Provide Novel Genetic Sources for Drought Tolerance
Sorghum is primarily grown in drought prone areas, therefore drought is one of the major limiting factors of sorghum production. Although multiple drought-resistant sorghum genotypes have been discovered and used to produce improved cultivars, it is still important to investigate additional sources of these genotypes so that the current dependance on only a limited number of genetic sources is improved. Enyew et al., from Addis Ababa University, the Swedish University of Agricultural Sciences, the Ethiopian Biotechnology Institute and the Ethiopian Institute of Agricultural Research, grew 320 Ethopian sorghum landrace plants and four improved varieties which were grown in three drought-prone locations in (Melkassa, Mieso and Mehoni) Ethiopia. They studied seven traits: chlorophyll content at flowering (CHLF), chlorophyll content at maturity (CHLM), green leaf number at flowering (GLNF), stay-green (SG), flag leaf area (FLA), peduncle length (PDL) and panicle exertion (PAE). The results of the multivariate analysis showed high phenotypic variation for all seven traits. Further investigation using combined and AMMI (Additive Main effects and Multiplicative Interactions) Analysis of variance indicated that SG, CHLM, CHLF and GLNF had a higher phenotypic variation due to the genotypes as opposed to variations ascribed to environmental differences or interactions between the environment and the genotype. Although, FLA, PE and PDL had a lower phenotypic variation than the previous traits, all six of these traits had high broad sense heritability, indicating that most of the differences were due to genetic variation and very little was due to environmental causes. This high heritability of the chlorophyll content leads the researchers to believe that it would be an ideal trait to include in a selected genotype in a sorghum breeding program for drought-resistance. Additionally, previous research found that chlorophyll content is positively correlated with stay-green and grain yield, suggesting that delaying leaf senescence is a crucial mechanism by which it increases grain yield (Ochieng et al., 2020; Abreha et al., 2022). When comparing the landraces with the improved varieties, the researchers discovered, through the analyses of AMMI, GGE biplot, and genotype selection index, that several of the landraces outperformed the improved varieties in CHLF, CHLM, and SG. These landrace varieties would be an ideal source for novel germplasm that can be used to breed sorghum cultivars with improved drought-tolerance.
Reference
Enyew M, Carlsson AS, Geleta M, Tesfaye K, Hammenhag C, Seyoum A, Feyissa T. Novel sources of drought tolerance in sorghum landraces revealed via the analyses of genotype-by-environment interactions. Front Plant Sci. 2022 Dec 7;13:1062984. PMID: 36570928. DOI: 10.3389/fpls.2022.1062984. Read more
Related Project Websites:
Dr. Feyissa’s page at Addis Abbaba University: http://www.aau.edu.et/ibt/tileye-feyissa/
