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ARS Home » Pacific West Area » Maricopa, Arizona » U.S. Arid Land Agricultural Research Center » Water Management and Conservation Research » Research » Publications at this Location » Publication #400109
Research Project: Increasing the Utility of Turf in Urban Environments of the Southwest U.S.

Location: Water Management and Conservation Research

Title: Genetic diversity in Ethiopian sorghum germplasm for root system architecture and trait association

Author
item ELIAS, MASARAT - Ethiopia Haramaya University
item LULE, DAGNACHEW - Addis Ababa University
item TIRFESSA, ALEMU - Ethiopian Institute Of Agricultural Research
item GELMESA, DANDENA - Ethiopia Haramaya University
item TESSO, TESFAYE - Kansas State University
item MENAMO, TEMESGEN - Jimma University
item Serba, Desalegn

Submitted to: Rhizosphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/18/2023
Publication Date: 7/20/2023
Citation: Elias, M., Lule, D., Tirfessa, A., Gelmesa, D., Tesso, T.T., Menamo, T., Serba, D.D. 2023. Genetic diversity in Ethiopian sorghum germplasm for root system architecture and trait association. Rhizosphere. 27. Article 100759. https://doi.org/10.1016/j.rhisph.2023.100759.
DOI: https://doi.org/10.1016/j.rhisph.2023.100759

Interpretive Summary: Sorghum productivity is limited in arid and semi-arid environments predominantly because of drought stress. The root system architecture (RSA) is an important trait for sorghum adaptation to such water-limited environments. The RSA has profound importance in moisture absorption from lower soil profile during moisture depletion. Understanding genetic variation for RSA could facilitate sorghum improvement for drought stress. In this study, we investigated the RSA of 291 sorghum genotypes collected from different growing environments using a purpose-built root chamber. The result indicated that the varieties can be grouped into several categories based on root angle, root length, root mass, as well as shoot traits such as leaf area and stomatal density. The present findings indicated the prevalence of ample genetic diversity among Ethiopian sorghum germplasm for RSA traits useful to improve its productivity in drought stressed environments.

Technical Abstract: Sorghum productivity in arid and semi-arid regions of Africa is generally very low, mainly due to limited water availability. As roots are the primary conduit for plants to access moisture and nutrients, root system architecture (RSA) is an important trait for adaptation to water-limited environments. Knowing the extent of genetic variation in RSA and its relationship with drought response is critical for improving the performance of the crop under drought stress. The objective of this study was to determine the degree of genetic variability for root and shoot traits in sorghum germplasm during the seedling stage. Two hundred and ninety-one sorghum germplasm adapted to different agroecologies of Ethiopia were phenotyped for root and shoot traits using a purpose-built root chamber in the greenhouse at Jimma University. The experiment was set up in a row-column design with three replicates. Significant genetic variation (P< 0.01) was observed for all traits examined except root hair number and shoot dry weight. Root angle varied from 9° to 21.3° with an average of 14.9° and showed moderate heritability of 44.38%. Root dry weight also exhibited moderate heritability (49.3%). Correlation and path coefficient analysis revealed that root angle (RA) was uncorrelated with other RSA traits indicating that these traits did not directly influence root angle significantly. Cluster analysis using these RSA traits grouped the 291 genotypes into four different clusters. The first three principal components accounted for about 50% of the total variation. The results demonstrate that the Ethiopian sorghum germplasm exhibits large variations in RSA traits that can be harnessed in breeding programs to enhance sorghum productivity under drought stress.