Hostname: page-component-7c8c6479df-24hb2 Total loading time: 0 Render date: 2024-03-27T08:28:14.471Z Has data issue: false hasContentIssue false

Geographical distribution and phenotypic diversity of wild/weedy sorghum [Sorghum bicolor (L.) Moench] in Ethiopia: implications for germplasm conservation and crop–wild gene flow

Published online by Cambridge University Press:  29 November 2012

Asfaw Adugna*
Affiliation:
Department of Biology, Addis Ababa University, Addis Ababa, Ethiopia Melkassa Agricultural Research Center, PO Box 1085, Adama, Ethiopia
Endashaw Bekele
Affiliation:
Department of Biology, Addis Ababa University, Addis Ababa, Ethiopia
*
*Corresponding author. E-mail: asfaw123@rediffmail.com

Abstract

Extensive studies of genetic diversity and population structure important for conservation of wild sorghum are yet lacking in Ethiopia, the centre of origin for cultivated sorghum. To assess both genetic diversity and the probability of gene flow between wild and cultivated types, collections of wild Sorghum bicolor were made from regions in Ethiopia where wild and cultivated sorghum coexist. Morphological data were recorded in situ for both quantitative and qualitative characters from 30 populations in five diverse geographical regions and eight agroecologies. High phenotypic diversity was observed among the wild and weedy sorghum populations. The overall standardized Shannon–Weaver diversity index (H′), computed from the frequencies of all qualitative traits, ranged from 0.47 to 0.98 with an average value of 0.76. Moreover, warm semi-arid lowland (SA2) agroecologies, which contain Tigray populations, supported the highest diversity for these traits. Subspecies verticilliflorum and drummondii (the two major subspecies of wild S. bicolor) were observed in diverse habitats throughout northern and central Ethiopia. In some areas, weedy types showed domestication traits including the absence of awns and reduced seed shattering. The existence of morphologically intermediate forms indicates that gene flow between cultivated and wild forms has likely occurred. Deployment of transgenic crop sorghum, therefore, would pose a distinct risk for transgene movement into wild Ethiopian populations.

Type
Research Article
Copyright
Copyright © NIAB 2012

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Adugna A (2012) Population genetics and ecological studies in wild sorghum [Sorghum bicolor (L.)] in Ethiopia: implications for germplasm conservation. PhD Thesis, Addis Ababa University.Google Scholar
Ahrens JD (1996) Benishangul-Gumuz, Situation Report, 10/96. Emergencies Unit for Ethiopia (UNDP-EUE) Development Programme. Available at: http://www.africa.upenn.edu/EUE/eue_ahrens1096.html.Google Scholar
Ayana, A and Bekele, E (1998) Geographical patterns of morphological variation in sorghum (Sorghum bicolor (L.) Moench) germplasm from Ethiopia and Eritrea: qualitative characters. Hereditas 129: 195205.CrossRefGoogle Scholar
Ayana, A, Bryngelsson, T and Bekele, E (2000) Genetic variation of Ethiopian and Eritrean sorghum (Sorghum bicolor (L.) Moench) germplasm assessed by random amplified polymorphic DNA (RAPD). Genetic Resources and Crop Evolution 47: 471481.Google Scholar
Ayana, A, Bryngelsson, T and Bekele, E (2001) Geographic and altitudinal allozyme variation in sorghum (Sorghum bicolor (L.) Moench) germplasm from Ethiopia and Eritrea: qualitative characters. Hereditas 135: 112.Google Scholar
Bioversity International (2010) Key access and utilization descriptors for sorghum genetic resources. Available at: www.bioversityinternational.org.Google Scholar
Chandler, S and Dunwell, JM (2008) Gene flow, risk assessment and the environmental release of transgenic plants. Critical Reviews in Plant Sciences 27: 2549.CrossRefGoogle Scholar
De Wet, JMJ (1978) Systematics and evolution of Sorghum Sect. Sorghum (Gramineae). American Journal of Botany 65: 477484.CrossRefGoogle Scholar
Dillon, SL, Shapter, FM, Henry, RJ, Cordeiro, G, Izquierdo, L and Lee, S (2007) Domestication to crop improvement: genetic resources for sorghum and saccharum (Andropogoneae). Annals of Botany 100: 975989.CrossRefGoogle ScholarPubMed
Doggett, H (1988) Sorghum. 2nd edn.Essex: Longman.Google Scholar
Duvall, MR and Doebley, JF (1990) Restriction-site variation in the chloroplast genome of Sorghum (Poacceae). Systematic Botany 15: 472480.Google Scholar
Ejeta, G and Grenier, C (2005) Sorghum and its weedy hybrids. In: Gressel, J (ed.) Crop Ferality and Volunteerism. Boca Raton, FL: Taylor and Francis, pp. 123135.Google Scholar
Harlan, JR and De Wet, JMJ (1974) Origin of cultivated plants: sympatric evolution in sorghum. Genetics 78: 473474.Google Scholar
Hutcheson, K (1970) A test for comparing diversities based on the Shannon formula. Journal of Theoretical Biology 29: 151154.Google Scholar
IPGRI and ICRISAT (1993) Descriptors for Sorghum [Sorghum bicolour (L.) Moench]. Rome/Patancheru: International Plant Genetic Resources Institute/ICRISAT.Google Scholar
Kamala, V, Sharma, HC, Manohar Rao, D, Varaprasad, KS and Bramel, PJ (2009) Wild relatives of sorghum as sources of resistance to sorghum shoot fly, Atherigona soccata. Plant Breeding 128: 137142.Google Scholar
Ministry of Agriculture and Rural Development (MOARD), (2005) Major Agro-ecological Zones of Ethiopia. Addis Ababa: Forestry, Land Use and Soil Conservation Department.Google Scholar
Muraya, MM, Geiger, HH, Mutegi, E, Kanyenji, BM, Sagnard, F, de Villiers, SM, Kiambi, D and Parzies, HK (2010) Geographical patterns of phenotypic diversity and structure of Kenyan wild sorghum populations (Sorghum spp.) as an aid to germplasm collection and conservation strategy. Plant Genetic Resources: Characterization and Utilization. doi:101017/S1479262110000225.Google Scholar
Mutegi, E, Sagnard, F, Muraya, M, Kanyenji, B, Rono, B, Mwongera, C, Marangu, C, Kamau, J, Parzies, H, de Villiers, S, Semagn, K, Traore, PS and Labuschagne, M (2010) Ecogeographical distribution of wild weedy and cultivated Sorghum bicolor (L.) Moench in Kenya: implications for conservation and crop-to-wild gene flow. Genetic Resources and Crop Evolution 57: 243253.CrossRefGoogle Scholar
Okeno JA, Mutegi E, de Villiers S, Wolt JD, Misra MK (2012) Morphological variation in the wild-weedy complex of Sorghum bicolor in situ in Western Kenya: preliminary evidence of crop-to-wild gene flow. International Journal of Plant Sciences 173: 507–515. Available at: http://dx.doi.org/10.1086/665266.Google Scholar
Reed, JD, Ramundo, BA, Claflin, LE and Tuinstra, MR (2002) Analysis of resistance to ergot in sorghum and potential alternate hosts. Crop Science 42: 11351138.Google Scholar
Rich, PJ, Grenier, C and Ejeta, G (2004) Striga resistance in wild relatives of sorghum. Crop Science 44: 22212229.Google Scholar
Stemler, ABL, Harlan, JR and De Wet, JMJ (1977) The sorghums of Ethiopia. Economic Botany 31: 446460.Google Scholar
Tesso, T, Kapran, I, Grenier, C, Snow, A, Sweeney, P, Pedersen, J, Marx, D, Bothma, G and Ejeta, G (2008) The potential for crop-to-wild gene flow in Sorghum in Ethiopia and Niger: a geographic survey. Crop Science 48: 14251431.Google Scholar
Tesso, T, Tirfessa, A and Mohammed, H (2011) Association between morphological traits and yield components in the durra sorghums of Ethiopia. Hereditas 148: 98109.CrossRefGoogle ScholarPubMed
VSN International Ltd. (2008) GenStat Discovery. 3rd edn.Hempstead: VSN International Ltd.Google Scholar
Zhao, Z (2007) The Africa biofortified sorghum project – applying biotechnology to develop nutritionally improved sorghum for Africa. In: Xu, Z, et al. (ed.) Biotechnology and Sustainable Agriculture 2006 and Beyond. Dordrecht: Springer, pp. 273277.Google Scholar
Zongo, JD, Gouyon, PH and Sandmeier, M (1993) Genetic variability among sorghum accessions from the Sahelian agroecological region of Burkina Faso. Biodiversity Conservation 2: 627636.Google Scholar
Supplementary material: File

Adugna Supplementary Material

Appendix

Download Adugna Supplementary Material(File)
File 2.5 MB