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Indirect estimates reveal the potential of transgene flow in the crop–wild–weed Sorghum bicolor complex in its centre of origin, Ethiopia

Published online by Cambridge University Press:  13 June 2016

Asfaw Adugna  and
Endashaw Bekele
Asfaw Adugna*
Affiliation:
Melkassa Agricultural Research Center, P.O. Box 1085, Adama, Ethiopia Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
Endashaw Bekele
Affiliation:
Department of Microbial, Cellular and Molecular Biology, Addis Ababa University, P.O. Box 1176, Addis Ababa, Ethiopia
*
*Corresponding author. E-mail: asfaw123@rediffmail.com
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Abstract

A study was carried out between 2008 and 2011 to investigate the potential risks of gene flow and its consequences in the crop–wild–weed S. bicolor complex in Ethiopia to aid efforts to conserve genetic diversity. Morphological measurements and genomic DNA samples were taken in situ from 30 wild and eight cultivated populations representing a total of 760 samples from five regions. Genetic diversity, gene flow, population structure and outcrossing rates of wild populations were computed using phenotypic measurements and/or polymorphic simple sequence repeat (SSR) markers. Moreover, morphological analyses of fitness of crop–wild hybrids were studied. High diversity was observed among the wild/weedy sorghum populations for phenotypic traits and SSRs. SSR diversity was high in both wild and cultivated populations, but the magnitude was greater in the former. Gene flow between the wild and the cultivated sorghum was observed to be higher than that within either pool. Wild sorghums exhibited variation in the multilocus outcrossing rate (range = 0.31–0.65) and fitness was not compromised in most wild × crop hybrids. The study indicated that crop-to-wild gene flow is possible in Ethiopia. Thus, genes from transgenic sorghum are expected to enter into the wild and non-transgenic cultivated populations and may spread and persist, if transgenic sorghum is deployed in Ethiopia and in other countries of Africa, which may pose risk of introduction of unwanted effects, which in turn may lead to loss of genetic diversity.

Keywords

gene flowgenetic diversityoutcrossingpopulation structuresorghumtransgenic
Type
Research Article
Information
Plant Genetic Resources , Volume 15 , Issue 6 , December 2017 , pp. 496 - 505
Copyright
Copyright © NIAB 2016 

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Footnotes

†

Current address Advanta Seed International, P.O. Box 10438, Eldoret, Kenya

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