Time filter

Source Type

Magomere T.O.,University of Nairobi | Magomere T.O.,Kenyatta University | Obukosia S.D.,Africa Harvest Biotechnology Foundation International | Shibairo S.I.,Masinde Muliro University of Science and Technology | And 2 more authors.
Journal of Biological Sciences | Year: 2015

Introgression of crop alleles in weedy sorghum populations may have an additive effect on the adaptive character of the weeds making them more competitive. The relative fitness in the F1 generation derived from weedy and crop sorghums was evaluated using competitive assays in densely planted plots. Replacement series assays were utilized to evaluate the competitiveness of the F1 in the greenhouse and in the field. Interspecific crosses between S. halepense×S. bicolor and S. sudanense×S. bicolor showed vigour in vegetative morphological parameters. Tillering, plant height at maturity and plant weight of the F1 increased up to 70, 50 and 100%, respectively. The analysis of reproductive fitness associated traits showed that the hybrids had Relative Crowding Coefficients (RCC) values of between 5.2 and 10.1 on the number of panicles per plant. High RCC values of up to 76.9 on the number of seeds per plant and values of up to 19.5 on the total seed weight were observed in the hybrid indicating that the hybrid was more competitive than the parents. The S. halepense×S. bicolor F1 progenies had less seed produced when grown in competition with S. bicolor and an RCC of 4.3 was observed. Ratooning was reduced in the F1 of S. halepense×S. bicolor when grown in competition with S. halepense and an RCC of 5.0 was observed. The F1 hybrid of S. sudanense×S. bicolor had significantly more panicles (6.3) than S. bicolor (1.9) but it was not different from S. sudanense (6.0). Both F1 populations had high levels of seed dormancy and forced germination gave 53% in S. halepense×S. bicolor and 69% in S. sudanense×S. bicolor which gave low values as compared to their parents. Results from the study indicate that the release of improved transgenic varieties should be preceded by investigation on the effect of their interaction with weedy members in the sorghum genus. © 2015 Asian Network for Scientific Information. Source

Henley E.C.,EC Henley Consulting | Henley E.C.,University of Georgia | Taylor J.R.N.,University of Pretoria | Obukosia S.D.,Africa Harvest Biotechnology Foundation International
Advances in Food and Nutrition Research | Year: 2010

Child malnutrition is increasing in Africa. Protein deficiency is an important cause since protein is essential for both growth and maintenance of muscle mass. Sorghum is a major staple food in Africa on account of its hardiness as a crop. However, sorghum protein is very deficient in the indispensable amino acid lysine and on cooking has poor protein digestibility. This results in sorghum having a very low Protein Digestibility Corrected Amino Acid Score (PDCAAS). The Africa Biofortified Sorghum project, a Grand Challenges in Global Heath project, is undertaking research to biofortify sorghum in terms of protein and micronutrient quality using genetic engineering. Lysine and protein digestibility have been improved by suppression of synthesis of the kafirin storage proteins. Transgenic biofortified sorghum has double the PDCAAS of conventional sorghum. This improvement should enable a young child to meet most of its protein and energy requirements from biofortified sorghum porridge. This together with the improvement in micronutrients could provide the basis of a sustainable and broadly comprehensive solution to child malnutrition in many African countries. © 2010 Elsevier Inc. Source

Magomere T.O.,University of Nairobi | Ngugi E.K.,University of Nairobi | Shibairo S.I.,Masinde Muliro University of Science and Technology | Mutitu E.,University of Nairobi | Obukosia S.D.,Africa Harvest Biotechnology Foundation International
Journal of Biological Sciences | Year: 2014

Utility of the PCR methodology in detection of crop alleles in weedy species has the potential for improvement through techniques that improve efficiency and minimize the cost and time required. This study evaluated the multiplex PCR procedure in concurrent detection of multiple crop alleles in wild sorghum populations and interspecific hybridization. Crop loci were amplified from seed and leaf samples of S. halepense, S. bicolor, S. sudanense, S. bicolor ssp. verticilliflorum open pollinated populations. Simultaneous amplification of combinations of loci SB1764, SB3420, SB5058 and SB5458 in the accessions gave the expected DNA banding profile. Loci combinations involving SB1764/SB5058, SB3250/SB1764 and SB1764/SB3008/SB5058 were important in determining polymorphism and interspecific hybridization within these species. Multiplex PCR reduced 2 loci and 3 loci assay time from 31-15.5 and 46.5-15.5 h, respectively. Multiplex PCR was useful in evaluation of the parental, F1, F2and BC1. Densitometric analysis of PCR fragments showed that amplifications from 35-50 ng of template had the best yield. Sorghum sudanense had higher affinity towards hybridization with the crop (45-76%) as well as the weedy materials (59-61%). Therefore, S. sudanense and its interspecific progeny seem to be an important bridge species in the sorghum genus. © 2014 Asian Network for Scientific Information. Source

Wambugu F.,Africa Harvest Biotechnology Foundation International | Obukosia S.,Africa Harvest Biotechnology Foundation International | Gaffney J.,DuPont Pioneer | Kamanga D.,Africa Harvest Biotechnology Foundation International | And 10 more authors.
Proceedings of the Nutrition Society | Year: 2015

The focus of the review paper is to discuss how biotechnological innovations are opening new frontiers to mitigate nutrition in key agricultural crops with potential for large-scale health impact to people in Africa. The general objective of the Africa Biofortified Sorghum (ABS) project is to develop and deploy sorghum with enhanced pro-Vitamin A to farmers and end-users in Africa to alleviate Vitamin A-related micronutrient deficiency diseases. To achieve this objective the project technology development team has developed several promising high pro-Vitamin A sorghum events. ABS 203 events are so far the most advanced and well-characterised lead events with about 12 μg β-carotene/g tissue which would supply about 40-50 % of the daily recommended Vitamin A at harvest. Through gene expression optimisation other events with higher amounts of pro-Vitamin A, including ABS 214, ABS 235, ABS 239 with 25, 30-40, 40-50 μg β-carotene/g tissue, respectively, have been developed. ABS 239 would provide twice recommended pro-Vitamin A at harvest, 50-90 % after 3 months storage and 13-45 % after 6 months storage for children. Preliminary results of introgression of ABS pro-Vitamin A traits into local sorghum varieties in target countries Nigeria and Kenya show stable introgression of ABS Vitamin A into local farmer-preferred sorghums varieties. ABS gene Intellectual Property Rights and Freedom to Operate have been donated for use royalty free for Africa. Prior to the focus on the current target countries, the project was implemented by fourteen institutions in Africa and the USA. For the next 5 years, the project will complete ABS product development, complete regulatory science data package and apply for product deregulation in target African countries. © The Authors 2015. Source

Magomere T.,Africa Harvest Biotechnology Foundation International | Magomere T.,Kenyatta University | Obukosia S.,Africa Harvest Biotechnology Foundation International | Albertsen M.,DuPont Pioneer | And 9 more authors.
Electronic Journal of Biotechnology | Year: 2016

Background: Introgression of transgenes from crops to their wild species may enhance the adaptive advantage and therefore the invasiveness of and weedy forms. The study evaluated the effect of Africa Biofortified Sorghum (ABS) genes from ABS event 188 on the vegetative and reproductive features of the F2 populations derived from crosses with Sorghum bicolor subsp. drummondii. Results: F1 populationswere obtained fromreciprocal crosses involving ABS event 188 and its null segregantwith inbredweedy parents from S. bicolor subsp. drummondii. Four F2 populations and four parental populationswere raised in RCBDwith 4 replications in a confined field plot for twoseasons. Vegetative and reproductive traitswere evaluated. The vigour shown in the F2 populations from the reciprocal crosses involving ABS event 188 and S. bicolor subsp. drummondii was similar to that in the crosses involving the null segregant and S. bicolor subsp. drummondii. Differences in vegetative and reproductive parameters were observed between the parental controls and the F2 populations. Examination of the above and below ground vegetative biomass showed lack of novel weedy related features like rhizomes. Conclusions: Therefore, release of cropswith ABS 188 transgenes into cropping systems is not likely to pose a risk of conferring additional adaptive advantage in the introgressing populations. The interaction of ABS genes in weedy backgrounds will also not have an effect towards enhancing the weedy features in these populations. © 2016 Pontificia Universidad Cat\u00f3lica de Valpara\u00edso. Production and hosting by Elsevier B.V. All rights reserved. Source

Discover hidden collaborations