1
|
Kaweesi T, Colvin J, Campbell L, Visendi P, Maslen G, Alicai T, Seal S. In silico prediction of candidate gene targets for the management of African cassava whitefly ( Bemisia tabaci, SSA1-SG1), a key vector of viruses causing cassava brown streak disease. PeerJ 2024; 12:e16949. [PMID: 38410806 PMCID: PMC10896082 DOI: 10.7717/peerj.16949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 01/24/2024] [Indexed: 02/28/2024] Open
Abstract
Whiteflies (Bemisia tabaci sensu lato) have a wide host range and are globally important agricultural pests. In Sub-Saharan Africa, they vector viruses that cause two ongoing disease epidemics: cassava brown streak disease and cassava mosaic virus disease. These two diseases threaten food security for more than 800 million people in Sub-Saharan Africa. Efforts are ongoing to identify target genes for the development of novel management options against the whitefly populations that vector these devastating viral diseases affecting cassava production in Sub-Saharan Africa. This study aimed to identify genes that mediate osmoregulation and symbiosis functions within cassava whitefly gut and bacteriocytes and evaluate their potential as key gene targets for novel whitefly control strategies. The gene expression profiles of dissected guts, bacteriocytes and whole bodies were compared by RNAseq analysis to identify genes with significantly enriched expression in the gut and bacteriocytes. Phylogenetic analyses identified three candidate osmoregulation gene targets: two α-glucosidases, SUC 1 and SUC 2 with predicted function in sugar transformations that reduce osmotic pressure in the gut; and a water-specific aquaporin (AQP1) mediating water cycling from the distal to the proximal end of the gut. Expression of the genes in the gut was enriched 23.67-, 26.54- and 22.30-fold, respectively. Genome-wide metabolic reconstruction coupled with constraint-based modeling revealed four genes (argH, lysA, BCAT & dapB) within the bacteriocytes as potential targets for the management of cassava whiteflies. These genes were selected based on their role and essentiality within the different essential amino acid biosynthesis pathways. A demonstration of candidate osmoregulation and symbiosis gene targets in other species of the Bemisia tabaci species complex that are orthologs of the empirically validated osmoregulation genes highlights the latter as promising gene targets for the control of cassava whitefly pests by in planta RNA interference.
Collapse
Affiliation(s)
- Tadeo Kaweesi
- Natural Resources Institute, University of greenwich, Chatham Maritime, Kent, United Kingdom
- Rwebitaba Zonal Agricultural Research and Development Institute, National Agricultural Research Organization, Fort Portal, Kabarole, Uganda
- National Crops Resources Research Institute, National Agricultural Research Organization, Kampala, Uganda
| | - John Colvin
- Natural Resources Institute, University of greenwich, Chatham Maritime, Kent, United Kingdom
| | - Lahcen Campbell
- Wellcome Genome Campus, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton, Cambridge, United Kingdom
| | - Paul Visendi
- Institute for Molecular Bioscience, Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Queensland, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Gareth Maslen
- Wellcome Genome Campus, European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton, Cambridge, United Kingdom
| | - Titus Alicai
- National Crops Resources Research Institute, National Agricultural Research Organization, Kampala, Uganda
| | - Susan Seal
- Natural Resources Institute, University of greenwich, Chatham Maritime, Kent, United Kingdom
| |
Collapse
|
2
|
Campbell LI, Nwezeobi J, van Brunschot SL, Kaweesi T, Seal SE, Swamy RAR, Namuddu A, Maslen GL, Mugerwa H, Armean IM, Haggerty L, Martin FJ, Malka O, Santos-Garcia D, Juravel K, Morin S, Stephens ME, Muhindira PV, Kersey PJ, Maruthi MN, Omongo CA, Navas-Castillo J, Fiallo-Olivé E, Mohammed IU, Wang HL, Onyeka J, Alicai T, Colvin J. Comparative evolutionary analyses of eight whitefly Bemisia tabaci sensu lato genomes: cryptic species, agricultural pests and plant-virus vectors. BMC Genomics 2023; 24:408. [PMID: 37468834 DOI: 10.1186/s12864-023-09474-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 06/21/2023] [Indexed: 07/21/2023] Open
Abstract
BACKGROUND The group of > 40 cryptic whitefly species called Bemisia tabaci sensu lato are amongst the world's worst agricultural pests and plant-virus vectors. Outbreaks of B. tabaci s.l. and the associated plant-virus diseases continue to contribute to global food insecurity and social instability, particularly in sub-Saharan Africa and Asia. Published B. tabaci s.l. genomes have limited use for studying African cassava B. tabaci SSA1 species, due to the high genetic divergences between them. Genomic annotations presented here were performed using the 'Ensembl gene annotation system', to ensure that comparative analyses and conclusions reflect biological differences, as opposed to arising from different methodologies underpinning transcript model identification. RESULTS We present here six new B. tabaci s.l. genomes from Africa and Asia, and two re-annotated previously published genomes, to provide evolutionary insights into these globally distributed pests. Genome sizes ranged between 616-658 Mb and exhibited some of the highest coverage of transposable elements reported within Arthropoda. Many fewer total protein coding genes (PCG) were recovered compared to the previously published B. tabaci s.l. genomes and structural annotations generated via the uniform methodology strongly supported a repertoire of between 12.8-13.2 × 103 PCG. An integrative systematics approach incorporating phylogenomic analysis of nuclear and mitochondrial markers supported a monophyletic Aleyrodidae and the basal positioning of B. tabaci Uganda-1 to the sub-Saharan group of species. Reciprocal cross-mating data and the co-cladogenesis pattern of the primary obligate endosymbiont 'Candidatus Portiera aleyrodidarum' from 11 Bemisia genomes further supported the phylogenetic reconstruction to show that African cassava B. tabaci populations consist of just three biological species. We include comparative analyses of gene families related to detoxification, sugar metabolism, vector competency and evaluate the presence and function of horizontally transferred genes, essential for understanding the evolution and unique biology of constituent B. tabaci. s.l species. CONCLUSIONS These genomic resources have provided new and critical insights into the genetics underlying B. tabaci s.l. biology. They also provide a rich foundation for post-genomic research, including the selection of candidate gene-targets for innovative whitefly and virus-control strategies.
Collapse
Affiliation(s)
- Lahcen I Campbell
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.
| | - Joachim Nwezeobi
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK.
- Wellcome Sanger Institute, Wellcome Genome Campus, Cambridge, Hinxton, UK.
| | - Sharon L van Brunschot
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
- CSIRO Health and Biosecurity, Dutton Park, QLD, Australia
- School of Biological Sciences, The University of Queensland, Brisbane, QLD, Australia
| | - Tadeo Kaweesi
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
- Rwebitaba Zonal Agricultural Research and Development Institute, Fort Portal, Uganda
| | - Susan E Seal
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
| | - Rekha A R Swamy
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
| | - Annet Namuddu
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
- National Crops Resources Research Institute, Kampala, Uganda
| | - Gareth L Maslen
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
- Imperial College London, South Kensington, London, UK
| | - Habibu Mugerwa
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
- Department of Entomology, University of Georgia, Griffin, GA, USA
| | - Irina M Armean
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Leanne Haggerty
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Fergal J Martin
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Osnat Malka
- Department of Entomology, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Diego Santos-Garcia
- CNRS, Laboratory of Biometry and Evolutionary Biology UMR 5558, University of Lyon, Villeurbanne, France
- Center for Biology and Management of Populations, INRAe UMR1062, Montferrier-sur-Lez, France
| | - Ksenia Juravel
- Department of Entomology, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Shai Morin
- Department of Entomology, The Hebrew University of Jerusalem, Rehovot, Israel
| | | | - Paul Visendi Muhindira
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, Australia
| | - Paul J Kersey
- European Molecular Biology Laboratory, European Bioinformatics Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
- Royal Botanic Gardens, Kew, London, UK
| | - M N Maruthi
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
| | | | - Jesús Navas-Castillo
- Instituto de Hortofruticultura Subtropical Y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Consejo Superior de Investigaciones Científicas, Málaga, Algarrobo-Costa, Spain
| | - Elvira Fiallo-Olivé
- Instituto de Hortofruticultura Subtropical Y Mediterránea "La Mayora" (IHSM-UMA-CSIC), Consejo Superior de Investigaciones Científicas, Málaga, Algarrobo-Costa, Spain
| | | | - Hua-Ling Wang
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
- College of Forestry, Hebei Agricultural University, Baoding, Hebei, China
| | - Joseph Onyeka
- National Root Crops Research Institute (NRCRI), Umudike, Nigeria
| | - Titus Alicai
- National Crops Resources Research Institute, Kampala, Uganda
| | - John Colvin
- Natural Resources Institute, University of Greenwich, Chatham, Kent, UK
| |
Collapse
|
3
|
Okul Valentor A, Ochwo-Ssemakula M, Kaweesi T, Ozimati A, Mrema E, Mwale E, Gibson P, Achola E, Edema R, Baguma Y, Kawuki R. Plot based heritability estimates and categorization of cassava genotype response to cassava brown streak disease. Crop Prot 2018; 108:39-46. [PMID: 29861529 PMCID: PMC5890358 DOI: 10.1016/j.cropro.2018.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 01/23/2018] [Accepted: 02/07/2018] [Indexed: 05/21/2023]
Abstract
Cassava brown streak disease (CBSD) caused by Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV) is a threat to food security in sub-Saharan Africa, where the disease persistently reduces overall root quality and quantity resulting in up to 100% yield losses. Complexities in CBSD symptom expression and the damage caused on leaves, stems and roots throughout the 12 months of cassava growth require that appropriate ways of categorizing genotype response and optimal stages of evaluation be identified. This study aimed at: 1) determining plot based heritability of CBSD based on symptom expression and 2) categorizing genotype resistance to CBSD based on symptom expression. Herein, 41 genotypes were evaluated for two years at Namulonge with an additional evaluation conducted across three locations. Evaluations were done at three, six, nine and twelve months after planting. Genotype responses to CBSD varied significantly. High broad sense heritability estimates of up to 0.81 (incidence) and 0.71 (severity) were obtained. Average disease severity scores had higher broad sense heritability estimates (0.53 and 0.65) than maximum disease severity scores (0.33 and 0.61) for root and foliar severities respectively. These findings are important in choosing an appropriate evaluation method for CBSD. Genotypes displayed differing CBSD responses in type, locality and severity of symptoms. This suggested that genotypes had differences in mechanisms of resistance that can be exploited in CBSD resistance breeding.
Collapse
Affiliation(s)
- A. Okul Valentor
- Makerere University, Department of Agricultural Production, P.O. Box 7062, Kampala, Uganda
- Corresponding author.
| | - M. Ochwo-Ssemakula
- Makerere University, Department of Agricultural Production, P.O. Box 7062, Kampala, Uganda
| | - T. Kaweesi
- National Crops Resources Research Institute, Root Crops Program, P.O. Box 7084, Kampala, Uganda
| | - A. Ozimati
- National Crops Resources Research Institute, Root Crops Program, P.O. Box 7084, Kampala, Uganda
| | - E. Mrema
- Makerere University, Department of Agricultural Production, P.O. Box 7062, Kampala, Uganda
| | - E.S. Mwale
- Makerere University, Department of Agricultural Production, P.O. Box 7062, Kampala, Uganda
| | - P. Gibson
- Makerere University, Department of Agricultural Production, P.O. Box 7062, Kampala, Uganda
| | - E. Achola
- Makerere University, Department of Agricultural Production, P.O. Box 7062, Kampala, Uganda
| | - R. Edema
- Makerere University, Department of Agricultural Production, P.O. Box 7062, Kampala, Uganda
| | - Y. Baguma
- National Crops Resources Research Institute, Root Crops Program, P.O. Box 7084, Kampala, Uganda
| | - R. Kawuki
- National Crops Resources Research Institute, Root Crops Program, P.O. Box 7084, Kampala, Uganda
| |
Collapse
|
4
|
Kawuki RS, Kaweesi T, Esuma W, Pariyo A, Kayondo IS, Ozimati A, Kyaligonza V, Abaca A, Orone J, Tumuhimbise R, Nuwamanya E, Abidrabo P, Amuge T, Ogwok E, Okao G, Wagaba H, Adiga G, Alicai T, Omongo C, Bua A, Ferguson M, Kanju E, Baguma Y. Eleven years of breeding efforts to combat cassava brown streak disease. Breed Sci 2016; 66:560-571. [PMID: 27795681 PMCID: PMC5010303 DOI: 10.1270/jsbbs.16005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/07/2016] [Indexed: 05/05/2023]
Abstract
Cassava (Manihot esculenta Crantz) production is currently under threat from cassava brown streak disease (CBSD), a disease that is among the seven most serious obstacles to world's food security. Three issues are of significance for CBSD. Firstly, the virus associated with CBSD, has co-evolved with cassava outside its center of origin for at least 90 years. Secondly, that for the last 74 years, CBSD was only limited to the low lands. Thirdly, that most research has largely focused on CBSD epidemiology and virus diversity. Accordingly, this paper focuses on CBSD genetics and/or breeding and hence, presents empirical data generated in the past 11 years of cassava breeding in Uganda. Specifically, this paper provides: 1) empirical data on CBSD resistance screening efforts to identify sources of resistance and/or tolerance; 2) an update on CBSD resistance population development comprising of full-sibs, half-sibs and S1 families and their respective field performances; and 3) insights into chromosomal regions and genes involved in CBSD resistance based on genome wide association analysis. It is expected that this information will provide a foundation for harmonizing on-going CBSD breeding efforts and consequently, inform the future breeding interventions aimed at combating CBSD.
Collapse
Affiliation(s)
- Robert Sezi Kawuki
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Tadeo Kaweesi
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Williams Esuma
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Anthony Pariyo
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Ismail Siraj Kayondo
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Alfred Ozimati
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Vincent Kyaligonza
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Alex Abaca
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Joseph Orone
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Robooni Tumuhimbise
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Ephraim Nuwamanya
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Philip Abidrabo
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Teddy Amuge
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Emmanuel Ogwok
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Geoffrey Okao
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Henry Wagaba
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Gerald Adiga
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Titus Alicai
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Christopher Omongo
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Anton Bua
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| | - Morag Ferguson
- International Institute of Tropical Agriculture (IITA), C/o International Livestock Research Institute (ILRI),
P.O. Box 30709, Nairobi 00100,
Kenya
| | - Edward Kanju
- International Institute of Tropical Agriculture (IITA),
P.O. Box 34441, Dar es Salaam,
Tanzania
| | - Yona Baguma
- National Crops Resources Research Institute,
9 km Gayaza-Zirobwe Road, P.O. Box 7084, Kampala,
Uganda
| |
Collapse
|
5
|
Kaweesi T, Kawuki R, Kyaligonza V, Baguma Y, Tusiime G, Ferguson ME. Field evaluation of selected cassava genotypes for cassava brown streak disease based on symptom expression and virus load. Virol J 2014. [PMID: 25526680 DOI: 10.1186/s1j%202985-014-0216-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
BACKGROUND Production of cassava (Manihot esculenta Crantz), a food security crop in sub-Saharan Africa, is threatened by the spread of cassava brown streak disease (CBSD) which manifests in part as a corky necrosis in the storage root. It is caused by either of two virus species, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), resulting in up to 100% yield loss in susceptible varieties. METHODS This study characterized the response of 11 cassava varieties according to CBSD symptom expression and relative CBSV and UCBSV load in a field trial in Uganda. Relative viral load was measured using quantitative RT-PCR using COX as an internal housekeeping gene. RESULTS A complex situation was revealed with indications of different resistance mechanisms that restrict virus accumulation and symptom expression. Four response categories were defined. Symptom expression was not always positively correlated with virus load. Substantially different levels of the virus species were found in many genotypes suggesting either resistance to one virus species or the other, or some form of interaction, antagonism or competition between virus species. CONCLUSIONS A substantial amount of research still needs to be undertaken to fully understand the mechanism and genetic bases of resistance. This information will be useful in informing breeding strategies and restricting virus spread.
Collapse
Affiliation(s)
- Tadeo Kaweesi
- National Crops Resources Research Institute, Root Crop Program, Namulonge, Uganda.
| | - Robert Kawuki
- National Crops Resources Research Institute, Root Crop Program, Namulonge, Uganda.
| | - Vincent Kyaligonza
- National Crops Resources Research Institute, Root Crop Program, Namulonge, Uganda.
| | - Yona Baguma
- National Crops Resources Research Institute, Root Crop Program, Namulonge, Uganda.
| | - Geoffrey Tusiime
- Makerere University, College of Agricultural and Environmental Sciences, Kampala, Uganda.
| | - Morag E Ferguson
- International Institute of Tropical Agriculture (IITA), c/o ILRI, P.O Box 30709, Nairobi, 00100, Kenya.
| |
Collapse
|
6
|
Kaweesi T, Kawuki R, Kyaligonza V, Baguma Y, Tusiime G, Ferguson ME. Field evaluation of selected cassava genotypes for cassava brown streak disease based on symptom expression and virus load. Virol J 2014; 11:216. [PMID: 25526680 PMCID: PMC4304613 DOI: 10.1186/s12985-014-0216-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 11/25/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Production of cassava (Manihot esculenta Crantz), a food security crop in sub-Saharan Africa, is threatened by the spread of cassava brown streak disease (CBSD) which manifests in part as a corky necrosis in the storage root. It is caused by either of two virus species, Cassava brown streak virus (CBSV) and Ugandan cassava brown streak virus (UCBSV), resulting in up to 100% yield loss in susceptible varieties. METHODS This study characterized the response of 11 cassava varieties according to CBSD symptom expression and relative CBSV and UCBSV load in a field trial in Uganda. Relative viral load was measured using quantitative RT-PCR using COX as an internal housekeeping gene. RESULTS A complex situation was revealed with indications of different resistance mechanisms that restrict virus accumulation and symptom expression. Four response categories were defined. Symptom expression was not always positively correlated with virus load. Substantially different levels of the virus species were found in many genotypes suggesting either resistance to one virus species or the other, or some form of interaction, antagonism or competition between virus species. CONCLUSIONS A substantial amount of research still needs to be undertaken to fully understand the mechanism and genetic bases of resistance. This information will be useful in informing breeding strategies and restricting virus spread.
Collapse
Affiliation(s)
- Tadeo Kaweesi
- National Crops Resources Research Institute, Root Crop Program, Namulonge, Uganda.
| | - Robert Kawuki
- National Crops Resources Research Institute, Root Crop Program, Namulonge, Uganda.
| | - Vincent Kyaligonza
- National Crops Resources Research Institute, Root Crop Program, Namulonge, Uganda.
| | - Yona Baguma
- National Crops Resources Research Institute, Root Crop Program, Namulonge, Uganda.
| | - Geoffrey Tusiime
- Makerere University, College of Agricultural and Environmental Sciences, Kampala, Uganda.
| | - Morag E Ferguson
- International Institute of Tropical Agriculture (IITA), c/o ILRI, P.O Box 30709, Nairobi, 00100, Kenya.
| |
Collapse
|