Professor Maruthi Gowda is a molecular plant virologist and vector entomologist with over 20 years of research experience in plant-virus-insect interactions, especially those involving geminiviruses, potyviruses and their whitefly vector, Bemisia tabaci, infecting cassava, vegetables and other staple food crops in the tropics.

He began his research career in India in 1996 as a MSc student at the University of Agricultural Sciences, Bengaluru, where he identified sources of resistance to the economically important tomato leaf curl disease. He then moved to the Natural Resources Institute at the University of Greenwich in 1998 to undertake PhD on cassava mosaic disease, which has caused devastating losses, famine and food shortages to millions of farmers in Africa. Following completion of his PhD in 2001, Professor Gowda joined the university as a post-doctoral fellow. He was promoted to a research fellow and subsequently senior research fellow and Reader.

Currently, as a Professor in Molecular Plant Pathology, Gowda leads a core team of researchers on two lines of research; investigating the reasons for the recent outbreak of cassava brown streak disease (CBSD) in the eastern and southern African region, and the introduction of tomato leaf curl New Delhi virus to Europe. He employs holistic, multi-disciplinary research from field epidemiology to molecular biology and tissue culture to next generation sequencing and functional genomics, to better understand plant-virus-vector relationships and mechanisms of disease resistance for developing improved disease control strategies. He was the first to identify the whitefly B. tabaci as the natural vector of cassava brown streak ipomoviruses (CBSIs). He has also developed robust low-cost diagnostic tests for CBSIs and cassava mosaic viruses, which are adapted in several African laboratories. Currently he is understanding the molecular mechanisms of host jump from tomato to cucurbits by the tomato leaf curl New Delhi virus, which is causing a major disease outbreak in the Mediterranean region.

He has contributed immensely for capacity development especially in African countries. He has developed brand-new molecular laboratories in Nigeria and Tanzania, and further contributed to the development of tissue culture and molecular laboratories in Malawi and Kenya for the diagnosis of cassava pests and diseases. He has conducted several training programmes in these countries and supervised 19 PhD students and two dozen MSc students over the years and teach in the NRI MSc research programmes on Sustainable Agriculture.

He has an excellent academic citizenship: developed international consortia, on several committees and regularly invited to give keynote talks. He has led the UK AAB’s Plant Virology Committee and organised two international conferences on Plant Virology, and he is the publications officer for the International Society for Tropical Root Crops. He reviews several project proposals for different donors and research articles for several journals annually. In summary, Prof Gowda has greatly contributed to the field of plant pathology, carrying out cutting edge research for developing strategies for the sustainable control of plant pests and diseases.

1. Wang H-L, Lei T, Liu S-S, Colvin J, Wang X-W, Cameron S, De Barro P, Navas-Castillo J, Liu Y-Q, Maruthi MN, Wang Y-J, Peng J-G, Omongo CA, Delatte H, Lee K-Y, Xia W-Q, Li Q, Krause-Sakate R, Ng J, Seal S, Fiallo-Olivé E, 2024, Insights into decrypting a global, pest-species group using an integrated approach. Insect Science (In press). DOI 10.1111/1744-7917.13361.
2. El Hamss H, Maruthi MN, Omongo C, Wang H, van Brunschot S, Colvin J, Delatte H, 2024. Microbiome diversity and composition in Bemisia tabaci SSA1-SG1 whitefly are influenced by their host’s life stage. Microbiological Research 278, 127538. https://doi.org/10.1016/j.micres.2023.127538.
3. Naganur P, Shankarappa KS, Mesta RK, Rao CD, Venkataravanappa V, Maruthi MN, Reddy LRCN, 2023, Detecting tomato leaf curl New Delhi virus causing ridge gourd yellow mosaic disease, and other begomoviruses by antibody-based methods. Plants 12(3):490. doi: 10.3390/plants12030490.
4. Ally HM, Hamss HE, Simiand C, Maruthi MN, Colvin J, Delatte H (2023) Genetic diversity, distribution, and structure of Bemisia tabaci whitefly species in potential invasion and hybridization regions of East Africa. PLoS ONE 18(5): e0285967. https://doi.org/10.1371/journal.pone.0285967.
5. Campbell L, Nwezeobi J, van Brunschot SL, Kaweesi T, Seal SE, Rekha AR, Namuddu A, Maslen GL, Mugerwa H, Armean IM, Haggerty L, Martin FJ, Malka O, Santos-Garcia D, Juravel K, Morin S, Stephens M, Douglas A, Muhindira PV, Kersey PJ, Maruthi MN, Omongo CA, Grimsley R, Navas-Castillo J, Fiallo-Olivé E, Mohammad I, Wang HL, Onyeka J, Alicai T, Patel MV, Colvin J, 2023, Comparative evolutionary analyses of eight whitefly Bemisia tabaci sensu lato genomes: cryptic species, agricultural pests and plant-virus vectors. BMC Genomics 24:408. https://doi.org/10.1186/s12864-023-09474-3.
6. Tugume AK, Mbanzibwa DR, Alicai T, Omongo CA, Maruthi MN, 2023, Endemism and re-emergence potential of the ipomovirus Sweet potato mild mottle virus (family Potyviridae) in Eastern Africa: half a century of mystery. Phytobiomes Journal 7:5-23. https://doi.org/10.1094/PBIOMES-05-22-0031-RVW.
7. El Hamss H, Maruthi MN, Ally H, Omongo C, Wang H, van Brunschot S, Colvin J, Delatte H, 2022. Spatio-temporal changes in endosymbiont diversity and composition in the African cassava whitefly, Bemisia tabaci SSA1. Frontiers in Microbiology, 13:986226. doi:https://doi.org/10.3389/fmicb.2022.986226.
8. El Hamss H, Ghosh S, Maruthi MN, Delatte H, Colvin J, 2021, Microbiome diversity and reproductive incompatibility induced by the prevalent endosymbiont Arsenophonus in two species of African cassava Bemisia tabaci whiteflies. Ecology and Evolution 11:18032–18041. DOI: 10.1002/ece3.8400.
9. Jayasinghe WH, Akhter MS, Nakahara K Maruthi MN, 2021, Effect of aphid biology and morphology on plant virus transmission. Pest Management Science. DOI 10.1002/ps.6629.
10. Masinde EA, Kimata B, Ogendo JO, Mulwa RM, Mkamilo G, Maruthi MN. 2021, Developing dual-resistant cassava to the two major viral diseases. Crop Science 61:1567–1581. https://doi.org/10.1002/csc2.20374
11. Kavil SP, Otti G, Bouvaine S, Armitage A, Maruthi MN, 2021, PAL1 gene of the phenylpropanoid pathway increases resistance to the Cassava brown streak virus in cassava. Virology Journal 18, 184. https://doi.org/10.1186/s12985-021-01649-2
12. Kriticos DJ, Darnell RE, Yonow T, Ota N, Sutherst RW, Parry HR, Mugerwa H, Maruthi MN, Seal SE, Colvin J, Macfadyen S, Kalyebi A, Hulthen A, De Barro PJ, 2020. Improving climate suitability for Bemisia tabaci in East Africa is correlated with increased prevalence of whiteflies and cassava diseases. Scientific Reports 16:10(1):22049. doi: 10.1038/s41598-020-79149-6.
13. Wang HL, Lei T, Wang X-W, Zhu D-T, Rao Q, Cameron S, Liu Y-Q, Zhao J-J, Shan H-W, Maruthi MN, Colvin J, Liu S-S, 2020. A newly recorded Rickettsia of the Torix group is a recent intruder and an endosymbiont in the whitefly Bemisia tabaci. Environmental Microbiology 22, 1207–1221. doi:10.1111/1462-2920.14927.
14. Wang HL, Lei T, Xia W-Q, Cameron SL, Liu Y-Q, Zhang Z, Maruthi MN, De Barro P, Navas-Castillo J, Omongo CA, Delatte H, Lee K-Y, Patel MV, Krause-Sakate R, Ng J, Wu S-L, Fiallo-Olivé E, Liu S-S, Colvin J & Wang X-W, 2019, Insight into the microbial world of Bemisia tabaci cryptic species complex and its relationships with its host. Scientific Reports 9, Article number: 6568. https://doi.org/10.1038/s41598-019-42793-8.
15. Ally HM, El Hamss H, Simiand C, Maruthi MN, Colvin J, Omongo CA, Delatte H, 2019, What has changed in the outbreaking populations of the severe crop pest whitefly species in cassava in two decades? Scientific Reports 9:14796 https://doi.org/10.1038/s41598-019-50259-0. IF3.9
16. Maruthi MN, Whitfield C, Otti G, Tumwegamire S, Kanju E, Legg JP, Mkamilo G, Kawuki R, Benesi I, Mhone A, Zacarias A, Munga T, Mwatuni F, Mbugua E, 2019, A method for generating virus-free cassava plants to combat viral disease epidemics in Africa. Physiological and Molecular Plant Pathology 105:77-87. https://doi.org/10.1016/j.pmpp.2018.09.002 6 Q2.
17. Macfadyen S, Paull C, Boykin LM, DeBarro P, Maruthi MN, Ghosh S, Otim M, Kalyebi A, Vassão DG, Sseruwagi P, Tek Tay W, Delatte H, Seguni Z, Colvin J, Omongo CA, 2018, Cassava whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), in sub-Saharan African farming landscapes: a review of the factors determining abundance. Bulletin of Entomological Research 108: 565-582. (Doi:10.1017/S0007485318000032). IF2.2 Q2.
18. Masinde EA, Mkamillo G, Ogendo JO, Hillocks R, Mulwa RMS, Kimata B, Maruthi MN, 2018, Genotype by environment interactions in identifying cassava (Manihot esculenta Crantz) resistant to cassava brown streak disease. Field Crops Research 215: 39-48. IF4.3 Q1 http://dx.doi.org/10.1016/j.fcr.2017.10.001.
19. Ghosh S, Bouvaine S, Richardson SCW, Ghanim M, Maruthi MN, 2018, Fitness costs associated with infections of secondary endosymbionts in the cassava whitefly species Bemisia tabaci. Journal of Pest Science 91:17–28.3 Q1 https://doi.org/10.1007/s10340-017-0910-8.
20. Maruthi MN, Jeremiah SC, Mohammed IU, Legg JP, 2017, The role of the whitefly, Bemisia tabaci (Gennadius), and farmer practices in the spread of cassava brown streak ipomoviruses. Journal of Phytopathology 165:707–717. DOI: 10.1111/jph.12609.
21. Maruthi MN, Bouvaine S, Tufan HA, Mohammed IU, Hillocks RJ (2014) Transcriptional response of virus-infected cassava and identification of putative sources of resistance for cassava brown streak disease. PLoS ONE 9(5): e96642. doi: 10.1371/journal.pone.0096642.
22. Sseruwagi P, Legg JP, Maruthi MN, Colvin J, Rey MEC, Brown JK. 2005. Genetic diversity of Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) populations and presence of the B biotype and a non-B biotype that can induce silverleaf symptoms in squash in Uganda. Annals of Applied Biology 147: 253-265. https://doi.org/10.1111/j.1744-7348.2005.00026.x
23. Muniyappa V, Maruthi MN, Babitha CR, Colvin J, Briddon RW, Rangaswamy KT. 2003. Characterisation of pumpkin yellow vein mosaic virus from India. Annals of Applied Biology 142: 323-331. https://doi.org/10.1111/j.1744-7348.2003.tb00257.x
24. Mohammed IU, Abarshi MM, Muli B, Hillocks RJ, Maruthi MN. 2012. The symptom and genetic diversity of cassava brown streak viruses infecting cassava in East Africa. Advances in Virology: Volume 2012, Article ID 795697, 10 pages doi:10.1155/2012/795697.
25. Legg J, Somado EA, Barker I, Beach L, Ceballos H, Cuellar W, Elkhoury W, Gerling D, Helsen J, Hershey C, Jarvis A, Kulakow Kumar PL, Lorenzen J, Lynam J, McMahon M, Maruthi M N, Miano D, Mtunda K, Natwuruhunga P, Okogbenin E, Pezo P, Terry E, Thiele E, Thresh M, Wadsworth J, Walsh S, Winter S, Tohme J, Fauquet C, 2014. A global alliance declaring war on cassava viruses in Africa. Food Security 6:231–248. DOI 10.1007/s12571-014-0340-x. 0 Q1.
26. Colvin J, Omongo CA, Maruthi MN, Otim‐Nape GW, Thresh JM. 2004. Dual begomovirus infections and high Bemisia tabaci populations: two factors driving the spread of a cassava mosaic disease pandemic. Plant Pathology 53(5), pp. 577–584. http://dx.doi.org/10.1111/j.0032-0862.2004.01062.x
27. Abarshi MM, Mohammed IU, Wasswa P, Hillocks RJ, Holt J, Legg JP, Seal SE and Maruthi MN, 2010. Optimization of diagnostic RT-PCR protocols and sampling procedures for the reliable and cost-effective detection of Cassava brown streak virus. Journal of Virological Methods 163: 353–359. http://dx.doi.org/10.1016/j.jviromet.2009.10.023
28. Patil BL, Ogwok E, Wagaba H, Mohammed IU, Yadav JS, Bagewadi B, Taylor NJ, Kreuze JF, Maruthi MN, Alicai T and Fauquet CM. 2011. RNAi-mediated resistance to diverse isolates belonging to two virus species involved in cassava brown streak disease. Molecular Plant Pathology 12: 31-41. http://dx.doi.org/10.1111/j.1364-3703.2010.00650.x
29. Mbanzibwa DR, Tian YP, Tugume AK, Patil BL, Yadav JS, Bagewadi B, Abarshi MM, Alicai T, Changadeya W, Mkumbira J, Muli MB, Mukasa SB, Tairo F, Baguma Y, Kyamanywa S, Kullaya A, Maruthi MN, Fauquet CM, Valkonen JPT, 2011. Evolution of cassava brown streak disease-associated viruses. Journal of General Virology 92:974-987. IF3.3 Q1. http://dx.doi.org/10.1099/vir.0.026922-0
30. Colvin J, Omongo CA, Govindappa MR, Stevenson PC, Maruthi MN, Gibson G, Seal SE, Muniyappa V. 2006. Host-plant viral infection effects on arthropod-vector population growth, development, and behaviour, with epidemiological and management implications. Advances in Virus Research 67: 419-452. IF2.7 http://dx.doi.org/10.1016/S0065-3527(06)67011-5

Professor Gowda is passionate about using advanced molecular technologies to mitigate the impact of pest and disease problems in the tropics, especially those of cassava in Africa and vegetable virus diseases in Europe and Asia. He is currently interested in gaining a greater understanding of cassava brown streak disease, which has been causing an epidemic in eastern Africa, negatively affecting the farmers. He is devising ways to control the disease. Similarly, he has been working leaf curl diseases of tomatoes and cucurbits in Europe and India to identify natural sources of resistance to viruses and their insect vector whiteflies using high throughput sequencing (RNA-Seq) and identify resistance genes with the aim of developing durable resistance to whiteflies and virus diseases.

Another complementary and exciting area of his research includes using endosymbiotic bacteria as bio-control agent against whitefly, the vector of viruses of major food crops such as cassava, tomato and cucurbits. Professor Gowda’s team is exploring to sue endosymbionts as a bio-control strategy to reduce number of whiteflies significantly and reduce virus transmission.

He is further interested in the use of the next generation technologies such as RNA-sequencing and functional genomics for identifying sources of resistance, gene mining and understanding the mechanism of resistance to begomoviruses, ipomoviruses and their insect vector whiteflies. Further, his interested in using RNAi approach for reducing the virus transmission abilities of whiteflies by blocking virus transmission mechanisms.

Professor Gowda’s overall aim is to use holistic approaches to find solutions for pest and disease problems.

• Teaching on two courses Plant Disease Management and Integrated Pest Management.
• Supervised 17 PhD students and over two dozen MSc students over the years.
• Training, capacity development and transfer of technologies to African countries, especially Nigeria, Malawi, Tanzania and Kenya. He has organised half a dozen training programmes on disease diagnostics in Africa and India.

VIRTIGATION: Emerging viral diseases in tomatoes and cucurbits: implementation of mitigation strategies for durable disease management, 2021-2025.

Tomato and cucurbits are affected by emerging viruses, such as begomoviruses and tobamoviruses, which reduce crop value both quantitatively and qualitatively while increase production costs due to the use of pesticides to control them. Virtigation will enable a deeper understanding of the effect of climate change on plant-virus-vector interactions, develop reliable diagnostic, and control methods including vaccines for plants and biopesticides against virus vectors, as well as integrated pest management strategies. The project will establish a pipeline for rapid mitigation of emerging crop diseases by developing advanced diagnostic tools enabling early detection of virus variants associated with hyper-virulence and/or expansion to new host species. New diagnostics methods combined with web-based meta-analysis will help prevent the entry and spread of begomovirus and tobamovirus-associated diseases in Europe and in other regions through introduction of improved quarantine measures. Natural resistances against viruses and vectors will be investigated and introgressed into preferred varieties to provide a durable mitigation strategy. We will embed research and implementation activities in a multi-actor co-creation and co-design approach with stakeholders for ensuring research activities and products meet the core needs and expectations of the value chain. This project is funded by the European Commission, led by the KU Leuven University in which Professor Gowda is leading the work package 4.

DualCassava: Dual-resistant cassava for climate resilience, economic development and increased food security of smallholders in eastern and southern Africa (DualCassava), 2018-2021.

Prof. Gowda led this African Union-funded multi-partner project, which was focused on mitigating the impact of the two viral diseases; cassava mosaic disease (CMD), cassava brown streak disease (CBSD) and drought on subsistence farmers in Tanzania and Malawi. We carried out socio-economic research, first, to understand the impact of the two diseases and drought on the poor. We then distributed drought-resistant virus-clean cassava varieties to farmers in drought-prone areas as a way of crop diversification to mitigate the impact of drought. We have identified dual-resistant cassava varieties and used state-of-the-art next generation sequencing for identifying genes that are contributing to resistance. The project was implemented successfully for controlling both CMD and CBSD and minimize the impact of drought on farmers in drought-prone areas. The project was ranked first for its impact and future potential among the 30+ projects funded by the African Union.

African cassava whitefly project phase I and II: outbreak causes and sustainable solutions project, 2014-2024

Professor Gowda was part of this mega project (two phases) lead by Prof John Colvin and Mark Parnell from NRI. Gowda contributed to three key areas of research and development; to identify natural sources of resistance to African cassava whitefly species in local and exotic cassava lines, and to investigate the role of endosymbionts on whitefly biology, virus transmission and population ecology to understand the phenomenon of whitefly super abundance in African countries. In phase II, Gowda lead research on cassava pre-breeding for the integration of whitefly resistance from South American cassava germplasm into farmer-preferred African cassava varieties.

Building Local Capacity for Surveillance Diagnosis, Characterisation and Control of Cassava Viruses in Northern Nigeria, 2014-2017

Professor Gowda was a Co-PI in this PEARL project lead by the Kebbi State University of Science and Technology in Nigeria, funded by the Bill and Melinda Gates Foundation. Main aim of the project was to build human and physical capacity through training and setting up a virus diagnostic laboratory that can now carry out surveillance, diagnosis and characterization of viruses affecting cassava in northern Nigeria. University researchers, postgraduate students, extension workers and quarantine officers were trained to identify cassava diseases in the field and also using diagnostic molecular techniques in the lab. Field surveys were conducted in the nine states of the northern Nigeria to determine the prevalence of CMD including the recently introduced severe strain East African cassava mosaic virus-Uganda (EACMV-Ug) in the region. The Nigerian cassava were resistant to CMD but highly susceptible to CBSD, which poses a serious threat to cassava production in the country. The long-term benefit of this project is to use the laboratory set up as a strategic point for disease surveillance in West Africa for cassava as well as other important food crops such as yams and legumes.

New cassava varieties and clean seed to combat CMD and CBSD project (5CP), 2012–2016.

Professor Gowda was a partner in this multi-partner project lead by the IITA and funded by the Gates Foundation. The project, implemented in five eastern African countries, identified CBSD resistance in 25 elite cassava lines in five target countries and developed a commercial seed system for cassava. Professor Gowda's developed a virus indexing programme for cleaning over 35 lines from virus infection using a combination of tissue culture, thermotherapy and chemotherapy, and virus diagnosis. Methodologies developed at NRI have wider applications beyond the scope of 5CP as they will contribute to prevent virus-susceptible cassava varieties from going extinct and the spread of virus-infected plants to new regions. The project was part of submission that was awarded the Queen’s Anniversary Prize-2016 for the University of Greenwich

LimitCBSD: Limiting the impact of cassava brown streak disease on smallholders, women and the cassava value chain. 2012–2015.

Professor Gowda lead this African Union-funded multi-partner project to mitigate the impact of CBSD in Kenya, Tanzania and Malawi. The main aim of the project was to better understand the recent disease outbreaks in east Africa and devise effective control strategies. We first carried out socio-economic research to understand the impact of the disease on farmers, on woman who are the main workforce for cassava cultivation. We then screened new cassava lines for viruses to identify resistant varieties and used next generation sequencing for identifying candidate genes.

Whitefly control using Wolbachia, 2012–2013.

This highly innovative Gates Foundation-funded project to control the agricultural pest whiteflies using endosymbiotic bacteria, Wolbachia was lead by Professor Gowda. Wolbachia infects over 75% of the earth's insect population and are shown to negatively affect the lifecycles of certain insect species and can also reduce pathogen transmission by them. Certain strains of Wolbachia are therefore used as potential bio-control agents for controlling diseases of medical importance (eg. dengue viruses) transmitted by mosquitoes. Since whiteflies are naturally infected with Wolbachia, we investigated whether a similar strategy can be employed to reduce the high whitefly populations on cassava in Africa and found that some endosymbiotic bacteria have similar effect to Wolbachia infections. This strategy has huge potential for controlling whiteflies and the viruses they transmit since it comes at no-cost to the farmers, is self-perpetuating and can be implemented together with existing control strategies. 

Responsible for winning external research grants for research and making strategic decisions as the leader of the research group Plant Diseases and Vectors.

• Hind Rattan Award-2020 for outstanding contributions in the field of science while keeping the flag of India high as a non-residential Indian. Awarded by the Non-residential Indian society in association with the Indian Diaspora abroad and the ministry of external affairs, Government of India
• Part of the team that was awarded Her Majesty the Queen’s Anniversary Prize - 2016 for outstanding contributions to Higher and Further Education for the University of Greenwich
• Grand Challenges Explorations Grant Round 8 by the Bill and Melinda Gates Foundation - 2012.
• Promising Young Researcher Award from the Higher Education Funding Council of England - 2005
• UK Department for International Development scholarship for higher education’s fully funded PhD scholarship in the UK – 1998