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Author: Natasha Nagarajan

Breaking Ground: Sudha Nair helps bridge gap between maize breeding and genetics

Sudha Nair is inspired every day by her passion for biology and genetics. The senior scientist at the International Maize and Wheat Improvement Center (CIMMYT) based in Hyderabad, India, works to define and practice the best strategies for applying genomics in agriculture.

“I always knew that science is what I would love to pursue,” said Sudha, an alumnus of both the Indian Agricultural Research Institute (IARI) in New Delhi and the National Institute of Agrobiological Sciences in Japan.

Originally from Kerala, India, Sudha did not expect a career in agriculture. “I studied for engineering after my high school as I was selected for that course before I was selected for the biology stream. It didn’t take me even a single moment to decide to leave the course six months later when I was selected for the undergraduate program in agriculture,” Sudha said. “I can’t say that it is love for agriculture that forced me to choose the field I am in, but it is the fascination for biological science. I love genetics and I love research; as long as I get to do this as part of my job, I am happy.”

Sudha’s first experience working with CIMMYT involved her PhD dissertation at IARI, which was a part of research conducted for the Asian Maize Biotechnology Network (AMBIONET), led by CIMMYT. “I had always looked at CIMMYT as an organization doing high quality applied science,” she said.

Starting in 2010 as a consultant for the Drought Tolerant Maize for Africa (DTMA) project, Sudha then interviewed for the position of maize fine-mapping specialist in 2011 and was selected as a scientist.  Her career at CIMMYT has now spanned close to a decade.

Her role involves implementation of molecular breeding in the maize breeding program in Asia. This includes discovery, validation and application of molecular markers for prioritized traits, genomic selection, and marker-based quality assurance and quality control in maize breeding – through current and past projects like Heat Tolerant Maize for Asia (HTMA), Climate Resilient Maize for Asia (CRMA) and the CGIAR Research Program on Maize (MAIZE).  Apart from this, she is currently involved in the Accelerating Genetic Gains in Maize and Wheat (AGG) project for incorporating elite and stress tolerance genetics from Asia in the elite African maize germplasm.

Sudha has been a part of a number of global maize projects including the Stress Tolerant Maize for Africa (STMA) project, which developed improved maize varieties tolerant to stresses such as drought and diseases, and HarvestPlus in maize, developing nutritionally enriched maize cultivars. She has also played a key role in developing CIMMYT’s second-generation tropicalized haploid inducers using marker-assisted breeding.

Sudha Nair speaking at a Heat Tolerant Maize for Asia (HTMA) annual review and planning meeting. (Photo: Sudha Nair/CIMMYT)
Sudha Nair speaking at a Heat Tolerant Maize for Asia (HTMA) annual review and planning meeting. (Photo: Sudha Nair/CIMMYT)

Bringing genetics and breeding together

Sudha is grateful for the role of CIMMYT in increasing acceptance and use of genomics in breeding programs. “When I started off as a graduate student, any work related to molecular genetics was called biotechnology, and we were considered as a different “breed”, who worked in silos to spend resources on “upstream research”, and whose results never saw any breeding applications. Breeding and molecular genetics were like parallel lines that would never meet,” she explained.

“In course of time, the research communities in applied breeding institutes like CIMMYT have brought about changes in strategies, goals, and more importantly, attitudes, and now all of us work towards one major goal of developing impactful products (varieties) for benefiting resource-constrained farming communities worldwide. All in all, I and my colleagues in the upstream research team in CIMMYT Global Maize Program have an important responsibility of providing core support to the breeding and seed systems teams in developing and delivering impactful products.”

When asked what the most enjoyable part of her work is, Sudha cited the practicality and applicability of her work. “Basically, my job responsibility is to design and implement the best strategies for applying genomics in maize breeding to achieve higher genetic gains,” she explained. “Being in an organization like CIMMYT, what is most satisfying about the role I am in is the translation of upstream research into tools for improving breeding efficiency and in turn into impactful maize varieties that the farming communities around the world cultivate.”

New greenhouse honors scientist, aims to further maize wild relatives research

On February 27, 2020, the International Maize and Wheat Improvement Center (CIMMYT) opened a new greenhouse at its research station in Tlaltizapán, in Mexico’s state of Morelos. The Garrison Wilkes Center for Maize Wild Relatives is named after a pioneering scientist in the field of maize genetics.

“The name teosinte refers to a group of wild relatives of maize,” said Denise Costich, manager of the maize germplasm collection at CIMMYT. “The seven members of this group — all in the genus Zea — are more grass-like than maize, produce hard-shelled seeds that are virtually inedible, and are capable of enduring biotic and abiotic stressors better than their crop relative.” Teosintes must be protected, Costich explained, as they possess some desirable qualities that could help improve maize resilience in difficult conditions. Since CIMMYT’s Germplasm Bank is the global source for teosinte seed, the new greenhouse, designed exclusively for the regeneration of teosinte accessions from the bank collection, will ensure that there will always be seed available for research and breeding.

Garrison Wilkes was one of the first scientists to emphasize the importance of the teosintes and their close biological relationship to maize. He spent more than 50 years working on maize conservation in collaboration with CIMMYT.  Together with scientists such as Angel Kato, a former CIMMYT research assistant and longtime professor, Suketoshi Taba, former head of CIMMYT’s Germplasm Bank, and Jesus Sanchez, as researchers at the University of Guadalajara, he contributed to the development of the global maize collection of CIMMYT’s Germplasm Bank as it exists today.

(From left to right) Garrison Wilkes, Angel Kato and Jesus Sanchez, study a teosinte population in Los Reyes, near Texcoco, Mexico, in 1992. (Photo: Mike Listman/CIMMYT)
(From left to right) Garrison Wilkes, Angel Kato and Jesus Sanchez, study a teosinte population in Los Reyes, near Texcoco, Mexico, in 1992. (Photo: Mike Listman/CIMMYT)

Keeping seeds alive

Teosintes are the wild plants from which maize was domesticated about 7,000 years ago. They are durable, with natural resistance to disease and unfavorable weather, and grow primarily in Mexico, Guatemala, Honduras and Nicaragua. “What makes [teosinte] a wild plant is its seed dispersal. Corn doesn’t disperse its seed — it’s stuck on the cob. To be a wild plant means they can sow their own seed and survive,” explained Wilkes. Keeping these seeds alive could be the key to developing resilient modern maize with the potential to feed millions.

One of the difficulties in growing maize and teosinte in Tlaltizapán to produce seed for global distribution is that the station is surrounded by sugarcane fields. Sugarcane carries a disease called the Sugarcane Mosaic Virus (SCMV), to which maize and teosinte are susceptible, and SCMV-positive seed cannot be distributed outside of Mexico. Additionally, if teosinte and maize are grown in close proximity to one another, it becomes very difficult to control gene flow between them via airborne pollen. Several experiments, ranging from growing the teosinte in pots to monitoring that the maize and teosinte flower at different times, could not fully guarantee that there was no cross-contamination. Therefore, in order to continue to cultivate maize and teosinte within the same station, the CIMMYT Germplasm Bank needed to create an isolated environment.

Garrison Wilkes describes characteristic features of the teosinte grown in the greenhouse. (Photo: Alfonso Cortés/CIMMYT)
Garrison Wilkes describes characteristic features of the teosinte grown in the greenhouse. (Photo: Alfonso Cortés/CIMMYT)

On average, the teosinte seed collections in the germplasm bank were nearly 19 years old, and 29% were not available for distribution due to low seed numbers. Researchers needed to find a way to produce more high-quality seed and get started as soon as possible. “My staff and I visited Jesus Sanchez, a world-renowned teosinte expert, and learned as much as we could about how to cultivate teosinte in greenhouses,” explained Costich “We realized that this could be the solution to our teosinte regeneration problem.”

Construction of the new greenhouse began in late 2017, with funding received from the 2016 Save a Seed Campaign — a crowdfunding initiative which raised more than $50,000. Donations contributed to activities such as seed storage, tours and educational sessions, seed collection, seed repatriation and regeneration of depleted seeds. With the new greenhouse, CIMMYT scientists can now breed teosinte without worrying about maize contamination, and prevent the extinction of these valuable species.

CIMMYT holds most of the world’s publically accessible collections of teosinte. “The wild relatives are a small part of our collection, but also a very important part, as they are theoretically the future of genetic diversity,” said Costich.“They have been important in the evolution of the crop. If we lose them, we can’t learn anything more from them, which would be a shame.”

Garrison Wilkes (left) poses with maize producer Ventura Garcia and her family. (Photo: Alfonso Cortés/CIMMYT)
Garrison Wilkes (left) poses with maize producer Ventura Garcia and her family. (Photo: Alfonso Cortés/CIMMYT)

US Under Secretary of Agriculture ready for further cooperation with CIMMYT

The US delegation stands for a group photo next to the sculpture of Norman Borlaug at the global headquarters of CIMMYT. (Photo: Eleusis Llanderal/CIMMYT)
The US delegation stands for a group photo next to the sculpture of Norman Borlaug at the global headquarters of CIMMYT. (Photo: Eleusis Llanderal/CIMMYT)

The existence of the International Maize and Wheat Improvement Center (CIMMYT) marks one of the longest and strongest bilateral relationships between Mexico and the United States of America. Beginning with a pilot program sponsored by the Mexican government and the Rockefeller Foundation in the 1940s, it would officially become CIMMYT in 1966, with many examples of strong collaboration between both countries throughout over 50 years of history.

United States Under Secretary of Agriculture for Trade and Foreign Agricultural Affairs Ted McKinney and dozens of other U.S representatives were officially introduced to this legacy when they visited CIMMYT on November 8, 2019.

The director of the Genetic Resources program, Kevin Pixley (left), gives a tour of the recently remodelled Germplasm Bank museum to US Under Secretary McKinney (second from left). (Photo: Eleusis Llanderal/CIMMYT)
The director of the Genetic Resources program, Kevin Pixley (left), gives a tour of the recently remodelled Germplasm Bank museum to US Under Secretary McKinney (second from left). (Photo: Eleusis Llanderal/CIMMYT)

“This is a place I’ve wanted to visit for a very long time,” McKinney stated as he first laid eyes on the CIMMYT offices, “the historical CIMMYT.”

After photos and a quick tour of the museum, McKinney talked to CIMMYT Director General Martin Kropff over Skype. They bonded over their respect for Norman Borlaug and his legacy, especially as McKinney had known him and later his granddaughter Julie personally while the two men worked at Dow Agrosciences.

Kropff gave a presentation on CIMMYT’s impact on agriculture in the United States. McKinney was amazed at how much of CIMMYT’s wheat research benefits farmers in the United States, and expressed enthusiasm for further cooperation. “We’re ready, willing and able to help in any way,” he stated.

The director of the Integrated Development program and regional representative for the Americas, Bram Govaerts, presented on CIMMYT’s work with the United States. Mark Rhoda-Reis, Bureau Director of the Wisconsin Department of Agriculture, was pleased to learn that CIMMYT has been working with the University of Wisconsin-Madison on drought-tolerant maize.

The US Under Secretary of Agriculture for Trade and Foreign Agricultural Affairs, Ted McKinney (center), speaks during one of the sessions at CIMMYT. (Photo: Eleusis Llanderal/CIMMYT)

The group then split off into two groups for tours of the wheat fields and the CIMMYT germplasm bank.  The delegation participated in a series of roundtable discussions on various topics such as climate change, sustainable agri-food systems, and the delegates’ objectives and needs related to agriculture in their respective states. A frequent topic was the dilemma of a public with a growing fear of technology, though technology is indispensable in the growth of the science of agriculture. “Research and education is the future of agriculture,” said one of the representatives.

The director of the Genetic Resources program, Kevin Pixley (center), shows some of the genetic materials at CIMMYT's Germplasm Bank to US Under Secretary McKinney (top-left). (Photo: Eleusis Llanderal/CIMMYT)
The director of the Genetic Resources program, Kevin Pixley (center), shows some of the genetic materials at CIMMYT’s Germplasm Bank to US Under Secretary McKinney (top-left). (Photo: Eleusis Llanderal/CIMMYT)

At the closing of their visit, the delegation was eager to spread their newfound knowledge about CIMMYT’s work and legacy. “I’m just so impressed with the work done here… the representation of all the countries in this facility is outstanding!,” said Chris Chin, Director of the Missouri Department of Agriculture.

“I was blown away. [CIMMYT] is so valuable to every country in the world,” stated Ignacio Marquez, a representative from the Washington State Department of Agriculture.

New publications: Understanding changes in farming systems to propose adapted solutions

A farmers group stands for a photograph at a demonstration plot of drought-tolerant (DT) maize in the village of Lobu Koromo, in Ethiopia’s Hawassa Zuria district. (Photo: P. Lowe/CIMMYT)
A farmers group stands for a photograph at a demonstration plot of drought-tolerant (DT) maize in the village of Lobu Koromo, in Ethiopia’s Hawassa Zuria district. (Photo: P. Lowe/CIMMYT)

Farming systems are moving targets. Agricultural Research and Development (R&D) must understand where they come from and where they are going to offer solutions that are adapted. This is one of the main objectives of the Trajectories and Trade-offs for Intensification of Cereal-based systems (ATTIC), project funded by the CGIAR Research Program on Maize (MAIZE) and implemented by the International Maize and Wheat Improvement Center (CIMMYT) and the Farming System Ecology group at Wageningen University & Research.

A recent study led by Yodit Kebede — who obtained her PhD last year under the ATTIC project — examined the drivers of change affecting smallholder farming in southern Ethiopia, farmer’s responses to these changes, and consequences for agricultural landscapes.

As in many parts of the developing world, small farms in southern Ethiopia have become smaller. Population increase and urban expansion have been major drivers of this change. Population has been increasing over 3% annually in Ethiopia, the second most populated country in Africa. Grazing areas and forests were converted to cropland, putting stress on the availability of livestock feed and fuelwood.

Farmers responded to these changes through three broad trajectories: diversification — mixed cropping and intercropping, particularly for the smallest farms —, specialization — often in high-value but non-food crops — and consolidation — maintenance or increase of farm area. Each of these trajectories has its own specific R&D needs, although farms following a consolidation trajectory are often favored by R&D programs. The same three trajectories can be identified in many rural areas where rural transformation has not taken place yet, in Africa and elsewhere in the developing world.

The loss of grassland and forest produced a landscape more susceptible to erosion and loss of soil fertility. However, all outcomes from these landscape changes may not be negative. Another study conducted by the same authors in the same study area demonstrated that an increasingly fragmented agricultural landscape may lead to increased pest control by natural enemies.

While aiming to mitigate against negative outcomes from landscape changes — for example, land degradation — policies should be careful not to inadvertently reduce some of the positive outcomes of these changes, such as increased pest control. As concluded by the study, “a better understanding of interlinkages and tradeoffs among ecosystem services and the spatial scales at which the services are generated, used, and interact is needed in order to successfully inform future land use policies”.

Read the full study:
Drivers, farmers’ responses and landscape consequences of smallholder farming systems changes in southern Ethiopia

See more recent publications by CIMMYT researchers:

  1. Estimation of hydrochemical unsaturated soil parameters using a multivariational objective analysis. 2019. Lemoubou, E.L., Kamdem, H.T.T., Bogning, J.R., Tonnang, H. In: Transport in Porous Media v. 127, no. 3, p. 605-630.
  2. Analyses of African common bean (Phaseolus vulgaris L.) germplasm using a SNP fingerprinting platform : diversity, quality control and molecular breeding. 2019. Raatz, B., Mukankusi, C., Lobaton, J.D., Male, A., Chisale, V., Amsalu, B., Fourie, D., Mukamuhirwa, F., Muimui, K., Mutari, B., Nchimbi-Msolla, S., Nkalubo, S., Tumsa, K., Chirwa, R., Maredia, M.K., He, Chunlin In: Genetic Resources and Crop Evolution v.66, no. 3, p. 707-722.
  3. Deep blade loosening increases root growth, organic carbon, aeration, drainage, lateral infiltration and productivity. 2019. Hamilton, G.J., Bakker, D., Akbar, G., Hassan, I., Hussain, Z., McHugh, A., Raine, S.R. In: Geoderma v. 345, p. 72-92.
  4. Maize crop nutrient input requirements for food security in sub-Saharan Africa. 2019. Berge, H.F.M. ten., Hijbeek, R., Loon, M.P. van., Rurinda, J., Fantaye, K. T., Shamie Zingore, Craufurd, P., Heerwaarden, J., Brentrup, F., Schröder, J.J., Boogaard, H., Groot, H.L.E. de., Ittersum, M.K. van. In: Global Food Security v. 23 p. 9-21.
  5. Primary hexaploid synthetics : novel sources of wheat disease resistance. 2019. Shamanin, V., Shepelev, S.S., Pozherukova, V.E., Gultyaeva, E.I., Kolomiets, T., Pakholkova, E.V., Morgounov, A.I. In: Crop Protection v. 121, p. 7-10.
  6. Understanding the factors influencing fall armyworm (Spodoptera frugiperda J.E. Smith) damage in African smallholder maize fields and quantifying its impact on yield. A case study in Eastern Zimbabwe. 2019. Baudron, F., Zaman-Allah, M., Chaipa, I., Chari, N., Chinwada, P. In: Crop Protection v. 120 p. 141-150.
  7. Predicting dark respiration rates of wheat leaves from hyperspectral reflectance. 2019. Coast, O., Shahen Shah, Ivakov, A., Oorbessy Gaju, Wilson, P.B., Posch, B.C., Bryant, C.J., Negrini, A.C.A., Evans, J.R., Condon, A.G., Silva‐Pérez, V., Reynolds, M.P. Pogson, B.J., Millar A.H., Furbank, R.T., Atkin, O.K. In: Plant, Cell and Environment v. 42, no. 7, p. 2133-2150.
  8. Morphological and physiological responses of Guazuma ulmifolia Lam. to different pruning dates. 2019. Ortega-Vargas, E., Burgueño, J., Avila-Resendiz, C., Campbell, W.B., Jarillo-Rodriguez, J., Lopez-Ortiz, S. In: Agroforestry Systems v. 93 no. 2 p. 461-470.
  9. Stripe rust resistance in wild wheat Aegilops tauschii Coss.: genetic structure and inheritance in synthetic allohexaploid Triticum wheat lines. 2019. Kishii, M., Huerta-Espino, J., Hisashi Tsujimoto, Yoshihiro Matsuoka. In: Genetic Resources and Crop Evolution v. 66, no. 4, p.  909-920.
  10. Comparative assessment of food-fodder traits in a wide range of wheat germplasm for diverse biophysical target domains in South Asia. 2019. Blummel, M., Updahyay, S.R., Gautam, N.R., Barma, N.C.D., Abdul Hakim, M., Hussain, M., Muhammad Yaqub Mujahid, Chatrath, R., Sohu, V.S., Gurvinder Singh Mavi, Vinod Kumar Mishra, Kalappanavar, I.K., Vaishali Rudra Naik, Suma S. Biradar., Prasad, S.V.S., Singh, R.P., Joshi, A.K. In: Field Crops Research v. 236, p. 68-74.
  11. Comment on ‘De Roo et. al. (2019). On-farm trials for development impact? The organization of research and the scaling of agricultural technologies. 2019. Wall, P.C., Thierfelder, C., Nyagumbo, I., Rusinamhodzi, L., Mupangwa, W. In: Experimental Agriculture v. 55 no. 2 p. 185-194.
  12. High-throughput phenotyping enabled genetic dissection of crop lodging in wheat. 2019. Singh, D., Xu Wang, Kumar, U., Liangliang Gao, Muhammad Noor, Imtiaz, M., Singh, R.P., Poland, J.A. In: Frontiers in Plant Science v. 10 art. 394.
  13. Differential response from nitrogen sources with and without residue management under conservation agriculture on crop yields, water-use and economics in maize-based rotations. 2019. Jat, S.L., Parihar, C.M., Singh, A.K., Hari S. Nayak, Meena, B.R., Kumar, B., Parihar M.D., Jat, M.L. In: Field Crops Research v. 236, p. 96-110.
  14. Drip irrigation and nitrogen management for improving crop yields, nitrogen use efficiency and water productivity of maize-wheat system on permanent beds in north-west India. 2019. Sandhu, O.S., Gupta, R.K., Thind, H.S., Jat, M.L., Sidhu, H.S., Singh, Y. In: Agricultural Water Management v. 219 p. 19-26.
  15. Impact of tillage and crop establishment methods on crop yields, profitability and soil physical properties in rice–wheat system of Indo‐gangetic plains of India. Kumar, V., Gathala, M.K., Saharawat, Y.S., Parihar, C.M., Rajeev Kumar, Kumar, R., Jat, M.L., Jat, A.S., Mahala, D.M., Kumar, L., Hari S. Nayak, Parihar M.D., Vikas Rai, Jewlia, H.R., Bhola R. Kuri In: Soil Use and Management v. 35, no. 2, p. 303-313.
  16. Increasing profitability, yields and yield stability through sustainable crop establishment practices in the rice-wheat systems of Nepal. 2019. Devkota, M., Devkota, K.P., Acharya, S., McDonald, A. In: Agricultural Systems v. 173, p. 414-423.
  17. Identification of donors for low-nitrogen stress with maize lethal necrosis (MLN) tolerance for maize breeding in sub-Saharan Africa. 2019. Das, B., Atlin, G.N., Olsen, M., Burgueño, J., Amsal Tesfaye Tarekegne, Babu, R., Ndou, E., Mashingaidze, K., Lieketso Moremoholo |Ligeyo, D., Matemba-Mutasa, R., Zaman-Allah, M., San Vicente, F.M., Prasanna, B.M., Cairns, J.E. In: Euphytica v. 215, no. 4, art. 80.
  18. On-farm trials as ‘infection points’? A response to Wall et al. 2019. Andersson, J.A., Krupnik, T.J., De Roo, N. In: Experimental Agriculture v. 55, no. 2 p. 195-199.
  19. Doing development-oriented agronomy: Rethinking methods, concepts and direction. 2019. Andersson, J.A., Giller, K.Ehttps://repository.cimmyt.org/handle/10883/20154. In: Experimental Agriculture v. 55, no. 2, p. 157-162.
  20. Scale-appropriate mechanization impacts on productivity among smallholders : Evidence from rice systems in the mid-hills of Nepal. 2019. Paudel, G.P., Dilli Bahadur KC, Rahut, D.B., Justice, S., McDonald, A. In: Land Use Policy v. 85, p. 104-113.

Vietnam strengthens ties with CIMMYT

Visitors from the Embassy of Vietnam in Mexico and members of CIMMYT senior management stand for a group photograph next to the Norman Borlaug statue at CIMMYT's global headquarters. (Photo: Jose Luis Olin Martinez for CIMMYT)
Visitors from the Embassy of Vietnam in Mexico and members of CIMMYT senior management stand for a group photograph next to the Norman Borlaug statue at CIMMYT’s global headquarters. (Photo: Jose Luis Olin Martinez for CIMMYT)

Vietnamese officials expressed interest in increased future cooperation with the International Maize and Wheat Improvement Center (CIMMYT). A delegation from the Embassy of Vietnam in Mexico visited CIMMYT’s global headquarters in Texcoco, Mexico, on October 21, 2019. The delegation was composed of Hien Do Tat, First Secretary of Technology Science, and translator Cuc Doan Thi Thu.

CIMMYT sends germplasm to Vietnam and has previously collaborated with the country through several projects. More than twenty Vietnamese scientists have received training from CIMMYT.

The Vietnamese delegation was particularly interested in CIMMYT’s work with drought-tolerant maize and requested expert help with fall armyworm, which has appeared in Vietnam for the first time earlier this year. They also expressed surprise at the range of CIMMYT activities, as they were under the impression that the organization’s sole purpose was plant breeding.

CIMMYT Director General Martin Kropff reinforced interest in further cooperation with Vietnam, emphasizing the importance of appropriate mechanization and sustainable intensification in agricultural development.

Vietnam produced 5.1 million tons of maize a year, grown on more than one million hectares, according to the latest available figures.