2023 UKZN Spring Graduation
New Breeds of Wheat Contribute to Drought Tolerance and Carbon Sequestration
Dr Kwame Shamuyarira’s graduation is the culmination of an academic journey at UKZN’s African Centre for Crop Improvement (ACCI) that began in 2017 and resulted in a study on the agro-morphological and root attributes associated with drought tolerance and carbon sequestration in wheat, an essential staple crop for feeding a growing global population.
Motivated by the challenges posed by climate change to crop production systems, Shamuyarira’s research contributed to the development of new wheat breeds with a balanced biomass allocation between roots and shoots, enhancing the crop’s drought tolerance and carbon sequestration capabilities for climate change mitigation.
‘Bread wheat productivity is crucial for food security for a growing global population,’ said Shamuyarira. ‘Wheat production, however, is affected by recurrent droughts and further exacerbated by a changing climate characterised by rising temperatures and erratic rainfall. Wheat breeders can identify agronomic and root-related traits in response to these challenges and develop resilient and productive cultivars.’
With growing interest in using field crops to store some atmospheric carbon lost from soils owing to poor agricultural practices, research suggests that increasing biomass allocation of new wheat genotypes to the root system may enhance carbon extraction from the atmosphere and sequester it within crop tissues and soils. This will also increase resilience to drought stress by improving water and nutrient retention and uptake by a deeper root system.
Shamuyarira assessed the variability in yield performance and biomass allocation between the shoots and roots of wheat genotypes under drought conditions. His study established wide variability among wheat lines regarding yield performance and root biomass. Excellent lines were selected and used as parents to develop new breeding populations, which show promise for further advancement to develop new cultivars with improved drought tolerance and carbon sequestration potential.
Originally from Zimbabwe, Shamuyarira completed his Bachelor of Science in Crop Science and Horticulture at the University of Fort Hare in South Africa before returning to Zimbabwe to teach at high school level for four years. Keen to achieve a master’s degree, he visited UKZN in 2017 and went door-to-door to find a supervisor.
ACCI Director Professor Hussein Shimelis offered Shamuyarira the opportunity to enrol under his supervision, co-supervised by Professor Toi Tsilo from the Agricultural Research Council’s Small Grains Institute and he focused on drought tolerance breeding in wheat supported by research funding from his supervisors.
He graduated in 2019 cum laude and continued to PhD studies supervised by Shimelis, Dr Sandiswa Figlan of the University of South Africa, and Dr Vincent Chaplot of UKZN and the Institute of Research for Development in France. His research contributed to a Water Research Commission of South Africa (WRC) project that supported his studies.
Shamuyarira credited his supervisors for their clear, effective, honest communication, constructive feedback, clear explanations of complex concepts, approachability and responsiveness. He thanked Shimelis for his patience, generosity, academic guidance and support; Chaplot for his mentorship, constructive criticism, suggestions, and motivation; and Figlan for her confidence in his abilities. He also thanked Drs Rebecca Zengeni, Isack Mathew and Admire Shayanowako for their assistance and constant encouragement during his studies, as well as other colleagues and lecturers who provided support and guidance.
Shamuyarira expressed gratitude to his parents for their sacrifices to provide him with the best education and to family members including his brother Mr Panashe Shamuyarira for their support. He thanked his wife Ms Annahmary Shamuyarira for her constant support and the strength she provided during the lengthy study and acknowledged the WRC and National Research Foundation for financial support.
Shamuyarira is now a lecturer at the University of the Free State and plans to pursue a career in research, focusing on abiotic stress tolerance in plants and enhancing nutritional quality in field crops. He hopes to contribute to cutting-edge developments and new technologies that will address plant genetics, hidden hunger and sustainable agriculture challenges.
Words: Christine Cuenod
Photograph: Sethu and supplied
Plant Breeder Overcomes Adversity to Develop Resilient Sorghum
Graduation marks an important milestone for Dr Muhammad Ahmad Yahaya, a plant breeder, geneticist and lecturer at Ahmadu Bello University (ABU) in Nigeria who navigated geographical and cultural differences to pursue his PhD through the African Centre for Crop Improvement (ACCI) at UKZN.
Inspired by the need he witnessed for crops bred by African plant breeders who understand the requirements of growers in very specific contexts and motivated to take on work that would be characterised by academic excellence and eventually contribute to food security, Yahaya looked beyond his borders to add to the experience he attained during his master’s studies at ABU.
He set his sights on the ACCI, known for its mission to train African breeders on African crops, in Africa. Yahaya sought out ACCI Director Professor Hussein Shimelis to supervise his studies thanks to Shimelis’ reputation for being committed to nurturing local talent.
Accompanied by his wife, Yahaya left Nigeria for Pietermaritzburg to undertake his research with the ACCI, finding that it lived up to its promise of being the “City of Choice” through the welcome he received from its residents and the tranquil environment at UKZN that was conducive to his academic pursuits.
Yahaya received funding from the International Crops Research Institute for the Semi-Arid Tropics’ (ICRISAT) Harnessing Opportunities for Productivity Enhancement for Sorghum and Millets (HOPE) II project, supported by the Bill & Melinda Gates Foundation.
The early days of his research were spent acclimatising to his new environment and refining his research proposal. His first year at the ACCI involved completing a mini-project, and Yahaya enjoyed the state-of-the-art facilities provided by the ACCI and UKZN’s Microscopy and Microanalysis Unit (MMU) to complete this work.
Yahaya’s PhD research, conducted on-site in Nigeria, was centred on sorghum, an essential cereal crop native to the arid landscapes of the northern part of the country. A participatory rural appraisal study revealed the struggles sorghum farmers experienced with drought, so Yahaya set out to improve sorghum productivity by developing new generation, locally adapted, drought-tolerant varieties. A rigorous examination of genetic materials from national and international research institutes laid the groundwork to identify potential parent candidates for improving sorghum resilience.
Yahaya’s research took a collaborative approach as he engaged with scientists across disciplines to enrich his study.
The ACCI’s model of proposal development in South Africa and research execution on home soil allowed Yahaya to access guidance when needed while autonomously conducting his research. The assistance he received from Shimelis left a lasting impression, as his supervisor dedicated countless hours to mentor him through challenging data analysis and interpretation tasks via virtual platforms. Remarkably, after just one session on the use of an analytical tool, Shimelis enabled Yahaya to master the nuances of data analysis and become highly skilled in precisely applying these techniques. Yahaya also benefited from data analysis workshops facilitated by ACCI for its PhD student cohort.
Despite the challenges of conducting research in Nigeria, including unstable power grids, limited internet connectivity, and suboptimal research infrastructure, Yahaya seized the opportunity to develop resilience and agility by using these experiences to crystallise his learning and probe the strengths and weaknesses he observed in the indigenous research ecosystem.
During his studies, he collaborated with the seed industry to register and release two high-yielding maize hybrids in 2022, followed by a fall-army worm-tolerant maize hybrid in 2023. He also published six peer-reviewed articles and actively participated in international conferences across Africa and Europe.
These activities and achievements provided Yahaya with a deeper understanding of his field and the skills to produce impactful research.
Yahaya is now focused on developing high-yielding sorghum cultivars with traits favoured by farmers and consolidating their role in the agricultural value chain.
‘My academic journey is far from over; graduation symbolises both a personal triumph and my dedication to a lifelong pursuit of agricultural prosperity in Africa,’ said Yahaya, for whom the years of PhD study serve as a testament to education, resilience and community-driven progress, resonating with the power of dedication and collaboration.
He thanked his family for their unwavering support.
Words: Christine Cuenod