Rooting for cassava: Insights on photosynthesis and associated physiology as a route to improve yield potential
Amanda P. De Souza, Lynnicia N. Massenburg, Deepak Jaiswal, Siyuan Cheng, Rachel Shekar, and Stephen P. Long
Due to an increase in world population, food demand is expected to grow by up to 110% in the next 30-35 years. The population of Sub-Saharan Africa is projected to increase by more than 120%. In this region, cassava (Manihot esculenta Crantz) is the second most important source of calories and contributes to ~ 30% of the daily calorie requirements per person. Regardless of its importance, the average yield of cassava in Africa has not increased significantly since 1961. An evaluation of modern cultivars of cassava showed that photosynthetically active radiation (PAR), interception efficiency (ɛi) and PAR conversion efficiency (ɛc) remains a major opportunity for genetic improvement of yield potential. Therefore, this review examines what is known of the physiological processes underlying productivity in cassava and seeks to provide some strategies and directions toward yield improvement through genetic alterations to physiology to increase ɛi and ɛc. Possible physiological limitations, as well as environmental constraints, are discussed.