Wheat Root Selections for Sustainable Production

Abstract

Global food security is at high risk due to depletion of natural resources and climate change. In that context wheat has a pivotal position because wheat is a major cereal. Tremendous advances in wheat improvement had been made through above ground parts in recent years without considering roots as a plant part. Existing wheat varieties have small and inefficient root systems that need to be replaced with extensive and efficient root system. Better roots can improve utilization of water and nutrients, and, in turn, yields. Better roots can reduce nitrate leaching and P fixation in soil and can help combating environmental pollution issues. Wheat yield potential has almost become stagnant in developed countries and higher yield in developing countries cannot be achieved due to resource limitations. A solution would be to increase photosynthetic capacity and efficiency but to support plants with higher above ground biomass, an extensive and deep root system would be required. Research on roots and its application for enhancing wheat productivity offers enormous potential but this area has been neglected in the past.

Here we review methodological challenges in studying roots, exploitation of existing genetic variability in root traits for further genetic improvement of wheat, and role of root data in increasing the efficiency of modeling studies. We found that roots have always been notoriously difficult to study. Old methods of soil core and monolith require more time and labor and are tidy. Advanced methods like minirhizotrons require huge initial investment and trained manpower to run the specialized devices, thereby, making these advances in technology less useful for developing countries. There is a need for improvement of drought tolerance and efficiency of input use in wheat production by exploiting genetic variability in landraces. The progress in wheat improvement through root traits remained a concern for scientists over decades as conventional hybridization methods of wheat improvement cannot provide quick solutions to current problems of stagnancy in potential yield. Advances in biotechnological tools can help to break prevailing stagnancy in yield.