Good Roots: Understanding the Differences Between Heirloom and Commercial Wheat and Barley Roots
The architecture of a plant’s root system has a strong impact on crop performance, and understanding the root structure is important for both plant breeders and farmers. Root architecture affects drought tolerance, nutrient and water uptake, and tolerance to mineral toxicity. For example, wheat and barley crops with more roots in the upper soil layer will absorb most of their nutrients from that area. However, a plant with this architecture will be less drought tolerant because water stores are located deeper within the ground. Meanwhile, roots that are longer and thinner reach a greater amount of soil and have greater chance of reaching the resources the plant needs.
In this study the researchers assessed the roots of heirloom and commercial cultivars of wheat and barley to better understand small grain root architecture and determine their potential for low input sustainable agriculture.
This study took place in the Plant Science Laboratory at the University of British Columbia in 2012. Five heirloom and four commercial wheat and barley cultivars were tested. The complete list of cultivars tested can be found at the research article's link included below. The seeds were sowed inside laboratory growth chambers on germination paper. After 10 days, the roots were removed from the chambers and were assessed for total root length, surface area, diameter, volume, number of tips, and branching angle.
Roots of heirloom cultivars had longer and thinner roots, greater surface area and higher number of tips compared with the roots of commercial cultivars. Cultivar ‘Glenn’ had the highest amount of thin roots, and the commercial cultivars ‘Scarlet’ and ‘Norwell’ had the coarsest roots.
Roots of Individual barley cultivars had differences in length, area, volume, and angle of branching. However, there were no differences between commercial and heirloom cultivars. The heirloom cultivar ‘Jet’ had the longest and finest roots with the greatest surface area and the highest branching angle. Commercial cultivar ‘Camus’ had the coarsest roots.
About this research
This brief is based on the following peer-reviewed journal article:
Heirloom wheat cultivars had deeper, longer and thinner roots, more surface area, higher number of tips, and greater branching angle compared to commercial cultivars. These traits are often linked with resistance to drought stress and improved phosphorus uptake. Commercial wheat cultivars had coarser roots.
Barley cultivars showed no difference between commercial and heirloom, though individual cultivars did vary.
The root architectures of the heirloom wheat and barley cultivars indicate they may be better suited for low phosphorus and/or drought conditions, typical of low input or organic production. The root architectures of the commercial cultivars, on the other hand, are more suitable for high input conditions.
When heirloom wheat cultivars were grown under organic or low input conditions, they tended to grow long roots with more surface area and yield potential. The longer and finer roots of the heirloom cultivars suggest breeding potential to increase the plant’s nutrient uptake efficiency and drought tolerance.