One is to record the visible roots on the outer surface of the root box by scanning or taking pictures of the root box surface or manually drawing the visible roots on transparent sheets. There are two ways to describe the root system in root boxes. Recently, some platforms using root boxes such as GLO-Roots and GrowScreen-Rhizo have been established for high-throughput root phenotyping. Root box, also called rhizobox, grows plants in transparent polyvinyl chloride (PVC), wood, glass plate, or metal boxes and has been widely used for soil-based root researches. Thus, a better understanding of resources captured by plant roots requires detailed datasets that include the root system architecture (RSA) and the heterogeneous soil conditions. Under these heterogeneous conditions, plants can adjust the placement of their new roots to capture the resources in response to the soil environment, which is known as “root plasticity”. Such physical, chemical, and biological properties of soil can vary depending on spatial and temporal scales. Soil comprises a complex distribution of particles of different sizes, compositions, physical properties, airspaces, variations in nutrient and water availability, and microbial diversity. On the other hand, the soil is also heterogeneous. They interact with one another under certain soil environments and influence plant functions that contribute to performance and eventually yield. These component roots show different functions with aging. The heterorhizy includes a taproot, adventitious roots, and S- and L-type lateral roots (LRs) for dicot crops, and seminal root(s), nodal roots, and their S- and L-type LRs for monocot crops. Root system consists of component roots that are different in emergence, morphology, anatomy, and function, called “heterorhizy”. The evaluation of root traits, using our methods, will contribute to developing agronomic management and breeding program for sustainable food production.ĭeveloping methods that generate detailed datasets containing the root system and its architecture in the specific soil environment enhance crop cultivation techniques that contribute to sustainable food production and promote crop breeding adapted to stressful soil environments. Moreover, staining of the root specimens enabled analyzing the interaction between soil and physiological function of RSA. The present method realized: fast and accurate production of the whole root specimen and precise calculation of the specimens’ root surface area. Moreover, staining of the buckwheat root specimens made it possible to examine the respiratory activity of each root at different depths. Staining of the soybean root specimens enabled us to observe the localized root proliferation induced by AM colonization. The root surface area calculated from the scanned soybean specimens showed a significant correlation with that calculated from the roots spread out in water (a common method). Also, the whole root specimens of soybean were made in about 7 min. The equipment enabled to sample the whole-root specimens of soybean and buckwheat, where the tips of the fine roots were alive (diameter < 0.2 mm). Both species showed significant differences between cultivars and/or among treatments in shoot and root traits. The root boxes allowed soybean and buckwheat plants to grow uniformly across the replications. For validation, we examined the root response of two soybean cultivars to arbuscular mycorrhizal (AM) inoculation and the effect of waterlogging stress on the physiological activity of buckwheat RSA. The objectives are to assess: whether the equipment can rapidly sample the entire root system whether root surface area is measurable from a scanned digital image of the root specimen and whether staining of the entire root specimens would provide multidimensional visual information on the interaction between soil and physiological function of root system architecture (RSA). This study introduces root system sampling equipment that makes the entire root specimen with minimum impairment and without displacement of the spatial arrangement of the root system in root boxes. However, most of the root study methods have paid little attention to make and preserve whole root specimens. Detailed datasets containing root system and its architecture in soil are required to improve understanding of resource capture by roots.

Root transparent rectangle