b'Manitobas Kevin Falk and Zaki Jubery and colleagues imaged thousands of soybean root systems and used machine to measure root traits and correlate differences in root system architecture to the genome of the plants. Falk says the work will enable breeding for drought-tolerant root systems.tems, using genomic prediction-based approaches, saysis needed to understand the optimum RSA in a broad Falk, integrated field scientist for Corteva Agriscience. range of growing conditions.My research was the first step to making thisIn any case, although RSA can greatly impact yield, happen but more work needs to be done, specificallycrop breeding programs have rarely used it as a direct continuing this work into the field environmentweselection criterion. Instead, RSA has been indirectly know that lab- or greenhouse-based research oftenselected for in plants that perform well in general and/doesnt align with what goes on in the field. Drought hasor perform well under dry conditions. Direct selection hit the western Canadian soybean grower hard in the lastfor RSA has not occurred because the traits involved few years, and the best way forward is drought-tolerantwith it are complex, as is the measurement of these traits soybean. But as with all of plant breeding, even withand the effects of environmental factors. In addition, genomic technology, its going to be a long haul. there have been a large number of root traits identified through different studies and software programs have Root System Architecture further complicated the identification of opportunities to Because RSA affects water/nutrient acquisition, plant- select the most informative and relevant suite of traits. microbe interaction, nutrient storage and structuralRoot traits are among the most difficult to study in anchorage of a plant, it can greatly impact yield. Soybeanplant sciences, Singh explains. While root research-taproots that elongate at a faster rate tend to burrow moreers have achieved success in trait identification, there deeply into the soil profile, possess increased root densi- are still challenges in the field-based root trait studies ties at depth, and can therefore better access water in dryinvolving large number of varieties. Its hard to dig up soils. However, for optimum plant performance, thesefield plants without disruption, and current sensors are deep roots need to be complemented with shallow lateralnot sensitive enough to do remote sensing in row crops. roots which enable the plant to efficiently forage for soil- So, it requires a very committed team to do long hours immobile nutrients. At this point in time, more researchof work. NOVEMBER 2020 GERMINATION.CA 37'