Differences in root biomass among wheat varieties shown by a qPCR assay wheat root DNA in soil samples

Methods. Two robust qPCR assays were developed to estimate the quantity of plant root DNA in soil samples, one specific to wheat and barley, and a second specific to black-grass. Results. The DNA qPCR method was comparable, with high correlations, with the results of root washing from soil cores taken from winter wheat field trials. The DNA qPCR assay showed both variety and depth as significant factors in the distribution of root biomass in replicated field trials. Conclusions. The results suggest that these DNA qPCR assays are a useful, high-throughput tool for investigating the genetic basis of wheat root biomass distribution in field-grown crops, and the impact of black-grass root systems on crop production.