Root Volumes of Avena Species1

Abstract

Volumes of root systems were measured at regular intervals during the growth cycle of one oat cultivar and one (Avena saliva L.) line and four weedy oat (A. sterilis L.) lines. The oat plants were grown hydroponically by using modified Hoagland nutrient solution to provide the nutrient source. The experimental design was a randomized block with three replicates, and a plot consisted of two plants imbedded in a 6.3‐cm cork. Root volume was measured on each plot at weekly intervals by water displacement. When mature, the plants in a plot were harvested, separated into roots, straw, and panicles, and dried. Subsequently, dry weights were taken on the three portionsThe oat lines and cultivars differed significantly in final root volume and weight and in panicle and straw weight. The relationship among genotypes for root volume varied with measurement period. The root volume per plot was quite similar for all genotypes until the 6th week. After 6 weeks the root volumes for five genotypes, CI 9170 and ‘Dal’ (A. saliva) and PI 324774, PI 324776, and PI 324780 (A. sterilis), did not change much (volumes of 2.5 ml/plot for CI 9170 to 6.5 to 8.0 ml/plot for the other four). But the volume of the A. sterilis line, PI 324748, increased from 10.0 ml/plot at week 6 to 28.0 ml/plot at week 16. PI 324748 also had significantly greater root, straw, and panicle weights at harvest.