1993 Volume 62 Issue 4 Pages 565-570
Vertical distribution of roots is known to influence environmental stress tolerance of crops. To estimate the genotypic characteristic on the vertical distribution of roots in the field, the growth angle of seminal roots of 7-day-old seedlings of 12 Japanese winter wheat cultivars was measured using the basket method in a pot experiment. For comparison, the same cultivars were grown in an upland field and monolith samples of the top 30 cm soil layer were taken at the stem elongation stage. Root length was measured in every 5 cm horizontal soil layer. Root growth angle showed negative correlation with root length percentage in the top 10 cm soil layers, but the angle showed positive correlation with the percentage in 10-30 cm depth layers. The root depth index (RDI) was calculated to characterize the root vertical distribution of the cultivars. The RDI was closely related to the growth angle of the seminal roots of the cultivars (r=0.779 ; P<0.01). It was, therefore, assumed that the determination of the growth angle of seminal roots in a pot experiment could be useful to estimate genotypic differences in the root vertical distribution at the stem elongation stage in the field.
