Noncytoplasmic Inheritance of Atrazine Tolerance in Velvetleaf (<i>Abutilon theophrasti</i>)

Abstract

An accession of velvetleaf ( Abutilon theophrasti Medik. # ABUTH) known to be highly tolerant of atrazine [6-chloro- N -ethyl- N -(1-methylethyl)-1,3,5-triazine-2,4-diamine] and a normal susceptible accession were crossed reciprocally. F 1 plants were intermediate in response to atrazine, but they were more like the tolerant parent than the susceptible parent. The response of F 1 plants was the same for each reciprocal cross, indicating that atrazine tolerance was not cytoplasmically inherited. Response of F 2 plants to atrazine was consistent with a ratio of one tolerant: two intermediate: one susceptible. These results and further evaluations of F 3 plants indicated that atrazine tolerance was controlled by a single, partially dominant gene.