Genotype dependent tolerance to herbicides of maize (Zea mays L.) inbred lines

Herbicide application in seed maize requires special attention due to their larger sensitivity than hybrid maize. The aim of study was to examine and define the sensitivity/tolerance of the five maize inbred lines with different susceptibility to herbicides (belonging to different heterotic groups), based on alterations of secondary metabolites (phenolics, protein sulfhydryl groups, phytic and inorganic phosphorus). Two groups of herbicides: triketons (mesotrione and topramezone) and sulfonylureas (rimsulfuron and foramsulfuron) were tested. Lines from independent heterotic group, which were sensitive to herbicides expressed visible damages together with significant reduce in grain yield, mainly induced by sulfonylurea herbicides. Parallel with that, significant increase in phenolics, phytic and inorganic phosphorus, as well as drop in protein sulfhydryl groups were observed in their leaves. Tolerant lines (belonging to Lancaster group) had mainly insignificant grain yield reduce, also with lesser variations in sulfhydryl groups, content of phytic and inorganic phosphorus, as well as increase in phenolics content. Among examined secondary metabolites, phytate is the main factor, contributing to herbicide tolerance in maize lines. Owing to lesser yield decrease and variation in content of examined secondary metabolites, expressed in treatments with triketone herbicides, they usage could be safe in maize lines.