Biological effects of rice-field herbicide machete on various strains of the nitrogen-fixing blue-green alga Nostoc muscorum

Abstract

The pre-emergence rice-field herbicide machete (2-chloro-2′, 6′-diethyl-N (butoxymethyl) acetanilide), is apparently toxic and lytic to parental, het+ nif11-, and Em-R het- nif2- strains of Nostoc muscorum. The intensity of the biological effects induced by the herbicide increases with the growth-promoting efficiency of various inorganic nitrogen sources. The herbicide has no effect on heterocyst differentiation, and induced biological perturbations are not reversed by glucose. Machete appears to be strong mutagen as 5-6% of the het+ nif11- and Em-R het- are prototrophic revertants. © 1978.