Soybean Plants and tissue Culture Selection for Glyphosate Tolerance

Abstract

Slection of soybean (Glycine max (L.) Merr.) plants for glyphosate tolerance was conducted in the greenhouse. A rate of glyphosate higher than 0.5 kg ai/ha caused severe phytotoxicity to all cultivars and breeding lines. Cultivars Doikham and S.J.5 were highly tolerant. Breeding lines 8416-7 and 8418-4 were moderately tolerant. Cultivars Chiangmai 60 and S.J4 were susceptible to glhphosate.
selection by cell suspension was similar to the whole plant selection. the maximum glyphosate concentration that cells of all cultivars and breeding lines could tolerate was 10 12-2M. When a suspension of cells previously cultured in medium containing glyphosate were transferred a second time into the same medium, cells of all cultivars and breeding lines could slightly adapt for tolerance at the same concentration of glyphosate. Moreover, cells of cultivars Chiangmai 60 and S.J.4 were better adapted than others.