In vitro selection of a glyphosate-tolerant sugarcane cellular line

Cell suspensions derived from Saccharum spp. varieties (PR62258, V64-10, V71-51) were used to study the effects of glyphosate on cell suspensions of commercial cultivars of sugarcane in order to select and develop a glyphosate-tolerant cellular line. A liquid medium with 0.8 mM/L glyphosate was used for selection. The results showed growth inhibition of approximately 50% for cell suspensions in mediums with 0.8 mM/L glyphosate. The results obtained in vitro were consistent with the results reported from in vivo tests. Plants were regenerated from sensitive cell suspensions and tolerant cell suspensions from cultivar V71-51. Tolerant cell suspensions tolerated a concentration that was 12.5-fold higher than that of the sensitive cell suspensions. Plants regenerated from tolerant cell suspensions tolerated a glyphosate concentration that was 6-fold higher than that of the plants regenerated from sensitive cell suspensions. Cell suspensions derived from tolerant regenerated plants tolerated a glyphosate concentration that was 5-fold higher than that of those derived from sensitive regenerated plants. The RAPD patterns obtained with OPA-07 revealed a 564-bp band that can be used to characterize the tolerant cellular line. This band is not present in the sensitive cellular line. Consequently, the tolerance persisted throughout the differentiation into plants and dedifferentiation into cell suspensions. This performance suggests that an in vitro selection of pre-existing variability has taken place.