Growth and physiological characteristics of roots in different flue-cured tobacco varieties under drought stress.

The experiment were carried out to study the effects of drought stress on growth and physiological characteristics of roots among three different genotypes of flue-cured tobacco including 'Nongda 202,''NC89' and'K326'in pot culture.The results showed that:after seriously drought stress,the root biomass including root fresh weight and root dry weight increased,whereas,the root activity,root absorbing area,SOD activity and POD activity all decreased.Compared with 'NC89' and 'K326','Nongda 202' appeared significantly greater root total absorbing area,active absorbing area,SOD activity and POD activity,but the root biomass including fresh weight and dry weight did not have significant difference.In conclusion,there are obvious differences among flue-cured tobacco genotypes in root growth and physiological characteristics,and their response to water condition.'Nongda 202'kept stronger root activity,SOD activity and POD activity,more root total and active absorbing area under seriously drought stress,which were the physiological basis of stronger drought resistance.