Temperature-dependent germination and endo-beta -mannanase activity in sesame seeds

the effects of temperature on germination and endo-b-mannanase activity in seeds of sesamum indicum was investigated. the minimum germination temperature (tmin) lies between 12.8°c and 13.2°c while the maximum temperature (tmax) is located between 45.5°c and 46°c. germinabilities are statistically not different from estimated viability (88%) between 18.8°c and 43.2°c. the mann-whitney test indicated the interval 31.9°c to 35.1°c as the optimum temperature (topt) range for germination rate. when seeds incubated at temperatures at or below the tmin and close to or above the tmax were transferred to 30°c, those incubated at lower temperatures achieved high germinability. on the other hand, the higher the pre-incubation temperature above tmax, the lower the germinability achieved near topt. seed endosperm cell wall was found to contain mannose as the main monosaccharide. an increase in endo-b-mannanase activity in the micropylar endosperm prior to seed germination was observed only at supra-optimum temperature.