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

• Autor(a) principal: CARVALHO,PATRÍCIA GONÇALVES BAPTISTA DE
• Data de Publicação: 2001
• Outros Autores: BORGHETTI,FABIAN, BUCKERIDGE,MARCOS SILVEIRA, MORHY,LAURO, FERREIRA FILHO,EDIVALDO XIMENES
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Revista Brasileira de Fisiologia Vegetal (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-31312001000200003
• topic: endosperm; germination rate; sesame

The effects of temperature on germination and endo-beta-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-beta-mannanase activity in the micropylar endosperm prior to seed germination was observed only at supra-optimum temperature.