Germinação in Vitro de Sementes de Mogango (cucurbita pepo l.) - cucurbitaceae

Abstract

An increase in osmotic pressure reduces the free energy of waterthrough an increase in solute concentration. The objective of this study wasto verify the effect of reduced osmotic pressure in in vitro germination ofsquash (Cucurbita pepo). Seed disinfestation was done with by an immersionin alcohol 70% for three min, washing three times with sterile distilled water,immersion in a solution of NaOCl (2.5%) for 10, 20, 30 or 40 min, and washingthree times with sterile distilled water. The culture medium was distilled waterand agar (7 g L-1), pH adjusted to 5.7. The concentrations of 0, 10, 20 or 30 g L-1 ofsucrose were used to increase osmotic pressure in the medium. A completerandom design was used with five replications of 10 seeds. The germinationindex, average time for germination day, germination energy of Baldwin, andgermination rate of viable seeds were evaluated. The osmotic pressure of 20and 30 g L-1 of sucrose in the culture medium showed the highest index ofgermination. The reduction of osmotic pressure do not increase the in vitrogermination percentage of squash seeds.