Germination of Syzygium malaccense and Syzygium jumbos seeds under different thermal conditions and seedling morphology

Abstract

The objective of this research was to analyze the influence of temperature on seed germination and seedling morphology for the S. malaccense and S. jambos. For germination, 250 seeds of each species, of ripe fruits, were used, which were washed in running water, dried in room condition for 24 hours and disinfected. The seeds were placed in plastic boxes with medium texture vermiculite substrate and submitted to different temperatures: 20, 25, 30, 35 degrees C and 20-30 degrees C in BOD'S, in a completely randomized design. The variables analyzed were: daily germination percentage, polyembryony and GSI. For morphological characterization, 30 seeds of both each species, submitted to a temperature of 30 degrees C and samples were collected at intervals representative of the germination. There is no influence of temperature on the germination of S. malacense seeds and for S. jambos there are losses of 35 degrees C. The temperatures of 25 20-30 and 30 degrees C, influence the highest percentage of polyembryony for S. malaccense, for S. jambos, only the temperature of 35 degrees C affected this process. The temperatures of 20 and 25 degrees C decreased the GSI, for both species. The seeds have green cotyledons, hypogeal germination with brown primary root and whitish, short and filiform secondary roots.