Physical and physiological analysis of Campomanesia xanthocarpa O. Berg and Eugenia involucrata DC. seeds (Myrtaceae) in different temperatures and substrates

Abstract

Studies for the physical aspects of seeds and germinative performance of native forest species are relevant for seed technologists and nurseries. The objective of this work was to evaluate the germination of C. xanthocarpa and E. involucrata seeds in different temperatures and substrates, and to measure the physical and biometric characteristics of the seeds. Seed biometry, water content (WC) and weight thousand seeds were the physical aspects evaluated. The germination tests were conducted at three temperatures (20, 25 and 30 °C) and three substrates (sand, vermiculite and ‘mata-borrão’ paper) for C. xanthocarpa; and three temperatures (20, 25 and 30 °C) and two substrates (sand and vermiculite) for E. involucrata; seed germination and vigor were evaluated. The weights thousand seeds for C. xanthocarpa and E. involucrata were 35.0 g (WC=25.6%) and 471.5 g (WC=52.1%), with 24,783 and 2,121 seeds per kilogram each. The dimensions of the C. xanthocarpa seeds are 7.97 x 5.55 x 2.02 mm and 12.81 x 10.02 x 7.49 mm in E. involucrate seeds. The germination and expression of vigor in C. xanthocarpa and E. involucrata seeds were favored at temperatures of 30 and 25 °C, the threshold at which the lowest average germination times (4.4 and 9.3 days) and higher rates were obtained germination speed (4.8 and 1.3), with germination of 99 and 76%. Therefore, the germination of C. xanthocarpa and E. involucrata seeds must be carried out on vermiculite substrate and temperatures of 30 and 25 °C, respectively.