Miele Tallon Matheus

Morfologia de frutos, sementes e plântulas e germinação de sementes de Erythrina variegata L.

Morphological characterization of fruits and seeds provides subsidies for species differentiation and characterization of ecological aspects of plants, such as dispersion, seedling establishment and ecological succession phase . Thereare few studies reported in regard to Erythrina variegata L. and in the literature there is no information about its behavior, especially about its system of propagation in the State of Espirito Santo. The objective of this study was to investigate the morphology of the fruits, seeds and seedlings of this species, characterizing the fruits externally, the seeds internally and externally, and describing the process of development and differentiation of the phases of the seedlings, as well as collecting information regarding the seed germination, using a completely randomized experimental design with the following treatments: intact seeds (control); mechanical scarification with sandpaper number 120, on the opposite side to the embryo; scarification with sandpaper and posterior soaking in water at ambient temperature for 6, 12 and 24 hours; thermal shock; and soaking in water at ambient temperature for 12 and 24 hours. The seeds did not show themselves impermeable to water through their teguments, thus, not requiring pre-germination treatments.

Caracterização morfológica de sementes, plântulas e da germinação de Dimorphandra wilsonii Rizz. - faveiro-de-wilson (Fabaceae-Caesalpinioideae)

The objective was to study the morphology of the seeds and seedlings of Dimorphandra wilsonii Rizz. characterizing the seeds internally and externally, as well as describing the processes of development and differentiation of the seedlings phases. The soaking curve, the thousand-seed weight and the number of seeds per kilogram were also determined. One kilogram of the seeds corresponded to a number of 2.560 seeds in average. The seeds have endosperm, in which the tegmen is strongly attached and the teguments are hard and impermeable to water. The seed and seedling morphology gives informations that facilitates the recognition of this species.

MATURAÇÃO FISIOLÓGICA DE SEMENTES DE Erythrina variegata L.

The study objective was to determine the physiological maturation of the Erythrina variegata L. seed. Each flower was identified according to its respective anthesis date. The fruit was collected weekly following the 21 st day after anthesis (DAA). The following characteristics were evaluated: length and diameter of each fruit; color, fresh mass, dry mass, water content of both fruit and seeds; the seed germination state and vigor. The experimental design utilized was the completely randomized. It was found that the fruit of E . variegata continues to grow in both length and diameter up until the 42 nd DAA. The seeds start to germinate on the 63 rd DAA, when the seed water content is 68.15% and the dry mass is 481.38 mg per seed. The maximum germination and vigor are obtained at the 77 th DAA which coincides with the maximum seed dry mass. At this time the fruit has a dark brown color with brown-purple seeds which have a corneous tegument and a water content of 21%. This is considered as being the physiological maturation point of the seeds. The dehiscence of the fruit occurs at the 91 st DAA.

EMBEBIÇÃO, OSMOCONDICIONAMENTO E VIABILIDADE DE SEMENTES DE Apuleia leiocarpa (VOGEL.) J. F. MACBR.

The aim of this work was to characterize the imbibition and to evaluate the physiological quality of Apuleia leiocarpa seeds after priming. It was done the immersion of intact and scarified seeds in distilled water for 96 hours. In the study of priming, the scarified seeds were separate on three lots (L1, L2, L3), the first has been conditioned in distilled water only (control), the second and the third were osmoconditioned in PEG 6000, at potentials of -0.4 and -0.8 MPa, respectively, for 10 hours. Then, the seeds were placed in plastic bags and kept under controlled temperature of 3°C ± 1. Sowing was performed after 0, 30, 60, 90 and 120 days of priming. Seed quality was evaluated by: germination percentage, germination speed index, relative frequency of germination, root length, shoot length, and seedling dry weight. The seed imbibition of Apuleia leiocarpa follows the three-phase model of water absorption, starting after three hours and culminates with the primary root protrusion after 72 hours. The primed seeds in -0.8 MPa of PEG maintained the physiological quality of seeds, while seeds primed in water and -0.4 MPa of PEG linearly reduced the percentage and speed of germination, the length and the dry weight of seedlings.