Conservação de sementes e ecofisiologia da germinação de Alibertia edulis (Rich) A. Rich. ex DC.

Abstract

This study aimed to assess the potential storage, germination and seed vigor of Alibertia edulis (Rich) A. Rich. ex DC., in different kind of package and environmental condition. Fruit samples were gathered from 10 matrices located on a cerrado region at Santa Madalena Farm, in the City of Dourados, Mato Grosso do Sul State – Brazil, and were taken to the Laboratory of Nutrition and Metabolism of Plants from UFGD (Universidade Federal da Grande Dourados). Seeds were split in two samples after the fruit had been processed, one was immediately seeded and the other one stored in aluminum foil packet, plastic bag (0,25mm thick) and glass bottle. All of them were kept in average temperature ranging from 5 to 10 ºC under constant white light along 7 to 21 days. After that, seeds were sowed in 128-cell trays and evaluated according to their emergence, emergence speed ratio, root/shoot length, cotyledon diameter, root/shoot dry weight, chlorophyll ratio, foliar area and Dickson index of quality for the experiment of the ecophysiology of seed germination. They were seeding in petri dishes, lined with two germitest® paper sheets and kept in B.O.D. chambers at average temperature 15, 20, 25 e 30°C and incubated in presence and absence of light. Germination, germination speed ratio, root/shoot average length and shoot/ratio dry weigh were evaluated. For evaluating salt stress, seed plates were moistened with 10 ml of KC1, NaC1 and CaC12 saline solutions at six concentrations of 0.0 (control), -0.4, -0.8, -1.2, - 1.6, -2.0 MPa for 40 days. It was evaluated the germination, germination speed ratio, average shoot/ root length and shoot/root dry weight and the relation shoot/root weight. Randomized design, with four replications of 25 seeds each, were used for every experiment. Newly processed seeds showed higher level of germination, however, in case of storage, this must be done in aluminum or glass for 7 days at 5°C. Seeds are indifferent to light and the best germination temperature was 25°C. Although salt were harmful in all response aspects, KCI was less prejudicial to germination and to shoot length.