Germination evaluation in distinct temperatures and substrates, and morphology of fruit, seed and seedling of Sebastiania brasiliensis

Em virtude da carência de trabalhos com sementes florestais nativas, este estudo objetivou conhecer as principais características morfológicas e germinativas de Sebastiania brasiliensis (Spreng.). Na descrição morfológica, foram observadas as características internas e externas dos frutos e sementes e o desenvolvimento inicial da plântula. Os testes de germinação foram realizados em dois substratos (areia e vermiculita) e sob três temperaturas (25 ºC, 30 ºC e 35 ºC). O delineamento utilizado foi o inteiramente casualizado, em esquema fatorial 2 x 3, com cinco repetições, calculando-se a porcentagem de germinação, o índice de velocidade de germinação (IVG) e o tempo médio. No estudo da morfologia, observou-se que os frutos são do tipo cápsula com três cocas (uma semente/coca). A semente é endospérmica, a testa é do tipo glabra, possuindo uma coloração marrom com pequenas manchas claras. O embrião é axial, foliáceo e espatulado. As plântulas têm desenvolvimento fanerocotiledonar, epígeo, com cotilédones foliáceos fotossintetizantes. Nos testes de germinação, as sementes submetidas à temperatura de 30 ºC e em vermiculita germinaram 86%, com IVG de 7,05 e melhor tempo médio de 3,39 na temperatura de 25 ºC em substrato vermiculita. Conclui-se que a temperatura de 30 ºC no substrato vermiculita propiciou a melhor germinação, e a morfologia indica características típicas para o gênero.Palavras-chave: Branquilho-leiteiro; análise germinativa; caracterização morfológica. AbstractGermination evaluation in distinct temperatures and substrates, and morphology of fruit, seed and seedling of Sebastiania brasiliensis. Due the lack of surveys/researches regarding native forest seeds, this study aimed to identify the main morphological and germination features/patterns of Sebastiania brasiliensis (Spreng.). For the morphological description, it was observed the internal and external features of fruits and seeds and early seedling development. We tested germination in two substrates (sand and vermiculite) and three temperatures (25 ºC, 30 ºC and 35 ºC). The experimental design was completely randomized in a 2 x 3 factorial with five replications, aiming to calculate the percentage, rate index and average time of germination. The fruit is a capsule with three cokes (one seed per coke). The seed is endospermic; testa is glabrous, brown with small spots. The axial embryo is foliaceous and spatulate. Seedlings have phanerocotylar epigeal development with foliaceous photosynthetic cotyledons. Seeds planted in vermiculite under 30 ºC of temperature revealed the best germination (86%), and an IVG of 7.05; the best average time was 3.39 at 25 ºC in vermiculite. As conclusion, vermiculite with 30 ºC of temperature led to better germination, and the morphology indicates typical characteristics for the genus Sebastiania.Keywords: Branquilho-leiteiro; germination analysis; morphological characterization.AbstractDue the lack of surveys/researches regarding native forest seeds, this study aimed to identify the main morphological and germination features/patterns of Sebastiania brasiliensis (Spreng.). For the morphological description, it was observed the internal and external features of fruits and seeds and early seedling development. We tested germination in two substrates (sand and vermiculite) and three temperatures (25 ºC, 30 ºC and 35 ºC). The experimental design was completely randomized in a 2 x 3 factorial with five replications, aiming to calculate the percentage, rate index and average time of germination. The fruit is a capsule with three cokes (one seed per coke). The seed is endospermic; testa is glabrous, brown with small spots. The axial embryo is foliaceous and spatulate. Seedlings have phanerocotylar epigeal development with foliaceous photosynthetic cotyledons. Seeds planted in vermiculite under 30 ºC of temperature revealed the best germination (86%), and an IVG of 7.05; the best average time was 3.39 at 25 ºC in vermiculite. As conclusion, vermiculite with 30 ºC of temperature led to better germination, and the morphology indicates typical characteristics for the genus Sebastiania.Keywords: Branquilho-leiteiro; germination analysis; morphological characterization