IN VITRO PROPAGATION OF Casearia sylvestris SWARTZ

• Published in: Ciência florestal Vol. 27; no. 4; pp. 1191 - 1199
• Main Authors: Paranhos, Jucara Terezinha, Lobler, Lisiane, Cechin, Joanei, Fernandes, Tiele Stuker, Fao, Elvis, Soriani, Hilda Hildebrand
• Format: Journal Article
• Language: Portuguese; Spanish
• Published: Universidade Federal de Santa Maria 01-10-2017
• Subjects: ECOLOGY; ENVIRONMENTAL STUDIES; FORESTRY; Brasil; micropropagação; reguladores de crescimento; growth regulators; micropropagation; in vitro seed germination; germinação in vitro de sementes; light regimes; regimes de luz
• ISSN: 1980-5098; 0103-9954; 1980-5098
• DOI: 10.5902/1980509830301

In order to do an in vitro propagation of Casearia sylvestris, a tree native to Brazilian forests, studies of in vitro seed germination were performed and aseptic seedlings obtained were used as explant donors for micropropagation. Mature and immature seeds, stored for 10 days at 10 or 25[degrees]C were inoculated in medium containing 10% of MS salts and kept in the light (a 16-hour photoperiod) or continuous dark, at 25[degrees]C. For immature seeds, gibberellic acid ([GA.sub.3]) was or was not tested at a concentration of 1.5 mg [l.sup.-1]. From the seedlings obtained, the cotyledon and apical segments were removed and cultured in complete MS medium with five combinations of 6-benzylaminopurine (BAP) and naphthalene acetic acid (NAA): 0.0; 0.25; 0.5; 1.0; 2.0 and 0.0; 0025; 0.05; 0.1; 0.2 mg [L.sup.-1], respectively. The aerial shoots formed in vitro were cultured in MS medium containing 0.0 or 1.5 mg [L.sup.-1] indole-3-butyric acid (IBA) for rooting. The highest percentage of germination (60%) occurred in mature seeds exposed to light, regardless of other treatments, and may be considered positive photoblastic. The highest percentage of germination of immature seeds (27%) occurred when previously stored at 10[degrees]C with or without [GA.sub.3]. The induction of aerial shoots was more efficient in apical segments in a medium containing the lowest combination of BAP and NAA or free of these growth regulators. The higher number of roots occurred in aerial shoots obtained from cotyledon segments, with or without IBA. After acclimatization, 83% of the plants survived. Keywords: in vitro seed germination; micropropagation; growth regulators; light regimes. Com o objetivo obter a propagacao in vitro de Casearia sylvestris, arvore nativa das florestas brasileiras, estudos de germinacao in vitro das sementes foram realizados e as plantulas assepticas obtidas foram usadas como doadoras de explantes na micropropagacao. Sementes maduras e imaturas, armazenadas por 10 dias a 10 ou 25[degrees]C foram inoculadas em meio contendo 10% de sais de MS e mantidas na luz (fotoperiodo de 16 horas) ou escuro continuo, a 25[degrees]C. Para sementes imaturas, testou-se ou nao acido giberelico ([GA.sub.3]) na concentracao de 1,5 mg [l.sup.-1]. Das plantulas obtidas, segmentos cotiledonares e apicais foram retirados e cultivados em meio MS completo com cinco combinacoes de 6-benzilaminopurina (BAP) e acido naftalenoacetico (ANA): 0,0; 0,25; 0,5; 1,0; 2,0 e 0,0; 0025; 0,05; 0,1; 0,2 mg [L.sup.-1], respectivamente. As brotacoes aereas formadas in vitro foram cultivadas em meio MS contendo 0,0 ou 1,5 mg [L.sup.-1] de acido indol-3-butirico (IBA) para o enraizamento. O maior percentual de germinacao (60%) ocorreu em sementes maduras expostas a luz, independentemente dos demais tratamentos, podendo ser consideradas fotoblasticas positivas. A maior percentagem de germinacao das sementes imaturas (27%) ocorreu quando previamente armazenadas a 10[degrees]C, com ou sem [GA.sub.3]. A inducao de brotos aereos foi mais eficiente em segmentos apicais e em meio contendo a menor combinacao de BAP e ANA ou isento destes reguladores de crescimento. O maior numero de raizes ocorreu em brotos obtidos a partir de segmentos cotiledonares, com ou sem AIB. Apos a aclimatizacao, 83% das plantas sobreviveram. Palavras-chave: germinacao in vitro de sementes; micropropagacao; reguladores de crescimento; regimes de luz.