Rogério Gomes Pêgo

Micropropagation of Syngonanthus elegantulus

The species Syngonanthus elegantulus Ruhland is an important native plant used as cut flowers, but extractive exploration has caused the endangered status of this plant. Therefore, the objective of this study was to establish a protocol of the micropropagation of S. elegantulus. To this end, seed germination was tested in media containing different concentrations of WPM salts. For plantlet establishment, MS and WPM media were evaluated with 50 and 100% of the salt concentrations. Different the sucrose levels in the WPM medium were also evaluated. For multiplication, the plantlets were inoculated in WPM media with 0.0, 0.5, 1.0, 2.0 and 4.0 mg L-1 TDZ and 0.0, 0.5 and 1.0 mg L-1 NAA in all possible combinations. The pre-acclimatization effect was tested in the plantlets using the following substrates: sand, PlantmaxTM and vermiculite. The concentration of the medium did not influence the percentage of germination, but the germination speed index was inversely proportional to the nutrient addition to the culture medium. The best medium for plantlet establishment was WPM at the original salt concentration plus 17 g L-1 sucrose. The addition of 0.5 and 1.0 mg L-1 NAA is recommended for callus induction. The highest number of shoots was obtained in the presence of 1.0 mg L-1 TDZ or the combination of 1.0 mg L-1 TDZ with 0.5 mg L-1 NAA. S. elegantulus presented higher survival when acclimatized directly in sand.

Germinação in vitro e desenvolvimento pós-seminal de plântulas de Pilosocereus aurisetus (Werderm.) Byles & G.D. Rowley (Cactaceae)

Pilosocereus aurisetus e uma especie de cactos de importância economica e ambiental que se encontra em risco de extincao. A propagacao em areas naturais ocorre, principalmente, de forma sexuada; entretanto, nao ha registro da germinacao e viabilidade de sementes e morfologia pos-seminal de plântulas dessa especie. Assim, objetivou-se avaliar a germinacao de sementes e descrever a morfologia do desenvolvimento pos-seminal de plântulas de P. aurisetus. Para isso, sementes, armazenadas em condicoes ambientais por 19 meses, foram submetidas aos tratamentos: embebicao em agua por 24 horas; pre-resfriamento; imersao em solucao de giberelina, nas concentracoes de 250 mg L-1 e 500 mg L-1; e um tratamento controle. As sementes foram colocadas para germinar em meio de cultura MS, por 30 dias, quando se avaliou a percentagem de germinacao. O delineamento estatistico foi o inteiramente casualizado, com cinco tratamentos e quatro repeticoes, sendo dispostas 25 sementes por parcela. A caracterizacao pos-seminal foi realizada por um periodo de 60 dias, utilizando-se microscopio binocular, com base nas Regras para Analise de Sementes. Maior percentagem da germinacao de sementes ocorreu no controle, ou quando embebidas por 24 horas, sendo observados 90% e 83%, respectivamente. A morfologia do desenvolvimento pos-seminal indicou que a germinacao e do tipo epigea, com hipocotilo de reserva; suas plântulas sofrem modificacoes na regiao do colo, para a emissao de raizes, e apresentam cerdas no apice caulinar, mesmo na fase inicial da expansao cotiledonar. A diferenciacao e inicio da formacao das costelas iniciam-se aos 60 dias apos a germinacao, com o desenvolvimento do epicotilo.

Sulfuric acid on breaking dormancy seeds, emergence and post-seminal morphology of Canna edulis L.

he objective of this study was to evaluate the efficiency of time scarification of seeds in sulfuric acid to break the dormancy of seeds, seedling emergence and post-seminal morphology of C. edulis. This way, were determined biometric characteristics of seeds with the help of pachymeter and digital balance. To dormancy breaking, the seeds were immersed in sulfuric acid during 0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 hours and sown in sand in a condition greenhouse. After 21 days emergence percentage, emergence speed index (IVE), shoot length and seedling dry weight of plants were recorded. At 0, 2, 4, 8, 12, 16, 20 days after sowing, the seedlings taken digital images and post-seminal morphology was characterized. The fruit of C. edulis contains an average of 19.27 globoses seeds of black coloration measuring about 5.62 mm in diameter, the average weight of 1000 seeds is 128.8 grams. The highest percentage of seedling emergence of 60% and 90% are obtained from seed treated with 0.5 hours in sulfuric acid at 10 and 21 days after sowing, respectively. The seeds have hypogeal germination with development of fasciculate roots with root axes differentiated at 4 days after sowing. The protophyll is observed from the eighth day and the seedlings have intense purple coloration at 16 days after sowing.

Biometry of fruits and seeds, seeds germination and post-seminal development of areca palm

Areca palm is an ornamental palm largely used in landscape which propagate occur by seeds germination. However, the biometry and the endogenous and exogenous factors than can limit propagation of this plant are poorly known, so this work was aimed characterize biometrics of fruits and seeds of areca palm and evaluate the germination of seeds in different substrates. For this, the biometric analyses of length, diameter and weight were recorded; the description of internal and external morphology of frit and seed were also studded. The treatments to improvement of seed germination were intact seeds (T1), intact seeds soaked in 500 mg L -1 GA 3 solution (T2), physically scarified seeds with the aid of sandpaper (T3) and physically scarified seeds after immersion in 500 mg L -1 GA 3 solution (T4). The Seeds were sown in containers containing sand, coir dust or vermiculite. The areca pal fruits and seeds are both, elliptical shape and the weight of fruits and seeds is 1.70g and 1.04g, respectively. There is positive correlation between fruit weight and length and diameter of the fruit and just like the diameter has a positive correlation with the diameter of the seed. The mechanical scarification improve the seed germination. The Coir dust is the most atrophied substrate to seed germination of areca palm. The seed germination of Areca palm is hypogeal and the protrusion of the haustorium was observed at 59 days after sowing and the plantlets is fully grown at 153 after sowing.

RESPOSTAS FISIOLÓGICAS DE PLÂNTULAS DE Erythrina verna SOB TRATAMENTOS PRÉ-GERMINATIVOS DE SEMENTES E PROFUNDIDADE DE SEMEADURA

The objective of this work was to determine the most appropriate pre-germinative treatment of seeds and sowing depth for the production of Erythrina verna seedlings. For this, the following pre-germinative treatments were initially studied: control (intact seeds); mechanical scarification on the area opposite to hilum, with the help of sandpaper number 80; mechanical scarification on the raphe region, with the help of sandpaper number 80; soaking in water for 24 hours. In a second experiment, the seeds were sown at the depths of 1, 2, 3, 4, 5 and 6 cm. After 15 days, we evaluated the percentage of emergence, emergence speed index, shoot length and seedling root length, dry weight of shoot and root dry mass of seedlings. The seeds of Erythrina verna present coat dormancy that can be broken by mechanical scarification in the area opposite to the hilum. The seedlings present the best physiological quality when seeds are sowing at 1 to 3 cm depth, where the highest percentages of emergence, speed of emergence index, length of shoot and

Physiological responses of Erythrina verna seedlings on seed pre-germinative treatments and sowing depth

Este trabalho objetivou determinar o melhor tratamento pre-germinativo de sementes e a profundidade de semeadura mais adequada para a producao de mudas de Erythrina verna. Para isso, os seguintes tratamentos pre-germinativos foram estudados: testemunha (sementes intactas), escarificacao mecânica na regiao oposta ao hilo com auxilio de lixa no 80, escarificacao mecânica na regiao da rafe com auxilio de lixa no 80, embebicao em agua por 24 horas. Em um segundo experimento, as sementes foram semeadas nas profundidades de 1, 2, 3, 4, 5 e 6 cm. Apos 15 dias avaliou-se a porcentagem de emergencia, indice de velocidade de emergencia, comprimento da parte aerea e comprimento da raiz das plântulas, massa seca de parte aerea e massa seca de raiz das plântulas. As sementes de Erythrina verna apresentam dormencia tegumentar que pode ser superada pela escarificacao mecânica na regiao oposta ao hilo. As plântulas apresentam a melhor qualidade fisiologica quando as sementes sao semeadas a profundidade de 1 a 3 cm, onde a maior porcentagem de emergencia, indice de velocidade de emergencia, comprimento da parte aerea e da raiz e massa seca da parte aerea sao obtidos.