Flávia Carvalho Santos

Micropropagação do abacaxizeiro ornamental

ABSTRACT Protocol for in vitro micropropagation of ornamentalpineapple The Ananas comosus var. erectifolius is an ornamental pineapplecultivar which greatly interests Brazilians and foreign landscapersand flower producers for being an exotic and rustic tropicalornamental plant. The market demand for high quality of cuttingsrequires efficient methods of propagation and in this context thetissue culture stands out as a viable alternative to obtain plants withgenetic and phytossanitary quality in a short time. In the presentwork we studied the influence of concentrations of BAP (0; 0.5; 1.0;1.5 mg L -1 ) and NAA (0; 0.12; 0.24; 0.48 mg L ) in the MS mediumculture within 0; 2.5; 5.0; 7.5 g L -1 of agar, in order to establish an invitro protocol for multiplication and rooting of ornamental pineapple.Plantlets with 1.5±0.5 cm already established in vitro , extracted frombuds of ornamental pineapple fruits crown were inoculated asepticallyin flasks. After inoculation the plantlets were kept in a growth roomat 26±1

Viabilidade do pólen de laranjas doces em diferentes condições de armazenamento

O presente trabalho foi realizado visando avaliar a viabilidade de graos de polen armazenados das cultivares copas citricas Natal, Pera e Valencia. O polen foi submetido a 3 temperaturas de armazenamento: -10oC (freezer), 4oC ( refrigerador) e temperatura ambiente; 2 ambientes (com e sem dessecador) e na presenca e ausencia de silica-gel. A avaliacao do indice de germinacao foi feita com o polen fresco e a cada 7 dias, durante 9 semanas. Para avaliar a germinacao foi utilizado meio constituido de 1% de agar e 10% de sacarose, 800 mg L-1 de nitrato de calcio (Ca(NO3)2 4H2O), 200 mg L-1 de Acido Borico (H3BO3) e pH corrigido para 6,5. Os graos de polen foram incubados a temperatura de 25 ± 2oC por 12 horas. As avaliacoes foram realizadas atraves da porcentagem de graos de polen germinados. Constatou-se que os graos de polen possuem reducao na viabilidade com o aumento do tempo de armazenamento; o armazenamento em freezer (-10oC) foi mais eficiente do que em refrigerador (4oC) e a temperatura ambiente. Melhores resultados foram alcancados com os tratamentos em freezer com silica-gel dentro de dessecador e em freezer sem silica-gel dentro de dessecador. A cultivar Valencia apresentou-se superior as demais em todos os tratamentos.

Fontes de nitrogênio, polpa de banana e ágar no desenvolvimento in vitro de plântulas de orquídea

Foram realizados dois experimentos com o objetivo de estudar os efeitos de fontes de nitrogenio, polpa de banana e agar no desenvolvimento in vitro de orquidea Cattleya loddigesii. O primeiro experimento constituiu-se de NH4NO3 (0; 25; 50; 75 e 100% da formulacao de 330 mg L-1) e KNO3 (0; 25; 50 e 100% da formulacao de 380 mg L-1) acrescidas ao meio MS. No segundo experimento, os tratamentos consistiram de concentracoes de agar (0; 2; 4; 6 e 8 g L-1), no meio de cultura Knudson C, acrescido de polpa de banana nanica (0; 50; 100; 150 e 200 g L-1) em todas as combinacoes possiveis. Apos a inoculacao as culturas foram mantidas em sala de crescimento com irradiância em torno de 35 μmol m-2 s-1, temperatura de 25±1oC e fotoperiodo de 16 horas, por 90 dias. Com base no peso da materia fresca das plântulas, numero de raizes, comprimento da parte aerea e comprimento da maior raiz, a adicao de 17,5 a 41,16% da formulacao original de NH4NO3 ao meio MS proporcionou melhor desenvolvimento in vitro em plântulas de Cattleya loddigesii. Maior numero de folhas foi obtido com a adicao ao meio MS de 100% da formulacao original de NH4NO3 e 50% de KNO3. A multiplicacao in vitro de plântulas de orquidea Cattleya loddigesii e viavel em meio Knudson C liquido com a utilizacao de 128,42 g L-1 de polpa de banana nanica.

Receptiveness of the stigma and in vitro germination of orange pollen, submitted to different temperatures

The study was carried out in order to evaluate the effect of temperature and in vitor stigma receptivity on regeneration of orange cultivar (Valencia, Pera and Natal) pollen. Two experiments were carried out, in the first the ideal temperature of germination was assessed. Pollen was obtained from flowers at the balloon stage and inoculated in culture medium with 10 g L-1 agar, 200 mg L-1 boric acid, 100 g L-1 sucrose, 800 mg L-1 calcium nitrate, pH adjusted to 6,5 and incubated in a BOD chamber at temperatures of 23, 24, 25, 26 and 27oC during a 24-hour photoperiod. After 12 hours of incubation, the best temperature for pollen grain germination was 25oC for all varieties. In a second experiment, in order to test the receptivity of the stigma, flowers were collected at different flowering stages: small bud, balloon and open flower. The stigmas were by immersion exposed to hydrogen peroxide (perioxidase reaction), 3% for 3 minutes. Through the technique of Zeisler (1938), better results were detected at the balloon stage with 80 to 100% receptivity, while for the open flower the receptivity presented maximum indexes.

Micropropagação do maracujazeiro-do-sono

Micropropagation of Passiflora setacea DC. Propagation of Passiflora setacea DC. is extremely difficult, therefore tissue culture techniques become a viable alternative. The objective of this study was to evaluate the in vitro germination and determine the best culture medium for micropropagation. This work was carried out in two stages; in the first, seeds were placed in ½ MS culture medium and 30 g L -1 of sucrose, distributed in tubes and supplemented with different AG 3 concentrations. The pH of culture medium was adjusted for 5.8 before adding 6.0 mg L -1 of agar. After seed inoculation, the cultures were kept in a growth room under 35 µmol.m -2 .s -1 , 26±1oC and photoperiod of 16 hours. Just after germination, the seedlings were transferred to tubes containing ½ MS, constituting a second experiment, in order to test culture media with different sucrose concentrations. The experiments were arranged in a complete randomized design, in a 3x3 factorial, with four repetitions and 15 seeds/plot (first experiment) and a 4x4 factorial, with four repetitions and 3 plants/plot (second experiment). The best results for micropropagation were obtanied in MSM medium with 28.51 and 28.74 g L -1 of sucrose. The highest germination speed index was obtained with 20 mg L -1 of AG 3 combined with seed tip scarification.

Desiccation sensitivity from different coffee seed phenological stages 1

Maturity stage and drying method are the factors that most influence coffee seed quality. The objective of this study was to assess the physiological quality and investigate the electrophoretic patterns of catalase and endo-s-mannanase enzymes and heat resistant proteins in coffee seeds harvested at different phenological stages and dried under different conditions. Physiological quality was assessed when the seeds had developed the green, greenish-yellow, cherry, overripe and dry stages after three treatments: no drying, conventional drying and fast drying. After each treatment, the physiological quality of the seeds was assessed using the germination test and electrophoretic patterns of heat resistant proteins and the activity of catalase and endo-s-mannanase enzymes. Seeds harvested at the cherry phenological stage had the best physiological quality, and the drying process reduced quality at the cherry, overripe and dry stages. This reduction was greater under the faster drying process, but at the greenish-yellow stage, seeds had better physiological quality after slow drying. Regarding the results from electrophoretic analysis, endo-s-mannanase and catalase activities increase as the ripeness stages advance; the activity of endo-s-mannanase is directly associated with the deterioration process; the expression of heat resistant proteins increases with maturation process and is associated with seed physiological quality.