Ester Alice Ferreira

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

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.

Prolongamento do período de colheita da tangerineira Ponkan com aplicação de GA3 e 2,4-D

This experiment was carried out on a ten year-old commercial orchard in Sao Joao Del Rei county-MG in order to extend the harvest season of tangerine Ponkan (Citrus reticulate Blanco). One evaluated the effects of Giberelic Acid (GA3) at 0, 10, 20 and 30 mg.0L-1 and Diclorofenoxiacetic acid (2,4- D) at 0 and 10 mg.L-1 applied two times: on 4/24 and 5/17 when the fruits still had a green peel color the evaluations were made: the first one on 7/25, when the harvest time in the region was ending, and the second 30 days after. The experimental design adopted was the one of randomized blocks, with a factorial of 4 x 2 x 2, with four split-plot replicates. The results showed that 2,4-D at 10 mg.L-1 influenced fruits texture and extended the harvest and also increased fruit acidity and reduced the ratio; GA3 at 20mg.L-1 increased the diameter and weight of the fruits harvested in August and presented higher juice rate and there was no difference on total soluble sugar in solid solute tenor.

BIOACTIVE COMPOUNDS AND ANTIOXIDANT ACTIVITY OF PINEAPPLE FRUIT OF DIFFERENT CULTIVARS

Pineapple is widely consumed and appreciated not only due to its taste and aroma, and also to its nutritional, functional and antioxidant properties, including its vitamin C and carotenoid contents. Brazil is one of the largest world’ pineapple producer, and Perola and Smooth Cayenne cultivars are the most commonly grown and marketed, but their susceptibility to fusariosis can compromise cultivation. New cultivars resistant to this pathogen are available to meet the demands of pineapple producers and consumers. The aim of this study was to evaluate the content of bioactive compounds and antioxidant activity of pineapple fruits of Imperial, Victoria, IAC Fantastico and Gomo de Mel cultivars, as well as traditional Perola and Smooth Cayenne cultivars. Fruits grown in the Triângulo Mineiro region were evaluated by colorimetry, determination of ascorbic acid and phenolic compounds by spectrometry, antioxidant activity by ABTS and carotenoid profile by HPLC. Regarding color, Gomo de Mel cultivar showed lower brightness and higher value of parameter b*, indicating a more intense yellow color in this fruit. This result is consistent with the highest carotenoid concentration in this cultivar. Another cultivar that stood out was Imperial, which, while maintaining high carotenoid levels, also showed high concentrations of vitamin C and phenolic compounds, and higher antioxidant activity. Victoria cultivar showed low levels of bioactive compounds and antioxidant activity, even lower than IAC Fantastico cultivar, which showed levels of bioactive compounds similar to traditional Perola and Smooth Cayenne cultivars.