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ABSTRACT The study aimed to evaluate the influence of silver nitrate on the in vitro flowering of Capsicum frutescens cv. Cayenne associated with different light spectra and gas exchange. After 36 days of germination in MS medium, two seedlings previously germinated, were subjected to experiments in glass flasks containing two types of culture medium: I) MS culture medium; or II) Culture medium with the addition of 40 µM of AgNO3. The explants were maintained in a growth room with a 16-hour photoperiod, temperature of 25 ± 2 °C, light intensity (72 μmol m-2 s-1) from different light spectra. The experiment was conducted in a completely randomized design, 4 x 2 factorial scheme, with eight replicates, and the experimental unit composed of two seedlings. After 74 days of in vitro cultivation, the following parameters were evaluated: number of bifurcations, number of oxidized buds, number of open buds, number of green buds, number of aborted buds, number of leaves, root length, shoot length, total fresh and dry mass of shoots, and total fresh and dry mass of root. Thus, the combination of light spectrum, addition of gas exchange and AgNO3 favors the growth and development of Capsicum frutescens cv. Cayenne.

Basella alba L. (Malabar spinach) is a non-conventional food plant (PANC) with high nutritional value and economic potential. Light is a critical factor in plant growth, acting directly on the photosynthetic process. The photoselective meshes combine the physical protection of plants with the selective filtering of solar radiation to promote physiological responses. This work evaluates the growth of B. alba under different light environments. The experiment occurred in a greenhouse at the Center for Agrarian, Environmental and Biological Sciences of the Federal University of Recôncavo da Bahia in a completely randomized design with plots comprising one useful plant and five replications. The plants were grown in three light environments: red ChromatiNet mesh, aluminet-thermo reflective mesh (both with 50% irradiance), and under full sun. The red mesh increased the root dry matter mass and stem diameter. The aluminet mesh increased the average number of leaves by about 50% compared to the plants cultivated under full sun. The results show that the cultivation of B. alba in different light environments promotes morphophysiological changes with positive increments in growth.

This study aimed to evaluate the effect of changing light spectral quality, using colored shading nets, on the characteristics of tamarind (Tamarindus indica L.) leaf anatomy to obtain more conducive plants. Tamarind seedlings were grown under blue, white, black and red shade nets, in a completely randomized design. After 90 days, the leaves were evaluated anatomically and micromorphologically. Plants grown under white net had greater palisade parenchyma, abaxial epidermis cells and midrib thicknesses. Better results for adaxial epidermis and leaf blade were observed under white and blue nets. Higher stomatal density was obtained under blue and red nets. Tamarindus indica leaves present anatomical plasticity in response to changes in the radiation spectrum. In view of these results, the white and blue nets can be recommended to obtain plants more efficient to planting. [ABSTRACT FROM AUTHOR]