Morphological characterization of fruit, seed and seedling, and seed germination test of Campomanesia guazumifolia

<div><p>Abstract: Campomanesia guazumifolia (Cambess.) O. Berg. is a native fruit species, with ecological importance and potential to be exploited by food and medical industries. There is a lack of studies enabling its on-site conservation and propagation for commercial purposes. The objective of this work was to morphologically characterize the fruit, seed and seedling development stage of this species, as well as to determine an efficient protocol for the germination test, aiming at the commercial production of seedlings. Different temperatures (20, 25, 30 and 20-30 °C), substrates (blotting paper, sand and vermiculite) and light regimes (presence and absence) were tested in order to evaluate the germination power of seeds. Fruits are bacoid, rounded, with a fleshy pericarp and hairy surface, and with an intense yellow coloration. Seeds have a reniform shape and a lateral recess, with a membranous, brown and verrucose-glanulose tegument. It has a crass embryo, with a well developed hypocotyl-radicle axis and vestigial cotyledons. Seedlings are epigeal and phanerocotylar. It is recommended to conduct the germination test for the species with temperatures of 25 or 30 ºC, on paper substrates, with light presence or absence, and with the first test count performed 23 days and the final count 50 days after sowing.</p></div

Morphophysiological characteristics of guanandi fruit and seeds during ripening and harvesting time

<div><p>Abstract: The objective of this work was to determine the relationship of the morphological and physiological characteristics of guanandi (Calophyllum brasiliense) fruit and seeds with ripening and harvesting time. The reproductive cycle of a native plant population, located in the coast of the state of Paraná, Brazil, was monitored from anthesis until fruit dispersion, during three years. Monthly harvests were performed, and the morphological and physical aspects (color, size, dry mass, and moisture content) of fruit and embryos were evaluated, as well as the physiological ones (germination and vigor) of seeds. The ripening process of guanandi seeds occurred between 200 and 240 days after anthesis (DAA), with anthesis peak in February and fruit dispersion in October. The maximum dry matter mass accumulation was not synchronized with the maximum physiological potential of the seeds. Germination potential was reached close to the middle of the maturation process, and maximum vigor at the end of the cycle. Fruit external color did not change from 110 DAA onwards. The morphological characteristics related to harvesting time are fruit pulp and embryo weakly adherent to the endocarp and to the tegument, respectively, as well as the dark-brown color of these tissues.</p></div

Osmotic stress on genetically transformed tobacco plant seeds

<div><p>Abstract: Salinity and water deficit limit the productivity of several crops; thus, studies related to the genetic transformation of seeds in a model plant, such as tobacco, can be an alternative to minimize negative impacts caused by environmental conditions. The purpose of this work was to evaluate the tolerance to osmotic stress of seeds from genetically transformed tobacco plants, with the introduction of the proline-synthesizer gene (p5csf129a), under salinity and water deficit conditions. To do so, five events with differences in proline content were selected, ranging from 0.70 to 10.47 µmoles.g-1 of fresh mass. The used saline concentrations were: zero (distilled water); 50; 100; 150 and 200 mmol.L-1 of NaCl, whereas for the water deficit, simulated with PEG 6000, the following osmotic potentials were used: zero (distilled water); -0.2; -0.4; -0.6 and -0.8 MPa. Each tested treatment was evaluated through germination, first germination count and germination speed index tests. It is possible to conclude that seeds from genetically transformed tobacco plants with overexpression of the gene p5csf129a, a proline synthesizer, are more tolerant to osmotic stresses. Tabacco seeds with a proline content of 10.47 µmol.g-1 showed a better perfomance, revealing higher physiological potential.</p></div