Physiological Quality of Swingle Citrumelo Seed after Refrigerated Storage of Fruits and Seeds

For citrus, there is no definition of the ideal fruit harvesting point for seed extraction. Some studies have shown the positive effect of postharvest refrigerated storage of fruits to obtain quality seeds. This study aimed to evaluate the influence of the fruit maturation stage on the germination of Swingle citrumelo (CS) seeds after the refrigerated storage of fruits and seeds. CS fruits were harvested at 180 days after anthesis (DAA); 210 DAA and 240 DAA. Fruits and seeds were stored in cold chamber for 0, 15, 30, and 45 days. Physicochemical analyses were performed on fruits (colour, soluble solids, acidity and ratio) and seeds (water content, germination, and emergence). Germination of seeds extracted from fruits harvested at 180, 210, and 240 DAA, without refrigerated storage, showed a positive correlation with colour index. The refrigerated storage of fruits and seeds extracted from fruits harvested at 210 DAA, increased the seed germination rate. Peel colour (IC) was correlated positively with the germination of Swingle citrumelo seeds. The results of this study revealed that the absence of refrigerated storage, harvesting Swingle citrumelo fruits, with ripe characteristics (end of harvest), results in a high seed germination rate. On the other hand, refrigerated storage of fruits and seeds extracted from fruits harvested at mid-harvest increases the seed germination rate.

Morphological variability of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) cones in the context of seed extraction

In the paper generating curves given by fourth-degree polynomials were used to model the shape of Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) cones from the Polish Forest Districts of Kołaczyce (one batch) and Opole (two batches), and to calculate the surface area and volume of individual cones. However, it was not possible to construct generalized equations for the surface area and volume of Douglas fir cones due to the high variability of empirical coefficients. The surface area and volume of the cones were also calculated from their length and diameter based on formulas for a cylinder and a barrel corrected by constants k1 and k2. The mean surface area of closed Douglas fir cones determined for the first, second, and third batch using the generating function was 4,348.4 mm2, 3,857.0 mm2, and 2,844.7 mm2, and the volume was 27,212.4 mm3, 21,012.9 mm3, and 12,844.4 mm3, respectively. The corresponding values calculated from the geometric formulas for solids were 4,332.0 mm2, 3,838.0 mm2, and 2,862.9 mm2 for the surface area and 27,366.0 mm3, 20,648.9 mm3, and 13,375.3 mm3 for the volume. The evaporation area of open cones was found to be five times greater than that of closed cones, with the difference being statistically significant. The outer and inner surfaces of scales taken from the middle segment of Douglas fir cones were photographed using a Quanta 200 scanning microscope (FEIC). The characteristic elements of scale morphology were evaluated by means of MultiScan Base software package. The outer and inner surfaces of Douglas fir scales were found to differ in some important ways, similarly as it has been reported in the literature for the Scots pine, silver fir, European larch, and black alder. The outer surface of scales is formed by thick-walled cells with marked protrusions, while the inner surface reveals cells with thin, frayed walls in the region adjacent to the seeds and wings. Knowledge of the geometry of Douglas fir cones and the morphology of their scales may be helpful in optimizing seed extraction parameters for those cones. Key words: seed extraction, model, shape curve, surface area, volume, scanning electron microscope

BIOACTIVITY ANALYSIS OF Annona glabra L. SEED EXTRACTS FOR WOOD PROTECTION AGAINST TERMITES (Cryptotermes cynocephalus Light. AND Coptotermes curvignathus Holmgren.)

Pond apple (Annona glabra L.) belongs to the family of Annonaceae. The seed of A. glabra contains bioactive substance that is toxic to some organisms, however the effectiveness to control wood degrading termites has not yet been scientifically reported. This research analyzes the efficacy of A. glabra seed extract to wood degrading termites. Seed extraction was conducted using n-hexane and ethyl acetate. The paper disc test showed that the extract of A. glabra is toxic to Cryptotermes cynocephalus (dry-wood termites) and Coptotermes curvignathus (subterranean termites). The higher extract concentration (up to 63%) resulted in a higher termite mortality (up to 100%) and lower weight loss of paper sample (less than 1%). Ethyl acetate extract of A. glabra seeds has a better toxicity effect than n-hexane extract against dry wood termites and subterranean termites.

The Kinematics of Scale Deflection in the Course of Multi-Step Seed Extraction from European Larch Cones (Larix decidua Mill.) Taking into Account Their Cellular Structure

The objective of the study was to elucidate the kinematics of cone opening in the European larch (Larix decidua Mill.) during a four-step seed extraction process and to determine optimum process time on that basis. Each step lasted 8 h with 10 min of water immersion between the steps. The study also described the microscopic cellular structure of scales in cones with a moisture content of 5% and 20%, as well as evaluated changes in cell wall thickness. The obtained results were compared with the structural investigations of scales conducted using scanning electron microscopy (SEM) of characteristic sites on the inner and outer sides of the scales. The greatest increment in the scale opening angle was noted on the first day of the process (34°) and in scales from the middle cone segment (39°). In scales with a moisture content of 5% and 20%, the greatest changes in cell wall thickness were recorded for large cells (57%). The inner and outer structure of scales differed in terms of the presence and size of cells depending on the moisture content of the cones (5%, 10%, or 20%). The study demonstrated that the moisture content of cones was the crucial determinant of the cellular structure and opening of scales in larch cones. The scale opening angle increased with decreasing moisture content but did not differ significantly for various segments of cones or various hours of the consecutive days of the process. This finding may lead to reducing the seed extraction time for larch cones. The internal and external structure of scales differed depending on moisture content, which also determined the size and wall thickness of cells.

Molecular interaction of natural dye based on Zea Mays and Bixa Orellana to nanocrystalline TiO2 into dye sensitized solar cells.

This work studies the interaction between natural dyes obtained from Peruvian Zea mays and Bixa orellana seeds and nanostructured titanium dioxide in order to evaluate their function as sensitizers into solar cell devices. The effective attachment of dyes to the TiO2 layer is corroborated by the comparison of UV-Visible absorption and FT-IR spectra of the extracted dye solutions and sensitized TiO2 electrodes. The principal compounds from the seed extraction of Zea mays and Bixa orellana are cyanidin-3-glucoside (C3G) and bixin, respectively, which were analyzed in an isolated dye/cluster TiO2 system by molecular dynamic simulation. The results showed that the chemisorption is carried out through a consecutive deprotonation process and Ti-O bond formation by the monodentate OH and COOH anchoring groups, for C3G and bixin, respectively. Finally, we tested the effect of the dye – TiO2 interaction on the charge transfer by the comparison of the current-voltage (I-V) curves and incident photon-to-current conversion efficiency (IPCE) of the cells. We found that dye agglomeration in films with Bixa orellana and the high charge recombination of films with Zea mays are critical points to be solved. For this reason, we propose the pretreatment of the TiO2 film before sensitization with Bixa orellana and analyze the effects of pH in Zea Mays solution, in order to obtain better device efficiencies.

Determinação de alterações morfológicas durante a maturação de sementes de melão com uso de raios X

The search for melon with high physiologic quality is essential to have competitive material compared to the imported. The analysis of images realized through X-ray is a technique that verify internal morphology and relates with the seed performance. In this way, the goal of this study was to evaluate the seed physiological quality from melon of Anton cultivar in function of different phase of maturation of stored and non-stored fruits through the visualization of internal morphology of seeds using X-ray images. The experiment was managed from December of 2016 to February of 2018. The yellow-melon fruits analyzed were cultivated in Embrapa Hortaliças greenhouse. The fruits were picked in five distinct periods: 30, 45, 60, 75, and 90 days after anthesis (DAA). In each period were picked a total of 30 fruits where 15 fruits had their seeds immediately extracted after been picked, and 15 fruits were stored. The 15 fruits stored were packed in plastic box properly identified for a period of fifteen days in airy place with room temperature. The 30 fruits were subjected to the same process of seed extraction, washing and drying. The dried seeds from stored and non-stored fruits were submitted to the following analyses: X-ray test and the germination test. The treatment of 60 DAA over storage shown better performance with 67% in the germination test on the first counting and 87% of normal seedlings. This result is similar to the noted in the X-ray test where the treatment demonstrated 96% of filled seeds showing the viability of this tool to determine physiologic quality in the melon seeds.