Light-based methods are being further developed to meet the growing demands for food in the agricultural industry. Optical imaging is a rapid, non-destructive, and accurate technology that can produce consistent measurements of product quality compared to conventional techniques. In this research, a novel approach for seed quality prediction is presented. In the proposed approach two advanced optical imaging techniques based on chlorophyll fluorescence and chemometric-based multispectral imaging were employed. The chemometrics encompassed principal component analysis (PCA) and quadratic discrimination analysis (QDA). Among plants that are relevant as both crops and scientific models, tomato, and carrot were selected for the experiment. We compared the optical imaging techniques to the traditional analytical methods used for quality characterization of commercial seedlots. Results showed that chlorophyll fluorescence-based technology is feasible to discriminate cultivars and to identify seedlots with lower physiological potential. The exploratory analysis of multispectral imaging data using a non-supervised approach (two-component PCA) allowed the characterization of differences between carrot cultivars, but not for tomato cultivars. A Random Forest (RF) classifier based on Gini importance was applied to multispectral data and it revealed the most meaningful bandwidths from 19 wavelengths for seed quality characterization. In order to validate the RF model, we selected the five most important wavelengths to be applied in a QDA-based model, and the model reached high accuracy to classify lots with high-and low-vigor seeds, with a correct classification from 86 to 95% in tomato and from 88 to 97% in carrot for validation set. Further analysis showed that low quality seeds resulted in seedlings with altered photosynthetic capacity and chlorophyll content. In conclusion, both chlorophyll fluorescence and chemometrics-based multispectral imaging can be applied as reliable proxies of the physiological potential in tomato and carrot seeds. From the practical point of view, such techniques/methodologies can be potentially used for screening low quality seeds in food and agricultural industries.
Bidens pilosa is an aggressive species that competes with crops and, in addition, has a high capacity to acquire resistance or tolerance to herbicides. Thus, the objective of the present study was to investigate the allelopathic effects of aqueous extract of Urochloa ruziziensis on germination, development, respiration, antioxidant enzymes and cells morphology of B. pilosa seedlings during initial growth at laboratory.The seeds were sown with water or U. ruziziensis extract at concentrations of 250, 500 and 900 ppm, and after four days the percentage of germinated seeds, root and hypocotyl development, as well as respiration, peroxidase and catalase activity by seedlings, were analysed. The results were submitted to analysis of variance (ANOVA) and the means compared by the Tukey test and regression analysis. The cellular structures of the root with U. ruziziensis extract treatment (0, 500 and 900 ppm) were also analysed by transmission electron microscopy. The application of the extract reduced the germination of the seeds. The root growth increased, however, there was a reduction in the dry matter mass at 500 ppm. Mitochondrial respiration decreased and there was an increase in the activity of the peroxidase and catalase enzymes at 500 ppm. Morphological changes in the cells were also found, mainly with this concentration. Thus, it is possible can be concluded that allelochemicals present in extract from U. ruziziensis have the potential to provoke oxidative stress in B. pilosa seedlings in laboratory, mainly at a concentration of 500 ppm. This oxidative stress caused alterations mainly in the energetic metabolism of this plant, being this a primordial factor for its growth and survival. y= -52,09x + 407,1 R 2 = 83% y= -40,71x + 322,8 R 2 = 89% y= -40,71x + 322,8 R 2 = 90% Aqueous extract of Urochloa ruzizienses Oxygen consumption (nmol min -1 g -1 )
O emprego do microscópio eletrônico de transmissão (MET) é bastante difundido no estudo de materiais biológicos, pois ele permite definição de imagens intracelulares, permitindo estudos de morfologia celular e de aspectos gerais das organelas. As imagens são produzidas por meio da interação inicial de um feixe de elétrons com a amostra, que é mantida sob condições de alto vácuo. Tanto o ambiente de vácuo como a própria irradiação dos elétrons durante a observação, representam condições adversar para a amostra, especialmente no caso de materiais orgânicos ou biológicos, que são por natureza hidratados, frágeis e elétricamente isolantes. Considerando que existem várias técnicas de preparo para MET, mas pouca descrição detalhada destas técnicas na literatura, principalmente para o preparo de raízes de plântulas, assim, esse trabalho teve como objetivo aplicar e adaptar essas técnicas para o estudo de boa qualidade de raízes de plântulas. As amostras primeiramente foram lavadas em tampão fosfato salina, passando pela fixação primária com glutaraldeído, depois pós-fixação com tetróxido de Ósmio, onde posteriormente foram desidratadas com acetona e infiltradas com resina Epon, finalizando com a polimerização, ultramicrotomia e contrastação da amostra. Contudo, essa descrição detalhada da metodologia aplicada para raiz de plântulas, pode ser utilizada com segurança e eficácia por outras pessoas, pois quase não existem descrições adaptadas de metodologia de MET na literatura, principalmente para raiz de plântulas.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.