Universidade Federal de Viçosa

About: Universidade Federal de Viçosa is a education organization based out in Viçosa, Brazil. It is known for research contribution in the topics: Population & Biology. The organization has 16012 authors who have published 26711 publications receiving 353416 citations.

Light quality in plant tissue culture: does it matter?

Abstract: The primary issues regarding the lack of protocol reproducibility among laboratories are environmental factors. Light (quantity and particularly quality), is one of those main factors, and studies seldom present the spectral quality of the light sources used. With the advent of light-emitting diode (LED) technology, impressive progress has been made in environmental controls and morphogenetic responses, as directed by the light used in the culture shelves. A wide array of LED lights with different spectra are currently available and light is important in large-scale propagation, especially liquid bioreactor systems. LED technology continues to evolve rapidly and has created additional possibilities. This laboratory has dedicated extensive efforts to implement photoautotrophic propagation, and light is a key component of the system. This review presents relevant topics on the influence of light in various plant tissue culture-based techniques.

Food technology neophobia and consumer attitudes toward foods produced by new and conventional technologies: A case study in Brazil

Abstract: New food technologies are promoting innovations in the food sector. However, not all technologies are accepted and understood by consumers; some cause resistance. The present work sought to study the behavior of Brazilian consumers in relation to different food technologies. A questionnaire was administered to a representative sample of 389 respondents in Belo Horizonte-MG, Brazil. Questionnaire collected information on consumer perceptions regarding new technologies by means of the Food Technology Neophobia Scale (FTNS), translated and validated into Portuguese, in addition to familiarity and willingness to try yogurts labeled such as traditional, pasteurized, organic, genetically modified, enriched with bioactive proteins and nanotechnology. Results suggested that neophobia regarding food technology is important to explain consumer behavior in relation to new technologies, especially for nanotechnology. Participants were less familiar with foods labeled as GM and nanotechnology, and willingness to try these products was lower. Consumers are still wary of GM and nanotechnology, possibly due to lack of assurance that these foods are safe for human health and the environment. For new food technologies (such as nanotechnology) that are still recent, communication is very important, being decisive for the consolidation of consumer perceptions, and consequently for the acceptance of these innovations on the market.

Effects of soil water deficit and nitrogen nutrition on water relations and photosynthesis of pot-grown Coffea canephora Pierre

Abstract: Coffea canephora plants (clone INCAPER-99) were submitted to low N (LN) or high N (HN) applications and two watering regimes (daily irrigation and irrigation every 5 days for a month). Although water potential was not altered significantly by N, HN plants showed higher relative water content than did LN plants under water deficit. Only HN plants exhibited some ability for osmotic adjustment. Plants from both N treatments increased their cell wall rigidity under drought, with a more pronounced augmentation in HN plants. In well-watered plants, carbon assimilation rate increased with increasing N while stomatal conductance did not respond to N supply. Under drought conditions, carbon assimilation decreased by 68–80% compared to well-watered plants, whereas stomatal conductance and transpiration rate declined by 35% irrespective of the N applications. Stable carbon isotope analysis, combined with leaf gas exchange measurements, indicated that regardless of the watering treatments, N increased the long-term water use efficiency through changes in carbon assimilation with little or no effect on stomatal behaviour.