Verticalidade foliar e interceptação de luz: eficiência de conversão em biomassa

• Autor(a) principal: Beraldo, Amanda Naves [UNESP]
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/155826; http://www.athena.biblioteca.unesp.br/exlibris/bd/capelo/2017-08-30/000889919.pdf
• topic: Fisiologia vegetal; Analise foliar; Plantas - Efeito da luz; Plantas - Fotomorfogênese; Plantas - Analise; Biomassa vegetal; Folhas - Anatomia; Fotossintese

The light capture is a low efficiency process in plants, as they effectively use only 8% sunlight. A better distribution and penetration of sunlight within the plant canopy is observed in plants with vertical leaves (paraheliotropic and/or static vertical leaves) because light may be intercepted by both leaf surfaces (adaxial and abaxial sides). By doing so, photoinhibition, water deficit, leaf heating, irradiance excess, and auto-shading are minimized. These responses have been studied using momentary measured parameters (leaf gas exchange and chlorophyll fluorescence), however little is known about the effects of different leaf angles on the conversion of sunlight into biomass. We have tested the hypothesis that the biomass production in plants with leaves artificially maintained at the vertical position is higher than those with leaves forced at the horizontal position. We used pots (50 L) to cultivate 30 sugar-cane plants (Saccharum oficinarum L. cv. IACSP95-5000), of which ten had their leaves kept at the vertical position, ten had their leaves kept at the horizontal position and ten grew naturally (control). During cultivation, the leaves were counted every two weeks. After seven months, leaves area (AF, cm2) were determined and the distinct plant organs (Leaves, stems, sheaths and roots) were set apart and oven-dried (60C) until obtaining constant dry mass (g). Data was submitted to a one-way analysis of variance (ANOVA), and mean results accompanied by the Tukey test (α = 5%). There was no significant difference in height between control plants and those with leaves arranged vertically; however, the height of the plants with leaves arranged horizontally was lower than both treatments. The aerial biomass was higher in plants with leaves arranged vertically in relation to other treatments, resulting in 22.9% and 15% more mass in relation to plants with leaves set...