Photoperiod-related changes in plant resource allocation: a physiological view

• Ano de defesa: 2022
• Autor(a) principal: Silva, Welson Junior
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Universidade Federal de Viçosa
• Palavras-chave em Português: Ritmo circadiano; Fotoperiodismo; Biomassa; Ecofisiologia Vegetal
• Link de acesso: https://locus.ufv.br//handle/123456789/29194; https://doi.org/10.47328/ufvbbt.2022.282

Fabaceae is one of the most consumed botanical families in both human and animal diets, due to its high nutritional value of nitrogen and protein. In fact, about 35 tons of leguminous grains are consumed annually revealing its enormous importance. Contrasting environmental conditions drastically affect the allocation of resources to cultivated plants of agronomic interest. Photoperiod is an environmental condition that plays an essential role in modulating resource allocation being also able to influence plant growth, survival and interactions in the environment. Accordingly, our understanding of the details that govern the flow of nutrients and differential patterns of plant development and growth remains fragmented. The present work was carried out to analyze the impacts on the physiology, metabolism, anatomy and resource allocation of plants of the Fabaceae family (Vigna unguiculata and Pisum sativum) caused by photoperiod variation [short days (8 light/16 dark) or long days (16h light/8h dark)]. Long days negatively affected the growth of both plants and this lower growth was associated with lower photosynthetic rates. By contrast, under short day conditions, high photosynthesis (A N ) was associated with higher stomatal density, as well as higher stomatal conductance (g s ). Significant variations in morphological characteristics in vegetative organs in different photoperiods were observed among the genotypes. Long days culminated in reductions of growth parameters (e.g., dry weight of roots, stems and leaves and the number of leaves) yet root length and leaf area were higher. The different photoperiod conditions also altered the concentration of macro and micronutrients as revealed by an increase of mineral nutrients observed in short days plants. In conclusion, the resource allocation pattern in the investigated plants is strongly modified in response to fluctuations in light supply. Further detailed molecular and metabolic studies are still needed to better understand the effects of photoperiod on differential resource allocation. Keywords: Circadian rhythm. Photoperiodism. Biomass partitioning