Physiological responses of spring rapeseed [Brassica napus] to red - far - red ratios and irradiance during pre - and post - flowering stages
Early shade signals promote the shade avoidance syndrome [SAS] which causes, among others, petiole and shoot elongation and upward leaf position. In spite of its relevance, these photomorphogenic responses have not been deeply studied in rapeseed [Brassica napus]. In contrast to other crops like mai...
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| Otros Autores: | , , , , |
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| Formato: | Artículo |
| Lenguaje: | Inglés |
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| Acceso en línea: | http://ri.agro.uba.ar/files/intranet/articulo/2014rondanini.pdf LINK AL EDITOR |
| Aporte de: | Registro referencial: Solicitar el recurso aquí |
| Sumario: | Early shade signals promote the shade avoidance syndrome [SAS] which causes, among others, petiole and shoot elongation and upward leaf position. In spite of its relevance, these photomorphogenic responses have not been deeply studied in rapeseed [Brassica napus]. In contrast to other crops like maize and wheat, rapeseed has a complex developmental phenotypic pattern as it evolves from an initial rosette to the main stem elongation and an indeterminate growth of floral raceme. In this work, we analyzed [1] morphological and physiological responses at individual level due to low red-far-red [R-FR] ratio during plant development, and [2] changes in biomass allocation, grain yield and composition at crop level in response to high R-FR ratio and low irradiance in two modern spring rapeseed genotypes. We carried out pot and field experiments modifying R-FR ratios and irradiance at vegetative or reproductive stages. In pot experiments, low R-FR ratio increased the petiole and lamina length, upward leaf position and also accelerated leaf senescence. Furthermore, low R-FR ratio reduced main floral raceme and increased floral branching with higher remobilization of soluble carbohydrates from the stems. In field experiments, low irradiance during post-flowering reduced grain yield, harvest index and grain oil content, and high R-FR ratio reaching the crop partially alleviated such effects. We conclude that photomorphogenic signals are integrated early during the vegetative growth, and irradiance has stronger effects than R-FR signals at rapeseed crop level. |
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| ISSN: | 1399-3054 |