tailieunhanh - Báo cáo lâm nghiệp:"Influence of cotyledon removal on early seedling growth in Quercus robur L."

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí lâm nghiệp đề tài:"Influence of cotyledon removal on early seedling growth in Quercus robur L." | Ann. For. Sci. 60 2003 69-73 INRA EDP Sciences 2003 DOI forest 2002075 69 Original article Influence of cotyledon removal on early seedling growth in Quercus robur L. Francisco García-Cebrián Jordán Esteso-Martínez and Eustaquio Gil-Pelegrín Unidad de Recursos Forestales Servicio de Investigación Agroalimentaria Gobierno de Aragón Apdo 727 Zaragoza Spain Received 2 July 2001 accepted 7 February 2002 Abstract - The process of resource transfer from seed to growing plant in terms of dry matter and nitrogen was studied in Quercus robur L. seedlings. In a factorial experiment seedlings were subjected to cotyledon excision and shading just after shoot emergence. In another experiment we removed the cotyledons at emergence and 7 14 and 21 days later. The transfer of resources from cotyledons to growing plant seemed to be almost complete at a very early stage. Cotyledon excision just after shoot emergence resulted in a significant reduction in seedling growth. Shading had a minor effect during this period. However the influence of cotyledons on seedling growth declines soon. Their artificial suppression had no significant effect when it was performed later than two weeks after shoot emergence. The consequences of this fact on the relationship between dispersion by jays and seedling growth are discussed. Quercus robur L. reserve effect cotyledon nitrogen transfer Résumé - Influence de l excision des cotyledons sur la croissance initiale des semis de Quercus robur L. On a étudié le mécanisme de transfert des réserves de glands de Quercus robur L. vers le semis évalué par le poids sec et la teneur en azote. Dans une expérimentation factorielle après la germination les cotylédons ont été enlevés et les semis placés sous ombrage. Dans une deuxième expérimentation les cotylédons ont été supprimés à différentes périodes à la germination 7 14 et 21 jours après. Le transfert des réserves des cotylédons vers le semis semble être terminé très tôt. L excision des .