tailieunhanh - Báo cáo khoa học: "Effects of drought on the induced defence reaction of Scots pine to bark beetle-associated fungi"

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: "Effects of drought on the induced defence reaction of Scots pine to bark beetle-associated fungi. | 91 Ann Sci For 1993 50 91 -97 Elsevier INRA Note Effects of drought on the induced defence reaction of Scots pine to bark beetle-associated fungi L Croisé F Lieutier INRA Station deZoologie Forestiers Ardon 45160 Olivet France Received 3 April 1992 accepted 14 September 1992 Summary Water stress was imposed on Scots pine saplings grown in a greenhouse. Predawn leaf water potential VwD was monitored regularly while carbohydrate reserves were quantified in the phloem xylem and shoots. Trees were inoculated in the bole with a bark beetle-associated fungus at 4 different periods of the year the induced defence reaction was quantified 2-3 wk later by its length and the total amount of resin. A decrease in the induced reaction length and resin quantity was observed in the most severely stressed trees. However no clear relationship could be established between the concentration of carbohydrates soluble or hydrolysable and the intensity of the defence reaction. pinus sylvestris phytopathogenic fungus induced defence reaction I water stress predawn leaf water potential carbohydrate reserve Resume Action d un stress hydrique sur la reaction de defense induite du pin Sylvestre contre des champignons issus d insectes Scolytides. Un stress hydrique a été applique en serre sur des pins Sylvestres de 6 ans. Des champignons phytopathogènes préalablement isolés d in-sectes Scolytides ont été directement inoculés dans le liber de ces arbres afin de préciser I effet de la contrainte hydrique sur les caractéristiques de la reaction locale de defense longueur et quantité totale de résine . L etat hydrique des arbres a été suivi régulièrement par des mesures du potentiel hydrique de base au niveau des aiguilles irwD . Les reserves glucidiques de I arbre ont été dosées dans le liber I aubier et les pousses au moment des inoculations. Quatre series d experience ont alnsi été réallsées sur les mẽmes arbres de mai à octobre 1989. Pour des potentiels de base allant jusqu a -2 MPa vwD est .