Báo cáo khoa học: reproductive material of pedunculate oak (Quercus robur L) and sessile oak (Quercus petraea Matt Liebl) in France: problems and results

Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: reproductive material of pedunculate oak (Quercus robur L) and sessile oak (Quercus petraea Matt Liebl) in France: problems and results...
Nội dung trích xuất từ tài liệu:
Báo cáo khoa học: "reproductive material of pedunculate oak (Quercus robur L) and sessile oak (Quercus petraea Matt Liebl) in France: problems and results" Note Forest reproductive material of pedunculate oak (Quercus robur L) and sessile oak (Quercus petraea Matt Liebl) in France: problems and results R Fernandez CEMAGREF, Genetic Improvement and Forest Nursery Laboratory, Domaine des Barres, 45290 Nogent-sur-Vernisson, FranceSummary — Genetic improvement of indigenous oaks (pedunculate and sessile) is only at its begin-ning but a first step has been reached with the implementation of the 1966 EC directive concerningthe collection and the marketing of forest reproductive material (seed and seedlings). Two difficultiesof implementation are analysed: specific purity of stands and reproductive material, and validity ofthe regions of provenance. A conclusion is drawn after nearly 20 years of application.Quercus robur / Quercus petraea / seed stand / region of provenance / seed / seedlingRésumé — Les matériels forestiers de reproduction de chênes pédonculé et sessile enFrance : difficultés et résultats. L’amélioration génétique des chênes indigènes (pédonculé et ses-sile) en est à ses débuts, mais une première étape a été franchie avec la mise en application de ladirective CEE de 1966 pour la récolte et la commercialisation des matériels forestiers de reproduc-tion (graines et plants) : 2 difficultés d’application sont analysées (pureté spécifique des peuple-ments et des lots de matériels forestiers de reproduction, validité des régions de provenance) et unbilan est tiré après presque 20 ans d’application de la réglementation. de provenance /Quercus robur / Quercus petraea / peuplement / région porte-graines / plantssemencesINTRODUCTION periority) and tested stands (superiority for 1 or several traits in comparative tests). For oaks, only the first stand type exists.In France, the genetic improvement of pe-dunculate and sessile oak is As phenotypic selection principles have just begin-ning with particular emphasis on its intra- recently been described by Fernandez (1991),this paper will focus on 2 particularspecific variability. However, since 1973, aspects of the implementation of the regu-France has been applying an EC directiverequiring forest seed collection in 2 types lation: specific purity and validity of the re-of stands: selected stands (phenotypic su- gions of provenance.SPECIFIC PURITY tion started in 1973-1975. Since many mixed stands were selected then, com- plete checking is needed and will be com-Among the ’genetic’ criteria usually consid- pleted in less than 5 years from 1992.ered for seed stand selection, specific puri-ty is most important, particularly in mixedstands where natural interspecific hybridi- Seed and seedling specific purityzation is likely to occur or where it is diffi-cult to discriminate between species.Moreover, the regulation is very strict and A seed discrimination method can be ap-imposes more than 99% purity in seedlots plied with 85% confidence (Dupouey andand seedlings. This implies that methods Le Bouler, 1989) but, as it requires 2are necessary to identify oaks species measurements/acorn, it is difficult to usewhen stands are selected and to control widely. Seedlings can easily be identified,seedlot and seedling purity, from collection but only when in leaf. Therefore, checkingto planting. stand purity before selection is of the ut- most importance.Specific purity at the stand level VALIDITY OF REGIONS OF PROVENANCEIt has recently been demonstrated that ar-tificial hybridization of sessile and pedun-culate oak is possible, but that intermedi- A of provena ...