Tuyển tập các báo cáo nghiên cứu về lâm nghiệp được đăng trên tạp chí lâm nghiệp quốc tế đề tài: Variabilité clonale de la race polonica du mélèze d’Europe pour la résistance à Lachnellula willkommii. | 155 Ann. For. Sci. 56 1999 155-166 Inra Elsevier Paris Article original Variability clonale de la race polonica du meleze d Europe pour la resistance à Lachnellula willkommii Luc E. Pâquesa Giberte Sylvestre-Guinotb Claude Delatourb Station d amelioration des arbres forestiers Inra centre d Orleans 45160 Olivet France b Laboratoire de pathologie forestiere Inra centre de Nancy 54280 Champenoux France Re u le 9 janvier 1998 accepté le 19 aout 1998 Abstract - Genetic variation among clones of Larix decidua polonica for resistance to Lachnellula willkommii. Forty clones of European larch selected from four native stands in the Blizyn region central Poland were tested for resistance to Lachnellulla willkommii. In spring 1991 artificial inoculation mycelium on sorghum straw inserted into a hole drilled in twigs was conducted in three French sites Orleans Peyrat-le-Château and Cendrieux . Each clone represented by between 3 to 15 11-year-old ramets received between 20 to 40 inoculations. The development of larch canker symptoms bark necrosis pathogenic resins fructification was observed for three growing seasons. The overall infection rate Ti defined as the proportion of inoculation points showing at least one of the symptoms varied from 10 to 30 according to the site. This confirms the rather weak to moderate susceptibility to canker of the polonica race and reveals a strong site effect on the infection success and further development. A broad clonal variability is shown worthy of mention is the absence of an immune clone together with a sufficiently high level of genetic control h2bs for Ti for the selection of clones for resistance to be conducted efficiently. Nevertheless two main factors somewhat limit the scope of this study i the instability of ranking of clones over sites and h a large within-clone variability. Progress in the experimental use of this artificial inoculation technique is expected from a better understanding of the host-pathogen .
