Towards the Molecular Analysis of Heterobasidion annosum : Root and Butt Rots

Uppsala

International Union of Forest Research Organizations, Swedish University of Agricultural Sciences

1994

S. 292-302

27 Lit. Ang.

Bandaufführung

13462

73670

Modern molecular biology provides new tools to increase our understanding of the epidemiology, genetics, pathogenicity and host resistance of Heterobasidion annosum. Amplification of specific or random genomic Heterobasidion annosum sequences by PCR makes it possible to separate different intersterility groups, to demonstrate their genetic relatedness and to reveal the genetic dynamics of Heterobasidion annosum populations. PCR and sequence data have indicated that P group is separate from the other groups, and S and F are very closely related. Heterobasidion annosum produces several cell-wall degrading enzymes that are likely to be involved in the wood decay process. Laccases were produced most abundantly, and two laccases (Mw 67 kDa and 65 kDa) were biochemically purified. Attempts to test their potential role in pathogenicity involved the cloning of the laccase genes and the development of a gene transfer system for Heterobasidion annosum. It is auggested that new molecular methods will improve disease control rapidly by enhancing precise disease detection and monitoring of population dynamics, but the exploiting of basic information of pathogenicity and host defence will take a long time.