Barrier Zone Formation as a Resistance Mechanism of Elms to Dutch Elm Disease
1985; Brill; Volume: 6; Issue: 1 Linguagem: Inglês
10.1163/22941932-90000916
ISSN0928-1541
AutoresKarel J.M. Bonsen, R. J. Scheffer, D. M. Elgersma,
Tópico(s)Bioenergy crop production and management
ResumoHost responses of elms susceptible and resistant to Dutch elm disease were histologically examined. In a time course study the susceptible elm clone Ulmus × hollandica 'Belgica' and U. × hollandica '390', a clone which shows a high degree of resistance to non-aggressive isolates and a moderate degree of resistance to aggressive isolates of Ophiostoma ulmi , were inoculated in twig or trunk with either an aggressive or a non-aggressive isolate of O . ulmi . For purposes of comparison, the susceptible elm U . americana and the more resistant clones U . × hollandica 'Groeneveld', U . 'Lobel' and U . 'Sapporo Autumn Gold' were included. Depending on clone-isolate compatibility, infected twigs reacted by a walling off process, by barrier zone formation, or failed to resist the infection and died. Trees inoculated into the trunk reacted comparably but in the case of a compatible combination they always formed a barrier zone and the cambium never died in the year of inoculation.
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