The host range of crown gall

Abstract

Crown gall is a plant tumor disease caused by the specific action of the bacterium Agrobacterium tumefaciens. In the current literature its host range is not clearly defined or is thought to be restricted to the dicotyledonous class of the angiosperms. We reviewed the susceptibility of 1193 species belonging to 588 genera and 138 families; 643 are host plants belonging to 331 genera and 93 families. Our list seems to be so far the most extensive source of information on crown gall susceptibility of plants. We attempted to correlate the susceptibility of plants to crown gall with known and/or presumed taxonomic relationships (according to the taxonomic systems of Engler and Takhtajan). No lower plant is known to be a host for crown gall. About 60% of the gymnosperms and the dicotyledonous angiosperms examined were sensitive for crown gall. In the latter class, there is no significant relationship between the taxonomic position of a plant family and its susceptibility. According to the literature, the susceptible monocots are limited to the Liliales and Arales. The common opinion that the host range of crown gall is restricted to the dicotyledonous plants, is thus incorrect. © 1976 The New York Botanical Garden.