Open AccessEvaluation of Elm Clones for Tolerance to Dutch Elm Disease
Author(s) -
Alden M. Townsend,
L. W. Douglass
Publication year - 2004
Publication title -
arboriculture and urban forestry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.222
H-Index - 47
eISSN - 2155-0778
pISSN - 1935-5297
DOI - 10.48044/jauf.2004.022
Subject(s) - biology , cutting , dutch elm disease , hybrid , inoculation , horticulture , cultivar , clone (java method) , crown (dentistry) , botany , veterinary medicine , genetics , medicine , dna , dentistry
Rooted cuttings of ten hybrid elm (Ulmus) clones, including one named 'Patriot', and all derived from various crosses of 'Homestead', 'Prospector', 'Urban', and Selection 970, were established along with a randomly selected American elm clones and three disease-tolerant cultivars ('Frontier', 'Homestead', and 'Prospector') in a replicated field plot. When the rooted cuttings were 3 years old, they were inoculated with a mixed spore suspension of Ophiostoma novo-ulmi and O. ulmi, the fungi that cause Dutch elm disease. Analyses of variance and regression showed significant variation among clones in crown dieback, survival, and height growth over a 7-year time period following inoculation. The American elm clone and selection 15-87 (an 'Urban' x 'Prospector' clone) showed the most crown dieback and lowest survival rate and were among the slowest in growth rate, 7 years after inoculation. Selections and cultivars showing the least dieback and highest survival were most hybrids from parentages of 'Urban' x 'Prospector', those from 'Homestead' x 'Prospector', and 'Homestead' x 970; and cultivars 'Patriot', 'Homestead', and 'Prospector'. Many of the same disease-tolerant clones and cultivars also showed the greatest height growth after inoculation. Significant variation in disease symptoms occurred among clones from the 'Urban' x 'Prospector' cross. Results of this study emphasize the importance of selection and testing of specific clones within full-sib families.