Differential Resistance of Gordonieae Trees to Phytophthora cinnamomi

Bibliographic Details
Authors and Corporations: Meyer, Elisabeth M., Ranney, Thomas G., Eaker, Thomas A., Ivors, Kelly
Title: Differential Resistance of Gordonieae Trees to Phytophthora cinnamomi
In: HortScience, 44, 2009, 5, p. 1484-1486
American Society for Horticultural Science
Physical Description:1484-1486
ISSN/ISBN: 2327-9834
Summary:<jats:p>Trees in the Theaceae tribe Gordonieae are valuable nursery crops, but some of these taxa are known to be highly susceptible to root rot caused by <jats:italic>Phytophthora cinnamomi</jats:italic> Rands. The objective of this study was to evaluate a collection of Gordonieae taxa for resistance to this pathogen. These taxa included <jats:italic>Franklinia alatamaha</jats:italic> Bart. Ex Marshall, <jats:italic>Gordonia lasianthus</jats:italic> (L.) Ellis, <jats:italic>Schima wallichii</jats:italic> Choisy, <jats:italic>S. khasiana</jats:italic> Dyer, <jats:italic>×Schimlinia floribunda</jats:italic> Ranney &amp; Fantz, and <jats:italic>×Gordlinia grandiflora</jats:italic> Ranney &amp; Fantz. <jats:italic>Abies fraseri</jats:italic> (Pursh) Poir. was also included in the study as a positive control. Container-grown trees were inoculated with three isolates of <jats:italic>P. cinnamomi</jats:italic> and symptoms were rated over an 84-day period during the summer of 2008. Disease symptom ratings from 1 (healthy) to 4 (dead) were collected twice weekly and area under the disease progress curve (AUDPC) values were calculated. None of the <jats:italic>S. khasiana</jats:italic> or <jats:italic>S. wallichii</jats:italic> exhibited any root rot symptoms or mortality, whereas the remaining species showed symptoms of infection at varying levels over time. Symptoms in <jats:italic>F. alatamaha</jats:italic> and <jats:italic>A. fraseri</jats:italic> were apparent before other taxa, and mortality for both species reached 100% by the end of the experiment. Comparison of AUDPC values indicated that <jats:italic>F. alatamaha</jats:italic> was the most susceptible followed by <jats:italic>A. fraseri</jats:italic>. There was no significant difference in AUDPC among the more resistant taxa, including <jats:italic>G. lasianthus</jats:italic>, both <jats:italic>Schima</jats:italic> species, and the intergeneric hybrids. Values for AUDPC in the hybrid taxa were similar to their more resistant parental genus, indicating that resistance to <jats:italic>P. cinnamomi</jats:italic> is a partially dominant trait in these plants. These results further suggest the potential to breed improved hybrids of Gordonieae trees with substantial resistance to <jats:italic>P. cinnamomi</jats:italic>.</jats:p>
Type of Resource:E-Article
Source:American Society for Horticultural Science (CrossRef)
Language: Undetermined