Screening of Metrosideros polymorpha (‘ōhi‘a) varieties for resistance to Ceratocystis lukuohia

2020 ◽  
Vol 51 (1) ◽  
Author(s):  
Blaine Luiz ◽  
Elizabeth A. Stacy ◽  
Lisa M. Keith
Keyword(s):  
Metrosideros Polymorpha

Vacuum steam treatment of Metrosideros polymorpha logs for eradication of Ceratocystis huliohia and C. lukuohia

Plant Disease ◽  
2021 ◽  
Author(s):  
Jennifer Juzwik ◽  
Marc A Hughes ◽  
Zhanghing Chen ◽  
Anna Yang ◽  
Lisa Keith ◽  
...  
Keyword(s):  
Ambient Temperature ◽  
Efficient Method ◽  
Plant Material ◽  
Large Diameter ◽  
Steam Treatment ◽  
Metrosideros Polymorpha ◽  
Forest Trees ◽  
Phytosanitary Treatment ◽  
C 30 ◽  
Time Required

A new and devastating disease, rapid ohia death (ROD), in Hawaii led to a state quarantine that regulates inter-island transport of ohia wood and plant material to prevent spread of the causal pathogens. Heat treatments of ohia logs in commercial trade were considered for phytosanitary treatment. Vacuum steam (VS) was evaluated for its ability to eradicate the pathogens, Ceratocystis lukuohia and/or C. huliohia, in main stem logs from ROD-affected forest trees. Replicate loads of three de-barked logs (24 to 43 cm diameter; 1.7 to 2.0 m long) were VS-treated at 56° C for 30 min (5 loads) or 60° C for 60 min (4 loads) at a sapwood depth equal to 70% of log radius. Percent isolation of Ceratocystis from VS and ambient temperature logs prior to treatment and summarized by source tree ranged from 12 to 66% and 6 to 31% based on carrot baiting assays of tissue taken from outer and inner sapwood, respectively. No viable Ceratocystis was detected in either sapwood locations for the 60° C/ 60 min schedule or for the inner locations for the 56° C/ 30 min schedule following treatment. Only one subsample (0.48%, n=208) of the latter schedule treatment yielded Ceratocystis. Time required for treatment ranged from 7.4 to 15 h for the 56° C/ 30 min schedule and from 8.6 to 19.2 h for the 60° C/ 60 min schedule. These results demonstrate VS is an effective and efficient method for treating large diameter ohia logs that mill owners and regulatory plant pathologists may consider for use in Hawaii.

Photosynthesis and Freezing Avoidance in Ohia (Metrosideros polymorpha) at Treeline in Hawaii

2000 ◽  
Vol 32 (4) ◽  
pp. 381-387 ◽  
Author(s):  
S. Cordell ◽  
G. Goldstein ◽  
P. J. Melcher ◽  
F. C. Meinzer
Keyword(s):  
Metrosideros Polymorpha

scholarly journals Sap-Feeding Behavior and Tree Selection in the Endangered Akiapolaau (Hemignathus Munroi) in Hawaii

The Auk ◽  
2004 ◽  
Vol 121 (2) ◽  
pp. 548-556
Author(s):  
Liba Pejchar ◽  
Jack Jeffrey
Keyword(s):  
Energy Source ◽  
Feeding Behavior ◽  
Sap Flow ◽  
Convergent Evolution ◽  
Metrosideros Polymorpha ◽  
Flow Volume ◽  
National Wildlife Refuge ◽  
Niche Specialization ◽  
Sap Feeding ◽  
Tree Characteristics

Abstract The Akiapolaau (Hemignathus munroi), an endangered Hawaiian honeycreeper, drills 3–5 mm deep holes in particular ohia trees (Metrosideros polymorpha) and drinks the sap that emerges, a remarkable example of convergent evolution in sap-feeding behavior with mainland woodpeckers and Australian sugar-gliders. There has been little research on how this species selects sap trees (“Aki trees”) and what advantages they confer. We marked the locations of and collected sap samples and microhabitat data from 101 Aki trees and 73 randomly selected control trees in Hakalau Forest National Wildlife Refuge, Hawaii. Aki trees were rare (2 ha−1), spatially clustered, and defended by Akiapolaau. Sap flow volume and speed were substantially greater in Aki trees than in controls. Aki trees also were larger, had thinner bark, and were more likely to be located on convex east-facing slopes where more light is available. Those results support the hypothesis that Aki trees are selected on the basis of high sap flow and a suite of unique microhabitat and tree characteristics. Sap may be an important energy source in times of low insect availability and a potent alternative to nectar for the Akiapolaau. Aki trees are both a fascinating example of niche specialization and a factor that should be considered when conserving or restoring habitat for this endangered species.

Sign in / Sign up

Export Citation Format

Share Document