Abstract Detail

Molecular Ecology

Flores-Renteria, Lluvia [1], Morrow, Jennifer [2], Hall, Aidan [2], Esveld, Jessica [2], Ramadoss, Niveditha [5], Rymer, Paul [2], Riegler, Markus [2].

Higher risk of psyllid-induced dieback in northern populations of grey box (Eucalyptus molucanna).

Eucalyptus moluccana, an important woodland tree across eastern Australia, has suffered from land clearing. In western Sydney it is a dominant tree species in the critically endangered Cumberland Plain Woodland (CPW). Recently, a psyllid of the genus Cardiaspina has caused extensive canopy dieback and tree mortality in the CPW. Using greenhouse and common garden experiments we tested the potential for psyllid invasiveness outside of the Sydney region. We evaluated whether psyllid preference differs among provenances of E. moluccana throughout its range from the Sydney basin to northern Queensland, and among closely related species. We used next generation sequencing to evaluate whether the historical land clearing of the Sydney Basin has resulted in genetic bottlenecks which can cause plant susceptibility to pests. Our experiments suggest that the psyllid species has a high host specificity and successfully completes its life cycle only on E. moluccana. This finding was corroborated at different life stages (resting, courtship and oviposition behavior, and psyllid development). Most psyllids landed and oviposited only on E. moluccana. Interestingly, E. moluccana provenances from Queensland had higher numbers of psyllids on them than Sydney provenances, and the psyllid therefore poses a threat to E. moluccana populations outside the psyllid’s current distribution. Northern Queensland provenances had lower genetic diversity, whereas Sydney provenances presented higher genetic diversity likely due to hybridization with closely related Eucalyptus species. Further studies are necessary to evaluate whether hybridization contributes to psyllid susceptibility in E. moluccana and eucalypts in general.

1 - San Diego State University, 4319 Yale Ave, San Diego State University, La Mesa, CA, 91942, United States
2 - Hawkesbury Institute for Environment, Western Sydney University, Locke
3 - Hawkesbury Institute for Environment, Western Sydney University, Locke
4 - Hawkesbury Institute for Environment, Western Sydney University, Locke
5 - San Diego State University, San Diego California, United States
6 - Hawkesbury Institute for Environment, Western Sydney University, Locke
7 - Hawkesbury Institute for Environment, Western Sydney University, Locke

Keywords:
Eucalyptus
climate change
Psyllid oubreak
mortality.

Presentation Type: Oral Paper
Session: MOL1, Molecular Ecology
Location: San Pedro 2/Starr Pass
Date: Wednesday, July 31st, 2019
Time: 2:15 PM
Number: MOL1004
Abstract ID:1047
Candidate for Awards:None