Photo: Department of Conservation
It’s likely that myrtle rust will have significant impact on New Zealand myrtles, including species extinction. Breeding approaches can reduce the negative impacts of the disease and help maintain healthy New Zealand myrtle populations.
This research helps inform people about what breeding approaches to take and what species to target in their response to myrtle rust.
Researchers developed a high-level resistance breeding strategy to maintain healthy New Zealand myrtle populations. It includes a decision framework to help prioritise different breeding responses to native myrtle species and the many non-native myrtles.
Strategies include seed collections to preserve genetic diversity, selection for enhanced resistance, and conservation plantings.
Seed collections are recommended for highly susceptible, already threatened species, taonga species or trees, and conservation plantings for high priority species. A prioritisation list of important New Zealand myrtle species was developed.
The importance of ongoing consultation with Māori and co-developing culturally appropriate breeding programmes for selected species is stressed.
All New Zealand native myrtles are classified as nationally threatened, however they haven’t received a lot of attention in terms of long-term conservation outside their natural habitats, for example seed banking.
Researchers assessed the optimum conservation strategies for some New Zealand myrtle plants.
They investigated options for storing seeds from myrtle plants, including assessing tolerance to desiccation (drying); establishment of tissue culture (e.g. plant cuttings) storage; development of cryopreservation (freezing) techniques.
What they found and what it means
Download the report: Seedbanking and germplasm research strategy (This report is also a chapter in the Myrtle rust research programme 2017-2019: understanding the pathogen, hosts, and environmental influences).
New research Integrated ex situ conservation strategies for endangered New Zealand Myrtaceae species builds on this strategy and was published in the New Zealand Journal of Botany in May 2020. Read more.