Myrtle rust threat triggers seed-banking rush on native species

Fungal plant disease myrtle rust poses a threat to 33 New Zealand native plant species. Photo / File

Hundreds of officials across the country are scrambling to gather seeds of more than 30 native plant species now threatened by deadly fungal disease Myrtle Rust.

Auckland Council and other regional authorities have been directed to go out and collect seed of important native myrtle trees, in a nationwide emergency seed-banking effort being led by the Department of Conservation (DoC).

The rust, which poses a major threat to cherished native myrtle species like pohutukawa, manuka and rata, as well as well as feijoa and bottle brush, has been confirmed to have spread from the Kerikeri nursery where it was first found last week.

Officials say it may now be impossible to contain the wind-blown scourge.

The impact it will have on some of the country's most important plant species, and the $300 million manuka honey industry, remains unclear.

But one assessment produced by the Government in 2011 warned large areas of the country could be affected and, at one extreme, some species could die on a "landscape scale", as had happened in other countries.

Over the past few years, authorities have been stocking up the jointly-run NZ Indigenous Flora Seed Bank to maintain an insurance supply of seeds of species that could be devastated in such a catastrophe.

But efforts have ramped up since the Kerikeri incursion, with DoC sending out dozens of staff across the whole of the North Island and the upper part of the South Island to collect targeted seeds.

Seeds were being stored at the Margot Forde Germplasm Centre run by AgResearch at Palmerston North, with extra storage facilities now being developed at major botanic gardens to provide a back-up.

DoC's science and policy director of threats, Allan Ross, said there were 33 native species potentially at risk, including five that were already classified either as threatened, vulnerable or at risk.

In Auckland, teams have been directed to head out into parkland and gather seed from six target species, including manuka and swamp maire.

While banking the seeds could allow researchers to identify strains resistant to the disease, the priority now was to get the "seed in hand", Auckland Council biodiversity manager Rachel Kelleher said.

Major botanic gardens at Auckland, Wellington, Christchurch and Dunedin and other public gardens at Taranaki, Gisborne and Hamilton would now also work with DOC under a new agreement rushed forward by the incursion.

Landcare Research scientist Dr Andrea Byrom, director of the Our Biological Heritage National Science Challenge, said scientific institutes working under the challenge were due to meet on Monday to discuss the incursion.

The situation wasn't helped by the fact it was the wrong time of the year to be collecting seed, Byrom said.

"So that's part of the problem, and if it goes fast and really takes off, then we could get caught - especially with some critically threatened species."

Projects already launched under the joint programme might also be re-framed to tackle aspects of the threat, such as diagnostics, work on strains and surveillance.