The Mont Gambier site, the key to a selective breeding program for pine plantations

You’ve heard of birds and bees, but do you know pollen and trees?

A selection of elite trees in South Australia have worked hard during the baby-making season to create better genetics for plantation wood.

Radiata pines were chosen for Australia’s only softwood breeding and gene conservation research site located in Mount Gambier and managed by the National Forestry Cooperative Tree Breeding Australia.

Managing Director Tony McRae said the site’s goal is the selective breeding of plantation trees.

“These are not just any babies, they come from the best parents who have very good characteristics,” he said.

However, these seeds will not reach commercial plantations; instead, they will be planted in trials across the country to track their genetic success.

Researchers are studying trees over their lifetimes for attributes such as wood quality and growth rate, and the information will further develop the genetics available to planting companies.

“We plant up to 9,500 seeds [in each trial] which are genetically unique, coming from some 300 different families, ”said Dr. McRae.

“We will combine this data with trials that have been planted in previous years or decades… we are generating new data daily.”

He said from there the best genetics are brought back to the breeding site.

“Of the hundreds of thousands that we have in trials, we could bring 30 to 50 new parents, so we know the right parents based on how well the trials perform.”

When pollen meets trees

It takes about two years to obtain viable seeds, from the first pollination until the pine cones are harvested, and pollination can only take place within a narrow window of six weeks.

Meanwhile, pine technicians such as David McKersie find open flowers on trees and place paper bags on them, protecting them from wild pollen.

When the flower scales begin to open, specific pollen is injected into the sac through resealable holes.

“It’s usually about six days [after bagging] until we do the first pollination, then we do three pollinations four days apart, ”McKersie said.

The sac is removed about six weeks later after the flower closes and a pine cone forms.

“Then we wait two years, we take the cones from the trees, dry them, extract the seeds …

Each cone contains an average of 40 seeds but this does not guarantee a high yield.

“Even if they do, it’s actually the viable seed you get in the end. [that matters], because you may have a cone full of seeds or the seeds may be waste.

“Whether this is due to pollen, the freezing of any other condition is speculation.”

Branching out

Dr McRae said the growing conditions improve the chances of success.

“The very important thing is to choose a site where the environment is suitable for flowering and seed production; Mount Gambier is reasonably gentle, ”he said.

As genetics begin in the Limestone Coast, the data is available to member logging companies across the country.

“We consolidate this data into an index that will represent the value of a particular genotype or tree for their particular situation when growing them in a commercial setting,” said Dr McRae.

“By growing better and using better genetics, you can produce more wood from the same unit of area for the same resources you use.