Smokebush pollen shocks PhD student

A PhD student who was trying to find ways to improve propagation methods for blue- flowered smokebush species found that its pollen holds the world record for growth rate.

On close investigation of the blue smokebush plant, Lynley Stone discovered that the pollen germinated instantly instead of taking many hours to develop a tube to carry sperm to the female parts of the flower.

As well as germinating immediately, the growth rate of the tube was up to 20 times faster than any recorded previously.

“We have no idea why smokebush pollen grows so much more quickly than other plants,” Lynley said.

“However, it may explain why smokebush has been such a challenging plant to breed artificially.

“These rare plants have been notoriously hard to grow from both seeds and cuttings so we were searching for an alternative method of propagating the plants.

“There is a global demand for blue flowers, which we hope to fill with the very pretty blue varieties of smokebush found in the Stirling Ranges in the south-west corner of Western Australia.”

Lynley tackled this problem by attempting to produce clonal lines from embryos developed in tissue culture from leaves stems and seeds (somatic embryogenesis).

“Although we were successful in producing embryos we kept reaching a stumbling block converting them into small plants,” she said.

“Hopefully a closer understanding of this unique propagation technique will hold the key to developing a way to grow strains of the plants for commercial purposes.”

In the meantime, the observation of unusual pollen germination has kept Lynley busy, as she tries to unlock the mystery of how and why the pollen tubes grow so remarkably fast. Lynley collaborated with the Department of Agriculture and the Department of Conservation and Land Management, funded by an Australian Research Council Strategic Partnerships with Industry grant.

The Department of Agriculture will continue her work when she completes her PhD next year.