Tissue culture – how safe is safe?

Dr Jenny Aitken, Managing Director of The
Tree Lab, shows tissue culture examples.

Tissue culture is a relatively safe way to import new plants into New Zealand, although there are still issues to consider, tree and woody tissue culture specialist Dr Jenny Aitken told delegates at the Biosecurity Summit.

Dr Aitken, Managing Director of The Tree Lab in Rotorua, said the development of “sterile” tissue culture started in the early 1900s. Commercialised tissue culture for propagation began in the early 1970s, and was now used for mass propagation, breeding, safer imports and disease screening.

With a global focus on reducing biosecurity risks to farm, forestry and horticulture industries, tissue culture was considered one of the safest ways to import plants free of pathogens and pests.

Dr Aitkin said tissue culture imports were safer than seeds, cuttings or plants in soil and in soil-less substrates, but there were several myths about tissue culture.

The myths:

• tissue cultures are pest and disease free;
• charcoal in tissue culture media masks plant pests and diseases;
• tissue cultures cannot be used for screening disease;
• tissue cultures of the same clone will have the same diseases;
• shoots or clumps within the same vessel can have different virus, fungi and insect status.

The facts:

• viruses can be present in the tissue cultures of some species and have to be tested for;
• fungi, bacteria and insects grow well on media containing charcoal;
• tissue cultures can be used for screening diseases;
• multiple shoots from one clone are genetically identical and disease free;
• shoots, plantlets or tissues in the same vessel generally have the same properties.

Dr Aitken said tissue culture was still the safest method for plant germplasm imports of seeds, cuttings and whole plants or fruits. Further research and new technology would make the difference in answering the question “how safe is safe?”

• Dr Aitken is the Managing Director of her own company, The Tree Lab, which also has a company in South America – The Tree Lab Chile. She worked as a scientist at the Forest Research Institute (now Scion) and also held the position of Forest Genetics, Biotechnology and Research and Development Manager at Carter Holt Harvey. Dr Aitken was a founding member of the science team for ArborGen, a specialist forest biotechnology business. The Tree Lab is a plant tissue culture company specialising in the introduction of new plant germplasm into New Zealand and globally. The company has a Level 3 (high-security) Post-Entry Quarantine (PEQ) plant tissue culture quarantine facility, and over the past six years has worked with MAF Biosecurity New Zealand on the introduction of new plants for use in the horticulture, forestry and biofuel industries.

Page last updated: 14 January 2009