Micropropagation of salt tolerant eucalypts and dieback resistant jarrah facilitated by nodal bud culture

D. Willyams
The production of 109,306 elite eucalyptus plants by micropropagation first required developing a culture initiation method utilising nodal buds. Seedlings surviving the high stress selection were transferred into coarse sand in 8-L pots and placed in a low light greenhouse. Slow release and foliar fertilisers were applied and fungicides sprayed fortnightly. After seedlings recovered and resprouted, sections of young shoots were removed. These were sterilised with 10% bleach (0.4% Cl-) for 15 min and rinsed 3× in sterile water. The nodes were excised and placed on agar solidified media (½ MS major and minor mineral salts, supplemented with an additional 50 µM sodium-ferric EDTA with a 100 µM final concentration, 500 µM myoinositol, 3 µM thiamine HCl, 4 µM nicotinic acid, 100 µM zeatin, 10 µM gibberellic acid, 90 mM sucrose, 0.25% agar and 0.25% Phytagel®, at pH 5.8) in 50-mL polycarbonate tubes. New axillary shoots were excised into 250-mL glass jars, with the same media. Thereafter shoot multiplication and rooting media were optimised for each species to facilitate mass plant production. Ventilating the culture vessels improved shoot quality. Plant production costs of salt-tolerant Eucalyptus camaldulensis clones were evaluated using a ratio based on in vitro rooting and in vivo acclimatization. Combining this with field performance data allowed nursery production to focus on low cost clones with high field growth. Micropropagated plants of jarrah (E. marginata) clones resistant to dieback (Phytophthora cinnamomi) were too expensive to use for planting programs. Instead plants were produced for seed orchard establishment. The seed collected from these orchards is used for seedling production.
Willyams, D. (2016). Micropropagation of salt tolerant eucalypts and dieback resistant jarrah facilitated by nodal bud culture. Acta Hortic. 1113, 119-126
DOI: 10.17660/ActaHortic.2016.1113.17
https://doi.org/10.17660/ActaHortic.2016.1113.17
alkaline tolerant plants, DRJ, Eucalyptus camaldulensis, Eucalyptus marginata, River Red Gum
English

Acta Horticulturae