Selection and breeding of eucalypts for ornamental horticulture

An improvement programme has been underway at the University of Adelaide, Waite Campus, for over 10 years, producing interspecific hybrid eucalypts through controlled pollination. The improvement programme has over 700 hybrid individuals currently under assessment for their floricultural and horticultural merit. In order to select superior individuals from the large number available, a list of essential characters was developed, and these characters prioritised. These characters provided the selection criteria, and were divided into primary and secondary criteria, resulting in a two-phase selection protocol. Criteria of primary importance relate specifically to bud and flower characters, although fruit and general tree characters can also be of importance. The primary characters are considered in combination. The second phase relates to performance characters; response to cultivation practices, clonal propagation techniques and the postharvest vase life of the buds and flowers. These characters are considered singly, and poor response to any will result in the culling of that genotype from further consideration as a superior cultivar, although it may have merit as a parent for future crossings. Ongoing pollinations will introduce new hybrids into the programme each year and all will be assessed using the two-phase selection protocol. Hybrids that are superior in all respects will be trialled for commercial production, with the aim of release to the industry.