2004, Wu, S, Collins, G, Sedgley, M

An integrated molecular linkage map of olive (Olea europaea L.) was constructed based on randomly amplified polymorphic DNA (RAPD), sequence characterized amplified region (SCAR), and microsatellite markers using the pseudo-testcross strategy. A mapping population of 104 individuals was generated from an F1 full-sib family of a crossbetween 'Frantoio' and 'Kalamata'. The hybridity of the mapping population was confirmed by genetic similarity and nonmetric multidimensional scaling. Twenty-three linkage groups were mapped for 'Kalamata', covering 759 cM of the genome with 89 loci and an average distance between loci of 11.5 cM. Twenty-seven linkage groups were mapped for 'Frantoio', covering 798 cM of the genome with 92 loci and an average distance between loci of 12.3 cM. For the integrated map, 15 linkage groups covered 879 cM of the genome with 101 loci and an average distance between loci of 10.2 cM. The size of the genomic DNA was estimated to be around 3000 cM. A sequence characterized amplified region marker linked to olive peacock disease resistance was mapped to linkage group 2 of the integrated map. Thesemaps will be the starting point for studies on the structure, evolution, and function of the olive genome. When the mapping progeny pass through their juvenile phase and assume their adult characters, mapping morphological markers and identification of quantitative trait loci for adaptive traits will be the primary targets.

2002, Guerin, J, Wu, S, Mekuria, G, Collins, G, Jones, GL, Burr, M, Wirthensohn, M, Lavee, S, Sedgley, M

The olive research program at the University of Adelaide is focused on the selection of improved olive cultivars. Superior selections have been obtained from populations of feral olives that have escaped from cultivation and now grow wild throughout the southern areas of Australia. Several trees have been deemed 'superior' based on oil yield and quality data obtained by Soxhelt extraction, gas chromatography and organoleptic assessment. Techniques developed for analysing new selections will also be used to provide quality assurance to the Australian olive industry.Cultivar identification of Australian and international accessions is a routine practice using DNA fingerprinting by random amplified polymorphic DNA (RAPID) analysis.A genetic marker linked to peacock spot disease resistance was identified using bulked segregant analysis and a linkage map for olive has been generated that will be used to locate further molecular markers linked to agronomic traits. These markers will be used on new selections to make predictions about their performance under long-term cultivation. We have also investigated the degree of cross- and self-incompatibility between the cultivars Frantoio, Manzanillo, Kalamata, Pendolino and Picual, using a 5 x 5 diallel cross.

2006, Glocke, P, Delaporte, K, Collins, G, Sedgley, Margaret

The genus 'Eucalyptus' contains many species suitable for the floriculture and amenity horticulture industries in Australia. A development program has been underway at the University of Adelaide, with the aim of producing new and novel hybrid eucalypt varieties for these industries through controlled pollination between selected ornamental species. As each new hybrid plant reaches reproductive maturity, it is assessed for desirable characters and the very best plants selected for further development, including response to production systems and vegetative propagation. Plants that perform well in cultivation and can be propagated vegetatively will be registered with Plant Breeders Rights and made available through commercial nurseries.

2006, Withensohn, M, Collins, G, Channuntapipat, C, Sedgley, Margaret

In 1999, we presented our work at XI GREMPA on conservation of almond (Prunus dulcis) germplasm by cryopreservation of almond shoot tips. "Nonpareil", "Ne Plus Ultra" and an almond-peach hybrid rootstock, Prunus dulcis "Titan" x P. persica "Nemaguard" were successfully cryopreserved for 6 months using a one-step vitrification technique. That work has since been extended to test for plant viability and genetic integrity after storage under liquid nitrogen for up to 2 years. Mean survival of shoot tips was 80% for "Ne Plus Ultra", 54% for "Nonpareil", and 78% for the hybrid rootstock, and there were no significant differences in survival between 3 days and 2 years. Genetic stability was tested by comparing DNA from the original trees, with leaves regrown from tissue culture, and from leaves regrown from cryopreserved shoot tips. Some changes in the structure and methylation of the DNA were found that were probably related to the in vitro culture process. These changes may have affected agronomic performance. Fruit and kernel characteristics have been monitored and compared to authentic non-preserved cultivars.

2006, Glocke, P, Delaporte, K, Collins, G, Sedgley, Margaret

Micropropagation via enhanced axillary shoot proliferation was investigated in the ornamental Eucalyptus cv. 'Urrbrae Gem' using in vitro germinated seedlings and was successfully achieved using woody plant medium (WPM) supplemented with 2.2 μM benzylaminopurine, 1.0 μM α-naphthaleneacetic acid, and 1.5 μM gibberellic acid (GA₃), gelled with 5 g l−1 Phytagel®. Shoot proliferation was greater on WPM and QL media with GA3 compared to B5, AP, and TK media with or without GA3. GA3 was required for shoot elongation as the internodes were otherwise very short and unsuitable for multiplication or root initiation. Root initiation was improved using (1/2) WPM supplemented with 20 μM indole-3-butyric acid (IBA) over a 7 d pulse, followed by subculture to IBA-free medium, compared to placing shoots on low levels of IBA for 4–6 wk. Plantlets were successfully hardened off to the natural environment via a fogger at 67% relative, humidity at 21°C for 3 d and continued to thrive as potted plants. This is the first report of successful, micropropagation in an ornamental eucalypt (subgenus Symphyomyrtus) from seedling explants.

2002, Wu, S, Collins, G, Sedgley, M

Self- and cross-incompatibility of the olive cultivars Frantoio, Manzanillo, Kalamata, Pendolino, and Picual were investigated using a 5.3.5 diallel matrix. Pistils were collected seven days after controlled pollinations on the day of flower opening, and pollen tubes were detected by fluorescence microscopy. Diallel analysis showed significant specific combining ability, general combining ability and reciprocal effects between cultivars for pollen tube growth in the pistil. 'Frantoio' was cross-compatible, as either a male or female parent, with each of the other cultivars, butshowed a high degree of self-incompatibility.'Manzanillo', 'Kalamata', 'Pendolino', and 'Picual' were cross-incompatible, and all except for 'Manzanillo', were self-incompatible. It is concluded that 'Frantoio' is a good generalpolleniser for the other cultivars investigated. Pollen tube growth decreased in discrete steps from stigma to upper style, and from upper style to lower style, with the result that only one, and rarely more, pollen tube penetrated ovules. The sex ratio of flowers, and pollen viability using fluroesce in diacetate staining and in vitro germination, were examined. 'Frantoio', 'Manzanillo' and 'Pendolino' had more than 80% perfect flowers, while 'Kalamata' and 'Picual'had less than 30%. 'Frantoio' had the highest pollen viability, 'Kalamata' and 'Picual' were intermediate, and'Manzanillo' and 'Pendolino' the lowest. Pollen staining and both in vitro and in vivo germination provided the same male fertility rankings of cultivars.