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Geraldton waxflower (Chamelaucium uncinatum Schauer) is one of Australia's most economically important cut flower exports. Postharvest bud and flower abscission is a major problem encountered during transport, handling and marketing of waxflower. Abscission may be caused by wound-induced endogenous ethylene production brought about by Botrytis cinerea infection.The aims of this research were to develop improved understanding of the Botrytis cinerea - Chamelaucium uncinatum pathosystem, with a view to devising better strategies for control of grey mould on waxflower flowers. The infection process and environmental factors which influence infection were studied. Host plant resistance mechanisms were characterised and prospects for biological control were explored.The effects of inoculation site, timing of inoculation and conidial load on timing of flower abscission were determined in addition to influences of temperature and relative humidity. Furthermore, the effects of waxflower pollen, nectar and eluate from excised flower tissues on Botrytis cinerea conidial germination, germ tube elongation and flower abscission were observed. Visible signs of Botrytis cinerea infection of waxflower flowers were evident 2 days after inoculation. Waxflower flower abscission occurred around 4 days after inoculation coinciding with cell degradation inside the pistil, and sporulation of the fungus on external surfaces of the flower. The reproductive tissues including the stigma and anthers appeared to be the primary infection sites for Botrytis cinerea. Inoculation of the waxflower stigma or anthers with 2.5 µl of Botrytis cinerea conidial suspension caused flower abscission as readily as spraying the whole flower with Botrytis cinerea conidial suspension. Inoculation with increasing Botrytis cinerea conidial concentrations led to progressively earlier flower abscission. However, the timing of inoculation was not as important as conidial load or position. Temperatures of between 15 to 25°C and high relative humidity (ea. 100% RH) greatly enhanced flower abscission, compared to lower temperatures (ea. 10°C) and lower relative humidity (ea. 95% RH). Additional nutrients such as pollen or nectar were not required to stimulate either conidial germination or flower abscission. ………………………

Geraldton waxflower (Chamelaucium uncinatum Schauer, family Myrtaceae), indigenous to western Australia, is cultivated commercially in South Africa as a cut-flower crop and exported to markets in the Northern Hemisphere. In September 2000, disease symptoms were observed on 4-year-old plants in a commercial orchard of C. uncinatum cv. Ofir in Philippe, in the Western Cape Province. The base of the petals and the calyxes of the waxflowers showed brown necrotic lesions. Eventually the calyx and all the petals turned brown, and the flowers shriveled and abscised. B. cinerea Pers.:Fr was consistently isolated from affected petal and calyx tissues. When placed in a moist chamber, conidia and mycelia formed on the surface of dead and infected tissue. Koch's postulates were confirmed by spraying flower stems of C. uncinatum cv. Ofir with a spore suspension (1 × 106 conidia per ml). Inoculated flower stems were placed in a bottle filled with water and enclosed in transparent plastic bags for 24 h at 21°C. Typical symptoms developed on the petals and calyx within 3 days after inoculation. B. cinerea was reisolated from affected tissues. Botrytis flower blight or gray mold, causing a flower petal disease, has been recorded on C. uncinatum in Australia (1), but this is the first record of Botrytis flower blight of C. uncinatum in South Africa. Because Geraldton waxflower is a major cut-flower crop grown for export, this disease can cause significant losses to the industry, especially under cool, wet growing conditions. Reference: (1) A. Tomas et al. Aust. Plant Pathol. 24:26, 1995.

Chamelaucium uncinatum (wax flower), an evergreen shrub belonging to the Myrtaceae family, is suitable for growing in containers. In the Albenga area (northern Italy), this species is grown as a potted plant. In April 2009, symptoms of a previously unknown blight were observed in a commercial glasshouse in the Savona Province (northern Italy) on 80% of 500 potted plants of cv. Snow Flake. Glasshouse temperatures ranged between 16 and 22°C and plants were drip irrigated. Initially, leaves and calyces appeared chlorotic. Subsequently, necrotic lesions developed on flower stalks and occasionally the corollas. After 10 days, soft, gray mycelium became apparent on symptomatic tissue, especially on the foliage. Severely infected leaves and flowers eventually became completely necrotic and abscised. Tissues were excised from diseased leaves, immersed in a solution containing 1% sodium hypochlorite for 10 s, and then cultured on potato dextrose agar (PDA) medium. A fungus developed abundant mycelium when incubated under constant fluorescent light at 23 ± 1°C. Numerous, small sclerotia also developed on PDA plates incubated for 20 days at 8 ± 1°C. Sclerotia were dark, spheroid, and measured 0.5 to 1.8 × 0.5 to 1.5 (average 1.2 × 1.0) mm. Conidia were smooth, gray, unicellular, ovoid, measured 8.5 to 11.1 × 7.1 to 8.6 (average 9.7 × 7.8) μm, and similar to those described for Botrytis cinerea (2). The internal transcribed spacer (ITS) region of rDNA was amplified using primers ITS4/ITS6 and sequenced. BLAST analysis (1) of the 495-bp segment showed 100% similarity with the sequence of Botryotinia fuckeliana (perfect stage of B. cinerea). The nucleotide sequence has been assigned the GenBank Accession No. GQ149477. Pathogenicity tests were performed by spraying leaves of healthy potted C. uncinatum with a spore suspension (2 × 104 conidia/ml) obtained from PDA cultures of the pathogen. Each plant received 30 ml of the inoculum. Plants sprayed with water only served as controls. Three plants per treatment were used. Plants were covered with plastic bags for 5 days after inoculation and maintained in a growth chamber at 20 ± 1°C. The first foliar lesions developed on leaves 7 days after inoculation and were similar to those observed in the commercial glasshouse, whereas control plants remained healthy. B. cinerea was consistently reisolated from these lesions. The pathogenicity test was completed twice. To our knowledge, this is the first report of the presence of B. cinerea on C. uncinatum in Italy as well as in Europe. The disease has been reported in California (3) and more recently in South Africa (4). In Italy, the economic importance of the disease is currently still limited. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, England, 1971. (3) A. M. French. California Plant Disease Host Index. Calif. Dep. Food Agric., Sacramento, 1989. (4) L. Swart and S. Coertze. Plant Dis. 86:440, 2002.

An effective protocol for protoplast isolation from young leaves and somatic embryogenic cells of species in the Chamelaucium group and the use of superoxide dismutase (SOD) and catalase (CAT) to enhance protoplast viability are described. Mesophyll protoplasts were isolated from young leaves of a white Geraldton waxflower (Chamelaucium uncinatum) line 583, using a mixture of 1% (w/v) cellulase R10, 0.5% (w/v) macerozyme R10, and 0.1% (w/v) pectolyase. Viability of isolated mesophyll protoplasts increased dramatically when SOD and CAT were added. The highest increase of 7.61-fold in viability and 4.34-fold of viable protoplast yield were achieved when a combination of SOD at 500 units mL−1 and CAT at 2,000 units mL−1 was added to the enzyme mixture. Somatic embryogenic cell-derived protoplasts were isolated from embryogenic suspension cells of C. uncinatum line 583 when 1% (w/v) hemicellulase was added to a combination of 2% (w/v) cellulase R10, and 1% (w/v) macerozyme R10. Addition of SOD at 500 units mL−1 and CAT at 2,000 units mL−1 to the enzyme mixture improved viability only slightly, to above 90%, but improved yield significantly (6.6-fold). This combination of enzymes was also used to isolate protoplasts from embryogenic suspension cells of Chamelaucium repens and from young leaves of C. uncinatum, Actinodium calocephalum, Verticordia etheliana, Verticordia grandis, Verticordia hughanii, and Verticordia mitchelliana successfully with viability >80% and viable yield >7 × 105 cells g−1 fresh weight (or per milliliter packed cell volume in the case of suspension cells).

Celikel, Fisun G./0000-0002-4722-2693 WOS: 000289130300011 Cut Acacia holosericea (Velvet Leaf Wattle) foliage has a short vase life, possibly because of blockage in xylem vessels. We indirectly investigated a hypothesised role for peroxidase and phenoloxidase enzyme activities in xylem occlusion of Acacia stems by using their inhibitors. We also tested these inhibitors with cut Chamelaucium uncinatum (Geraldton waxflower), another woody stemmed cut flower. The peroxidase inhibitors used were 3-amino-1,2,4-triazole (AT), catechol (CH), hydroquinone (HQ), p-phenylene diamine (PD) and copper sulphate (CS, Chamelaucium only). The catechol oxidase inhibitors were tropolone (TP), 4-hexylresorcinol (HR) and 2,3-dihydroxynaphthalene (DN). A laccase inhibitor, cetyltrimethylammonium bromide (CM), was also used. Other phenoloxidase inhibitors tested were p-chlorophenol (CP), p-nitrocathechol (NC), p-nitrophenol (NP) and sodium metabisulphite (SM). 2-Mercaptoethanol (ME), phenyl hydrazine (PH) and salicylhydroxamic acid (SH) were used as inhibitors of both peroxidase and phenoloxidase. Twelve inhibitors (CH, HQ DN, HR, TP, CM, CP, NC, NP, SM, PH and SH) significantly improved water uptake, maintained relative fresh weight and increased vase life of Acacia at least once in two experiments. In Chamelaucium, six inhibitors had significant positive effects on water relations (CH, PD, CS, CM, CP and PH) and vase life (AT, CH, PD, CS, ME and PH), while four of them (DN, TP, NC and NP) were phytotoxic at applied concentrations. Only one of the 46 inhibitor treatments inhibited transpiration and increased fresh weight, suggesting that the inhibitors mainly acted by increasing water uptake. Overall, results indicate that oxidative enzyme activities, potentially through phenolic deposition, contribute to xylem occlusion in woody cut sterns of Acacia and Chamelaucium. (C) 2010 Elsevier B.V. All rights reserved. Australian GovernmentAustralian Government Prof. Fisun Celikel was the grateful recipient of an Endeavour Research Fellowship Award from the Australian Government. Mayati Che Husin (PhD student) and Dr. Iftikhar Ahmad Hashmi (visiting researcher) are thanked for their technical assistance in some experiments. Allan Lisle is gratefully recognised for advice on experimental design and assistance with statistical analyses. We thank the reviewers for valuable comments.

Waxflower is one of Australia's major native cut flowers for the export market. A number of interspecific hybrid cultivars such as the ‘Pearl’ series bred by the Department of Agriculture and Food, Western Australia have increased the competitiveness of waxflower on world markets. To improve the breeding efficiency, resistance gene analog polymorphisms (RGAP) are investigated as molecular markers for the early identification of interspecific hybrids between Chamelaucium uncinatum and C. megalopetalum. The results show that RGAP can be effectively applied to generate DNA markers to identify true waxflower hybrids. The RGAP marker system provides a reliable, simple, fast and inexpensive approach for hybrid identification in waxflower breeding.

Insufficient water uptake by cut flowers and foliage species is often due to stem end occlusion and poor stem hydraulic conductance that involve bacterial growth and/or wound healing. S-carvone has putative antibacterial and anti-wound healing activity. S-carvone (0, 0.318 and 0.636 mM) was evaluated as a vase solution for Acacia holosericea (Mimosaceae), Baeckea frutescens (Myrtaceae), Chamelaucium uncinatum cv. ‘Mullering Brook’ (Myrtaceae) and Chrysanthemum sp. cv. ‘Dark Splendid Reagan’ (Asteraceae). S-carvone was also tested in vitro for activity against a vase solution bacterium. S-carvone at 0.318 and 0.636 mM showed significant (P

Infections by Botrytis cinerea cause ethylene-mediated flower fall in cut Geraldton waxflower (Chamelaucium uncinatum). Methyl jasmonate (MJ) is a known host plant defence elicitor, and MJ treatments have demonstrated potential to suppress Botrytis on waxflower. However, MJ can also induce waxflower flower abscission. Flower fall in waxflower can be prevented by treatments with anti-ethylene agents. Pot and field experiments were conducted to determine if combining MJ and anti-ethylene treatments could suppress Botrytis and prevent flower fall. Waxflower 'My Sweet Sixteen' plants were spray-treated pre- and postharvest with MJ (1000 mu M), treated postharvest with either 1-methylcyclopropene (MCP fumigation; 0.08 mu l L-1) or silver thiosulphate (STS pulse; 0.5 mM), and then challenged with Botrytis. Pre- and postharvest MJ treatments reduced Botrytis development, but increased flower fall. In combination with MJ treatment, MCP treatment did not reduce either Botrytis disease or flower fall. MJ in combination with STS reduced (P < 0.05) disease severity for up to 6 days on sprigs harvested from pot-grown plants. However, this combination tended to increase Botrytis disease severity on sprigs from field-grown plants 6 days after inoculation. This inconsistency between pot- and field-grown plants suggests an overriding influence of environment and/or plant management on inducible host defence.

Chamelaucium uncinatum is a West Australian endemic shrub that is grown as a garden ornamental and for the cut flower market. Commercial cultivars are highly susceptible to infection by Puccinia psidii, which causes leaf, stem, bud and flower rust. Pathogenicity tests showed that wild-sourced C. uncinatum plants have no apparent natural resistance to this pathogen.

Flower fall from cut Geraldton waxflower (Chamelaucium uncinatum) during transport and handling is principally associated with pre-harvest infection and post-harvest invasion by the fungal pathogen Botrytis cinerea. As a first step towards a biological disease management program, the potential use of honey bees (Apis mellifera) as vectors of Trichoderma harzianum (Trichodex((R))) for biological control of Botrytis on waxflower flowers was investigated. Two modifications to basic beehive design were tested to enable and/or enhance acquisition of biocontrol agent by bees. Based on experiments with these designs, a third improved design is proposed herein. Laboratory and limited field studies were conducted to determine if bees successfully acquired biocontrol agent and delivered it to waxflower cv. 'Lollipop' flowers. Bees acquired T harzianum upon exit from the Trichodex((R)) inoculum dispenser at 5960 1197 (n=5) colony forming units (cfu)/bee. However, despite demonstrated removal of Trichodex((R)) from the hives by bees and transfer of T harzianum to artificial flowers (viz. plastic trays containing honey), transfer of biocontrol agent to waxflower 'Lollipop' flowers was not achieved in the course of this study.

The export market for the Australian species Caustis blakei and Sticherus flabellatus has mostly been met by bush-harvesting. Consolidation of the export market for these species is dependent upon their domestication, which will depend upon understanding their responses to fertiliser phosphorus (P).Two greenhouse experiments were conducted to investigate the P nutrition of the Australian native species Sticherus flabellatus, waxflower (Chamelaucium uncinatum x C.floriferum) 'Wanneroo' and Caustis blakei 'M63' and 'B84'.Caustis did not show deficiency symptoms at no added P, but showed P toxicity symptoms at P application rates > 11 g p m(-3) medium as MCP. The critical P concentration in the plant tops associated with a 10% decrease in yield from the maximum was 0.26% for Caustis 'M63' and 0.33% for Caustis 'B84'. The two Caustis cultivars did not develop P toxicity symptoms or show any decline in tops dry weight when fertilised with RP. Growth of Caustis 'M63' in growth substrates with different P adsorption capacity and fertilised with MCP showed that the severity of P toxicity increased with a decrease in P adsorption capacity of the growth substrate which was in the order Palmwoods soil > Mt Cotton soil > potting medium.Waxflower grown under non-leaching conditions showed reduced tops weight at no added P or when fertilised with RP. The external P requirement for production of 90% of the maximum dry weight of tops of waxflower was estimated to be 110 g p m(-3) medium when P was applied as MCP. However, waxflower did not develop P toxicity symptoms even at rates of 352 g P m(-3) medium. Sticherus did not respond significantly to P application as either MCP or RP. However, Sticherus grew much better when grown under leaching conditions than when grown under non-leaching conditions. Although leaching conferred some advantages in the growth of Sticherus and in the reduction of P toxicity in Caustis, it also caused a considerable loss of P and other nutrients.

SummaryExposure to ethylene gas elicits flower abscission from cut stems of Geraldton waxflower (Chamelaucium uncinatum Schauer). Ethylene response rates in plants are mediated by temperature. At 20°C, flower abscission from waxflower ‘Purple Pride’ occurred upon 12 h exposure to 1 µ11–1 ethylene. This ethylene treatment did not cause flower abscission at either 10 or 2°C. Moreover, flowers held at 2°C were insensitive to 48 h exposure to 1, 10 and 100 µ11–1 ethylene. However, increasing the duration of treatment with 1 µ11–1 ethylene at 10 and 2°C to 48 and 144 h, respectively, induced flower abscission. When flowers were held at 20°C in air without exogenous ethylene following continuous exposure to 1 µ11–1 ethylene at 2°C, the duration required to elicit flower abscission was reduced from 144 to 72 h. Collectively, these responses show that maintaining harvested waxflower at low temperature (e.g. 2°C) is an effective means to minimise ethylene-mediated flower abscission.

Three field experiments were conducted to investigate the effects of soil‐applied nitrogen (N) on plant chemical composition, nutrient removal, and the use of plant analysis to assess N status of Australian waxflowers. Experiments were conducted in commercial plantings of Chamelaucium uncinatum cultivar Alba and a Chamelaucium hybrid (C. floriferum × C. uncinatum) known locally as Walpole wax, at 3 sites in South Australia. Nitrogen, as ammonium nitrate, was applied at rates up to 160 g plant−1 over several side dressings during the growing season. To assess plant nutrient status, stem tips (25–40 mm long tips of stems) were sampled during the growing season and whole stems at harvest. Nitrogen concentration in both stem tips and whole stems was sensitive to variations in N supply; however, the magnitude of the effect varied between sampling times and sites. In stem tips sampled during spring, the increase in N concentrations ranged from 19.8% at site 2 to 74.6% at site 1. Nitrogen concentrations...

Chamelaucium uncinatum was used as a model plant to evaluate the potential of the DIF technique (DIF = difference between mean day temperature and mean night temperature) at micropropagation level for the architectural control up to the final plant development in greenhouse eleven months after the treatment. Three clones were propagated. The temperature regimes during two subsequent subcultures and the rooting phase were: mean temperatures of 20 and 24°C x DIF conditions of +8, -8, 0. A 12h photoperiod (PPFD= 30 μmol sec -1 m -2 ) was supplied by Osram lumilux white lamps. The growth media were based on the MS basal formulation. The rooted plants were acclimatized, potted and grown in greenhouse for eleven months till blooming. Multiplication rates were modified by the thermic regime (DIF level x average temperature level) but remained in a range of high values. The conditions of DIF -8 affected dry matter content negatively. The rooting percentages was unaffected by the negative DIF. At the end of the rooting phase the height of the micropropagated plant and the mean internode length reached the lowest value at DIF -8 or 0. As a general rule genotype modulated the differential response to the DIF level. Eleven months later at the onset of blooming in the greenhouse one of the three clones displayed height reduction after propagation with DIF -8 while an other clone displayed the same response after propagation with DIF 0. Blooming was regular irrespective of the DIF treatment.

Seasonal fluctuations in the concentrations of 12 nutrients were assessed over 3 years for Chamelaucium uncinatum cultivars Alba and Purple Pride and for Chamelaucium hybrid (C. floriferum × C. uncinatum) known locally as Walpole wax. The plantings were located in the Mount Lofty Ranges, Lower South East and Lower Murray regions of South Australia. Tips of stems, 25–40 mm long, were collected on a monthly basis. The nutrient data were used to identify the most suitable time for tissue analysis; to determine the magnitude of the differences in nutrient composition between cultivars; and to determine the correlations between nutrients. The effect of the sampling error was also determined. The seasonal decrease in concentrations of nitrogen (N), phosphorus (P), potassium (K), magnesium (Mg), and sulfur (S) corresponded with vegetative flushing (growth dilution effect). Concentrations of the variably mobile nutrients copper (Cu) and zinc (Zn) were unstable, particularly during autumn–winter. Concentr...

Variation in leaf essential oils and morphometric characters among 38 locations of Chamelaucium uncinatum were used to describe infraspecific diversity and geographic patterns of variation. Four chemical types were designated: citronellal, α -pinene or limonene dominant, or one in which all three monoterpenes were co-dominant. The citronellal and limonene types were geographically restricted but the α -pinene and co-dominant types were widespread. The citronellal type also demonstrated higher diversity (by Shannon–Weiner index) in the oil profile than the other types. Biochemical differentiation was not strongly paralleled by morphological differences between chemotypes; only the citronellal-type differed morphologically from the other three types with respect to floral bud and leaf characters. Based on biochemical and morphological differences, and geographic localization, it was concluded that the citronellal type may represent a recently evolved ecotype of C. uncinatum .

Since 1995 severe losses were recorded on the production of Chamelaucium uncinatum in the vicinity of La Plata. In 2010, with the aim to confirm the identity of the causal agent of Geraldton waxplant basal rot, molecular studies were added to the morphological observations of the pathogen. P. nicotianae was identified as the causal agent of the disease., Centro de Investigaciones en Fitopatología

A new genus of tetrastichine eulophid, Oncastichus LaSalle, is described to contain a single new species, Oncastichus goughi Headrick and LaSalle. This species is native to Australia, and is a gall former on the Geraldton waxflower, Chamelaucium uncinatum. Oncastichus goughi was accidentally introduced into California where it causes economic damage to the Californian horticultural industry. This is the first example of a tetrastichine Eulophidae becoming an economically important introduced pest species.

The major pest of the cut-flower crop, Geraldton wax, Chamelaucium uncina-tum Schauer, is a gall-forming wasp, Oncastichus goughi Headrick & Lasalle. Little information is available concerning the activity and distribution of this pest in California. The objectives of this study, then, were to determine if sticky cards would trap adult gall wasps in the field and to determine the seasonal and varietal distribution of these wasps in southern California Geraldton wax fields. Field trials determined that either yellow or green insect sticky cards may be used to trap populations of adult gall wasps. Trap data indicated that populations of adult gall wasps peaked during fall (October-November) and varied throughout the remainder of the year. Furthermore, among the varieties examined, the cultivar 'Lady Stephanie' was least susceptible to adult gall wasps, whereas the cultivar White' was most susceptible.

A range of commercial fungicides was tested in vitro for efficacy against Botrytis cinerea Pers. as part of a larger project investigating causes of postharvest flower fall in Geraldton waxflower (Chamelaucium uncinatum Schauer.). Another part of the study examined the potential for control of fungal decay by postharvest treatment of flowering stems with calcium.

Calibrated heat balance stem flow gauges were used to study the daily water use by Geraldton wax (Chamelaucium uncinatum Schauer), a plant endemic to the coastal sand plains north of Perth, Western Australia. Sap flow was recorded for the trunk, primary and secondary branches, and partially shaded lower east and sun‐lit upper west branches in order to assess the influence of climatic variables, stem development, and exposure. Irradiance and leaf area strongly influenced diurnal sap flow. Sap flow in primary and secondary branches was comparable when expressed on a unit leaf area basis. Defoliation reduced water use of the secondary branch. Shedding of leaves under water stress, a common phenomenon in Geraldton wax, probably has similar effects. The level of internal shading influenced water use in the crown (1.2 and 1.5 kg/day per m2 leaf area for branches with east and west exposure respectively). The difference in water use was prominent during the afternoon when the east branch was shaded. The...

For bioassay insects, 14 days storage at 1°C was required for 100% kill of adult flour beetles ( Tribolium confusum Koch.), and 10 days at 1°C killed 100% of Mediterranean fruit fly larvae ( Ceratitis capitata Wied.). A CO 2 enriched atmosphere of between 45% and 60% (11% and 8% O 2 , respectively) reduced the time required to achieve 100% mortality of these bioassay insects to 7 days at 1°C. Increasing the CO 2 content of the atmosphere to 80% (4% O 2 ) did not further reduce the time to achieve 100% mortality. Vase life of red kangaroo paw ( Anigozanthos rufus ) was reduced below that of the unstored control after just 3.5 days at 1°C. Geraldton wax ( Chamelaucium uncinatum ) cultivar ‘Newmarracarra’ was similarly affected after 14 days, and acorn banksia ( Banksia prionotes ) after 28 days. Vase lives of Geraldton was cultivar ‘Newmarracarra’ and of red kangaroo paw were not reduced following 7 days storage at 1°C in 15% CO 2 , compared with controls stored in air. However, Geraldton wax and red kangaroo paw vase lives were shortened and flower colour was altered after storage for 7 days in 30% CO 2 (15% O 2 ). Geraldton wax and red kangaroo paw had no vase lives following storage in 80% CO 2 (4% O 2 ) at 1°C for 3.5 days. Heat treatments of hot water dips (46°C for 30 min or 56°C for 10 min) and vapour heat (66°C for 10 min) killed 100% of adult flour beetles and Mediterranean fruit fly larvae, but damaged and shortened the vase lives of Geraldton wax and banksia.

Flowering in a number of cultivars of Geraldton Wax ( Chamelaucium uncinatum Schauer) is promoted by exposure to short days. For the cultivar ‘Purple Pride’ the critical photoperiod above which flowering does not occur was between 13 and 13.5 h for 3–4-month-old plants grown from cuttings. In 14 and 16 h photoperiods no flowering occurred in these young plants, although in plants older than 5 or 7 months there was often a low level of flowering. One cultivar failed to flower in any daylength and in a hybrid line there was a complex response to temperature and photoperiod. Temperatures of 20–25°C and high irradiance favoured flowering of ‘Purple Pride’. At lower temperature (below 16°C) there was poor flowering. The flowers also developed more slowly but were larger when open. Higher temperature (above 25°C) led to rapid flower bud appearance, but flower number was drastically reduced and the flowers were much smaller. Cool (12–15°C) temperatures imposed during 3–6 weeks of short days blocked the induction of flowering. By contrast, these temperatures were favourable for flowering of a hybrid between Chamelaucium floriferum and C. uncinatum , although the effect of daylength was far greater. Flower development proceeded even at these cool temperatures. Both paclobutrazol and chlormequat inhibited shoot growth and generally had little effect on flowering. Benzyladenine caused substantial branching and could either depress or promote flowering. Flower drop was triggered within 3 days with ethephon. The implications of these findings for the regulation of flowering under field and greenhouse conditions are discussed.

Gamma irradiation doses above 0.05 kGy for Geraldton wax, 0.1 kGy for banksia and 1.0 kGy for kangaroo paw caused significant (P

Root formation on both Chamelaucium and Correa cuttings maintained at high humidity in an enclosed fog tunnel was significantly enhanced when ambient CO2 was increased from 350 to 800 μbar. CO2 enrichment resulted in decreased transpiration and increased water potential of cuttings implying an effect of CO2 on stomatal conductance. CO2 enrichment led to increased starch levels in cuttings of both species probably by raising the intercellular partial pressure of CO2. Increased starch content with CO2 enrichment was able to account for 70–90% of the dry weight increase in Correa, but only for 10–30% of the dry weight increase in Chamelaucium. It is suggested that the stimulation of rooting associated with CO2 enrichment probably derives from the improved water relations of the cuttings rather than from increased carbohydrate levels.

The foliage of cut Geraldton waxflower (Chamelaucium uncinatum Schau., Myrtaceae) often desiccates before flowers on the same sprig become senescent. The results of pressure-volume analysis comparing leafy and flowering sprigs suggest that leaves have relatively higher turgor and lower osmotic potentials than flowers, and that leaves are less elastic. For a similar fall in relative water content, the water potential decreases more in foliage than in flowers. Provision of exogenous ABA (10 ppm [37.8 μM]) in the vase solution effectively reduced vase solution usage and extended foliage longevity. The improved water balance achieved with ABA was apparently the result of stomatal closure. Inorganic salt (10 mM KCl) added to the vase solution also extended the longevity of Geraldton waxflower foliage.

The composition of the essential oils of different genotypes of Chamelaucium uncinatum has been examined. The major compounds were identified as α-pinene, citronellal, limonene, linalool and α-terpinyl acetate. Three chemotypes of C. uncinatum were identified based on the relative proportions of α-pinene, citronellal and limonene present. Oils with α-pinene as the principal constituent were the most common.

Schisandra (Schisandra chinensis (Turcz.) Baill) is a perennial plant belonging to Magnoliaceae. It is a very important medicinal herb in China and is mainly used for treatment of insomnia and memory decay. From July to September 2008, an unknown leaf blight and fruit rot on schisandra were first observed at Jingyu County, Jilin Province. The same symptoms were detected in other areas of Jilin Province, such as Ji'an City, Baishan City, and Hunchun City. Initially, some small, brown spots appeared on the tip or margin of the leaves. Light brown or brown necrotic lesions developed and eventually covered entire leaves. Seriously affected leaves were rolled or distorted and eventually became completely dry and brittle. Small spots appeared on the surface of mature fruits, coalesced, and the fruits finally dropped. Gray mycelia and conidiophores developed on the diseased leaves and fruits. To isolate the causal agent, conidia and conidiophores were scraped aseptically from the internal tissues, suspended in sterile water, and streaked onto the surface of potato dextrose agar (PDA). Single-hyphal tips were transferred on PDA and the isolated fungus was identified as Botrytis cinerea Pers.: Fr. on the basis of its morphological characteristics and internal transcribed spacer (ITS) sequence. Colonies of B. cinerea on PDA were colorless at first and became gray to brown 20 days later with the mycelium growth and conidia producing in cultures. Conidia are single celled, lemon shaped, colorless to a light color, and 4.4 to 15.0 × 7.0 to 10.0 μm. Sclerotia formed about 1 week later, were black-brown and varied in size (2.0 to 5.0 × 2.0 to 4.0 mm) and shape. The ITS region of rDNA was amplified from DNA extracted from single-spore isolate BC12 of B. cinerea using primers ITS4/ITS5 and sequenced (GenBank Accession No. GU724512), BLAST analysis (1) of the 535-bp segment showed 99% similarity with the sequence of Botryotinia fuckeliana (perfect stage of B. cinerea). Pathogenicity tests were carried out on healthy schisandra plants that were 4 years old. After the surface of the leaves and fruits was disinfected with 5% sodium hypochlorite, a conidial suspension of 105 conidia/ml was sprayed on 10 schisandra leaves, and plugs of the fungus obtained from the colony margins were transferred onto a 3- × 3-mm wound on the surface of disinfected fruit. Ten control schisandra leaves and 10 fruits were inoculated at the same time. Plants were covered with polyethylene bags and incubated at 25°C in a greenhouse with relative humidity of 85% for 3 days. Similar symptoms to those observed on diseased leaves and fruits in the field were observed on inoculated schisandra leaves and fruits 7 days after inoculation, whereas control leaves and fruits showed no symptoms. The pathogen was successfully reisolated. The gray mold disease caused by B. cinerea was reported in many plants, such as Lavandula stoechas and Chamelaucium uncinatum in Italy (2,3). However, to our knowledge, this is the first report of gray mold disease of schisandra caused by B. cinerea in China. References: (1) S. F. Altschul et al. Nucleic Acids Res. 25:3389, 1997. (2) A. Garibaldi et al. Plant Dis. 94:968, 2009. (3) A. Garibaldi et al. Plant Dis. 94:380, 2010.

In 1982 the new crops research program was initiated in the Florist and Nursery Crops Laboratory to increase the diversity of florist crop germplasm in the United States. Anigozanthos, Chamelaucium, Correa, a dwarf form of Eustoma grandiflorum ‘Little Blue Belle’, Chamelaucium, Cupressus, and other crops have been introduced to the industry with information that describes propagation, culture, and controlled flowering. Rooting of cutting or in vitro tissue culture propagation of new crops had included Achimenantha, Chamelaucium uncinatum, ‘Purple Pride’, and Eustoma grandiflorum, ‘Little Belle Blue’, Ornithogalum dubium, Lachenalia aloides, and Lilium. In addition, a new production technology using bulbils as propagules was developed for Lilium elegans, Asiatic hybrid lily. This production technology is discussed.

Postharvest longevity of some cut flowers is shortened by exposure to ethylene gas. Adverse effects of ethylene may be prevented by treatment with 1-methylcyclopropene (1-MCP) gas. Responses of 14 different native Australian cut flowers to 1-MCP and ethylene applied at concentrations of 10 nL·L-1 and 10 μL·L-1, respectively, were examined. Each gas was applied alone for 12 hours at 20 °C and they were also applied in series. Vase lives of Ceratopetalum gummiferum, Chamelaucium uncinatum, Grevillea `Kay Williams' and `Misty Pink', Leptospermum petersonii, Telopea `Shady Lady', and Verticordia nitens were reduced by ethylene treatment. Treatment with 1-MCP generally protected these cut flowers against subsequent exposure to ethylene. The 1-MCP treatment usually did not extend their vase lives in the absence of exogenous ethylene.

Geraldton waxflower is susceptible to postharvest floral abscission caused by Botrytis cinerea infection. Pot- and field-grown waxflower cv. Mullering Brook plants and/or their harvested sprigs were spray treated with three known host plant defence elicitors, methyl jasmonate (MeJA), benzothiadiazole (BTH) or silicon (Si), and challenged with Botrytis cinerea after harvest. The efficacy of multiple MeJA, MeJA combined with BTH or Si and combined preand postharvest MeJA treatments in suppressing B. cinerea disease and floral abscission was assessed. Preharvest foliar applications of MeJA (1000 μM; two or four times), MeJA combined with BTH (150 mg/L) and MeJA combined with Si (1500 mg SiO2/L) generally did not suppress B. cinerea development and floral abscission from harvested sprigs. MeJA plus Si applied to pot-grown plants slightly and significantly (P

Ethylene-mediated flower abscission caused by Botrytis infection afflicts cut Geraldton waxflower stems. Preharvest spray applications of three known host plant defence elicitors, benzothiadiazole (BTH), methyl jasmonate (MeJA) or silicon (Si), were applied to Geraldton waxflower cvv. Mullering Brook and My Sweet Sixteen. Their individual efficacy in postharvest suppression of Botrytis disease developmentwas assessed. Field applications of BTH or Si generally had no significant (P > 0.05) effect on Botrytis disease severity on either cultivar. MeJA sprays did not significantly (P > 0.05) reduce disease severity on cv. Mullering Brook, but slightly and significantly (P < 0.05) suppressed Botrytis on cv. My Sweet Sixteen at concentrations of 500 and 750 mu M MeJA. One Si treatment, 1500 mg SiO2/L, significantly (P < 0.05) reduced. oral abscission on cv. Mullering Brook. Overall, field applications of these three host plant defence elicitor chemicals as spray treatments had little effect on vase life, water uptake and relative fresh weight of the cut flower sprigs. Moreover, they did not suppress Botrytis or associated postharvest. oral abscission in cut Geraldton wax flower flowers.

Cut Geraldton waxflower (Chamelaucium uncinatum Schauer) flowers are often infected with Botrytis cinerea. Release of infection from quiescence can cause ethylene production by invaded host tissues and result in flower abscission. Postharvest floral organ abscission is a major problem for the commercial waxflower industry. Methyl jasmonate (MeJA) occurs naturally in plant tissue and has a signalling role in eliciting induced systemic resistance against disease. MeJA treatments have been shown to suppress B. cinerea infecting cut rose flowers. The present experiments investigated the potential of exogenous MeJA treatments for B. cinerea management on harvested waxflower. MeJA treatments of 10 and 100 µL liquid MeJA/L of air applied to cv. Purple Pride and 1 µL MeJA/L to cv. Mullering Brook gave reductions in disease severity for uninoculated stems. However, concentrations of 100 µL MeJA/L applied to Purple Pride in addition to 1 and 10 µL MeJA/L applied to Mullering Brook increased the incidence of floral organ fall. Flower abscission upon treatment with MeJA may be due to induced systemic resistance-associated upregulation of ethylene biosynthesis. MeJA treatments had no direct effect on B. cinerea hyphal elongation in vitro. Collectively, these results show that while MeJA treatment may elicit defence in waxflower against Botrytis, the chemical also causes floral organ fall. Thus, exogenous MeJA treatments do not have potential for B. cinerea management on harvested waxflower.

Postharvest abscission of Geraldton waxflower (Chamelaucium uncinatum Schauer) flower buds and flowers is ethylene-mediated. Exposure of floral organs to exogenous ethylene (1 mu L L-1) for 6 h at 20 degrees C induced separation at a morphologically and anatomically distinct abscission zone between the pedicel and. oral tube. Flower buds with opening petals and flowers with a nectiferous hypanthium were generally more responsive to exogenous ethylene than were flower buds enclosed in shiny bracteoles and aged (senescing) flowers. The anatomy of abscission-zone cells did not change at sequential stages of floral development from immature buds to aged flowers. The zone comprised a layer of small, laterally elongated-to-rounded, closely packed and highly protoplasmic parenchyma cells. Abscission occurred at a two- to four-cell-wide separation layer within the abscission zone. The process involved degradation of the middle lamella between separation layer cells. Following abscission, cells on both the proximal and distal faces of the separation layer became spherical, loosely packed and contained degenerating protoplasm. Central vascular tissues within the surrounding band of separation layer cells became torn and fractured. For flower buds, bracteoles that enclose the immature floral tube also separated at an abscission zone. However, this secondary abscission zone appeared less sensitive to ethylene than the primary ( central). oral-tube abscission zone as bracteoles generally only completely abscised when exposed to 10 mu L L-1 ethylene for the longer period of 24 h at 20 degrees C. The smooth surfaces of abscised separation-layer cells suggest that hydrolase enzymes degrade the middle lamella between adjacent cell walls.

A naturally occurring mutant of Chamelaucium uncinatum Schauer (Geraldton wax) is described. It has double flowers with the staminodes transformed into petals. Pollen is exuded from the anthers but is not deposited on the pollen presenter in a lipid droplet, which is normal for the species. An anomalous secondary flower with petals, stamens, and gynoecium is present in the ovary.

Geraldton waxflower is the most economically importantnative Australian cut flower export. Infection of wax flower by Botrytis cinerea can lead to unacceptable levels of flower abscission after harvest. An investigation was conducted into the nature and identities of constitutive antifungal compounds in flowers and leaves. Antifungal activity against B, cinerea (pathogen) and Cladosporium cladosporioides (bioassay organism) was observed in leaf and flower extracts. Leaf tissue contained less antifungal activity than flower tissue. Four antifungal compounds were common to the three different waxflower cultivars studied. Two antifungal compounds were identified as the sesquiterpene, globulol, and the monoterpene, grandinol. At least two unidentified phenolic compounds also demonstrated strong antifungal activity. Notwithstanding general similarities in antifungal profiles, it was evident from TLC bioassays that variations exist in some antifungal compounds between different wax flower cultivars.

Chamelaucium uncinatum Schauer. (Geraldton wax) is well known as a garden and cut-flower species in Western Australia. The location of pigmented cells and the shape of the epidermal cells that interact with incident light can affect flower colour. This study examined the location of pigments within petals of three C. uncinatum cultivars, 'Purple Pride', 'CWA Pink' and 'Alba', which represent the range of colours found in this species. The white cultivar ('Alba') lacked coloured pigments in the petals while the pink ('CWA Pink') and purple ('Purple Pride') cultivars had pigmented vacuoles in petal epidermal and mesophyll cells. A waxy coating was present on petal epidermal cells of all cultivars and cells of the adaxial epidermis were found to be conical. Patterns in petals of 'CWA Pink' and 'Purple Pride' were due to cultivar-specific location of pigments.

Intracellular inclusions in the pedicel and calyx-tube tissues of Chamelaucium uncinatum Schauer (Myrtaceae) flowers are irregular in shape. They were shown, by polarised light and scanning electron microscopy, to be birefringent 8.9–29.5 μm druse (i.e. aggregate) crystals. Energy-dispersive X-ray spectroscopy showed that these crystals were predominantly composed of calcium. Histochemical and acid-solubility tests indicated that the crystals were calcium oxalate. Raman microprobe spectroscopy was used to confirm this chemical identity. The calcium oxalate crystals were located in xylem-vessel lumens and also in parenchyma cells adjacent to vascular tissues. Thus, the crystals may function to regulate soluble calcium concentrations in C. uncinatum tissues near sites where calcium is unloaded from the xylem.

Postharvest flower abscission from cut Geraldton waxflower (Chamelaucium uncinatum) is mostly caused by fungal invasion. Elevated plant tissue calcium concentrations through postharvest application reduces fungal disease severity in various crops. Such results may be explained by strengthening of plant cell walls by calcium. Strengthening provides a structural barrier to fungal hyphae, thereby restricting invasion of plant cells. Postharvest pulsing with calcium solution substantially increased calcium concentrations in waxflower tissues. 45Ca�tracer revealed calcium distribution throughout flowering sprigs, including infection sites such as stylar tissue. However, pulsing waxflower sprigs with calcium did not suppress either disease or flower abscission, nor did it enhance vase life.