John A. Considine

Rhizogenesis and root growth of Carica papaya L.in vitro in relation to auxin sensitive phases and use of riboflavin

High rooting percentages and high-quality adventitious root systems for papaya (Carica papaya L.) were obtainedin vitro by appropriate auxin source, duration of exposure to auxin and use of riboflavin. Root initiation of papaya shoots was higher using IBA than IAA, NAA or PCPA. Maximum rooting percentage (96%) was achieved by exposure of shoots to a medium containing 10 µM IBA for 3 days before transfer to a hormone-free medium. However, the resultant plants had small shoots and callused roots. Shoot and root growth were improved when shoots were transferred after 2 days from medium containing 10 µM IBA to hormone-free medium containing 10 µM riboflavin. Good root initiation, and root and shoot growth were also obtained when shoots were incubated for 2 days in darkness on a medium containing 10 µM IBA and 31 µM riboflavin before transfer to light. Alternatively, cultures could be placed in the light on medium containing 10 µM IBA, and after 1 day the medium overlaid with 300 µM riboflavin (1 ml over 10 ml of medium).

Infraspecific variability in the volatile leaf oils of Chamelaucium uncinatum (Myrtaceae)

Abstract 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 .

Pollination and fruit set in the tamarillo (Cyphomandra betacea (Cav.) Sendt.) 1. Floral biology

Abstract The floral biology of the tamarillo Cyphomandra betacea (Cav.) Sendt. ‘Oratia Round’ was examined using field‐grown and glasshouse‐grown plants. The tamarillo exhibits a modular growth pattern, initiating a number of leaves (usually 3–4) and then a terminal inflorescence. Inflorescence structure is compound and may consist of up to 50 flowers. Flowers open sequentially along each axis of the inflorescence. Individual flowers close at night but reopen each day, for up to 5 days. The stigma is wet and although exudate was present from 3 days before to 7 days after flower opening (Day ‐3 to Day +7), the effective pollination period (by hand pollination) was from Day ‐1 until Day +1 only. An insect vector is required for pollination and both honey bees and bumble bees were observed to visit and pollinate tamarillo flowers. The tamarillo is self‐compatible although the nature of pollen release onto the thorax and abdomen of bees visiting the flowers could effect both self pollination and cross pollina...

Medium and long term storage of Anigozanthos manglesii (D. Don) pollen

Abstract The viability of kangaroo paw pollen (Anigozanthos manglesii) was estimated by germination in vitro and by fluorescence and the more reliable method was then used to assess the effect of storage conditions on pollen longevity. Pollen germination was more accurate than staining for pollen of low and intermediate viability levels. Effective storage could be achieved in a number of ways depending on the duration required. Dehydrated pollen retained viability longer in storage than did hydrated pollen. Pollen from intact anthers could be stored for up to 5 weeks at room temperature with 50% or better germination provided it was stored on silica gel. Pollen isolated from anthers and stored at 2°C had reduced viability in comparison with that stored at room temperature or at ‐80°C. Pollen stored at ‐196°C lost only 5% viability after 20 weeks and presumably this would be the most suitable method for long term storage for breeding or conservation purposes.

Water use by Geraldton wax (Chamelaucium uncinatum Schauer) as measured by heat balance stem flow gauges

Abstract 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...

Flowering and fruiting rootless cuttings of kiwifruit

Abstract Fully‐functional flowers and young fruit were produced in vitro on rootless, one‐bud kiwifruit (Actinidia deliciosa) cuttings. The cuttings were made from dormant canes with diameters ofbetween 7 and 10 mm, lengths of at least 150 mm, and weights of more than 12 g. Cuttings made from nodes 5, 10, and 15 on canes were more successful for flower production than cuttings made from nodes 20 and 25. The cuttings were grown in water or dilute nutrient solution and the new shoots bore flower buds. Anthesis only occurred on shoots which were modified by removing the shoot tip and all but one leaf and its subtended flower bud. Earlier shoot modification resulted in more flower buds reaching anthesis. Competition between reproductive and vegetative structures appeared to be a major factor determining the degree of flower development. The use of this system as a tool in different areas of research is discussed.

Morphological responses of Geraldton wax to transient soil-water deficit

Changes in leaf angle and flower diameter of Geraldton wax (Chamelaucium uncinatum) in response to declining shoot water potential (ψshoot)) were assessed as indicators of plant water status. Leaves and petals in Geraldton wax moved vertically as ψshoot decreased. In cv. Purple Pride, the leaf angle of recently-matured, fully-expanded leaves and the diameter of fully developed flowers showed strong linear correlations with declining ψshoot (r2 = 0.90 and 0.94 respectively). The relationships were less strong when applied to almost fully expanded leaves (r2 = 0.51) and young flowers (r2 = 0.64). Older leaves showed no consistent correlation between leaf angle and ψshoot (r2 = 0.01). Similar results were observed in cvv. Alba and Lady Stephanie, but the change in orientation for a given change in ψshoot was smaller in cv. Alba than those observed in cvv. Purple Pride and Lady Stephanie. Vertical orientation of leaves and flower petals in droughted plants could be used as indicators of level of water deficit.

Chapter 3 – Wine Chemistry

Wine is the result of complex chemistry and biochemistry. Particular issues that are covered in this chapter include the role of acids and of buffering in the wine-making process and as a selection pressure against most microorganisms. A secondary, but nonetheless vitally important, issue is that of oxidation status during and after wine making, and the role of natural products and additives in sustaining an appropriate oxidation–reduction status in the wine. A third consideration is the role of natural constituents in determining the sensory attributes of wine: taste, palate texture and aromatic aspects, and how these interact with the microorganisms that process the juice to the final wine.

Chapter 4 – Safety

Wineries and laboratories are hazardous environments and those who use or manage them have a duty of care to others within the site. They are required by law to adopt safe working practices and to maintain a safe working environment. This chapter outlines the principal areas of concern: safe handling and storage of chemicals and solvents; developing safe work practices for confined environments; and electrical and mechanical safety. It also provides a guide to documentation for materials safety (chemicals and solvents, principally) and the need to document and train students and staff in safe operational practices for machinery and processes. It should be read in conjunction with local regulations and law, which will take precedent. The chapter emphasizes the importance of developing a culture of individual responsibility for personal safety.

Microbiology and Methods

Wine is a coproduction between the grapevine and microorganisms, yeasts and bacteria. This chapter provides an introduction to the yeasts and bacteria that are oenologically important (Saccharomyces and Oenococcus) and the fault-causing yeasts such as Brettanomyces and bacteria such as Acetobacter. Practices to assist the winemaker to reduce the risk of infection by fault-causing microbes are presented, including how to set critical control points as part of a hazard analysis and critical control point (HACCP) approach to quality assurance. Techniques are described for sampling, culturing, identifying and counting oenologically constructive and impairing microorganisms.