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A comprehensive review of the morphology, anatomy, taxonomy, chemistry and ecology of the endemic New Zealand facultative shrub epiphyte Pittosporum cornifolium (Pittosporaceae) is presented. Strong habitat specificity restricts this species to lowland forest and coastal habitats, which are widely yet discontinuously distributed north of latitude 42°15′S. Pittosporum cornifolium is typically associated with old growth forest systems and low nutrient substrates, with low mean daily temperatures in the coldest month (<0.6 °C) and high mean October vapour pressure deficits (>0.5 kPa) apparently restricting its distribution. Significant morphological variability is evident in leaves and flowers, especially with respect to plants from the Poor Knights Islands. Genetic analyses of five mainland populations and individuals representing Poor Knights Islands populations revealed relatively low genetic diversity at the population level which is likely to be the result of geographic isolation. Molecular phylogenetic studies suggest a New Caledonian origin for the species with close affinities to both P. pimeleoides subspecies. Several lines of evidence suggest recognition of the Poor Knights Islands entity as a new taxon. However, analysis of additional morphological, reproductive and molecular data across the full geographic range will be required to confirm current inferences. Although populations have declined, P. cornifolium is not currently threatened, however, it should be considered for reintroduction to sites in districts where its range has been severely reduced. [ABSTRACT FROM PUBLISHER]

Parthenocarpy is a condition where an ovary develops into a fruit without fertilization and seed formation. Parthenocarpy might be useful in breeding tomato (Lycopersicon esculentum Mill.) to be adapted to a wide range of temperatures normally unfavorable for fruit setting. The expression of parthenocarpy in tomato, cv. Oregon Pride, was facultative with seedless, few seeded (1-20 seed(s)/fruit), and normal seeded fruit being produced on the same plant in the same growing season. The greatest degree of parthenocarpy, leading to seedlessness, occurred above a daily mean temperature of 24-25˚C. When there was sufficient viable pollen, and an appropriate daily mean temperature of 18-21˚C, there was some fertility leading to low numbers of seed produced. Very low fruit set following emasculation compared to open pollination indicated the requirement of pollination stimulus for fruit set and further development. Precocious ovary development due to genetic stimuli combined with aberration of female fertility by interfering with ovule development might account for very low seed content in fruit of facultative parthenocarpic lines. [ABSTRACT FROM AUTHOR]

To better understand the dynamics of Fe2 + oxidation in facultative wastewater stabilization ponds, water samples from a three-pond system were taken throughout the period of transition from anoxic conditions with high aqueous Fe2 + levels in the early spring to fully aerobic conditions in late spring. Fe2 + levels showed a highly significant correlation with pH but were not correlated with dissolved oxygen (DO). Water column Fe2 + levels were modeled using the kinetic rate law for Fe2 + oxidation of Sung and Morgan. [5] The fitted kinetic coefficients were 5 ± 3 × 106 M-2 atm-1 min-1; more than six orders of magnitude lower than typically reported. Comparison of four potential Fe redox couples demonstrated that the pε was at least 3–4 orders of magnitude higher than would be expected based on internal equilibrium. Surprisingly, measured nitrate and DO (when present) were typically consistent with both nitrate (from denitrification) and DO levels (from aerobic respiration) predicted from equilibrium. Although the hydrous Fe oxide/FeCO3 couple was closest to equilibrium and most consistent with the observed pH dependence (in contrast to predicted lepidocrocite), Fe2 + oxidation is kinetically hindered, resulting in up to 107-fold higher levels than expected based on both kinetic and equilibrium analyses. [ABSTRACT FROM AUTHOR]