bluuebunny/crossref_metadata_2025 huggingface dataset:
Pollen Tube Growth and Early Seed Development in Eucalyptus regnans F. Muell. (Myrtaceae) in Relation to Ovule Structure and Preferential Outcrossing
Authors: Sedgley M , Hand FC , Smith RM , Griffin AR
Published: December 2005

Pistils of Eucalyptus regnans were observed by bright field, fluorescence, phase contrast, Nomarski, and
scanning electron microscopy from 4 weeks prior to anthesis to 16 weeks after self- and cross-
pollination. The transmitting tissue of the style had a central canal which extended for half its length.
The unfertilised ovary contained a mean of 30.5 ovular structures with 16.5 normal ovules, 2.5 abnor-
mal ovules, and 11.5 sterile ovulodes. The ovules were arranged in two rows in three (occasionally four)
locules. The ovulodes always occupied positions at the stylar end of the ovary, but with this exception
there was no pattern to the occurrence of the abnormal ovules. Pollen tubes grew between the cells'of
the transmitting tissue, and not in the stylar canal. Penetration of the ovules had commenced by 5 days
after both self- and cross-pollination. The early fertilised ovule contained a zygote and free-nuclear
endosperm, and embryos with between 1 and 16 cells were present at 16 weeks after pollination. Not
all normal ovules were fertilised, despite adequate numbers of pollen tubes. Ovulodes were never
observed to be penetrated by a pollen tube, but with this exception there was no relationship between
position on the placenta and either the penetration of ovules by a pollen tube or the occurrence of
fertilised ovules. There was no difference between self- and cross-pollination in either the number
of ovules penetrated by a pollen tube, or the number of fertilised ovules up to 16 weeks following
pollination.
Structure and Composition of the Abrupt Rain-Forest Boundary in the Herberton Highland, North Queensland
Authors: Unwin GL
Published: December 2005

Structural and floristic features of the rainforest-eucalypt forest boundary are described for two sites
on the seasonally clouded eastern slopes of the Herberton Highland, north Queensland. Permanent
sample plots, transects and canopy profiles were used to analyse variations across the narrow ecotone.
The forest ecotone was found highly variable, spatially and temporally. Within rainforest, richness of
woody species was maintained through to the closed forest edge. However, structural changes were
more pronounced towards the boundary than were floristic variations and a fringe of immature rainforest
varied in depth from 20-500 m.
In the open forest margin, tall trees of Eucalyptus grandls were restricted to a narrow zone between
the rainforest edge and the broad expanse of medium height Eucalyptus intermedia. Within this transition,
young rainforest trees and some shrubs were observed, during a 12-year interval, to be establishing
beneath tall E. grandis, displacing fire-prone grasses in the process.
The distribution of old E. grandis within rainforest provides a record of recent boundary change.
On evidence presented, the rainforest-eucalypt forest boundary is dynamic and parts of the rainforest
are expanding due to favourable contemporary fire regimes.
In Vitro Germination of Eucalyptus Pollen: Response to Variation in Boric Acid and Sucrose
Authors: Potts BM , Marsden-Smedley JB
Published: December 2005

The effect of boric acid (0-450 ppm) and sucrose (0-40%) on pollen germination and pollen tube growth
in Eucalyptus globulus, E. morrisbyi, E. ovata and E. tirnigera was examined in vitro. Over the con-
centrations tested, sucrose had by far the largest effect upon both pollen germination and tube lengths.
The optimum sucrose concentration for pollen germination (30%) and pollen tube growth (20%) differed
markedly with very little (<lo%) germination occurring in the absence of sucrose. The interaction of
sucrose and boric acid was significant. However, in general both pollen germination and pollen tube
growth were increased by the addition of up to 100 ppm boric acid, but above this level the response
plateauxed. The four species differed significantly in their pattern of response to both boric acid and
sucrose and the predicted optima derived from analysis of response surfaces differed between species.
The predicted sucrose concentration for optimal germination and growth of E. urnigera pollen was
consistently less than the other species and in terms of the optimal level of boric acid for pollen tube
growth species can be ranked in the order E. globulus > E. ovata > E. morrisbyi = E. urnigera. Pollen
germination and tube growth of all four species on a medium comprising 20% sucrose and 200 ppm
boric acid would not differ significantly from the observed maximum response of each species and this
could suffice as a generalised medium. However, if only percentage germination is to be assessed 30%
sucrose would be preferable. It is argued that subtle interspecific differences in optimal in vitro con-
ditions for pollen germination and pollen tube growth are likely to reflect differences in pollen physiology
which in vivo may have important implications for the success of hybridisation where pollen competition
occurs.
Site and Seasonal Effects on Susceptibility of Eucalyptus marginata to Phytophthora cinnamomi
Authors: Tippett JT , Mcgrath JF , Hill TC
Published: December 2005

Susceptibility of Eucalyptus marginata stems and roots to invasion by Phytophthora cinnamomi was
compared at four sites in the northern jarrah forest and reasons for differences in tree susceptibility were
sought. The sites were located in both the low (750 mm year -I ) and high (1 100 mm year -1) rainfall
zones and differed in understorey composition and soil nutrient status. Stems were inoculated at
monthly intervals between October 1983 and April 1984. Measurement of stem lesions induced by
inoculation showed that rate of fungal growth in trees at all sites generally increased during the
October-December (1983) period. During February and March (1984) there was a large difference in
the susceptibility of stems and roots in low-rainfall zone sites compared with those in high-rainfall zone
sites. Roots inoculated during February at three of the four sites showed the same relative susceptibilities
as stems inoculated one week later. Mean relative water contents (RWC) of the phloem (inner bark)
were used to compare the water status of the saplings at the four sites and the observed inhibition of
the fungus in the sapling stems and roots at the driest sites, coincided with the months when phloem
RWC values were at their lowest. Phloem was also sampled from pole-sized trees at the four sites and
seasonal changes in RWC values, soluble carbohydrate concentrations and phenols were monitored for
12 months. Soluble carbohydrate concentrations in the phloem of some of the saplings inoculated at
each site were also determined. Concentrations of carbohydrates and phenols did change seasonally and
differed between sites but no evidence was found to suggest that they had a direct effect on fungal
growth.
Relationship Between Diaspore Characteristics and Distribution of Grasses Around Sheep Camps on the Northern Tablelands of New-South-Wales
Authors: Rogers RW , Whalley RDB
Published: December 2005

Twenty-seven common grasses on the Northern Tablelands of New South Wales were classified according
to their occurrence on or off sheep camps in unfertilised natural pastures. A number of seed and
seed germination attributes were examined in relation to the distribution of the individual species.
Camps had a greater proportion of introduced grasses, and of annual or short-lived perennials, than
off-camp zones. The sheep camp grasses in general had heavier seeds, more rapid germination, and their
seeds in general did not have a sharp callus, antrorse hairs on the callus, or awns. If awns were present
on sheep camp species a lower proportion were hygroscopically active than for off-camp species. There
were no differences in the presence or absence of accessory floral structures in the dispersal unit, hairs
on the coleorrhiza or in the shapes of seeds between sheep camp and off-camp grasses.
The differences in seed and seed germination characteristics found between sheep camp and off-camp
species are explained in terms of the differences in environment (water stress and damage by sheep)
encountered by grasses germinating and establishing on and off the sheep camps.
Inheritance of Resistance of Cowpea to Phytophthora vignae in Whole Plants, Cuttings and Stem Callus Cultures
Authors: Bateman KS , Hinch JM , Ralton JE , Clarke AE , Mckenzie JA , Imrie BC , Howlett BJ
Published: December 2005

The inheritance of resistance of cowpea to Phytophthora vignae race 2 has been examined in seedlings
from F1, F2 and backcross generations from crosses between a susceptible cultivar, cv. Poona, and a
near-isogenic resistant cultivar, cv. Caloona. Resistance is dominant and controlled by a single gene
(gene complex). A non-subjective method, based on comparison of the lengths of lesions produced on
hybrid and parental seedlings after inoculation of cut epicotyls, was used to classify hybrid plants as
resistant and susceptible. This method takes into account the variation in responses to infection between
batches of plants assayed on different days. Two other criteria were used to indicate resistance: the
presence of reddening responses, 3 days post-inoculation; and the ability of plants to recover 35 days
after inoculation of cut epicotyls. Resistance is also expressed in excised leaves of rooted cuttings, and
in stem callus derived from cv. Caloona and F1 plants.
Staurocytic Stomatal Complexes in Species of Monocalyptus sensu Carr and Carr (Eucalyptus, Myrtaceae)
Authors: Carr DJ , Carr SGM
Published: December 2005

Adult leaves of the species of five groups of eucalypts, previously thought to be related on grounds of
comparative morphology, especially of the flower, are shown to have stomatal complexes conforming
to the type, rare among angiosperms, known as staurocytic. They develop from anisocytic complexes,
typical of the seedling leaves. Adults leaves of many of the species have complexes with mostly four
or five subsidiary cells. The spectrum of frequencies of subsidiary cells may be characteristic of
individual species.
Developmental Pattern and Structural Organisation of Leaf Chloroplasts in Lepidozamia peroffskyana
Authors: Bonatti PM , Fornasiero RB
Published: December 2005

The ontogenesis of chloroplasts during leaf development in Lepidozamia peroffskyana Regel is
described; this cycad lives in the ground layer of the evergreen subtropical closed forest of south-eastern
Australia. Characteristic features in young plastids are long bands of multilayered thylakoids,
resembling photosynthetic structures of some green algae and ferns. 'Optional' structures, namely
prothylakoid bodies and crystalline inclusions, are present in the pre-grana stages, in relation to the
slow rate of leaf development. Mature chloroplasts are characterised by a great number of randomly
oriented high grana stacks, a lack of starch, a high ratio of appressed to exposed thylakoids, and a low
ratio of Chl a to Chl b; these shade features appear coherent with the natural habitat of Lepidozamia.
However, since similar structures have been reported in mature chloroplasts of other cycads living in
exposed sites, the existence of a genetically superimposed structural pattern is hypothesised, reflecting
a primitive adaptation to weak light conditions of this group of ancient seed plants.
Breeding System and Tests for Pollen-Limitation in Two Species of Banksia
Authors: Goldingay RL , Whelan RJ
Published: December 2005

Three factors that potentially influence fruit set (breeding system, inadequate cross-pollination and
variable floral display) were examined for two species of Banksia. Firstly, self-pollination and autogamy
treatments failed to produce any fruit in B. spinulosa and produced very few fruit in B. paludosa. This
suggests that cross pollen is required to produce the level of fruit set observed in the field. Secondly,
when plants were given abundant cross pollen, fruit set was not altered in B. spinulosa but was in
B. paludosa. Although the number of follicles per inflorescence was was not different for open-
pollinated (control) and manipulated B. paludosa inflorescences, the latter produced twice the proportion of inflorescences with follicles produced by control plants and twice the total number of follicles
per plant. Thirdly, larger floral display in open-pollinated B. spinulosa plants was associated with a
greater production of fruit. However, larger floral display was not associated with a greater reproductive
output in B. paludosa, and we suggest that recurrent pollen-limitation in this species may be responsible
for this result.
Anatomical Aspects of Root Bud Development in Hoop Pine (Araucaria cunninghamii)
Authors: Burrows GE
Published: December 2005

Root bud development was studied in the severed, secondarily thickened, lateral roots of 20-year-old
hoop pines (Araucaria cunninghamii Aiton ex D. Don). The buds arose adventitiously in the
parenchyma of the proliferated pericycle at positions opposite the diarch primary xylem poles, although
they were not associated with lateral roots. The buds had an orthotropic mainstem and juvenile leaf
morphology and could thus be a useful source of material for vegetatively propagating elite hoop pines.
The Conservation Genetics of Eucalyptus paliformis L. Johnson et Blaxell and E. parvifolia Cambage, Two Rare Species From South-Eastern Australia
Authors: Prober SM , Tompkins C , Moran GF , Bell JC
Published: December 2005

Eucalyptus paliformis is restricted to a small, isolated plateau on the eastern escarpment of south-eastern
Australia. Eucalyptus parvifolia populations are scattered discontinuously in a narrow band of nearby
grazing land that has been substantially cleared over the last 100 years. Allozyme diversity was examined
in six of the seven known populations of E. paliformis and in all the eight known populations of
E. parvifolia to help assess the potential for the survival of these species under current conditions of
management. Levels of genetic diversity in E. paliformis are comparable to levels in other eucalypts of
restricted distribution and, in conjunction with its large population sizes, are likely to be adequate for
its survival. The greatest threat to E. paliformis is its localised distribution, which renders it susceptible
to extinction by disturbance. By contrast, the levels and distribution of diversity in E. parvifolia, and
estimates of migration between populations, suggest that the high variability measured in this species
may be a consequence of a once more continuous distribution. The recent dissection of its range through
clearing is likely to lead to a decline in levels of genetic diversity in E. parvifolia, which, when combined
with destruction of the habitat where it can best outcompete other eucalypts, suggests its survival is
threatened.
Fire-Related Dynamics of a Banksia Woodland in South-Western Western Australia
Authors: Hobbs RJ , Atkins L
Published: December 2005

We studied the post-fire vegetation development of a low open woodland dominated by Banksia
attenuata and B. menziesii near Perth, Western Australia. Two similar stands burned in autumn and
spring displayed different regeneration patterns, with seedling regeneration occurring only in the autumn
burn area. Vegetative regrowth was more rapid and post-fire species numbers were higher in the spring
burn area. Introduced annuals increased significantly in the autumn fire area. Longer-term vegetation
development was studied in a series of stands ranging in age since last fire from 1 to >44 years. Species
richness was greatest in the 5-year-old stand, and many shrub species were most abundant 2-5 years after
fire. Non-native annuals were found only in stands less than 5 years old since last fire. Dominance by
the shrub Eremaea pauciflora increased with stand age, although shrub structure and total biomass did
not vary greatly except in the oldest stand studied. The proportion of total shrub biomass accounted
for by leaves declined with stand age. Both the two major Banksia species had mixed size structures
with seedlings present in all stands, indicating that neither is dependent on fire for recruitment.
The results indicate that while autumn burns promote seedling regeneration they may also increase
invasion by non-natives, and spring burning may be preferable in these Banksia woodlands. Burning
rotations longer than those required for fuel reduction purposes are necessary to maximise conservation
values.
Aspects of Phyllode Anatomy in Some Australian Phyllodinous Acacias, With Particular Regard to Stickiness
Authors: Boughton VH
Published: December 2005

Phyllodes of species of Acacia from the sections Julflorae, Plurinerves, Lycopodiifoliae and
Phyllodineae are described in respect of the disposition of the stomates relative to the phyllode surface,
size of the substomatal cavities, outline of the phyllode as seen in transverse section, and disposition
of the smaller vascular bundles. The first three of these characters are shown to be related to stickiness
and the third and fourth to the relative humidity or aridity of the environment. The geographical
distribution of sticky species in central and eastern Australia is determined. Sticky species occur
throughout the region but are commoner in the more arid interior than in the more humid coastal
regions. No relationship is apparent between stickiness and membership of the sections.
Sex-Ratios and Related Characteristics in Spinifex sericeus (Poaceae)
Authors: Maze KM , Whalley RDB
Published: December 2005

Spinifex sericeus R.Br. is a dioecious, stoloniferous grass which occurs on sand dunes around much of
the south-eastern coastline of Australia, New Zealand and New Caledonia.
Sex ratios of ramets of S. sericeus and some associated characteristics were studied on the mid-north
coast of New South Wales. Generally there was a male bias in the observed ramet sex ratio, although
the extent of this bias varied with the beach investigated, the position in the dunes and the time of
sampling. Male inflorescences matured and died more rapidly than females, and hence the observed
male bias was greatest at the beginning of the flowering period. Male ramets were found to have more
sexual tillers per clump than female ramets.
The genet sex ratio was estimated from plants grown from seed and separated from each other
throughout the experimental period. Males and females were found to be equal in number, although
this equality may not be a true reflection of the genet sex ratio in the field.
Factors That Influence the Yield and Viability of Cucumber (Cucumis sativus L) Cotyledon Protoplasts
Authors: Kantharajah AS , Dodd WA
Published: December 2005

Protoplasts isolated from cotyledons of aseptically germinated cucumber seedlings were divided into
three size classes. The relationships between tissue age, isolation procedure, yield and protoplast size
were investigated. During germination and up to an age of 13 days, the percentage of protoplasts in
each size class underwent considerable change with a big reduction in percentage of the largest protoplasts
in older cotyledons. Protoplast size and yield could also be manipulated by varying the isolation
technique. In this context, temperature, incubation time and shaker speed were significant. By selecting
tissue of appropriate age and using a carefully selected isolation procedure the percentage of viable
cucumber protoplasts with the ability to form a cell wall and divide can be increased considerably.
The Effect of Auxins and Antiauxins on Shoot-Bud Induction and Morphology in the Moss, Bryum atrovirens Will ex Brid
Authors: Chopra RN , Vashistha BD
Published: December 2005

The protonema of the moss Bryum atrovirens remains bud-free under ordinary cultural conditions on
Nitsch's basal medium. Exogenously applied auxins (Indole-3-acetic acid; 2-4-dichlorophenoxyacetic
acid; α-naphthaleneacetic acid and β-naphthoxyacetic acid) induced buds on protonemata, whereas
antiauxins (Maleic hydrazide and 2,3,5-triiodobenzoic acid) failed to do so. Morphology of the gametophores
depended upon the concentration of auxin in the medium. In general, normal leafy gametophores
resulted at lower concentrations, and at higher levels of auxins morphology was adversely
affected. Simultaneous application of 6-benzylaminopurine and 2,4-dichlorophenoxyacetic acid
advanced bud formation as well as increased bud number, but had no significant effect on the improvement
of shoot morphology.
Comparative Responses to Temperature of the Major Canopy Species of Tasmanian Cool Temperate Rain-Forest and Their Ecological Significance .II. Net Photosynthesis and Climate Analysis
Authors: Read J , Busby JR
Published: December 2005

Net photosynthesis was measured in foliage of Tasmanian rainforest canopy species grown at 20°C and
acclimated sequentially to a range of temperatures. Some trends in photosynthetic response (both instantaneous
and acclimatory) correlated with aspects of species' distributions with respect to altitude, latitude
and climate, and with their frost resistance. This was particularly evident in Athrotaxis selaginoides
D.Don and Nothofagus cunninghamii (Hook.) Oerst. which are common at high altitudes. High-altitude
provenances of these species showed a low optimum acclimation temperature (16-17°C) and maintained
a high rate of photosynthesis (as a proportion of their maximum rate) at 8°C (84% and 76% respectively).
However, the co-occurring winter-deciduous Nothofagus gunnii (Hook. f.) Oerst. showed a
higher optimum acclimation temperature for photosynthesis (23°C) and a lower rate of photosynthesis
at 8°C (60% of its maximum rate) and is apparently adapted photosynthetically to summer temperature
conditions. Provenances of N. cunninghamii showed trends in photosynthetic responses (maxima and
responses to extremes) and specific leaf area which correlated with the climate of the collection site and
with frost resistance. This population variation may permit the very wide geographic and climatic range
of this species, allowing tolerance of extreme temperatures as well as a relatively high competitive ability
under more equable climates. Atherosperma moschatum Labill. showed a low photosynthetic tolerance
of high and low temperatures compared with the other species. This is consistent with the general
restriction of this species to microhabitats with an ameliorated climate and indicates that its wide latitudinal
range is not due to a broader photosynthetic tolerance of temperature than co-occurring species.
The determinants of the narrow latitudinal range of the Tasmanian endemic species, particularly those
which are common at low altitudes (Phyllocladus aspleniifolius (Labill.) Hook, f., Eucryphia lucida
(Labill.) Baill. and Lagarostrobos franklinii (Hook. f.) C.J. Quinn are less clear. Limited acclimation
to high temperatures in E. lucida (and P. aspleniifolius under some conditions), and in the high altitude
species, N. gunnii and A. selaginoides, suggests that the sensitivity of these species to high summer
temperatures may directly limit their distribution. However, interpretation of the sensitivity of these
species to high summer temperatures and low precipitation shown by the climate analysis is complicated
by the interactions of these climatic features with the incidence of fire.
The Breeding Systems of Three Cooccurring Legumes: Dillwynia hispida, Dillwynia uncinata and Pultenaea densifolia (Leguminosae, Papilionoideae)
Authors: Gross CL
Published: December 2005

The breeding systems of Dillwynia hispida Lindley, D. uncinata (Turcz.) J. Black and Pultenaea
densifolia F. Muell. were determined using glasshouse trials and field experiments. Each species is self-incompatible
and thus relies on pollen vectors to effect seed-set. Calculations of pollen-ovule ratios are
compatible with this conclusion. Increase in the age of pollen led to a decline in fruit-set, which was
more pronounced in Dillwynia uncinata than D. hispida or P. densifolia. In this study, Pultenaea
densifolia pollen was never more than 60% viable which may explain the extremely high pollen-ovule
ratio of this species. In all three species, esterase production on stigmas implied that they were fully
receptive by day 3 of flowering. Stigma morphologies were assessed by scanning electron microscopy
and the results used to discuss their incompatibility mechanisms.
The Environments and Primary Production of Cushion Species at Mt Field and Mt Wellington, Tasmania
Authors: Gibson N
Published: December 2005

Primary production of four species of alpine cushion plants were studied over a 2-year period. The
climate of these areas was found to be severe but with a high degree of variability on a seasonal and
yearly basis. The growing season at the higher altitude sites generally exceeded 6 months. Net above
ground primary production of the four cushion species ranged from 282 to 709 g m-2 year-1. Reproductive
effort fluctuated between species and years, ranging from 0 to 30% of net above ground production.
Patterns in dry matter accumulation suggest no individual species would show consistently
superior growth rates under present climatic conditions. Soil moisture and soil nutrient status was found
to be similar between all sites. Altitude of the sites (830-1400 m) was found to be strongly correlated
with the timing of flowering and/or seed set but appeared to have little effect on net primary production.
An Assessment of the Allelopathic Potential of Eucalyptus
Authors: May FE , Ash JE
Published: December 2005

Previous studies have shown that various Eucalyptus species can yield allelopathic chemicals which may
be effective in suppressing understorey vegetation. However, the techniques employed in many studies
do not resemble natural ecological processes. This study used germination of Lolium and growth of
Lolium, Lemna, Eucalyptus and Acacia to test for allelopathy. Extraction techniques mimicked typical
daily rainfall rates upon quantities of foliage, leaf litter and bark litter that are typically encountered
in forests; root leachates were obtained hydroponically; stemflow was obtained following rainfall; soils
were leached with water; and volatiles from leaves were studied in an enclosed chamber. Fresh intact
leaves caused little growth suppression, in contrast to coarsely chopped leaves and extracted leaf essential
oils which were both highly suppressive. Whole leaf litter, shed bark and, especially, stemflow yielded
suppressive leachates. Evaporative concentration of leachates in soils was demonstrated, which
increased their inhibitory effect. It is apparent that allelopathy must be considered in relation to rainfall
and the soil water balance. Decay was shown to reduce the allelopathic effects of leaf and bark litter
leachates but some inhibitory chemicals remained after 5 months. It was concluded that allelopathy is
likely to be a cause of understorey suppression by Eucalyptus species especially in drier climates.
Soil Seed Banks of Adjacent Unlogged Rain-Forest Types in North-Queensland
Authors: Graham AW , Hopkins MS
Published: December 2005

The size and floristic composition of soil seed banks under four adjacent, unlogged and structurally
different rainforest types were assessed by exposing 17 surface soil samples (to 40mm depth) to
germination-house conditions. The mean size of the seed bank in the undisturbed forest types was 240
seeds m-2 (s.d. 139). Seeds of secondary species dominated the soil seed banks in all forest types,
although weed seeds constituted only 0.6-4.0%. Some forest types had characteristic component secondary
species in the buried seed bank. Agglomerative classification and multidimensional scaling analysis
of quantitative sample data indicated that the parent structural-environmental forest type was the
dominant influence in determining composition of the soil seed banks. Comparisons of the seed banks
of the intact rainforest with those of nearby disturbed forests showed the former to be 35 to 50% smaller
in total size, and lacking in some distinctive secondary species. It was concluded that disturbance, both
within and adjacent to rainforest, may influence soil seed bank compositions, and hence future patterns
of regeneration.
Influence of Fire and Edaphic Factors on Germination of the Arid Zone Shrubs Acacia aneura, Cassia nemophila and Dodonaea Viscosa
Authors: Hodgkinson KC , Oxley RE
Published: December 2005

The germination of some shrub species may be enhanced following fire in shrublands and woodlands.
This paper reports the germination response of Acacia aneura, Cassia nemophila and Dodonaea viscosa
- common shrub species in semi-arid and arid woodlands - to laboratory fires over a range of
intensities and durations.
Seeds were subjected to fires of different intensities in the controlled environment of a glasshouse.
Depth of seed placement in the soil, soil moisture level and amount and type of fuel influenced the
percentage of seeds that germinated. Amounts of shredded paper fuel, equivalent to typical grass fuel
levels in semi-arid woodlands did not enhance the germinability of seeds of any of the species, except
for A. aneura on a moist or wet soil surface. A high, dense fuel load (simulating slow burning, low-
intensity litter fires) either increased or decreased the germinability of surface and buried seeds of all
species, depending upon soil moisture level and depth of seeds. The germination response to the heat
of fires differed significantly between species: A . Aneura germination increased substantially at low levels
of peak temperature up to 60°C whereas germination of C. nemophila increased to a lesser extent and
D. viscosa was not affected at all over this low temperature range. Seeds of all species were killed by
slow burning litter fires when the temperature exceeded 80°C. These results confirm the view that fire-
promoted germination does not result from the burning of fine fuels per se but occurs only where there
is litter buildup and when the soil temperature does not exceed the lethal threshold of 70-80°C.
Predation by Insects Limits Seed Production in Banksia spinulosa var neoanglica (Proteaceae)
Authors: Vaughton G
Published: December 2005

Application of insecticide to inflorescences of Banksia spinulosa var. neoanglica indicated that damage
by flower and seed predators halved the number of seeds produced per plant. Both the proportion of
inflorescences that produced fruits and the number of seeds produced per infructescence increased by
45% when insects were excluded. Infructescences in the insecticide treatment produced 28% more
follicles than in the control group. Insects damaged the seed in 13% of follicles in the control group
whereas there was no damage in the insecticide treatment. The proportion of follicles with aborted seed
did not differ between the two groups. The greater seed set occurring when insects were excluded did
not affect the weight of individual seeds or reproductive output in the next flowering season. Some
inflorescences did not produce fruit even when insects were excluded suggesting that factors besides
predation also limit fecundity of B. spinulosa.
Influence of Propazine and Chlorthal Dimethyl on Mycorrhizal Development in Pinus radiata Seedlings
Authors: Marks GC , Becker SL
Published: December 2005

In an investigation into the side effects of herbicides on mycorrhizal formation in Pinus radiata nurseries,
propazine and chlorthal dimethyl were added at concentrations that approximated to normal (2.20 and
1.88 g a.I-1L) and half-normal (1.10 and 0.94 g a.i.-1L) field application rates respectively to P.
Radiata seedlings growing in terra cotta pots. A humus-rich, surface soil from a 40-year-old P. radiata
plantation was used as mycorrhizal inoculum. Root length, mycorrhizal numbers and type, and seedling
growth were assessed and a histological examination of bulk mycorrhizal samples was carried out.
Propazine applied at both dosage rates and chlorthal dimethyl at the higher rate significantly sup-
pressed root growth during the first 3 months and mycorrhizal formation during both the early and later
stages of growth. However, neither herbicide affected shoot growth after 3 months and both increased
shoot growth at the end of 6 months.
Two mycorrhizal types were identified, a white-coloured, heavily dichotomised ectomycorrhiza with
a thick mantle and a reddish-coloured, weakly dichotomous ectendomycorrhiza. The roots of chlorthal
dimethyl treated seedlings strongly suppressed intracellular penetration in the ectendomycorrhiza, producing an unusual association with only a Hartig net, which was similar to that seen in senescing
associations and some long roots of conifers. The ratio of white to red mycorrhizal numbers was highest
in the untreated controls and was reduced by both herbicides.
Both herbicides appeared to effect mycorrhizal formation through their influence on root morpho-
genesis and host physiology.
Aerial and Belowground Phytomass of Banksia Scrub-Heath at Eneabba, South-Western Australia
Authors: Low AB , Lamont BB
Published: December 2005

Three Banksia spp. accounted for 80% of the aerial biomass of scrub-heath on deep sand. Reproductive
structures contributed relatively more than leaves or stems to biomass of a non-sprouting Banksia, which
also retained most of its dead leaves, than to the two resprouting species. Sclerophyllous hemicryptophytes
accounted for only 1% of the aerial biomass. Litter contributed 19% of above-ground dead plus
live phytomass and was poorly decomposed.
The overall root f shoot ratio, to a depth of 2.5 m, was a high 2.35. Rootstocks, laterals and proteoid
roots made major contributions to below-ground phytomass even though they were confined to the
uppermost 15 cm of soil. Despite an exponential decline in root mass with depth, the gradient was less
than in related ecosystems due to the abundance of well developed tap roots and vertical laterals (sinkers)
to a depth of at least 5 m.
The Dynamics of Callitris columellaris/Eucalyptus albens Communities Along the Snowy River and Its Tributaries in South-Eastern Australia
Authors: Claytongreene KA , Ashton DH
Published: December 2005

The vegetation in the rain shadow areas of the Snowy River region was studied. Five distinct woodland
communities were recognised from a numerical classification, a community dominated by
C. columellaris at lower altitudes on north and west aspects, three mixed C. columellaris/E. albens
communities which are also aspect and altitude dependent, and a higher altitude, cool aspect, E. albens
dominated community.
Although C. columellaris and E. albens occupy separate niches, they compete strongly. Contrasting
dispersal and germination behaviour between the two species may explain the current distribution and
structure of these woodlands.
Embryology and Reproductive Ecology of the Darling Lily, Crinum flaccidum Herbert
Authors: Howell G , Prakash N
Published: December 2005

In Crinum flaccidum the anthers are versatile and tetrasporangiate with a secretory tapetum of binucleate
cells. Successive cytokinesis in microspore mother cell results in isobilateral and decussate microspore
tetrads. The mature pollen grains are single, spheroidal, disulculate, echinate and 2-celled. In the
mature anthers, fibrous thickenings develop not only in the endothecium but also in two or three middle
cell layers and the connective tissue before latrorse dehiscence. A lobed tissue in each of the three locules
of the ovary serves ovular and placental functions. Each extension of the 5-7 paired lobes represents
an ategmic ovule. The development of the female gametophyte conforms to the Polygonum type.
Usually only one gametophyte is present in each lobe but occasionally several may occur. Bulb growth
is monopodial with normally three umbels produced per plant, each carrying an average of 10 flowers,
only two or three of which are open at any one time. Nectar sugar concentration was measured at
14.2% (w/w), of which 44.8% of solids was sucrose and 3.9% either glucose or fructose. The protandrous
flowers are phalenophilous, pollinated by sphingid moths. The endosperm formation is of the
nuclear type. In the absence of seed coats and the nucellus at maturity, the outer layers of the endosperm
become corky following the activity of a phellogen. Embryogeny appears to be of the Asterad type.
The mature embryo is straight and chlorophyllous. The large (5.3 g) seeds are 89% water and show
no dormancy, germinating without an external supply of water, sometimes while still on the parent plant.
Co-Occurrence of Vulpia Species on the Northern Tablelands of New South Wales
Authors: Mcintyre S , Whalley RDB
Published: December 2005

A survey of 100 sites on the northern tablelands, New South Wales (Australia) was conducted to
determine the composition of Vulpia populations in ruderal and pasture habitats. Of the four species
recorded, two were widespread and common [Vulpia bromoides (L.) Gray and V. myuros (L.) Gmel.]
and two were rare and newly recorded for the region [V. muralis (Kunth) Nees and V. ciliata (Pers.)
Link]. Mixed stands of the two common species occurred at 88% of the sites sampled, although
V. bromoides was more abundant with an average frequency of 61% compared with 38% for V. myuros.
Two forms of V. myuros were present and these usually occurred in mixed stands, with forma myuros
more widespread and abundant than forma megalura [V. megalura (Nutt.) Rydb.].
Relative frequencies were compared for a range of site characteristics: habitat type, parent material,
latitude, aspect and altitude. However, variation in abundance of V. bromoides and V. myuros in
relation to these factors was insignificant, suggesting that both species have a broad ecological amplitude. Although ecological differentiation between species could not be detected at the scale of this
survey, it is likely that such differences may exist at a smaller spatial, or on a temporal scale.
Temperature Effects on the Seed-Germination of 10 Kwongan Species From Eneabba, Western-Australia
Authors: Bellairs SM , Bell DT
Published: December 2005

The germination responses of 10 species (Acacia blakelyi, A. pulchella, Allocasuarina humilis,
Beaufortia elegans, Conostylis neocymosa, Eucalyptus tetragona, Kennedia prostrata, Leptospermum
spinescens, Melaleuca acerosa and Xanthorrhoea drummondii) to constant temperatures ranging from
5 to 35� C were studied. These Western Australian perennial species had optimum germination percentages
between 15 and 20�C, except Eucalyptus tetragona which had an optimum at 25�C and
Leptospermum spinescens which had an optimum at 10�C. Seeds were transferred from high and low
temperatures to 15�C to determine whether high or low temperatures induced dormancy. Low temperatures
tended not to affect subsequent germination but high temperature decreased subsequent germination
for some species. Wetting and drying stimulated the germination of Acacia blakelyi, A. pulchella
and Kennedia prostrata seeds.
Host Specificity of Lysiana exocarpi subsp Exocarpi and Other Mistletoes in Southern South-Australia
Authors: Yan ZG
Published: December 2005

A study was conducted of host specificity of six mistletoe species in 17 sites in southern South Australia.
The mistletoe Lysiana exocarpi occurred on eight of the 15 potential host species encountered in the
survey but disproportionally parasitised Heterodendrum oleifolium and Myoporum platycarpum as its
major hosts. More than 90% of L. exocarpi plants infested these two hosts. The other five mistletoe
species, Amyema linophyllum, A. miquelii, A. miraculosum, A. preissii, and A. quandang, were highly
host specific, occurring on only one host species or on species of closely related taxa.
Although L. exocarpi was found throughout the study area, its occurrence on M. platycarpum
showed significant geographic variation. Myoporum platycarpum was heavily infested by L. exocarpi
at sites with an annual rainfall of > 250 mm but not at sites with < 250 mm annual rainfall. At sites
with less rainfall, M. platycarpum was infested by another mistletoe species, A. miraculosum. Across
all sites, the proportion of M. platycarpum trees infested by L. exocarpi was significantly correlated with
annual rainfall. No such trend was detected for H. oleifolium infested by L. exocarpi.
Floral Initiation and Development in Relation to the Time of Flowering in Banksia coccinea R.Br and B. menziesii R.Br (Proteaceae)
Authors: Fuss AM , Sedgley M
Published: December 2005

Floral initiation and development in Banksia coccinea and B. menziesii were investigated using scanning
electron microscopy in relation to the time of flowering. Floral initiation in both species occurred in
late spring. The sequence of floral development was similar for both species but the timing was different.
Ten stages of floral development were identified. Stage 1 was a vegetative meristem. Stage 2 signified
the transition to the reproductive state, and was characterised by a broadening of the meristem with the
production of involucral bracts. There were increases in both height and diameter of the meristem as
common bracts (stage 3), floral bracts (stage 4) and florets (stage 5) were initiated. At stage 6 the developing
inflorescences were macroscopically visible. This was followed by appearance (stage 7) and
subsequent extension of the florets (stage 8). The styles continued to extend once floret extension had
ceased causing the perianth to split and the styles to protrude (stage 9), thus imparting to the inflorescences
their characteristic colour. Anther dehiscence occurred prior to anthesis of the floret, and the
pollen was deposited on the pollen presenter, a distal modified region of the style. At anthesis (stage 10)
styles were released from the perianth limb, presenting pollen to foraging insects and birds. Phyllotaxy
was spiral throughout development, with a transition from a single genetic spiral in the vegetative shoot
to 13 spirals initiating simultaneously in the developing inflorescence. Floral development was slow,
taking from 6 to 8 months in B. menziesii prior to peak anthesis between April and July. In B. coccinea
macroscopic inflorescences were not observed until May, with peak anthesis occurring between August
and November, 9-12 months after initiation. Inflorescence colour showed wide variation in both species,
with red and pink being the dominant colours in B. coccinea and B. menziesii respectively.
Andromonoecy in Four Australian Species of Leptospermum
Authors: Andersen AN
Published: December 2005

Leptospermum myrsinoides, L. juniperinum, L. laevigatum and L. lanigerum are recorded as being
andromonoecious, with the proportion of total flowers that is functionally male averaging 36, 42, 48
and 14% respectively at Wilson's Promontory during the 1981-83 flowering seasons. For each species,
this figure varied markedly between individual plants, sites and seasons: for example, for L. myrsinoides
it ranged from 0 to 80% among individual plants at one site on one occasion, from 31 to 71% at one
site over three seasons, and from 31 to 71% at different sites during the one season. This variation is
consistent with the view that andromonoecy enables plants to regulate their sexual expression according
to changing environmental conditions. Rates of insect predation of male flowers (usually 52%) were
consistently lower than those of bisexual flowers (usually 5-10%) and in L. myrsinoides there was a
negative correlation between the rate of predation of bisexual flowers and the proportion of total flowers
that was male. A hypothesis is proposed that a benefit of andromonoecy is the satiation of flower
predators.
Carotenoids in Lichens From Tasmanian Forests
Authors: Czeczuga B , Kantvilas G
Published: December 2005

Column and thin-layer chromatography revealed the presence of the following carotenoids in the thalli
of 20 lichen species from Tasmanian forests: α-carotene, β-carotene, β -cryptoxanthin, lutein,
zeaxanthin, 5-hydroxy-5,6-dihydrozeaxanthin, β -carotene epoxide, lutein epoxide, antheraxanthin,mutatoxanthin,
violaxanthin, neoxanthin, α-doradexanthin, canthaxanthin and astaxanthin. 5-Hydroxy-5,6-dihydrozeaxanthin is
reported for the first time in lichens. The total content of carotenoids ranged from 15.28�g-1 dry wt in
Menegazzia confusa to 48.53�g-1 dry wt in Pseudocyphellaria glabra.
Phenology of Growth and Resource Deployment in Alexgeorgea nitens (Nees) Johnson and Briggs (Restionaceae), a Clonal Species From South-Western Western Australia
Authors: Meney KA , Pate JS , Dixon KW
Published: December 2005

Seasonal patterns are described for growth and partitioning of dry matter and selected nutrients between
different age classes and types of plant organs of ramets of non-reproductive, presumed female clones
of Alexgeorgea nitens in native sandplain habitat at Eneabba, south-western Western Australia. New
rhizome extension and associated production of new culms and nodal roots are initiated following onset
of rain in autumn. Rate of growth of these parts remains slow through winter, peaks in spring and early
summer and then becomes much reduced in the hot, dry summer. The bulk (87%) of the season's dry
matter increment of new ramet parts is estimated to be derived from current photosynthesis, the remaining
13% by mobilisation of dry matter from older parts of the ramet, especially from 1- and 2-yearold
culms. Growth of new organs is severely reduced by removal or shading of culms at the beginning
of the season. Older culms and rhizomes carry substantial starch reserves, but mobilisation of this
reserve accounts for 2% at most of the dry matter gain of new organs of intact ramets, 19% of that
of shaded and 65% of detopped ramets. A substantial fraction of the starch pool of a rhizome segment
normally remains until its senescence, possibly as a long-term energy reserve, utilisable after destruction
of above-ground parts by fire or grazing. Concentrations of N, P, K, Ca and Mg in organ dry matter
of A. nitens are generally very low in comparison with species other than those Cyperaceae or
Restionaceae from similar habitats. There is no evidence of preferential storage in below-ground parts,
and efficiencies of emptying of nutrient reserves from senescing ramet parts are not high. Mobilisation
from older source organs of ramets of intact, unstressed clones is estimated to provide 14% of the new
organ's seasonal gain of P, 16% of Mg, 21% of Ca, 22% of N and 58% of K. Annual factorial increases
of a ramet in the studied nutrient elements range from 1.3 (for K) to 2.4 (for P), indicating flexibility
in exploiting sources of different nutrients as their respective availabilities change from season to season.
Effect of Drought and Defoliation on the Susceptibility of Eucalypts to Cankers Caused by Endothia gyrosa and Botryosphaeria ribis
Authors: Old KM , Gibbs R , Craig I , Myers BJ , Yuan ZQ
Published: December 2005

Seedlings, saplings and mature eucalypts were susceptible to infection by Endothia gyrosa and Botryosphaeria ribis. Eucalyptus regnans and E. delegatensis were more susceptible than E. grandis and E. saligna. In trees not subjected to stress, cankers were limited in extent and often healed. When trees were defoliated, either manually or by severe insect attack, stem concentrations of both starch and soluble carbohydrates were reduced and canker development in some pathogen/host combinations was increased. Seedlings subjected to water stress were not predisposed to canker formation. The association of E. gyrosa with branch dieback of rural eucalypts suffering from chronic defoliation suggests that canker fungi contribute to the crown dieback syndrome in south-eastern Australia.