Stackhousia tryonii Bailey: a Nickel-Accumulating Serpentine-Endemic Species of Central Queensland.

1990 ◽  
Vol 38 (2) ◽  
pp. 121 ◽  
Author(s):  
GN Batianoff ◽  
RD Reeves ◽  
RL Specht

Stackhousia tryonii Bailey, which appears to be endemic to the serpentinite soils of the Port Curtis district, central Queensland, is a hyper-accumulator of nickel. Concentrations of this element reach 1-20% of the dry weight of the leaves and 0.1-1% in other parts of the plant. This is the first discovery of such behaviour in a plant from eastern Australia. S. tryonii is easily distinguishable from the Queensland occurrences of a related species, S. monogyna Labill., by its smaller inflorescences and muchbranched, tufted, slender stems and distinctive sparsely tuberculate seed coat. S. monogyna shows no abnormal nickel accumulation. Detailed diagnostic comparative descriptions of S. tryonii and S. monogyna are provided, and notes are given on the ecology and distribution of the two species.

Sommerfeltia ◽  
2008 ◽  
Vol 31 (1) ◽  
pp. 161-177 ◽  
Author(s):  
U. Peintner

Cortinarius alpinus as an example for morphological and phylogenetic species concepts in ectomycorrhizal fungiExtensive morphological and molecular analyses of closely related species from alpine, subalpine and montane habitats should enable a comparison of ecological, morphological and phylogenetic species concepts in ectomycorrhizal mushrooms. One fundamental question of this study was whether alpine species really exist, and which criteria, besides the specific habitat, could reliably be used for the de-limitation of such taxa. For this reason, 56 rDNA ITS sequences were generated or downloaded from GenBank for 10 closely related species of Cortinarius subgenus Myxacium, section Myxacium. Several collections were sequenced for each of the following taxa: Cortinarius absarokensis, C. alpinus, C. favrei, C. fennoscandicus, C. grallipes, C. mucosus, C. muscigenus, C. septentrionalis, C. trivialis and C. vernicosus. Moreover, spore statistics were carried out for 38 collections of alpine and subalpine taxa. These data provide clear evidence for C. favrei being a synonym of C. alpinus. C. absarokensis and C. alpinus can clearly be delimited based on pileus diameter and average dry weight per basidiome, even in overlapping habitats, but spore size and shape is not a good distinguishing character. Phylograms have very short branches, and base differences between ITS sequences are generally very low in this group, and give no resolution for the included taxa of this section. Based on these results, species concepts of ectomycorrhizal mushrooms are discussed in detail.


2007 ◽  
Vol 55 (6) ◽  
pp. 618 ◽  
Author(s):  
Kim N. Hamilton ◽  
Sarah E. Ashmore ◽  
Rod A. Drew ◽  
Hugh W. Pritchard

Combinational traits of seed size and seed-coat hardness in Citrus garrawayi (F.M.Bailey) (syn. of Microcitrus garrowayi) were investigated as markers for estimation of seed morphological and physiological maturity. Seed size (length) and coat hardness correlated well with changes in seed coat and embryo morphological development, dry-weight accumulation, decreases in moisture content and a significant increase in germinability. Seed moisture content decreased from 82 ± 1% in immature seeds to 40 ± 1% at seed maturation. The outer integument of immature seeds consisted of thin-walled epidermal fibres from which outgrowths of emerging protrusions were observed. In comparison, mature seed coats were characterised by the thickening of the cell walls of the epidermal fibres from which arose numerous protrusions covered by an extensive mucilage layer. Immature seeds, with incomplete embryo and seed-coat histodiffereniation, had a low mean germination percentage of 4 ± 4%. Premature seeds, with a differentiated embryonic axis, were capable of much higher levels of germination (51 ± 10%) before the attainment of mass maturity. Mature seeds, with the most well differentiated embryonic axis and maximum mean dry weight, had the significantly highest level of germination (88 ± 3%).


2002 ◽  
Vol 16 (6) ◽  
pp. 893 ◽  
Author(s):  
I. Beveridge

The monotypic nematode genus Coronostrongylus Johnston & Mawson, 1939 from the stomachs of macropodid marsupials was reviewed and was found to consist of a least seven closely related species. Coronostrongylus coronatus Johnston & Mawson, 1939 is found most commonly in Macropus rufogriseus, but occurs occasionally in M. dorsalis, M. parryi and Petrogale inornata. Coronostrongylus johnsoni, sp. nov. is most commonly found in M. dorsalis, but occurs also in M. rufogriseus, M. parma, Thylogale stigmatica, Petrogale godmani and P. brachyotis. Coronostrongylus barkeri, sp. nov. is most prevalent in Onychogalea unguifera, but occurs also in M. rufus, M. robustus and P. brachyotis. Coronostrongylus closei, sp. nov. is restricted to Petrogale persephone. Coronostrongylus sharmani, sp. nov. occurs only in rock wallabies from eastern Australia: P.�coenensis, P. godmani and P. mareeba; C. spratti, sp. nov. occurs in P. inornata and P. assimilis. Coronostrongylus spearei, sp. nov. is restricted to Papua New Guinea where it is found in Dorcopsulus vanhearni, Dorcopsis hageni and D. muelleri. Although all of the nematode species occur in one principal host species or a series of closely related host species, occurrences in geographically disjunct areas and in phylogenetically distant hosts are features of C. coronatus, C. barkeri, sp. nov. and C. johnsoni, sp. nov. The occurrence of seven closely related nematode species found in a wide range of macropodid host species is more readily accounted for by a hypothesis involving multiple colonisations of hosts than by the hypothesis of co-speciation.


2003 ◽  
Vol 81 (6) ◽  
pp. 531-540 ◽  
Author(s):  
Gurusamy Chinnasamy ◽  
Arya Kumar Bal

The developmental patterns of seed, seed coat, and hardseededness were studied in naturally growing crop plants of beach pea (Lathyrus maritimus (L.) Bigel.) at six reproductive growth stages (S1–S6). Grass pea (Lathyrus sativus L.) seeds were used for comparison in some experiments. The accumulation of fresh and dry weight in pod shell and seed of beach pea and pod shell of grass pea followed an almost sigmoidal pattern. However, grass pea seed showed a linear pattern of weight accumulation. During maturation, moisture content of pod shells and seeds decreased because of dehydration. Beach pea seeds were able to germinate precociously at S4. Seeds collected between S1 and S3 failed to germinate because of immaturity, whereas the development of hard seed coats prevented germination in seeds gathered at S5 and S6. An imbibition test revealed that hardseededness completely prevented water absorption of S5 and S6 seeds even after 24 days of soaking. In grass pea, precocious seed germination was observed at S3. However, speed of germination, germination percentage, seedling length and dry weight increased as seeds approached maturity. Lipid and protein accumulation in seeds of both species increased progressively with maturity and showed a positive correlation with seed weight accumulation. In both beach pea and grass pea seeds, S6 was identified as a physiological maturity stage.Key words: beach pea, grass pea, hard seed, imbibition, Lathyrus, seed coat, seed development, water impermeability.


1988 ◽  
Vol 66 (2) ◽  
pp. 388-393 ◽  
Author(s):  
P. Pukittayacamee ◽  
A. K. Hellum

Germination of Acacia auriculiformis A. Cunn. ex Benth. seeds was related to seed development. Full physiological development of seeds, indicated by maximum seed dry weight, was reached 82 days after anthesis; however, maximum percent germination was not reached before day 89. Later, germination declined gradually as dormancy and mortality increased. Most seeds were capable of germination without pretreatment at the time of collection, indicating that seed coats were not impermeable to water. Germination of seeds with moisture content from 14 to 29% can be achieved. Anatomical studies revealed that seeds reached maturity after compressing the parenchyma cells against the inside of the seed coat. The physical properties of the seed coat, therefore, did not control its permeability to water. After the developmental period, seed dormancy increased by further drying of seeds during storage.


2016 ◽  
Vol 88 (3 suppl) ◽  
pp. 1809-1818
Author(s):  
LILIAN P.G. DA ROSA ◽  
JOSÉ F.A. BAUMGRATZ ◽  
SEBASTIÃO J. DA SILVA NETO

ABSTRACT Taxonomic and floristic studies in the state of Rio de Janeiro allowed the rediscovery of Miconia gigantea, an endemic species to the Atlantic Forest, until recently known only from the type specimen, collected over 100 years by A.F.M. Glaziou. We present an amended and detailed description of M. gigantea, providing characteristics of the flowers, fruits and seeds, in addition to illustrations, comments about taxonomic affinities with closely related species, the presently known distribution together with new occurrence records, and the conservation status.


Zootaxa ◽  
2006 ◽  
Vol 1328 (1) ◽  
pp. 39
Author(s):  
MELINDA L. MOIR ◽  
MURRAY J. FLETCHER

Two new species of Achilini from eastern Australia are described and keys to the genera of Achilini in Australia, and species of the genus Anabunda, are provided. In addition, the type species of Anabunda is redescribed and the recorded distribution extended. The new species are Anabunda murrayfletcheri sp. nov. from Queensland, and A. minuta sp. nov. from New South Wales and Queensland. Both represent short-range endemic species, possibly under threat because of rapid urbanisation within their ranges. Biogeography and plant associations are discussed briefly.


1994 ◽  
Vol 45 (8) ◽  
pp. 1799 ◽  
Author(s):  
M Tyndale-Biscoe

The quantity of dung buried and shredded by dung beetles at four sites in south-eastern Australia was found to be positively correlated with the dry weight (biomass) of beetles in the pads. Each of the four sites has two abundant native species of dung beetles, and one to five well-established introduced species present. At Uriarra, where only one introduced species is common, a mean of 7 . 2 l � 1.94% (1990-91) and 6.01�1.31% (1991-92) of the dung was buried per week. At Fyshwick, with two common introduced species of dung beetles, 22.27� 4.03% (1990-91) and 12 04�2 72% (1991-92) of the dung was buried per week. Braidwood, with four introduced species, had a mean of 15.81� 2.82% (1991-92) weekly dung buried, and Araluen, with five introduced species, had 30.18�8- 73% (1992-93) dung buried per week. Dung beetle numbers were low at all sites during the first half of 1991-92 season due to a drought throughout the region. Dung shredding averaged less than 12% over the seasons at all sites, but fluctuated from 0 to 70%, depending mainly on beetle numbers in the dung pads on individual occasions. Increasing numbers of exotic dung beetles throughout the pastoral areas of Australia should result in increased amounts of dung buried and shredded, with correspondingly increased benefits to Australian agriculture.


2005 ◽  
Vol 53 (1) ◽  
pp. 33 ◽  
Author(s):  
Emma K. Gras ◽  
Jennifer Read ◽  
Chantal T. Mach ◽  
Gordon D. Sanson ◽  
Fiona J. Clissold

Eucalyptus species often show marked differences in morphology and ecophysiology between adult and juvenile leaves. Given these differences, it was hypothesised that juvenile and adult leaves would present different levels of resources to a herbivore, and potentially different levels of putative anti-herbivore defences. This hypothesis was tested in some eucalypts growing in native forest in south-eastern Australia. There were no significant differences in levels of water, protein or carbohydrates (per unit dry weight) between mature adult and juvenile leaves. No difference was recorded in concentration of total phenolics between leaf forms, but more protein was precipitated (an estimate of tannin activity) in extracts from juvenile leaves. Cyanogenic glycosides were absent from mature leaves, but present in young leaves of both leaf forms in E. polyanthemos. No significant difference in concentration of any terpene was recorded between adult and juvenile leaves in E. nitens and E. regnans. Specific leaf area was lower in adult leaves, and fibre concentration was higher in adult leaves of some species, suggesting that resources in the adult leaf may be less accessible to a herbivore. However, there was no difference in leaf toughness between leaf forms, even though toughness per unit leaf thickness was higher in juvenile leaves. Hence, no major trends in resource concentration were apparent between the leaf forms, and of the defences investigated, only tannin activity varied significantly between the leaf forms.


HortScience ◽  
1992 ◽  
Vol 27 (11) ◽  
pp. 1166b-1166
Author(s):  
Stephanie Rademan ◽  
Dyremple Marsh

A wide range of methodologies, ranging from Leonard jar to growth pouch have been used to investigate the nitrogen fixation process in leguminous crops. The effectiveness of most of these research methods have been questioned. Problems encountered vary from difficulty in root separation to water log conditions. This study was undertaken to determine the effect of different growing media on nodule development and harvestability. Black and Red seed coat kidney bean were surface sterilized and inoculated with the Rhizobium phaseoli strain UMR 1899. Seeds were planted in 8.5 cm diameter sterile clay pots containing the respective growing medium. These growing media were sand, Promix GM, Promix BX, and fritted clay. The black seed coat kidney bean had higher germination rate under all media for all dates recorded. Black kidney bean grown in sand and fritted clay had plant heights significantly greater than ones grown in the other media on the third harvest date. Nodule activities as measured by shoot dry weight and nodule number were significantly higher in both beans grown in fritted clay than in other media. Promix GM plants with dry weight of .45g for the black bean and .32g for the red beans were the lowest. Nodule separation from the growing media was easiest when plants were grown in sand, however, this was not significantly different from that of plants grown in fritted clay.


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