Drosera × sidjamesii (Droseraceae): systematics and ecology of a natural hybrid from Western Australia

2007 ◽  
Vol 20 (1) ◽  
pp. 44 ◽  
Author(s):  
Allen Lowrie ◽  
John G. Conran
Keyword(s):  
Western Australia ◽  
Parental Species ◽  
Elevation Gradient ◽  
Natural Hybrid ◽  
Peat Soils ◽  
Cytological Examination ◽  
White Sand ◽  
Water Field ◽  
Almost All ◽  
High Degree

The natural hybrid Drosera × sidjamesii Lowrie & Conran from Lake Gnangarra north of Perth, Western Australia is described and defined as a cross between D. nitidula Planch. subsp. omissa Marchant & Lowrie auct. non Diels and D. pulchella Lehm., between which it shows a high degree of intermediacy for almost all characters. Cytological examination of the hybrid and its parents confirms that the former at 2n = 46 is a combination of the 2n = 28 in D. nitidula subsp. omissa and 2n = 18 in D. pulchella. The hybrid grows along a narrow ecotone between the parental species, largely on sandy peat and along a presumed soil moisture/elevation gradient caused by the nearby lake. Nevertheless, within this ecotone the hybrid is significantly more frequent than either parental species, with D. pulchella mainly growing in peat soils closer to the lake and D. nitidula subsp. omissa on white sand further from the water. Field observations of morphotypes also suggest that the hybrid has arisen several times at the site, and that a limited number of plants at the site are becoming fertile and setting seed.

Corrigendum to: Drosera × sidjamesii (Droseraceae): systematics and ecology of a natural hybrid from Western Australia

2007 ◽  
Vol 20 (2) ◽  
pp. 186
Author(s):  
Allen Lowrie ◽  
John G. Conran
Keyword(s):  
Western Australia ◽  
Parental Species ◽  
Elevation Gradient ◽  
Natural Hybrid ◽  
Peat Soils ◽  
Cytological Examination ◽  
White Sand ◽  
Water Field ◽  
Almost All ◽  
High Degree

The natural hybrid Drosera � sidjamesii Lowrie & Conran from Lake Gnangarra north of Perth, Western Australia is described and defined as a cross between D. nitidula Planch. subsp. omissa Marchant & Lowrie auct. non Diels and D. pulchella Lehm., between which it shows a high degree of intermediacy for almost all characters. Cytological examination of the hybrid and its parents confirms that the former at 2n = 46 is a combination of the 2n = 28 in D. nitidula subsp. omissa and 2n = 18 in D. pulchella. The hybrid grows along a narrow ecotone between the parental species, largely on sandy peat and along a presumed soil moisture/elevation gradient caused by the nearby lake. Nevertheless, within this ecotone the hybrid is significantly more frequent than either parental species, with D. pulchella mainly growing in peat soils closer to the lake and D. nitidula subsp. omissa on white sand further from the water. Field observations of morphotypes also suggest that the hybrid has arisen several times at the site, and that a limited number of plants at the site are becoming fertile and setting seed.

scholarly journals Stoichiometry and compositional plasticity of the yeast nuclear pore complex revealed by quantitative fluorescence microscopy

2018 ◽  
Vol 115 (17) ◽  
pp. E3969-E3977 ◽  
Author(s):  
Sasikumar Rajoo ◽  
Pascal Vallotton ◽  
Evgeny Onischenko ◽  
Karsten Weis
Keyword(s):  
Nuclear Pore Complex ◽  
Yeast Cells ◽  
Nuclear Pore ◽  
Altered Expression ◽  
Copy Numbers ◽  
Quantitative Image ◽  
Multiple Copies ◽  
Almost All ◽  
High Degree

The nuclear pore complex (NPC) is an eightfold symmetrical channel providing selective transport of biomolecules across the nuclear envelope. Each NPC consists of ∼30 different nuclear pore proteins (Nups) all present in multiple copies per NPC. Significant progress has recently been made in the characterization of the vertebrate NPC structure. However, because of the estimated size differences between the vertebrate and yeast NPC, it has been unclear whether the NPC architecture is conserved between species. Here, we have developed a quantitative image analysis pipeline, termed nuclear rim intensity measurement (NuRIM), to precisely determine copy numbers for almost all Nups within native NPCs of budding yeast cells. Our analysis demonstrates that the majority of yeast Nups are present at most in 16 copies per NPC. This reveals a dramatic difference to the stoichiometry determined for the human NPC, suggesting that despite a high degree of individual Nup conservation, the yeast and human NPC architecture is significantly different. Furthermore, using NuRIM, we examined the effects of mutations on NPC stoichiometry. We demonstrate for two paralog pairs of key scaffold Nups, Nup170/Nup157 and Nup192/Nup188, that their altered expression leads to significant changes in the NPC stoichiometry inducing either voids in the NPC structure or substitution of one paralog by the other. Thus, our results not only provide accurate stoichiometry information for the intact yeast NPC but also reveal an intriguing compositional plasticity of the NPC architecture, which may explain how differences in NPC composition could arise in the course of evolution.

scholarly journals Endoparasitic helminths of water frog complex in Poland: do differences exist between the parental species Pelophylax ridibundus and Pelophylax lessonae, and their natural hybrid Pelophylax esculentus?

2011 ◽  
Vol 48 (2) ◽  
pp. 108-115 ◽  
Author(s):  
M. Popiołek ◽  
B. Rozenblut-Kościsty ◽  
M. Kot ◽  
W. Nosal ◽  
M. Ogielska
Keyword(s):  
20Th Century ◽  
Parental Species ◽  
Helminth Species ◽  
Natural Hybrid ◽  
Intensity Of Infection ◽  
Water Frog ◽  
Pelophylax Ridibundus ◽  
Water Frogs ◽  
Pelophylax Esculentus ◽  
Cosmocerca Ornata

AbstractParasitic fauna of water frogs was mainly studied in the second half of the 20th century. However, these studies were done without differentiation into species and hybrids and pooled the 3 taxa as “water frogs” or “green frogs”. The aim of this study was to make an inventory of helminth species as well as their prevalence and intensity of infection in the two parental species (Pelophylax ridibundus and P. lessonae) and the hybrid (P. esculentus) of water frogs from 3 big populations composed of hundreds or thousands of individuals inhabited natural and seminatural landscapes in Poland. Eight helminth species were found: Polystoma integerrimum, Diplodiscus subclavatus, Opisthoglyphe ranae, Gorgodera cygnoides, Haematoloechus variegatus, Oswaldocruzia filiformis, Cosmocerca ornata and Acanthocephalus ranae. The results were compared with data from other, polish and European studies. Additionally we compared the level of infection among water frog taxa.

scholarly journals Ecological Observations on Hybrid Populations of European Plethodontid Salamanders, Genus Speleomantes

Diversity ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 285
Author(s):  
Enrico Lunghi ◽  
Fabio Cianferoni ◽  
Stefano Merilli ◽  
Yahui Zhao ◽  
Raoul Manenti ◽  
...  
Keyword(s):  
Body Condition ◽  
Parental Species ◽  
Stomach Contents ◽  
Trophic Niche ◽  
Natural Hybrid ◽  
Ecological Information ◽  
Total Length ◽  
Plethodontid Salamanders ◽  
The Future ◽  
First Time

Speleomantes are the only plethodontid salamanders present in Europe. Multiple studies have been performed to investigate the trophic niche of the eight Speleomantes species, but none of these studies included hybrid populations. For the first time, we studied the trophic niche of five Speleomantes hybrid populations. Each population was surveyed twice in 2020, and stomach flushing was performed on each captured salamander; stomach flushing is a harmless technique that allows stomach contents to be inspected. We also assessed the potential divergence in size and body condition between natural and introduced hybrids, and their parental species. Previously collected data on Speleomantes were included to increase the robustness of these analyses. In only 33 out of 134 sampled hybrid Speleomantes we recognized 81 items belonging to 11 prey categories. The frequency of empty stomachs was higher in females and individuals from natural hybrid populations, whereas the largest number of prey was consumed by males. We compared the total length and body condition of 685 adult salamanders belonging to three types of hybrids and three parental (sub)species. Three group of salamanders (one hybrid and two parental species) showed significantly larger size, whereas no difference in body condition was observed. This study provided novel ecological information on Speleomantes hybrid populations. We also provided insights into the potential divergence between hybrids and parental species in terms of size and body condition. We discuss our findings, and formulate several hypotheses that should be tested in the future.

scholarly journals A Relation Between Snow Cover, Cirrus Cloud, and Freezing Nuclei in the Atmosphere

1956 ◽  
Vol 9 (4) ◽  
pp. 545 ◽  
Author(s):  
EG Bowen
Keyword(s):  
Snow Cover ◽  
Western Australia ◽  
Cirrus Cloud ◽  
Nucleus Concentration ◽  
High Degree ◽  
Calendar Dates

It is reasonable to suppose that observations like that of cirrus cloud in the upper air and heavy falls of snow in relatively warm latitudes correspond to the presence of a large number of freezing nuclei in the atmosphere. A 300-year record of snow covering the ground at Tokyo and a 10-year record of cirrus cloud in Western Australia are examined and compared with one year's measurement of freezing nucleus concentration. The curves show a high degree of correlation, and all three tend to maximize on certain calendar dates.

scholarly journals Rocky pine forests in the High Coast Region in Sweden: structure, dynamics and history

2020 ◽  
Vol 38 ◽  
pp. 101-130
Author(s):  
Jennie Sandström ◽  
Mattias Edman ◽  
Bengt Gunnar Jonsson
Keyword(s):  
Human Impact ◽  
Fire History ◽  
Dead Wood ◽  
Forest Type ◽  
Basal Area ◽  
Pine Forests ◽  
Small Scale ◽  
Natural Dynamics ◽  
Almost All ◽  
High Degree

Almost all forests in Sweden are managed and only a small fraction are considered natural. One exception is low productive forests where, due to their limited economical value, natural dynamics still dominate. One example is the Scots pine (Pinus sylvestris L.) forests occurring on rocky and nutrient-poor hilltops. Although these forests represent a regionally common forest type with a high degree of naturalness, their dynamics, structure and history are poorly known. We investigated the structure, human impact and fire history in eight rocky pine forests in the High Coast Area in eastern Sweden, initially identified as good representatives of this forest type. This was done by sampling and measuring tree sizes, -ages, fire-scarred trees, as well as dead wood volumes and quality along three transects at each site. The structure was diverse with a sparse layer of trees (basal area 9 m2 and 640 trees larger than 10 cm ha-1) in various sizes and ages; 13 trees ha-1 were more than 300 years old. Dead wood (DW), snags and logs in all stages of decay, was present and although the actual DW (pine) volume (4.4 m3 ha-1) and number of units (53 ha-1) was low, the DW share of total wood volume was 18% on average. Dead wood can be present for several centuries after death; we found examples of both snags and logs that had been dead more than 300 years. Frequent fires have occurred, with an average cycle of 40 years between fires. Most fires occurred between 1500-1900 and many of them (13) during the 1600s. However, fires were probably small since most fire years were only represented at one site and often only in one or a few samples. The rocky pine forests in the High Coast Area are representative of undisturbed forests with low human impact, exhibiting old-growth characteristics and are valuable habitats for organisms connected to sun-exposed DW. Management of protected rocky pine forests may well include small-scale restoration fires and the limited DW volumes should be protected.

Colonization of depopulated crinoids by symbionts: who comes from the bottom and who from the water column?

2015 ◽  
Vol 95 (8) ◽  
pp. 1607-1612 ◽  
Author(s):  
E.S. Mekhova ◽  
P.Y. Dgebuadze ◽  
V.N. Mikheev ◽  
T.A. Britayev
Keyword(s):  
Water Column ◽  
Field Experiments ◽  
Dispersal Ability ◽  
Long Distance ◽  
Sandy Substrate ◽  
Limited Dispersal ◽  
Set Up ◽  
Almost All ◽  
High Degree

Previous experiments with the comatulid Himerometra robustipinna (Carpenter, 1881) demonstrated intensive host-to-host migration processes for almost all symbiotic species both within host aggregations and among hosts separated by several metres. The aim of this study was to check the ability of symbionts to complete long-distance migrations, by means of two in situ experiments which depopulated the crinoid host. Two different sets of field experiments were set up: exposure of depopulated crinoids (set 1) on stony ‘islands’ isolated from native crinoid assemblages by sandy substrate, and (set 2) in cages suspended in the water column. Hosts from set 1 were exposed for 1, 2, 3 and 4 weeks to assess whether substrate has an influence on the symbionts' long-distance migrations. In set 2 cages were exposed for 10–11 days, aiming to check whether symbionts were able to disperse through the water column with currents. These experiments allow the conclusion that post-settled symbionts can actively migrate among their hosts. Symbionts are able to reach their hosts by employing two different ‘transport corridors’, by drifting or swimming in water column, and by moving on the bottom. Comparison of experimental results allows the division of symbionts into two conventional groups according to the dispersal ability of their post-settled stages: (1) species able to complete long-distance migrations, (2) species unable to migrate or having limited dispersal ability. The finding of the free-living shrimp Periclimenes diversipes Kemp, 1922 in set 2 raises the question about the factors that affect such a high degree of specialization of crinoid assemblages.

Effects of the coastal brown ant Pheidole megacephala (Fabricius), on the ant fauna of the Perth metropolitan region, Western Australia

2000 ◽  
Vol 6 (1) ◽  
pp. 81 ◽  
Author(s):  
J. E. May ◽  
B. E. Heterick
Keyword(s):  
Western Australia ◽  
Abundant Species ◽  
Pitfall Trap ◽  
The Other ◽  
Metropolitan Region ◽  
Pheidole Megacephala ◽  
Apparent Displacement ◽  
Significant Difference ◽  
Almost All

This paper reports on the apparent displacement of native and exotic ants from gardens in the Perth Metropolitan region by the coastal brown ant (Pheidole megacephala (Fabricius)). Twelve gardens were sampled, four with P. megacephala present, and eight (the controls) where the ant was judged to be absent. Eight out of the 26 ant species recorded (including the coastal brown ant) were introduced. Ninety-two per cent of pitfall trap contents comprised the four most abundant species: P. megacephala, lridomyrmex chasei (Forel), Tetramorium simillimum (F. Smith) and Paratrechina ?obscura (Mayr). Three of the four P. megacephala-dominated gardens were depauperate of almost all other ant species. The fourth P. megacephala-infested garden had a relatively small number of coastal brown ants (104), and the highest number of ant species was found in that garden. The removal of this outlier garden left an average range of one to three species for the other three P. megacephala-infested gardens. Control gardens had between five and 12 ant species. Total ant abundance ranged from an average of 1 027 per P. megacephala-infested garden (increasing to 1 171 if the outlier garden is removed) to 146 at control gardens. There was a significant difference both in ant richness and ant abundance between the controls and P. megacephala-infested gardens (P < 0.05). This remained the case when figures for coastal brown ants were excluded from calculations.

Distribution of Phytophthora cinnamomi in the northern jarrah (Eucalyptus marginata) forest of Western Australia in relation to dieback age and topography

2002 ◽  
Vol 50 (1) ◽  
pp. 107 ◽  
Author(s):  
K. L. McDougall ◽  
G. E. St J. Hardy ◽  
R. J. Hobbs
Keyword(s):  
Spatial Distribution ◽  
Western Australia ◽  
Aerial Photography ◽  
Phytophthora Cinnamomi ◽  
Ex Situ ◽  
Patchy Distribution ◽  
Jarrah Forest ◽  
Eucalyptus Marginata ◽  
Almost All

The spatial distribution of Phytophthora cinnamomi Rands at seven dieback sites in the jarrah (Eucalyptus marginata Donn. ex Smith) forest of Western Australia was determined by the following two baiting techniques: in situ baiting with live Banksia grandis Willd. seedlings and ex situ baiting of sampled soil and root material. Four areas within each site were sampled, reflecting dieback age and position in the landscape. Approximate dieback ages of 50, 20 and 5 years were determined by aerial photography. The 50-year-old age class was divided into wet valley floor and dry gravelly slope. Phytophthora cinnamomi was recovered most frequently from the 5-year-old (dieback fronts) and wet 50-year-old areas by both baiting techniques. It was recovered from more than twice as many areas and about five times as many samples when in situ B. grandis baits were used compared with ex situ soil and root baiting. Almost all recoveries from in situ baits were made between October and December. From both methods, it appears that P. cinnamomi has a patchy distribution within dieback sites in the northern jarrah forest. It is easily detected only on dieback fronts and wet valley floors. On dry gravelly sites affected 20 years or more ago, P. cinnamomi is rare and may even be absent at some sites. This makes confident detection of the pathogen difficult. In situ baiting at least allows a temporal component to the sampling and will be a useful method of detection in areas where P. cinnamomi is rare or transient.

scholarly journals Bradyrhizobia Nodulating the Acacia mangium × A. auriculiformis Interspecific Hybrid Are Specific and Differ from Those Associated with Both Parental Species

2009 ◽  
Vol 75 (24) ◽  
pp. 7752-7759 ◽  
Author(s):  
Christine Le Roux ◽  
Diana Tentchev ◽  
Yves Prin ◽  
Doreen Goh ◽  
Yani Japarudin ◽  
...  
Keyword(s):  
Interspecific Hybrid ◽  
Large Scale ◽  
Parental Species ◽  
Root Nodules ◽  
Acacia Mangium ◽  
Rhizobium Strains ◽  
Homologous Strain ◽  
Yeast Extract Mannitol ◽  
Almost All

ABSTRACT In the context of an increasing utilization of the interspecific hybrid Acacia mangium × A. auriculiformis as a plantation tree in the tropical humid zone, its symbiotic characterization was carried out in comparison with that of its two parental species. Rhizobium strains of diverse geographical origins were isolated from root nodules of the hybrid and its parents. Almost all Acacia hybrid isolates were fast growing on yeast extract-mannitol medium, in contrast to those isolated from both parental species, which were mostly slow growing. The rhizobium strains were characterized through partial sequencing of the rRNA operon. In the phylogenetic tree, almost all strains isolated from the hybrid were grouped together in a clade close to Bradyrhizobium japonicum, while all strains isolated from both parental species were close to Bradyrhizobium elkanii. Inoculation experiments performed under in vitro or greenhouse conditions showed that all strains were infective with their original hosts but exhibited very variable degrees of effectivity according to the host plant tested. Thus, homologous strain-host associations were more effective than heterologous ones. This shows that there is still a high potential for isolating and testing new strains from hybrids to be used as inoculants in the context of large-scale afforestation programs.

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