Reproductive Biology of Australian Myrtaceae

1993 ◽  
Vol 41 (5) ◽  
pp. 511 ◽  
Author(s):  
DV Beardsell ◽  
SP Obrien ◽  
EG Williams ◽  
RB Knox ◽  
DM Calder
Keyword(s):  
Reproductive Success ◽  
Reproductive Biology ◽  
The Other ◽  
Pollination Biology ◽  
Breeding Systems ◽  
Evolutionary Relationships ◽  
Self Incompatibility ◽  
Flower Structure ◽  
Secondary Pollen Presentation ◽  
Pollen Presentation

The diverse floral structures of Australian Myrtaceae are discussed in relation to pollination biology, breeding systems, and ecological and evolutionary relationships. Although the reproductive biology of Eucalyptus has been studied widely, little is known about many of the other genera. The review concludes that additional work is needed on aspects of flower structure, pollination biota, late acting self-incompatibility, secondary pollen presentation and reproductive success.

Comparative flower structure of three species of sundew (Drosera anglica, Drosera linearis, and Drosera rotundifolia) in relation to breeding system

2003 ◽  
Vol 81 (11) ◽  
pp. 1129-1142 ◽  
Author(s):  
Gillian L Murza ◽  
Arthur R Davis
Keyword(s):  
Breeding System ◽  
Floral Morphology ◽  
Glandular Trichomes ◽  
The Other ◽  
Breeding Systems ◽  
Flower Structure ◽  
Drosera Rotundifolia ◽  
Pollen Colour ◽  
Secretory Tissue ◽  
Scanning Electron

Whereas much attention has been given to the fascinating prey-trapping leaves of carnivorous plants, less research has been conducted on their flower structure and breeding systems. Accordingly, a comparative study of the floral morphology and anatomy of the three species of sundews (Droseraceae: Drosera anglica Huds., Drosera linearis Goldie, and Drosera rotundifolia L.) in Saskatchewan was performed to ascertain the presence of floral rewards for potential pollinators and to obtain pollen to ovule ratios, an indicator of breeding system. Utilizing light and scanning electron microscopy, differences between the three species were apparent in length of styles, number of placentas, anther and pollen colour, and structure of glandular trichomes on sepals. The occurrence of features unique to each species does not support the concept of D. anglica as a hybrid of the other two species. Flowers of all three species lack nectaries, although clusters of papillate cells that were reminiscent of secretory tissue were observed at the apices of anthers and at the summits of ovaries. Pollen to ovule ratios were low for all species, ranging from 9.0 to 18.7 in D. rotundifolia and D. linearis, respectively, suggesting an autogamous breeding system for each species.Key words: Drosera anglica, Drosera linearis, Drosera rotundifolia, Droseraceae, comparative flower structure, pollen to ovule ratios, breeding system.

scholarly journals Resolving Phylogenetic Relationships within Passeriformes Based on Mitochondrial Genes and Inferring the Evolution of Their Mitogenomes in Terms of Duplications

2019 ◽  
Vol 11 (10) ◽  
pp. 2824-2849 ◽  
Author(s):  
Paweł Mackiewicz ◽  
Adam Dawid Urantówka ◽  
Aleksandra Kroczak ◽  
Dorota Mackiewicz
Keyword(s):  
Phylogenetic Analyses ◽  
Mitochondrial Genes ◽  
The Other ◽  
Phylogenetic Position ◽  
Evolutionary Relationships ◽  
Mitochondrial Genomes ◽  
Ancestral State ◽  
Phylogenetic Information ◽  
Long Time ◽  
Tree Topologies

Abstract Mitochondrial genes are placed on one molecule, which implies that they should carry consistent phylogenetic information. Following this advantage, we present a well-supported phylogeny based on mitochondrial genomes from almost 300 representatives of Passeriformes, the most numerous and differentiated Aves order. The analyses resolved the phylogenetic position of paraphyletic Basal and Transitional Oscines. Passerida occurred divided into two groups, one containing Paroidea and Sylvioidea, whereas the other, Passeroidea and Muscicapoidea. Analyses of mitogenomes showed four types of rearrangements including a duplicated control region (CR) with adjacent genes. Mapping the presence and absence of duplications onto the phylogenetic tree revealed that the duplication was the ancestral state for passerines and was maintained in early diverged lineages. Next, the duplication could be lost and occurred independently at least four times according to the most parsimonious scenario. In some lineages, two CR copies have been inherited from an ancient duplication and highly diverged, whereas in others, the second copy became similar to the first one due to concerted evolution. The second CR copies accumulated over twice as many substitutions as the first ones. However, the second CRs were not completely eliminated and were retained for a long time, which suggests that both regions can fulfill an important role in mitogenomes. Phylogenetic analyses based on CR sequences subjected to the complex evolution can produce tree topologies inconsistent with real evolutionary relationships between species. Passerines with two CRs showed a higher metabolic rate in relation to their body mass.

scholarly journals A new Synbranchus (Teleostei: Synbranchiformes: Synbranchidae) from ilha de Marajó, Pará, Brazil, with notes on its reproductive biology and larval development

2005 ◽  
Vol 3 (3) ◽  
pp. 319-328 ◽  
Author(s):  
Sandra E. Favorito ◽  
Angela M. Zanata ◽  
Maria I. Assumpção
Keyword(s):  
New Species ◽  
Larval Development ◽  
Reproductive Biology ◽  
Color Pattern ◽  
The Other ◽  
Larval Stages ◽  
Marajó Island ◽  
Northern Brazil

Synbranchus lampreia, new species, is described from rio Goiapi, Marajó Island, Pará, northern Brazil. It differs from the other two described species of the genus by its color pattern, which consists of large roundish black blotches scattered over a light brown or yellowish ground pigmentation and presence of inconspicuous brown small spots distributed among the large dark spots. The species is further distinguished from S. marmoratus by a higher number of vertebrae and from S. madeira by a shorter postanal length. Information about reproductive aspects is provided and larval stages are described and illustrated.

scholarly journals Performance of polychaete assisted sand filters under contrasting nutrient loads in an integrated multi-trophic aquaculture (IMTA) system

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Daniel Jerónimo ◽  
Ana Isabel Lillebø ◽  
Andreia Santos ◽  
Javier Cremades ◽  
Ricardo Calado
Keyword(s):  
Organic Matter ◽  
Reproductive Success ◽  
Particulate Organic Matter ◽  
Marine Invertebrates ◽  
The Other ◽  
Nutrient Loads ◽  
Effluent Water ◽  
Lower Content ◽  
Hediste Diversicolor ◽  
Sand Filters

AbstractPolychaete assisted sand filters (PASFs) allow to combine a highly efficient retention of particulate organic matter (POM) present in aquaculture effluent water and turn otherwise wasted nutrients into valuable worm biomass, following an integrated multi-trophic aquaculture (IMTA) approach. This study evaluated the bioremediation and biomass production performances of three sets of PASFs stocked with ragworms (Hediste diversicolor) placed in three different locations of an open marine land-based IMTA system. The higher organic matter (OM) recorded in the substrate of the systems which received higher POM content (Raw and Df PASFs – filtered raw and screened by drum filter effluent, respectively) likely prompted a superior reproductive success of stocked polychaetes (final densities 2–7 times higher than initial stock; ≈1000–3000 ind. m−2). Bioremediation efficiencies of ≈70% of supplied POM (≈1.5–1.8 mg L−1) were reported in these systems. The PASFs with lower content of OM in the substrate (Df + Alg PASFs – filtered effluent previously screened by drum filter and macroalgae biofilter) differed significantly from the other two, with stocked polychaetes displaying a poorer reproductive success. The PASFs were naturally colonized with marine invertebrates, with the polychaetes Diopatra neapolitana, Terebella lapidaria and Sabella cf. pavonina being some of the species identified with potential for IMTA.

Secondary Pollen Presentation in Angiosperms and Its Biological Significance

1993 ◽  
Vol 41 (5) ◽  
pp. 417 ◽  
Author(s):  
GJ Howell ◽  
AT Slater ◽  
RB Knox
Keyword(s):  
Close Association ◽  
Biological Significance ◽  
Selective Advantage ◽  
Floral Organ ◽  
Pollinator Behaviour ◽  
Secondary Pollen Presentation ◽  
Male Function ◽  
Increased Risk ◽  
Pollen Presentation ◽  
Male Phase

Secondary pollen presentation is the developmental relocation of pollen from the anthers onto another floral organ which then functions as the pollen presenting organ for pollination. Nine different types have been identified in sixteen angiosperm families according to which organ is used for presentation, whether the pollen is exposed or concealed within a structure and how pollen is loaded onto the presenting surface: (1) Enveloping bloom presenters (Araceae); (2) Perianth presenters with exposed pollen presentation (Epacridaceae); (3) Androecial presenters (Santalaceae); (4) Terminal stylar presenters with passive pollen placement and concealed stigmas (Rubiaceae and Proteaceae); (5) Terminal stylar presenters with passive pollen placement and sub-terminal stigmas (Marantaceae and Polygalaceae); (6) Terminal stylar presenters with active pollen placement (Asteraceae, Calyceraceae and Lobeliaceae); (7) Sub-terminal stylar presenters (Campanulaceae, Cannaceae, Fabaceae and Myrtaceae); (8) Exposed stigmatic presenters (Rubiaceae); (9) Indusial stigmatic presenters (Goodeniaceae and Brunoniaceae). Secondary pollen presentation occurs in three monocotyledon and thirteen dicotyledon families. The presentation types appear to have been independently derived indicating that secondary pollen presentation is a character with a selective advantage. In all but the enveloping bloom type of secondary pollen presentation, developmental relocation of pollen requires simultaneous, introrse anther dehiscence and a close association of the presenting organ to the anthers prior to anthesis. The various secondary pollen presentation systems may be modified to promote xenogamy or autogamy and this can even change during anthesis. Most plants which have secondary pollen presentation, display reduced herkogamy within the flower to facilitate pollination. Increased risk of self-pollination due to this may be overcome through dichogamy, herkogamy within inflorescences, dry stigmas, self-incompatibility systems and passive or active control over pollinator behaviour. Enhanced male function of the flowers of secondary pollen presenting plants is also evident through extension of the male phase by the protection, controlled release and precise placement and receipt of pollen. Plants displaying secondary pollen presentation are almost always protandrous.

scholarly journals Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania

2011 ◽  
Vol 59 (3) ◽  
pp. 262 ◽  
Author(s):  
Gunnar Keppel ◽  
Peter Prentis ◽  
Ed Biffin ◽  
Paul Hodgskiss ◽  
Susana Tuisese ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
New Caledonia ◽  
The Other ◽  
Evolutionary Relationships ◽  
Restricted Range ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Low Genetic Diversity ◽  
Cpdna Sequence ◽  
Relaxed Molecular Clock

We examined evolutionary relationships, hybridisation and genetic diversity in species of Dacrydium (Podocarpaceae) in Remote Oceania, where it is restricted to New Caledonia and Fiji. We used cpDNA sequence (trnL–trnF) data to construct a phylogeny and estimate taxon divergence by using a relaxed molecular clock approach. The phylogeny was verified using allozymes, which were also used to investigate genetic diversity of all species and the hybridisation dynamics of two endangered species, D. guillauminii and D. nidulum. Our results suggested that Dacrydium species in Remote Oceania form a monophyletic group that arose and diversified within the last 20 million years through long-distance dispersal and a range of speciation mechanisms. Whereas we detected no hybridisation between the Fijian species D. nausoriense and D. nidulum, we confirmed hybridisation between D. guillauminii and D. araucarioides in New Caledonia and determined introgression to be assymetric from the widespread D. araucarioides into the rare, restricted-range species D. guillauminii. In addition, D. guillauminii had lower genetic diversity than did the other species of Dacrydium studied, which had genetic diversity similar to that of other gymnosperms. Our results provided evidence for the recent and complex diversification of Dacrydium in Remote Oceania. In addition, low genetic diversity of and introgression from D. araucarioides, are of grave concern for the conservation of D. guillauminii.

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