Very Low Fruit : Flower Ratios in Grevillea (Proteaceae) are Independent of Breeding System

1998 ◽  
Vol 46 (4) ◽  
pp. 465 ◽  
Author(s):  
Luise Hermanutz ◽  
David Innes ◽  
Andrew Denham ◽  
Robert Whelan
Keyword(s):  
Fruit Set ◽  
Pollen Limitation ◽  
Breeding Systems ◽  
Mature Fruit ◽  
Closely Related Species ◽  
Woody Perennials ◽  
The Family ◽  
Self Compatibility ◽  
Species Specific

Members of the family Proteaceae have extremely low mature fruit : flower (FR : FL) ratios (range 0.001–0.163) compared with other temperate, hermaphroditic, woody perennials. Sutherland’s (1986) survey of FR : FL ratios indicated that compatibility was an important factor explaining levels of fruit set. The role of compatibility in regulating FR : FL ratios was tested in five closely related species of Grevillea (Proteaceae). Species-specific compatibility was compared using the self-compatibility index (SI = ratio of selfed fruit set to crossed fruit set) calculated at fruit initiation to minimise the confounding effect of other post-fertilisation fruit losses, such as inbreeding depression and pre-dispersal predation. Fruit : flower ratios at initiation ranged from 0.041–0.249, and at maturity 0.015–0.096. Grevillea species showed highly variable breeding systems: G. linearifolia was self-incompatible (SI = 0.003), G. sphacelata, G. mucronulata, and G. oleoides were partially self-compatible (SI = 0.07–0.28) and G. longifolia was self-compatible (SI = 0.61). Intrapopulation variability in the level of self-incompatibility was high in all species but G. linearifolia. The correlation between SI and FR: FL ratios was non-significant, indicating that compatibility has a minimal effect on fruit set in the Grevillea species studied, and that these data, together with other data on proteaceous species do not support trends observed in Sutherland’s survey. Low FR : FL ratios resulted from of a combination of pollen limitation, and high levels of flower and fruit predation.

scholarly journals Reproductive systems and post-pollination barriers between two closely related eu-bromelioids (Bromeliaceae) in the Atlantic Forest of Brazil

2019 ◽  
Vol 192 (4) ◽  
pp. 828-839
Author(s):  
Brayan Paiva Cavalcante ◽  
Everton Hilo De Souza ◽  
Joseph Hill Williams ◽  
Leonardo M Versieux
Keyword(s):  
Seed Set ◽  
Rapid Evolution ◽  
Pollen Tubes ◽  
Breeding Systems ◽  
Intergeneric Hybridization ◽  
Reproductive Barriers ◽  
Closely Related Species ◽  
Heterospecific Pollen ◽  
The Family ◽  
Self Compatibility

Abstract The eu-bromelioid clade provides a classic example of an exceptionally rapid radiation, in which many closely related species are found in sympatry. In this respect, species cohesion may be due to the rapid evolution of strong reproductive barriers, although interspecific and intergeneric hybridization is observed in the family. The objective of this study was to characterize the breeding systems and post-pollination reproductive barriers in Wittmackia patentissima and Hohenbergia ridleyi. Previously included in Aechmea, they show an almost complete absence of pre-pollination barriers, although their recent divergence may not have allowed time for complete ecological/reproductive isolation to have evolved. In manual pollinations, both species had > 40% fruit set in self and outcross treatments, but seed set from manual self-pollinations was < 50% that of outcrosses, and spontaneous self-pollination produced fewer than three seeds per fruit. Self-pollen and pollen tubes showed no evidence of self-incompatibility, but heterospecific pollen tubes were arrested in the lower part of the style and heterospecific seed set was zero in both species. The combination of self-compatibility and strong post-pollination, pre-fertilization reproductive barriers is consistent with the involvement of breeding system reproductive barriers in allowing closely related bromeliad species to occur in sympatry.

scholarly journals Sex aggregation and species segregation cues in swarming mosquitoes: role of ground visual markers

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Serge B. Poda ◽  
Charles Nignan ◽  
Olivier Gnankiné ◽  
Roch K. Dabiré ◽  
Abdoulaye Diabaté ◽  
...  
Keyword(s):  
Experimental Conditions ◽  
Closely Related Species ◽  
Laboratory Setup ◽  
Visual Markers ◽  
Constant Distance ◽  
Species Specific ◽  
Marker Size ◽  
Swarm Size ◽  
Species Segregation

Abstract Background Mating swarm segregation in closely related insect species may contribute to reproductive isolation. Visual markers are used for swarm formation; however, it is unknown whether they play a key role in swarm location, species segregation and sex aggregation. Methods Using two sympatric closely related species of the Anopheles gambiae complex, An. coluzzii and An. gambiae (s.s.), we investigated in both laboratory and semi-field conditions (i) whether males of the two species use visual markers (black cloths) to locate their swarm; and (ii) whether the presence/absence and size of the marker may differentially affect swarm characteristics. We also investigated whether conspecific virgin females use these markers to join male swarm sites. Results We showed that males of the two species used visual markers but in different ways: An. coluzzii swarm right above the marker whereas An. gambiae (s.s.) locate their swarm at a constant distance of 76.4 ± 0.6 cm from a 20 × 20 cm marker in the laboratory setup and at 206 ± 6 cm from a 60 × 60 cm marker in the semi-field setup. Although increased marker size recruited more mosquitoes and consequently increased the swarm size in the two species, An. coluzzii swarms flew higher and were stretched both vertically and horizontally, while An. gambiae (s.s.) swarms were only stretched horizontally. Virgin females displayed a swarm-like behavior with similar characteristics to their conspecific males. Conclusions Our results provided experimental evidence that both An. coluzzii and An. gambiae (s.s.) males use ground visual markers to form and locate their swarm at species-specific locations. Moreover, the marker size differentially affected swarm characteristics in the two species. Our results also showed that virgin females displayed a swarm-like behavior. However, these “swarms” could be due to the absence of males in our experimental conditions. Nevertheless, the fact that females displayed these “swarms” with the same characteristics as their respective males provided evidence that visual markers are used by the two sexes to join mating spots. Altogether, this suggests that visual markers and the way species and sexes use them could be key cues in species segregation, swarm location and recognition.

scholarly journals The role of APETALA1 in petal number robustness

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Marie Monniaux ◽  
Bjorn Pieper ◽  
Sarah M McKim ◽  
Anne-Lise Routier-Kierzkowska ◽  
Daniel Kierzkowski ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Genetic Variation ◽  
Reproductive Success ◽  
Genetic Basis ◽  
Phenotypic Expression ◽  
Specific Difference ◽  
Closely Related Species ◽  
Epistatic Interactions ◽  
Species Specific

Invariant floral forms are important for reproductive success and robust to natural perturbations. Petal number, for example, is invariant in Arabidopsis thaliana flowers. However, petal number varies in the closely related species Cardamine hirsuta, and the genetic basis for this difference between species is unknown. Here we show that divergence in the pleiotropic floral regulator APETALA1 (AP1) can account for the species-specific difference in petal number robustness. This large effect of AP1 is explained by epistatic interactions: A. thaliana AP1 confers robustness by masking the phenotypic expression of quantitative trait loci controlling petal number in C. hirsuta. We show that C. hirsuta AP1 fails to complement this function of A. thaliana AP1, conferring variable petal number, and that upstream regulatory regions of AP1 contribute to this divergence. Moreover, variable petal number is maintained in C. hirsuta despite sufficient standing genetic variation in natural accessions to produce plants with four-petalled flowers.

scholarly journals Duplication and functional divergence of a calcium sensor in the Brassicaceae

2020 ◽  
Vol 71 (9) ◽  
pp. 2782-2795 ◽  
Author(s):  
Shea M Monihan ◽  
Courtney A Magness ◽  
Choong-Hwan Ryu ◽  
Michelle M McMahon ◽  
Mark A Beilstein ◽  
...  
Keyword(s):  
Salt Tolerance ◽  
Functional Divergence ◽  
Calcium Sensor ◽  
The Family ◽  
Salt Affected Soils ◽  
Species Specific ◽  
And Function ◽  
Sisymbrium Irio ◽  
Functional Analyses

Abstract The presence of varied numbers of CALCINEURIN B-LIKE10 (CBL10) calcium sensor genes in species across the Brassicaceae and the demonstrated role of CBL10 in salt tolerance in Arabidopsis thaliana and Eutrema salsugineum provided a unique opportunity to determine if CBL10 function is modified in different species and linked to salt tolerance. Salinity effects on species growth and cross-species complementation were used to determine the extent of conservation and divergence of CBL10 function in four species representing major lineages within the core Brassicaceae (A. thaliana, E. salsugineum, Schrenkiella parvula, and Sisymbrium irio) as well as the first diverging lineage (Aethionema arabicum). Evolutionary and functional analyses indicate that CBL10 duplicated within expanded lineage II of the Brassicaceae and that, while portions of CBL10 function are conserved across the family, there are species-specific variations in CBL10 function. Paralogous CBL10 genes within a species diverged in expression and function probably contributing to the maintenance of the duplicated gene pairs. Orthologous CBL10 genes diverged in function in a species-specific manner, suggesting that functions arose post-speciation. Multiple CBL10 genes and their functional divergence may have expanded calcium-mediated signaling responses and contributed to the ability of certain members of the Brassicaceae to maintain growth in salt-affected soils.

scholarly journals The Role of Birds of the Family Corvidae in Transmitting Sarcocystis Protozoan Parasites

Animals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3258
Author(s):  
Evelina Juozaitytė-Ngugu ◽  
Saulius Švažas ◽  
Donatas Šneideris ◽  
Eglė Rudaitytė-Lukošienė ◽  
Dalius Butkauskas ◽  
...  
Keyword(s):  
Light Microscope ◽  
Sarcocystis Species ◽  
Protozoan Parasites ◽  
Intermediate Hosts ◽  
Specific Pcr ◽  
Sarcocystis Spp ◽  
The Family ◽  
Species Specific ◽  
Pcr Targeting

Members of the family Corvidae are ecologically flexible omnivorous birds, particularly adaptive to urban habitats, and living in proximity to humans; these birds may serve as definitive hosts (DH) for Sarcocystis spp., but research about this is lacking. In the present study, intestinal samples from 91 corvids collected in Lithuania were molecularly tested by species-specific PCR targeting the ITS1 and cox1 genes and subsequently sequenced for the presence of Sarcocystis spp. Under a light microscope, oocysts of Sarcocystis spp. were observed in 43 samples (47.3%), while molecular methods, detected Sarcocystis spp. in 77 birds (84.6%). Eleven Sarcocystis spp. (S. columbae, S. cornixi, potentially pathogenic S. halieti, S. kutkienae, S. lari, S. turdusi, S. wobeseri, S. arctica, S. lutrae, S. ovalis, and S. oviformis) were identified in the intestinal samples from six corvid species from Lithuania. Infections with multiple Sarcocystis spp. were detected in 79.2% of the infected corvid birds. Three of the identified Sarcocystis spp. use corvids as intermediate hosts (IH); therefore, corvids may serve as IH and DH of the same Sarcocystis species. Based on molecular results and on corvid diet, omnivorous corvids may play an important role in transmitting Sarcocystis spp.

Preferential outcrossing in Banksia ilicifolia (Proteaceae)

2005 ◽  
Vol 53 (2) ◽  
pp. 163 ◽  
Author(s):  
Bambang Heliyanto ◽  
Erik J. Veneklaas ◽  
Hans Lambers ◽  
Siegfried L. Krauss
Keyword(s):  
Breeding System ◽  
Fungal Pathogen ◽  
Fruit Set ◽  
Pollen Limitation ◽  
Genetic Load ◽  
Open Pollination ◽  
Self Pollination ◽  
Hand Pollination ◽  
Self Compatibility ◽  
Non Local

The breeding system of Banksia ilicifolia was assessed by performing controlled hand-pollination manipulations on flowers in a natural population in Perth, Western Australia. The percentage of 2000 flowers per treatment converted to fruits and seeds was assessed across 24 recipient plants following (1) self-pollination, (2) local outcross pollination (same population), (3) non-local outcross pollination (pollen sourced from another population 30 km away), (4) unpollinated but bagged flowers and (5) unpollinated, unbagged flowers (natural pollination). The relative performance of the resulting seeds was assessed by seed weight, germination rates and, in an unplanned component of the study, resistance to a fungal pathogen. The percentage of flowers converted to fruits following self-pollination was low (0.9%), but demonstrated self-compatibility. Fruit set following cross-pollinations (3.6 and 3.3% for non-local and local crosses, respectively) was significantly greater than that following self-pollination, open-pollination (0.4%) and autogamous (0.04%) treatments. Low fruit set for open-pollinated flowers, compared with self- and outcross-pollination treatments, suggests pollen limitation. Pollen tubes were observed in 15 and 20% of upper styles of flowers hand-pollinated with self and local outcross pollen, respectively. Seed germination was dependent on the source of pollen, where fewer selfed seeds germinated (37%) than did both non-local and local outcrossed seeds (83 and 91%, respectively). Selfed seedlings showed poorer survival (33.3%) following fungal attack than both non-local and local outcrossed seeds (69.2 and 68.5%, respectively). Only 13% of selfed seeds survived to be 2-month-old seedlings, compared with 63% for non-local and 57% for local outcrossed seeds. Ultimately, for 2000 flowers hand-pollinated with self pollen, only three seedlings survived to an age of 16 weeks, compared with 37 and 45 seedlings for local-cross and non-local cross treatments on 2000 hand-pollinated flowers, respectively. These results indicate that in this population, B. ilicifolia is self-compatible, but preferentially outcrossing, with strong early acting inbreeding depression. Consequently, the breeding system of B. ilicifolia promotes the maintenance of genetic variation and a high genetic load.

scholarly journals Comparative floral ecology and breeding systems between sympatric populations of Nothoscordum bivalve and Allium stellatum (Amaryllidaceae)

2020 ◽  
Vol 26 ◽  
Author(s):  
Daniel S Weiherer ◽  
Kayla Eckardt ◽  
Peter Bernhardt
Keyword(s):  
Fruit Set ◽  
Seed Set ◽  
Geometric Mean ◽  
Floral Biology ◽  
Breeding Systems ◽  
Outbreeding Depression ◽  
Sympatric Populations ◽  
Closely Related Species ◽  
Floral Ecology ◽  
Self Pollination

We compared the floral biology of two sympatric populations of closely related species over two seasons. In 2018, Nothoscordum bivalve (L.) Britton bloomed from April 23 to May 7 and Allium stellatum Nutt. Ex Ker Gawl bloomed from August 28 to October 4. Erect, white flowers of N. bivalve were scented and had septal nectaries. Erect, pink-purple flowers of A. stellatum had septal nectaries, no discernible scent, and a style that lengthened over the floral lifespan. Both species were pollinated by bees with the most common geometric mean of body dimensions between 2-3 mm. Most bees carried pure loads of the host plant’s pollen. Despite phenological isolation, the two herbs shared three bee species. Allium stellatum was also pollinated by the beetle Chauliognathus pensylvanicus DeGeer (Cantharidae). Tepal nyctinasty ensured mechanical self-pollination in N. bivalve. Protandry occurred in A. stellatum. In N. bivalve, the proportion of pollen tubes penetrating ovules was highest in bagged, self-pollinating flowers. However, in A. stellatum it was highest in exposed flowers and hand cross-pollinated flowers. Fruit set in N. bivalve was highest in exposed and bagged, self-pollinating flowers. In A. stellatum, fruit set was highest in both exposed and hand cross-pollinated flowers. Seed set was the same among all treatments for both species. We interpret these results as evidence that A. stellatum is a self-incompatible, obligate outcrosser. Nothoscodum bivalve is a self-compatible, obligate inbreeder employing mechanical and insect-mediated self-pollination. Outbreeding depression appears to occur in N. bivalve with a partial trend towards intraspecific cross-incompatibility.

Insects facilitate wind pollination in pollen-limited Crateva adansonii (Capparaceae)

2011 ◽  
Vol 59 (1) ◽  
pp. 61 ◽  
Author(s):  
Yash Mangla ◽  
Rajesh Tandon
Keyword(s):  
Fruit Set ◽  
Pollen Limitation ◽  
Airborne Pollen ◽  
Pollen Dispersal ◽  
Natural Populations ◽  
Pollen Grains ◽  
Floral Biology ◽  
Wind Pollination ◽  
Reproductive Assurance

Low fruit-set in obligately outbreeding plant species is attributed to a variety of reasons that can be ascertained from reproductive studies. In the present work, the causes of poor natural fruit-set in Crateva adansonii DC. were investigated. Floral biology, the role of wind and insects in pollination and the breeding system of the species were studied in two natural populations for three consecutive seasons (2006–08). The flowers exhibited traits conducive to a mixture of wind and insect pollination (ambophily). Although a variety of insects visited the flowers, they were ineffective in pollinating. Nevertheless, active foraging by the honeybees (Apis dorsata, A. mellifera and A. cerana indica) facilitated enhanced pollen dispersal in the air and resulted in indirect pollination by wind. Airborne pollen grains pollinated the plants only up to 10 m. Fruit-set from open pollination was comparable to wind-pollinated flowers. Supplemental pollination treatments established the occurrence of strong self-incompatibility (SI) (index of SI = 0.14). Spontaneous autogamy was prevented by pronounced herkogamy. Low natural fecundity in C. adansonii is due to pollination failure, pollen limitation (pollen limitation index = 0.98) and the sparse distribution of the conspecifics; partial SI may partly ensure reproductive assurance through geitonogamy. In the absence of a pollinator wind appears to act as a secondary mode of pollination.

scholarly journals A comparative study of the gastric ossicles of Trichodactylidae crabs (Brachyura: Decapoda) with comments on the role of diet and phylogeny in shaping morphological traits

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5028 ◽  
Author(s):  
Débora A. Carvalho ◽  
Pablo A. Collins ◽  
Renata Lima-Gomes ◽  
Célio Magalhães ◽  
Maria Victoria Torres ◽  
...  
Keyword(s):  
Comparative Study ◽  
Related Species ◽  
Morphological Traits ◽  
Closely Related Species ◽  
Natural Diet ◽  
Freshwater Crabs ◽  
The Family ◽  
Feeding Structure ◽  
And Function

The gastric armature of decapod foregut is a feeding structure that sparks controversial debates about the role dietary and historical components have in shaping its morphological traits. Having previous information about the natural diet is an interesting way to gather evidence on this issue. For the present study, we analyzed the morphological traits of gastric ossicles involved directly in the maceration of food in nine species of freshwater crabs of the family Trichodactylidae (Brachyura: Decapoda) representing five genera, three tribes and two subfamilies. The analyzed gastric ossicles were quite consistent among closely related species, suggesting that the observed traits had a clear phylogenetic component. However, it was also noted that the morphological traits of the gastric teeth of trichodactylid crabs match well with the natural diet and presented likeness with general features of other species with a similar trophic habit. We discuss the influence of phylogeny and function on the design of morphological traits and propose to quantify the role of phylogeny and function in shaping morphological traits through the analysis of phylogenetic signals.

Non-Normative Events and Family Functioning: The Role of the Family Psychologist

1993 ◽  
Author(s):  
Michele Harway ◽  
◽  
Nancy Boyd-Franklin ◽  
Robert Geffner ◽  
Marsali Hansen ◽  
...  
Keyword(s):  
Family Functioning ◽  
The Family
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