Pollinator behaviour, mate choice and the realised mating systems of Grevillea mucronulata and Grevillea sphacelata

2000 ◽  
Vol 48 (3) ◽  
pp. 357 ◽  
Author(s):  
Matthew B. G. Richardson ◽  
David J. Ayre ◽  
Robert J. Whelan
Keyword(s):  
Mate Choice ◽  
Mating System ◽  
Mating Systems ◽  
Fruit Set ◽  
Electrophoretic Analysis ◽  
Population Variation ◽  
Pollinator Behaviour ◽  
High Level ◽  
Almost All ◽  
Pollination Systems

Successful long-term conservation and management of populations of plants requires successful management of the suite of factors that determine their ‘realised’ mating systems. Within the genus Grevillea, mating systems are potentially complex. They may vary among species and among populations within a species, reflecting variation in pollinator behaviour and diversity (‘potential’ mating systems) and in breeding system (the ‘preferred’ mating system). We used a combination of pollinator observations, pollination experiments and electrophoretic analysis of seed from open pollinations, to examine variation in potential and preferred mating systems in two populations of each of two ‘spider-flowered’ Grevillea species: G. mucronulata (visited by honeyeaters and honeybees, although only birds effected pollen removal and transfer) and G. sphacelata (visited only by honeybees, which made frequent contact with pollen and stigmas). Almost all observed bird and insect foraging bouts on either species involved movements among inflorescences within plants or among inflorescences on closely neighbouring plants. On the basis of these data, the mating system was predicted to involve a high level of selfing or inbreeding. However, the pollination experiment revealed that both species were highly self-incompatible and showed a clear preference for outcross pollen in mate-choice experiments. For both species, fruit set through autogamy was lower than 0.7% and fruit set from self-pollinations was always significantly lower than for outcross pollinations (0–11% cf. 25–33% for G. mucronulata and 0% cf. 4.2–8.8% for G. sphacelata). Allozyme studies revealed that genotypes in open-pollinated seeds on 20 G. mucronulata and 20 G. sphacelata plants were surprisingly uniform, best explained by outcrossed matings between close neighbours. We found little between-population variation in any aspect of the mating system for either species. These studies reveal that the preferred mating system of the plant and the pattern of pollinator behaviour interact to determine the mating system in a population, emphasising the need for a multifaceted investigation of mating systems, especially in predicting the fates of populations that have pollination systems altered by disturbance, small size, isolation and introduced species such as the honeybee.

Plant mating systems and assessing population persistence in fragmented landscapes

2007 ◽  
Vol 55 (3) ◽  
pp. 239 ◽  
Author(s):  
David J. Coates ◽  
Jane F. Sampson ◽  
Colin J. Yates
Keyword(s):  
Mating System ◽  
Population Size ◽  
Mating Systems ◽  
Habitat Disturbance ◽  
Population Persistence ◽  
Population Variation ◽  
Conservation Strategies ◽  
Valuable Insight ◽  
Mixed Mating ◽  
Fragmented Landscapes

Population size and habitat disturbance are key factors likely to shape the mating system of populations in disturbed and fragmented landscapes. They would be expected to influence the availability and behaviour of the pollinator, the ability to find mates in self-incompatible species, inbreeding in self-compatible species and the size of the pollen pool. These in turn might be expected to influence key variables critical for population persistence such as seed production, seed germination and seedling fitness. Here we investigate mating-system variation in six rare species, i.e. Banksia cuneata, B. oligantha, Lambertia orbifolia (Proteaceae), Verticordia fimbrilepis subsp. fimbrilepis, Eucalyptus rameliana (Myrtaceae), Acacia sciophanes (Mimosaceae), and two common species, i.e. Calothamnus quadrifidus (Myrtaceae) and Acacia anfractuosa. All seven species are animal-pollinated relatively long-lived woody shrubs with mixed-mating systems. Population variation in mating-system parameters was investigated in relation to population size and habitat disturbance. We show that although the mating system will vary depending on pollination biology and life-history, as populations get smaller and habitat disturbance increases there is a trend towards increased inbreeding, smaller effective sizes of paternal pollen pools and greater variation in outcrossing among plants. From the species investigated in this study we have found that changes in the mating system can be useful indicators of population processes and can give valuable insight into the development of conservation strategies for the persistence of plant species following anthropogenic disturbance and landscape fragmentation.

scholarly journals Mating system modulates mate selection in aphidophagous ladybird, Menochilus sexmaculatus

2020 ◽  
Author(s):  
Swati Saxena ◽  
Geetanjali Mishra ◽  
Omkar
Keyword(s):  
Mate Choice ◽  
Mating System ◽  
Mate Selection ◽  
Mating Systems ◽  
Multiple Mating ◽  
Female Mate Choice ◽  
Egg Viability ◽  
Males And Females ◽  
Male Mate ◽  
Selection Of

ABSTRACTMate competition and selection of mates is strongly influenced by the organism’s mating system. Monogamous matings provide more benefits as compared to polygamous matings. However, it has been proven that in polygamous systems, females gain benefits from the males, therefore indulging in multiple mating, leading males to access maximum females. In zigzag ladybird, Menochilus sexmaculatus, mate choice has been studied on several pre-and postcopulatory factors. However, mate choice as a function of mating system is still remains untouched. In the present study, we hypothesised that the mating system modulates mate selection of beetles. Adults were held in different mating systems and then males and females were tested in mate choice trials. Polygynous males were more preferred over monogynous males. However, males preferred monandrous females over polyandrous females. In a second experiment, we also included relatedness as additional factor. In female mate choice trials, females preferred unrelated monogynous males which were earlier rejected over related polygynous and in male mate choice trials, males preferred unrelated polyandrous females over related monandrous females. The results were not confined only to mate choice but significant effect was also observed on time to commence mating, copulation duration, fecundity and percent egg viability.

scholarly journals Ant guards influence the mating system of their plant hosts by altering pollinator behaviour

2020 ◽  
Author(s):  
Nora Villamil ◽  
Karina Boege ◽  
Graham N. Stone
Keyword(s):  
Mating System ◽  
Community Composition ◽  
Mating Systems ◽  
Field Experiments ◽  
Plant Fitness ◽  
Pollinator Behaviour ◽  
Visitation Frequency ◽  
Pollinator Community ◽  
Plant Mating Systems ◽  
Plant Mating

AbstractAnt guards can increase plant fitness by deterring herbivores but may also reduce it by interfering with pollination, hence ant-plant interactions are ideal systems in which to study costs and benefits of mutualisms. While ant impacts on herbivory are well-studied, much less is known about impacts on pollinators and associated consequences for plant mating systems and fitness. We used field experiments to quantify the effect of ant guards on pollinator community composition, frequency and duration of flower visits, and cascading effects on plant mating system and plant fitness in Turnera velutina (Passifloraceae). Although ant patrolling did not affect pollinator community composition or visitation frequency, it decreased pollinator foraging time and flower visit duration. Such behavioural changes resulted in reduced pollen deposition on stigmas, decreasing male fitness whilst increasing outcrossing rates. This study contributes to understanding how non-pollinators, such as these defensive mutualists, can shape plant mating systems.

DFT Benchmark Study of the O--O Bond Dissociation Energy in Peroxides Validated with High-Level Ab-Initio Calculations

2019 ◽  
Author(s):  
Danilo Carmona ◽  
Pablo Jaque ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Reference Value ◽  
Basis Set ◽  
Basis Sets ◽  
Mean Deviation ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
The Mean ◽  
Experimental Values ◽  
High Level ◽  
Almost All

<div><div><div><p>Peroxides play a central role in many chemical and biological pro- cesses such as the Fenton reaction. The relevance of these compounds lies in the low stability of the O–O bond which upon dissociation results in radical species able to initiate various chemical or biological processes. In this work, a set of 64 DFT functional-basis set combinations has been validated in terms of their capability to describe bond dissociation energies (BDE) for the O–O bond in a database of 14 ROOH peroxides for which experimental values ofBDE are available. Moreover, the electronic contributions to the BDE were obtained for four of the peroxides and the anion H2O2− at the CBS limit at CCSD(T) level with Dunning’s basis sets up to triple–ζ quality provid- ing a reference value for the hydrogen peroxide anion as a model. Almost all the functionals considered here yielded mean absolute deviations around 5.0 kcal mol−1. The smallest values were observed for the ωB97 family and the Minnesota M11 functional with a marked basis set dependence. Despite the mean deviation, order relations among BDE experimental values of peroxides were also considered. The ωB97 family was able to reproduce the relations correctly whereas other functionals presented a marked dependence on the chemical nature of the R group. Interestingly, M11 functional did not show a very good agreement with the established order despite its good performance in the mean error. The obtained results support the use of similar validation strategies for proper prediction of BDE or other molecular properties by DF Tmethods in subsequent related studies.</p></div></div></div>

Methyl mercury in the dutch rhine delta

1994 ◽  
Vol 30 (10) ◽  
pp. 213-219 ◽  
Author(s):  
Hendrik Pieters ◽  
Victor Geuke
Keyword(s):  
Suspended Matter ◽  
Methyl Mercury ◽  
Mercury Contamination ◽  
Benthic Organisms ◽  
Considerable Decrease ◽  
Continuous Sedimentation ◽  
Highly Correlated ◽  
High Level ◽  
Almost All

Samples of yellow eel from various locations in the Dutch Rhine area have been analyzed for trend monitoring of mercury since 1977. In the western Rhine delta mercury levels in eels have hardly changed since the seventies, whereas in the eastern part of the Dutch Rhine area a considerable decrease of mercury concentrations in eel has occurred. Because of continuous sedimentation of contaminated suspended matter transported from upstream regions, accumulation rates and concentrations of mercury in eel in the western Rhine delta remained at a relatively high level. Analyses of methyl mercury in biota have been performed to elucidate the role of methyl mercury in the mercury contamination of the Dutch Rhine ecosystem. Low percentages of methyl mercury were observed in zooplankton (3 to 35%). In benthic organisms (mussels) percentages of methyl mercury ranged from 30 to 57%, while in fish species and liver of aquatic top predator birds almost all the mercury was present in the form of methyl mercury (&gt; 80%). During the period 1970-1990 mercury concentrations of suspended matter in the eastern Rhine delta have drastically decreased. These concentrations seemed to be highly correlated with mercury concentrations of eel (R = 0.84). The consequences of this relation are discussed.

scholarly journals A comparative study on the reproductive success of two rewarding Habenaria species (Orchidaceae) occurring in roadside verge habitats

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wenliu Zhang ◽  
Jiangyun Gao
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Plant Density ◽  
Flowering Plant ◽  
Floral Display ◽  
Pollinator Behaviour ◽  
Factors Affecting ◽  
Nectar Sugar ◽  
Viable Seeds ◽  
Viable Embryo

Abstract Background Most orchid species have been shown to be severely pollination limited, and the factors affecting reproductive success have been widely studied. However, the factors determining the reproductive success vary from species to species. Habenaria species typically produce nectar but exhibit variable fruit set and reproductive success among species. Here, we investigated the influence of the flowering plant density, inflorescence size, breeding system, and pollinator behaviour on the reproductive success of two rewarding Habenaria species. Results Our observations indicated that Habenaria limprichtii and H. petelotii co-occur in roadside verge habitats and present overlapping flowering periods. Both species were pollination limited, although H. limprichtii produced more fruits than H. petelotii under natural conditions during the 3-year investigation. H. petelotii individuals formed distinct patches along roadsides, while nearly all H. limprichtii individuals clustered together. The bigger floral display and higher nectar sugar concentration in H. limprichtii resulted in increased attraction and visits from pollinators. Three species of effective moths pollinated for H. limprichtii, while Thinopteryx delectans (Geometridae) was the exclusive pollinator of H. petelotii. The percentage of viable seeds was significantly lower for hand geitonogamy than for hand cross-pollination in both species. However, H. limprichtii may often be geitonogamously pollinated based on the behaviours of the pollinators and viable embryo assessment. Conclusions In anthropogenic interference habitats, the behaviours and abundance of pollinators influence the fruit set of the two studied species. The different pollinator assemblages in H. limprichtii can alleviate pollinator specificity and ensure reproductive success, whereas the more viable embryos of natural fruit seeds in H. petelotii suggested reducing geitonogamy by pollinators in the field. Our results indicate that a quantity-quality trade-off must occur between species with different breeding strategies so that they can fully exploit the existing given resources.

scholarly journals Liquid Biopsy and Other Non-Invasive Diagnostic Measures in PCNSL

Cancers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2665
Author(s):  
Alexander Baraniskin ◽  
Roland Schroers
Keyword(s):  
Central Nervous System Lymphoma ◽  
Circulating Tumor Dna ◽  
Mri Findings ◽  
Diagnostic Measures ◽  
Non Hodgkin Lymphoma ◽  
Specificity And Sensitivity ◽  
Demyelinating Lesions ◽  
Granulomatous Diseases ◽  
High Level ◽  
Almost All

Primary central nervous system lymphoma is a rare but highly aggressive form of non-Hodgkin lymphoma that remains confined to the CNS neuroaxis. The diagnosis of PCNSL requires a high level of suspicion as clinical presentation varies depending on the involved CNS areas. Neurological symptoms and MRI findings may mimic gliomas, demyelinating lesions, or infectious and granulomatous diseases. Almost all PCNSL patients undergo invasive surgical procedures for definite diagnosis. Stereotactic biopsy is still the gold standard in achieving a diagnostic accuracy of 73–97%. Both the potential procedural morbidity and mortality, as well as the time to definite histopathologic diagnosis resulting in delays of treatment initiation, have to be considered. On the contrary, minimally invasive procedures, such as MRI, CSF cytology, and flow cytometry, still have limited value due to inferior specificity and sensitivity. Hence, novel diagnostic approaches, including mutation analyses (MYD88) in circulating tumor DNA (ctDNA) and the determination of microRNAs (miR-21, miR-19b, and miR-92) as well as cytokine levels (IL10 and IL6) in blood, cerebrospinal fluid (CSF), and vitreous fluid (VRF), move into the focus of investigation to facilitate the diagnosis of PCNSL. In this review, we outline the most promising approaches that are currently under clinical consideration.

scholarly journals Gamete-mediated mate choice: towards a more inclusive view of sexual selection

2018 ◽  
Vol 285 (1883) ◽  
pp. 20180836 ◽  
Author(s):  
Jukka Kekäläinen ◽  
Jonathan P. Evans
Keyword(s):  
Sexual Selection ◽  
Mate Choice ◽  
Sperm Competition ◽  
Female Choice ◽  
Mating Systems ◽  
Molecular Level ◽  
Evolutionary Significance ◽  
Random Interactions ◽  
Physiological Processes ◽  
The Everyday

‘Sperm competition’—where ejaculates from two or more males compete for fertilization—and ‘cryptic female choice’—where females bias this contest to suit their reproductive interests—are now part of the everyday lexicon of sexual selection. Yet the physiological processes that underlie these post-ejaculatory episodes of sexual selection remain largely enigmatic. In this review, we focus on a range of post-ejaculatory cellular- and molecular-level processes, known to be fundamental for fertilization across most (if not all) sexually reproducing species, and point to their putative role in facilitating sexual selection at the level of the cells and gametes, called ‘gamete-mediated mate choice’ (GMMC). In this way, we collate accumulated evidence for GMMC across different mating systems, and emphasize the evolutionary significance of such non-random interactions among gametes. Our overall aim in this review is to build a more inclusive view of sexual selection by showing that mate choice often acts in more nuanced ways than has traditionally been assumed. We also aim to bridge the conceptual divide between proximal mechanisms of reproduction, and adaptive explanations for patterns of non-random sperm–egg interactions that are emerging across an increasingly diverse array of taxa.

POVERTY REDUCTION, UNEMPLOYMENT AND RURAL DEVELOPMENT; AFTERMATH OF COVID-19 PANDEMIC IN NIGERIA

2021 ◽  
Vol 9 (1) ◽  
pp. 36-49
Author(s):  
Oderinu Hassana ◽  
◽  
Kadir Mumini ◽  
Tijani Adebayo ◽  
Keyword(s):  
Economic Development ◽  
Rural Development ◽  
Rural Areas ◽  
Poverty Reduction ◽  
Design Method ◽  
Gear Up ◽  
Global Pandemic ◽  
High Level ◽  
Almost All ◽  
Self Administered Questionnaire

Nigeria has one of the countries whose experience of poverty and unemployment is on the high side makes this study to look into the effect of the economic lockdown during the global pandemic in the country, with the aim of making effort on how this effect can be translated into economic development. Survey research design method was adopted with self-administered questionnaire used to collect data. Findings revealed that in Nigeria COVID -19 outbreak effects was felt in almost all sectors and the aftermath greatly affected the country’s GDP and this adversely affect rural development in the country, which translated to a worrisome rate of poverty and unemployment. Hence, both individual and government have now seen that campaigning for economic diversification is not sufficient for economic development but rather a prompt swing into action by all is needed for sustainable development of rural areas to respond to the worrisome rate of unemployment and in turn high level of poverty caused by the COVID-19 lockdown in the country. It was recommended that government at all level as well as individuals and stakeholders should put in place actions that would gear up rural development and set policies at their various helms of affairs that would encourage economic participation of all citizens in all sector of the economy.

FOOD SAFETY KNOWLEDGE, ATTITUDES AND PRACTICES AMONG FEDERAL UNIVERSITY OF AGRICULTURE STUDENTS IN ABEOKUTA

2017 ◽  
Vol 15 (1) ◽  
pp. 94-107
Author(s):  
M O ADEGUNWA ◽  
M I SANUSI ◽  
H A BAKARE ◽  
A M OMEMU
Keyword(s):  
Food Safety ◽  
Contributing Factors ◽  
Safety Attitudes ◽  
Attitudes And Practices ◽  
Handling Practices ◽  
High Level ◽  
Almost All ◽  
The University ◽  
Safety Knowledge ◽  
Safety Attitude

Improper practices, poor attitudes and lack of knowledge by food handlers are contributing factors for the spread of foodborne diseases. Food safety knowledge is an important factor in improving food safety practices and subsequently food safety attitude. This study is aimed at exploring the food safety knowledge, practice and attitude of FUNAAB students. A self completed questionnaire was answered by randomly selected 270 students from each of the nine (9) colleges in the university and analyzed using SPSS software. The study revealed that almost all of the students had a high level of food safety awareness but the knowledge was not to large extent translated into practice. Majority of the students also had good food safety attitudes as many of them are willing to change their food handling behav-iour when they know they are incorrect (94.8%). The study further revealed similar level of food safety knowledge between the male and female. Despite the level of students’ knowledge, their choice of eating place on campus was determined by the price of the food. This study therefore concluded that good knowledge of food safety does not determine students’ safe handling practices and choice of eating place.Keywords: Food safety

Sign in / Sign up

Export Citation Format

Share Document