scholarly journals Pollination and Floral Biology of a Rare Morning Glory Species Endemic to Thailand, Argyreia siamensis

Plants ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 2402
Author(s):  
Awapa Jirabanjongjit ◽  
Paweena Traiperm ◽  
Tomoki Sando ◽  
Alyssa B. Stewart

Argyreia siamensis is extremely rare, and very little is known about its reproduction. The species has colorful flowers that seem likely to attract pollinators, but population sizes are typically small (<30 individuals). To determine whether poor reproduction contributes to its rarity, we investigated its mating system and potential pollinators in two populations. We also examined the staminal trichomes and floral nectary to investigate their role in pollinator attraction. The mating system was assessed with a bagging experiment and pollinator visits were recorded with action cameras. Additionally, we tested the staminal trichomes and floral nectary for terpenes and flavonoids and examined floral nectary micromorphology via scanning electron microscope and compound light microscope. Our results reveal that A. siamensis is self-incompatible and dependent on pollinators; the western population was pollinated by bees (Meliponini and Amegilla), while the eastern population was mainly pollinated by skipper butterflies (Hesperiidae). Both staminal trichomes and the floral nectary appear to contribute to pollinator attraction through the presence of terpenes and flavonoids (in both secretory structures) and nectariferous tissue and nectarostomata (in the nectary). Our results indicate that A. siamensis has reliable and effective pollinators and that insufficient pollination is likely not a primary cause of its rarity.

2005 ◽  
Vol 83 (3) ◽  
pp. 279-286 ◽  
Author(s):  
Carlos André Espolador Leitão ◽  
Renata Maria Strozi Alves Meira ◽  
Aristéa Alves Azevedo ◽  
João Marcos de Araújo ◽  
Kellen Lagares Ferreira Silva ◽  
...  

Triumfetta semitriloba Jacq. (Tiliaceae) is a tropical weedy species with floral nectaries and glands located at the margins of the leaves. The objectives of this work were to describe the anatomy of these secretory structures and to analyze their exudates. Sucrose, glucose, and fructose were identified in the product released by these secretory structures, characterizing them as nectaries. The nectaries of T. semitriloba are of a specialized type; a secretory epidermis comprised of pluricellular and multiserial nectariferous trichomes covers a nectariferous parenchyma, vascularized by phloem and xylem. A mass of phenolic compounds occurs in the head cells of the nectariferous trichomes of the foliar and bract nectaries; however, it is absent in trichomes of the floral nectary. The leaf and bract nectaries differed from those from flowers in their length and diameter. Structural features of the nectaries of T. semitriloba are typical of other taxa of the Malvales.Key words: foliar anatomy, histochemistry, Malvales, nectaries, Tiliaceae, Triumfetta semitriloba.


2019 ◽  
Vol 129 (2) ◽  
pp. 273-287
Author(s):  
Fernanda Figueiredo De Araujo ◽  
Reisla Oliveira ◽  
Theo Mota ◽  
João Renato Stehmann ◽  
Clemens Schlindwein

Abstract Details of the foraging patterns of solitary bees are much less well known than those of social species, and these patterns are often adjusted to exploit floral resources of one or only a few species. The specialized flower-visiting bees of Petunia are good models for investigating such foraging patterns. Here we analysed the floral biology and pollen presentation schedule of the endangered Petunia mantiqueirensis in mixed Araucaria forests of Serra da Mantiqueira, Brazil. Pollinators and their pollen foraging behaviour and food specialization were determined through analyses of scopa pollen loads. Flowers opened throughout the day and presented all their pollen resources within the first 30 min of anthesis, thus providing their pollen resources in an asynchronous fashion in one-flower packages throughout the day. Females of Pseudagapostemon fluminensis were the most frequent flower visitors, contacting stigmas in 96% of their visits, and were the unique effective pollinators of Petunia mantiqueirensis. These pollinators were responsible for the first three visits to 115 individually monitored flowers at any daylight hour, removing ~86% of a flower’s total pollen supply during the first visit. Although female bees harvest the majority of pollen resources of Petunia mantiqueirensis, analyses of scopa loads revealed that most of them also collect pollen from plants of other families while foraging for pollen in Petunia flowers.


1986 ◽  
Vol 23 (01) ◽  
pp. 1-13
Author(s):  
S. E. Hitchcock

Two stochastic models are developed for the predator-prey process. In each case it is shown that ultimate extinction of one of the two populations is certain to occur in finite time. For each model an exact expression is derived for the probability that the predators eventually become extinct when the prey birth rate is 0. These probabilities are used to derive power series approximations to extinction probabilities when the prey birth rate is not 0. On comparison with values obtained by numerical analysis the approximations are shown to be very satisfactory when initial population sizes and prey birth rate are all small. An approximation to the mean number of changes before extinction occurs is also obtained for one of the models.


2000 ◽  
Vol 30 (7) ◽  
pp. 1156-1164 ◽  
Author(s):  
F Thomas Ledig ◽  
Basilio Bermejo-Velázquez ◽  
Paul D Hodgskiss ◽  
David R Johnson ◽  
Celestino Flores-López ◽  
...  

Martínez spruce (Picea martínezii T.F. Patterson) is a conifer currently passing through a bottleneck, reduced to a few relict populations totaling less than 800 trees. We used isozyme markers to analyze the mating system and survey the level of genic diversity in two populations. The mating system was characterized by a high frequency of selfing. The multilocus outcrossing rates (tm) and 95% confidence intervals were only 0.399 (0.197 < tm < 0.601) for the smallest population and 0.589 (0.475 < tm < 0.703) or 0.685 (0.465 < tm < 0.905), depending on year, for the largest. These are among the lowest rates of outcrossing observed in conifers. The fixation indices for the two populations were -0.058 and 0.121, less than expected for such high levels of selfing. Expected heterozygosity, unbiased He, based on 22 loci in 13 enzyme systems, was 0.121 and 0.101 in the two populations. The proportion of the total genic diversity between populations, FST, was 2.4%. Nm, the number of migrants per generation, was about 1.00 or 10.17, depending on the method of estimation. The time since the two populations were isolated was estimated from Nei's genetic distance as only 150 to 15 000 years, which is consistent with a hypothesis of population collapse during late Pleistocene or Holocene warming. We discuss the implications for conservation.


2019 ◽  
Vol 28 (2) ◽  
pp. 307-319 ◽  
Author(s):  
Cengiz Kahraman ◽  
Basar Oztaysi ◽  
Sezi Cevik Onar

Abstract Confidence intervals are useful tools for statistical decision-making purposes. In case of incomplete and vague data, fuzzy confidence intervals can be used for decision making under uncertainty. In this paper, we develop interval-valued intuitionistic fuzzy (IVIF) confidence intervals for population mean, population proportion, differences in means of two populations, and differences in proportions of two populations. The developed IVIF intervals can be used in cases of both finite and infinite population sizes. The developed fuzzy confidence intervals are equivalent decision-making tools to fuzzy hypothesis tests. We apply the proposed confidence intervals to the differences in the mean lives and failure proportions of two types of radiators used in automobiles, and a sensitivity analysis is given to check the robustness of the decisions.


2019 ◽  
Author(s):  
Andrew Morgan ◽  
Nicholas Brazeau ◽  
Billy Ngasala ◽  
Lwidiko Mhamilawa ◽  
Madeline Denton ◽  
...  

Abstract Background: Tanzania’s Zanzibar archipelago has made significant gains in malaria control over the last decade and is a target for malaria elimination. Despite consistent implementation of effective tools since 2002, elimination has not been achieved. Importation of parasites from outside of the archipelago is thought to be an important cause of malaria’s persistence, but this paradigm has not been studied using modern genetic tools.Methods: We used whole-genome sequencing (WGS) to investigate the impact of importation, employing population genetic analyses of Plasmodium falciparum isolates from both the archipelago and mainland Tanzania. We assessed ancestry, levels of genetic diversity and differentiation, patterns of relatedness, and patterns of selection between these two populations by leveraging recent advances in deconvolution of genomes from polyclonal malaria infections.Results: We identified significant decreases in the effective population sizes in both populations in the timeframe of decreasing malaria transmission in Tanzania. Identity by descent analysis showed that parasites in the two populations shared large sections of their genomes, on the order of 5 cM, suggesting shared ancestry within the last 10 generations. Even with limited sampling,, we demonstrate a pair of isolates between the mainland and Zanzibar that are related at the expected level of half-siblings, consistent with recent importation.Conclusions: These findings suggest that importation plays an increasing role for malaria incidence on Zanzibar and demonstrate the value of genomic approaches for identifying corridors of parasite movement to the island.


2020 ◽  
Author(s):  
Andrew Morgan ◽  
Nicholas Brazeau ◽  
Billy Ngasala ◽  
Lwidiko Mhamilawa ◽  
Madeline Denton ◽  
...  

Abstract Background Tanzania’s Zanzibar archipelago has made significant gains in malaria control over the last decade and is a target for malaria elimination. Despite consistent implementation of effective tools since 2002, elimination has not been achieved. Importation of parasites from outside of the archipelago is thought to be an important cause of malaria’s persistence, but this paradigm has not been studied using modern genetic tools. Methods Whole-genome sequencing (WGS) was used to investigate the impact of importation, employing population genetic analyses of Plasmodium falciparum isolates from both the archipelago and mainland Tanzania. Ancestry, levels of genetic diversity and differentiation, patterns of relatedness, and patterns of selection between these two populations were assessed by leveraging recent advances in deconvolution of genomes from polyclonal malaria infections. Results Significant decreases in the effective population sizes were inferred in both populations that coincide with a period of decreasing malaria transmission in Tanzania. Identity by descent analysis showed that parasites in the two populations shared long segments of their genomes, on the order of 5 cM, suggesting shared ancestry within the last 10 generations. Even with limited sampling, two of isolates between the mainland and Zanzibar were identified that are related at the expected level of half-siblings, consistent with recent importation. Conclusions These findings suggest that importation plays an important role for malaria incidence on Zanzibar and demonstrate the value of genomic approaches for identifying corridors of parasite movement to the island.


2011 ◽  
Vol 54 (4) ◽  
pp. 419-429
Author(s):  
S. Kusza ◽  
S. Mihók ◽  
L. Czeglédi ◽  
A. Jávor ◽  
M. Árnyasi

Abstract. The aim of the study was to provide information on the genetic variability of the Hungarian Bronze turkey gene reserve population and its difference from the Broad-breasted turkey, and offer guidance and proposals for its future conservation strategies. Altogether, 239 Hungarian Bronze turkeys from 10 strains and 13 Broad-breasted turkeys as a control population were genotyped for 15 microsatellites. All loci were polymorphic with the average number of alleles per locus 3.20±1.146 in the Hungarian Bronze turkey. The mean expected (Hexp) and observed heterozygosity (Hobs) were not different (0.392 and 0.376, respectively) in the overall population, and similar values were obtained for hens and bucks and among hen strains. Inbreeding coefficient (FIS) and Shannon index (I) indicated that there was low inbreeding within hens and bucks. Our results confirm that the genetic diversity in the Hungarian Bronze turkey population has been preserved by the rotational mating system. Differences between the Hungarian Bronze turkey and the Broad-breasted turkey populations were determined. Nei’s unbiased values clearly indicated that the two populations are highly genetically differentiated.


2020 ◽  
Vol 11 ◽  
Author(s):  
Herbert Braunschmid ◽  
Stefan Dötterl

Floral scent, a key mediator in plant–pollinator interactions, varies not only among plant species, but also within species. In deceptive plants, it is assumed that variation in floral scents and other traits involved in pollinator attraction is maintained by negative frequency-dependent selection, i.e., rare phenotypes are more attractive to pollinators and hence, have a higher fitness than common phenotypes. So far, it is unknown whether the rarity of multivariate and/or continuous floral scent traits influences the pollination success of flowers. Here, we tested in the deceptive orchid Cypripedium calceolus, whether flowers with rarer scent bouquets within a population have a higher chance to getting pollinated than flowers with more common scents. We collected the scent of more than 100 flowers in two populations by dynamic headspace and analyzed the samples by gas chromatography coupled to mass spectrometry (GC/MS). From the same flowers we also recorded whether they set a fruit or not. We introduced rarity measures of uni- and multivariate floral scent traits for single flowers, which allowed us to finally test for frequency-dependent pollination, a prerequisite for negative frequency-dependent selection. Our results do not show rarity has an effect on the likelihood to set fruits in neither of the two populations and in none of the scent characteristics analyzed. Hence, there is no evidence of negative frequency-dependent pollination mediated by the floral scent of C. calceolus. We discuss that our approach to determine rarity of a scent is applicable to any univariate or multivariate (semi)quantitative trait.


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