scholarly journals Pollen adaptation to ant pollination: a case study from the Proteaceae

2020 ◽  
Vol 126 (3) ◽  
pp. 377-386 ◽  
Author(s):  
Nicola Delnevo ◽  
Eddie J van Etten ◽  
Nicola Clemente ◽  
Luna Fogu ◽  
Evelina Pavarani ◽  
...  
Keyword(s):  
Seed Set ◽  
Germination Rate ◽  
Pollen Grains ◽  
Relative Effect ◽  
The Other ◽  
Pollen Load ◽  
Pollination Services ◽  
Ant Pollination ◽  
Negative Effect ◽  
Floral Visitors

Abstract Background and Aims Ant–plant associations are widely diverse and distributed throughout the world, leading to antagonistic and/or mutualistic interactions. Ant pollination is a rare mutualistic association and reports of ants as effective pollinators are limited to a few studies. Conospermum (Proteaceae) is an insect-pollinated genus well represented in the south-western Australia biodiversity hotspot, and here we aimed to evaluate the role of ants as pollinators of C. undulatum. Methods Pollen germination after contact with several species of ants and bees was tested for C. undulatum and five co-flowering species for comparison. We then sampled the pollen load of floral visitors of C. undulatum to assess whether ants carried a pollen load sufficient to enable pollination. Lastly, we performed exclusion treatments to assess the relative effect of flying- and non-flying-invertebrate floral visitors on the reproduction of C. undulatum. For this, we measured the seed set under different conditions: ants exclusion, flying-insects exclusion and control. Key Results Pollen of C. undulatum, along with the other Conospermum species, had a germination rate after contact with ants of ~80 % which did not differ from the effect of bees; in contrast, the other plant species tested showed a drop in the germination rate to ~10 % following ant treatments. Although ants were generalist visitors, they carried a pollen load with 68–86 % of suitable grains. Moreover, ants significantly contributed to the seed set of C. undulatum. Conclusions Our study highlights the complexity of ant–flower interactions and suggests that generalizations neglecting the importance of ants as pollinators cannot be made. Conospermum undulatum has evolved pollen with resistance to the negative effect of ant secretions on pollen grains, with ants providing effective pollination services to this threatened species.

INFLUENCE OF CYTOPLASM ON SEED SETTING IN ALFALFA

1978 ◽  
Vol 58 (2) ◽  
pp. 341-346 ◽  
Author(s):  
R. MICHAUD ◽  
T. H. BUSBICE
Keyword(s):  
Seed Set ◽  
Pollen Grains ◽  
The Other ◽  
Seed Setting ◽  
Positive Effects ◽  
Male Function ◽  
Reciprocal Differences ◽  
Negative Effect ◽  
Medicago Sativa L ◽  
Partial Hybrid

Differences in cross-fertility were observed when four alfalfa (Medicago sativa L.) clones designated A, B, C, and D were used reciprocally as male or female. The clone C cytoplasm was determined to be the source of these reciprocal differences. Plants with clone C cytoplasm performed poorly as male parents, but normally as female parents. The mode of action of the clone C cytoplasm on the male function was not determined, but it appeared to be different from that which causes incomplete pollen development. Plants containing clone C cytoplasm produced an abundance of normal appearing pollen grains. In general, clone C cytoplasm had a negative effect on seed set, clone A and D cytoplasms had positive effects, and clone B cytoplasm had no effect relative to the other three. Selection among cytoplasms in alfalfa for improved seed set and for use in the production of partial-hybrid varieties was discussed.

scholarly journals Floral herbivory does not reduce pollination-mediated fitness in shelter rewarding Royal Irises

2017 ◽  
Author(s):  
Mahua Ghara ◽  
Christina Ewerhardy ◽  
Gil Yardeni ◽  
Mor Matzliach ◽  
Yuval Sapir
Keyword(s):  
Fruit Set ◽  
Seed Set ◽  
Pollen Grains ◽  
Reproductive Organs ◽  
Pollen Grain ◽  
Lower Number ◽  
Pollen Deposition ◽  
Pollination Services ◽  
Pollinator Visitation ◽  
Direct Damage

ABSTRACTFlorivory, the damage to flowers by herbivores can affect fitness both directly and indirectly. Flowers consumed by florivores may fail to produce fruit or produce lower seed set because of direct damage to reproductive organs. In addition, eaten flowers are less attractive to pollinators because of reduced or modified advertisement, which reduces pollination services. While observational data are abundant, experimental evidence is scarce and results are contrasting. We tested experimentally the effect of florivory on both pollinator visitation and reproductive success in three species of the Royal Irises, which have large flowers that are attractive to pollinators, and potentially also for florivores. We hypothesized that florivory will reduce pollen deposition due to reduced attractiveness to pollinators, while fruit set and seed set will depend on the extent of florivory. We performed artificial florivory in two experiments over two years. In the first experiment, each of the three floral units of a single Iris flower was subject to either low or high artificial florivory, or left un-touched as control. We counted the number of pollen grains deposited on each of the three stigmas as a measure of pollinator visitation. In the second experiment, three flowers of the same plant received low, high, or no artificial florivory and were further recorded for fruit and seed production. In 2016, high artificial florivory revealed lower number of pollen grains on stigmas of Iris atropurpurea, but in 2017 there was no difference. Similarly, number of pollen grains in high artificial was lower than low florivory in 2017 in I. petrana. No significant effect of florivory was found on pollen grain deposition, fruit set or seed set. The results remained consistent across species and across years. The results undermine the assumption that flower herbivory is necessarily antagonistic interaction and suggests that florivores may not be strong selection agents on floral reproductive biology in the Oncocyclus irises.

scholarly journals Variation in Manduca sexta Pollination-Related Floral Traits and Reproduction in a Wild Tobacco Plant

2021 ◽  
Vol 9 ◽  
Author(s):  
Julia Bing ◽  
Xiang Li ◽  
Alexander Haverkamp ◽  
Ian T. Baldwin ◽  
Bill S. Hansson ◽  
...  
Keyword(s):  
Manduca Sexta ◽  
Seed Set ◽  
Tobacco Plant ◽  
The Other ◽  
Floral Traits ◽  
Nicotiana Attenuata ◽  
Pollination Syndromes ◽  
Pollination Services ◽  
Flower Opening ◽  
Local Adaptations

Most flowering plants depend on animal pollination for successful sexual reproduction. Floral signals such as color, shape, and odor are crucial in establishing this (often mutualistic) interaction. Plant and pollinator phenotypes can vary temporally but also spatially, thus creating mosaic-like patterns of local adaptations. Here, we investigated natural variation in floral morphology, flower volatile emission, and phenology in four accessions of a self-compatible wild tobacco, Nicotiana attenuata, to assess how these traits match the sensory perception of a known pollinator, the hawkmoth Manduca sexta. These accessions differ in floral traits and also in their habitat altitudes. Based on habitat temperatures, the accession occurring at the highest altitude (California) is less likely to be visited by M. sexta, while the others (Arizona, Utah 1, and Utah 2) are known to receive M. sexta pollinations. The accessions varied significantly in flower morphologies, volatile emissions, flower opening, and phenology, traits likely important for M. sexta perception and floral handling. In wind tunnel assays, we assessed the seed set of emasculated flowers after M. sexta visitation and of natural selfed and hand-pollinated selfed flowers. After moth visitations, plants of two accessions (Arizona and Utah 2) produced more capsules than the other two, consistent with predictions that accessions co-occurring with M. sexta would benefit more from the pollination services of this moth. We quantified flower and capsule production in four accessions in a glasshouse assay without pollinators to assess the potential for self-pollination. The two Utah accessions set significantly more seeds after pollen supplementation compared with those of autonomous selfing flowers, suggesting a greater opportunistic benefit from efficient pollinators than the other two. Moreover, emasculated flowers of the accession with the most exposed stigma (Utah 2) produced the greatest seed set after M. sexta visitation. This study reveals intraspecific variation in pollination syndromes that illuminate the potential of a plant species to adapt to local pollinator communities, changing environments, and altered pollination networks.

scholarly journals Pollination and Seed Production in Viola

HortScience ◽  
2006 ◽  
Vol 41 (3) ◽  
pp. 633-639
Author(s):  
Daiichiro Miyajima
Keyword(s):  
Seed Set ◽  
Pollen Grains ◽  
Germination Percentage ◽  
Fertilization Success ◽  
The Other ◽  
Flowering Period ◽  
Flower Longevity ◽  
Ovule Number ◽  
Germination Of Pollen ◽  
Mature Seeds

The seed producing system in viola (Viola ×cornuta) was investigated to improve seed yield and to save labor. In a flower five anthers sequentially dehisced; pollen grains were continuously supplied to the anterior petal, which played a significant role in pollination, throughout the flowering period. Evidence from pollen and ovule number suggests that the species is facultative autogamy. Each flower opened more than 10 days was independent of the success in fertilization and kept seed producing ability during the flower longevity period. Pollen grains also maintained viability during the flower longevity period. Pollinators were indispensable for pollination of viola, but pollination in viola was done by a different mechanism from the typical insect-mediated pollination that sticky pollen grains adhere to the exposed stigmas. Pollen grains, accumulated around the entrance of the stigmatic cavity, entered into the cavity by the movement of pollinators. Although the visitation of pollinators was occasional, solitary bees primarily contributed to the pollination of viola. On the other hand, germination of pollen grains on the stigmatic surface was under 50%. Seed set was much lower than the germination percentage of pollen grains. A viola flower had the ability for additional pollinations and fertilization for some days after the fertilization success in some ovules in the flower. This characteristic suggested that repeated pollination is effective to increase the number of mature seeds in a capsule.

scholarly journals Some Unresolved Issues of Measuring the Efficiency of Pollinators: Experimentally Testing and Assessing the Predictive Power of Different Methods

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Ram Chander Sihag
Keyword(s):  
Foraging Behavior ◽  
Seed Set ◽  
Reproductive Potential ◽  
Pollen Grains ◽  
The Other ◽  
Transfer Efficiency ◽  
Optimum Number ◽  
Pollen Transfer ◽  
Pollen Transfer Efficiency ◽  
Northwest India

Knowledge of efficiency of pollinators is valuable in the derivation of (i) the degree of mutualism specialization of a flower visitor in the natural plant communities, (ii) the optimum number of pollinators needed for the maximum pollination in a plant population, and (iii) the pollinator risk assessment in the sustainable agriculture. Earlier researchers used many direct and indirect methods for measuring the pollination efficiency (PE) of flower visitors. However, a great ambiguity exists in the usage of this terminology that necessitated its fresh scrutiny. I tested the available three standard methods afresh to find the efficiency of pollinators. These included comparing the (i) number of pollen grains removed and deposited by the visitors; (ii) seed set resulting from a single and the multiple visits of the visitors; and (iii) “pollen transfer efficiency (PTE)” derived from the foraging behavior and abundances of the visitors. Observations were recorded on the visitors of four plant species in an agroecosystem of Northwest India. These plants represented a wide variety of the floral types across the angiosperms. The first two methods, namely, the “number of pollen grains removed and deposited” and the “seed set resulting from a single and the multiple visits,” were appropriate in finding differences between the efficiency ranks of the pollinators of those flowers where the number of deposited pollen grains was less than the number of ovules in the ovary. However, these two methods completely failed in situations where exactly reverse condition of pollen grains and ovules existed. Thus, these two methods of measuring the PE of visitors had limited approach and lacked a universal application over the entire angiosperm taxa. On the other hand, use of “pollen transfer efficiency”, derived from the foraging behavior and abundance of the visitors, seemed to have an edge over the other two methods as this was helpful in finding differences between the efficiency ranks of the pollinators of plants in all the three situations tested in this study. However, validation of all the three methods through the plant reproductive potential seemed to be an integral confirmatory step for drawing inferences about the efficiency of pollinators.

Pengaruh Luka Iris Pada Tikus Dengan Paparan Hidrogen Peroxida 3% terhadap Epitelisasi dan Pembentukan Eksudat pada Permukaan Epitel Kulit.

2020 ◽  
Vol 17 (2) ◽  
pp. 172
Author(s):  
HARMAN AGUSAPUTRA ◽  
MARIA SUGENG ◽  
AYLY SOEKAMTO ◽  
ATIK WULANDARI
Keyword(s):  
Hydrogen Peroxide ◽  
Wound Healing ◽  
The Other ◽  
Delayed Wound Healing ◽  
Peroxide Group ◽  
Hemostatic Effect ◽  
Significant Difference ◽  
Negative Effect ◽  
Wound Healing Effect ◽  
Epithelial Growth

<p><strong>Abstract</strong></p><p><strong>Background:</strong> Hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) as antiseptic has been used frequently to clean woundsin in hospitals and clinics. Hydrogen peroxide has the effectof strong oxidative that can kill pathogens. It can clean up debris and necrotic tissuesin wounds. Hydrogen peroxidealso has hemostatic effect that can help to stop bleeding. Besides antiseptic effects, hydrogen peroxide i s suspected of having negative effect in wound healing. Hydrogen peroxide presumably could cause delayed wound healing by exudate formation and delayed epithelial growth.</p><p><strong>Method</strong>: This study was conducted in the laboratory using 48 white mice that were divided into 2 groups. All the mice were purposely wounded. Afterwards in one group the wounds were clean up using hydrogen peroxide, while in the other group without hydrogen peroxide as control. The wounds of both groups were observed on day 1, day 3 and day 7. On day 1 and day 3, both groups did not show significant difference.</p><p><strong>R</strong><strong>esult</strong> : on day 7 showed that the wound healing in hydrogen peroxide group were delayed. Fifty percent of them had the formation of exudate and 62.5% of them showed delayed epithelial growth.</p><p><strong>Conclusion </strong>: This study could show hydrogen peroxide as wound antiseptic has delayed wound healing effect.</p><p><strong>Keyword</strong>: hydrogen peroxide, wound healing</p>

The Value of Information in the Hold-Up Problem

2004 ◽  
Vol 5 (2) ◽  
pp. 177-203 ◽  
Author(s):  
Thomas Pfeiffer
Keyword(s):  
Information System ◽  
Information Structure ◽  
Value Of Information ◽  
The Other ◽  
Information Control ◽  
Ceteris Paribus ◽  
Head Office ◽  
Specific Investments ◽  
Negative Effect ◽  
Central Management

Abstract In the literature, the information structure of the hold-up problem is typically assumed to be exogenous. In this paper, we introduce an additional stage at which the head office may grant individual divisions access to an information system before they undertake their specific investments. Although more information ceteris paribus enhances each divisions’ profits, more information can reduce divisions’ investments and destroy synergies for the other division that would have been generated by the investments. If this negative effect dominates, then information can be harmful for the entire company. Hence, information control can be a subtle force to deal with the hold-up problem to a certain extent. In this paper we analyze those conditions under which information is either harmful or beneficial for central management.

scholarly journals Extracts of Emmer Wheatgrass Grown with Distilled Water, Salinity or Selenium Differently Affect Germination and Cytosolic Ca2+ of Maize Pollen

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 633
Author(s):  
Alberto Marco Del Pino ◽  
Beatrice Falcinelli ◽  
Roberto D’Amato ◽  
Daniela Businelli ◽  
Paolo Benincasa ◽  
...  
Keyword(s):  
Biological Activity ◽  
Phenolic Acids ◽  
Triticum Turgidum ◽  
Germination Rate ◽  
Biological Response ◽  
Pollen Grains ◽  
Water Salinity ◽  
Distilled Water ◽  
Agonist Activity ◽  
Maize Pollen

In this work, the biological activity of emmer (Triticum turgidum L. spp. dicoccum (Schrank ex Shubler) Thell.) wheatgrass extracts obtained from grains sprouted with distilled water, or salinity (50 mM) or selenium (45 mg L−1 of Na2SeO3), was tested through an experimental biological model based on the germination and cytosolic Ca2+ homeostasis of maize pollen grains. The effects of thapsigargin (TG) and of four phenolic acids (PAs: ferulic, coumaric, salicylic and 3-HO benzoic) on maize pollen were also tested as controls. Wheatgrass extracts influenced both pollen cytosolic Ca2+ and germination. The Ca2+ agonist activity of emmer wheatgrass was transient, different from that of TG, which caused a depletion of the stored Ca2+ and a permanent alteration of Ca2+ homeostasis. The results obtained with extracts compared to those obtained with pure PAs suggest that PAs in unconjugated forms, which are known to be well represent in emmer wheatgrass, contribute to the biological activity of extracts. The extent of the biological response of emmer wheatgrass extracts was influenced by emmer sprouting conditions (i.e., distilled water, or salinity or selenium). Maize pollen treated with Se-enriched wheatgrass extracts showed a less perturbed cytosolic Ca2+ and a higher germination rate.

scholarly journals Olive mill wastewater effects on durum wheat crop attributes and soil microbial activities: A pilot study in Syria

2021 ◽  
Author(s):  
Jehan Khalil ◽  
Hasan Habib ◽  
Michael Alabboud ◽  
Safwan Mohammed
Keyword(s):  
Durum Wheat ◽  
Germination Rate ◽  
Soil Samples ◽  
Olive Mill Wastewater ◽  
The Other ◽  
Wheat Crop ◽  
Microbial Activities ◽  
Soil Microbial ◽  
Growing Seasons ◽  
Olive Mill

AbstractOlive mill wastewater is one of the environmental problems in semiarid regions. The main goals of this study were to investigate the impacts of different olive mill wastewater levels on durum wheat (Triticum aestivum var. Douma1) production and soil microbial activities (i.e., bacteria and fungi). A pot experiment was conducted during the growing seasons 2015/2017 to evaluate the effect of three levels of olive mill wastewater on both growth and productivity attributes of wheat. Vertisol soil samples were collected from southern Syria. Two months before wheat cultivation, three levels of olive mill wastewater: T5 (5 L/m 2), T10 (10 L/m2) and T15 (15 L/m 2) were added to pots filled with the collected soil samples. Also, a control (T0) free of olive mill wastewater was considered as a reference. Results showed a significant increase (p < 0.05) in germination rate (%), plant height (cm), ear length (cm), kernels number, kernels weight per ear (g) and grain yield (g/m2) compared to control. However, T5 treatment did not induce a significant increase in terms of ear length, kernels weight per ear or yield (in the second season). On the other hand, T10 treatment had recorded the best results compared with the other two treatments (T5, T15). Similarly, the results showed a significant increase in the number of bacterial and fungi cells by increasing olive mill wastewater concentration. This research provides promising results toward using olive mill wastewater in an eco-friendly way under Syrian conditions.

POLLEN PRODUCTION AND DISSEMINATING PROPERTIES OF TRITICALE RELATIVE TO WHEAT

1972 ◽  
Vol 52 (4) ◽  
pp. 569-574 ◽  
Author(s):  
K. C. YEUNG ◽  
E. N. LARTER
Keyword(s):  
Seed Set ◽  
Marker Gene ◽  
Pollen Grains ◽  
Triticum Aestivum L ◽  
Hybrid Seed Production ◽  
Pollen Production ◽  
Hexaploid Triticale ◽  
Anther Length ◽  
Anther Extrusion ◽  
Wide Range

A study of the pollen production properties of three hexaploid triticale strains (Triticale hexaploide Lart.) showed that their anther length was significantly greater than that of wheat anthers (Triticum aestivum L. em Thell.) and the estimated number of pollen grains per anther ranged from 15,000 to 21,000. In comparison, a total of 8000 grains per anther was estimated for wheat, cult Manitou. Eighty-nine percent anther extrusion occurred in triticale cult Rosner, while Manitou averaged 70% anther extrusion. The period of anthesis of triticale varied according to strain but generally was of longer duration than in Manitou and thereby promoted outcrossing. Using a triticale strain carrying a dominant marker gene, 50% seed-set was obtained at a distance of 12 m leeward of the pollen source; however, a small percentage was still obtained at a distance of 30 m. It would appear from the limited number of triticales used in this study that a wide range of variability exists within this species in its pollen production and disseminating properties. With appropriate selection pressures, strains with an outbreeding habit could be developed for the purpose of hybrid seed production.

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