Greater reproductive assurance of asexual plant compared to sexual relative in a low density sympatric population – experimental evidence for pollen limitation

2021 ◽  
Author(s):  
Patrik Mráz ◽  
Viera Mrázová
Keyword(s):  
Experimental Evidence ◽  
Pollen Limitation ◽  
Low Density ◽  
Reproductive Assurance ◽  
Sympatric Population

Beyond Simple Reproductive Assurance: Cleistogamy Allows Adaptive Plastic Responses to Pollen Limitation

2011 ◽  
Vol 172 (7) ◽  
pp. 862-869 ◽  
Author(s):  
Loren P. Albert ◽  
Lesley G. Campbell ◽  
Kenneth D. Whitney
Keyword(s):  
Pollen Limitation ◽  
Reproductive Assurance ◽  
Plastic Responses

scholarly journals Bees may drive the reproduction of four sympatric cacti in a vanishing coastal mediterranean-type ecosystem

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7865
Author(s):  
Pablo C. Guerrero ◽  
Claudia A. Antinao ◽  
Beatriz Vergara-Meriño ◽  
Cristian A. Villagra ◽  
Gastón O. Carvallo
Keyword(s):  
Interannual Variation ◽  
Mating Systems ◽  
Pollen Limitation ◽  
Statistical Significance ◽  
Sympatric Species ◽  
Reproductive Assurance ◽  
Hand Pollination ◽  
Mediterranean Type Ecosystem ◽  
Pollinator Assemblage ◽  
And Control

Background Sympatric congeneric plants might share pollinators, or each species might avoid competition by evolving specialized traits that generate partitions in pollinator assemblages. In both cases, pollen limitation (a decrease in the quality and quantity of compatible reproductive pollen) can occur, driving the plant mating system to autogamy as a mechanism of reproductive assurance. We assessed the relationships between pollinator assemblages and mating systems in a group of sympatric congeneric plants. We attempted to answer the following questions: (i) How similar are pollinator assemblages among sympatric cactus species? (ii) Which mating systems do sympatric cactus species use? Methods We studied sympatric Eriosyce taxa that inhabit a threatened coastal strip in a mediterranean-type ecosystem in central Chile. We performed field observations on four taxa and characterized pollinators during the years 2016 and 2017. We estimated differences in the pollinator assemblages using the Bray–Curtis index. To elucidate the mating systems, we conducted hand-pollination experiments using three treatments: manual cross-pollination, automatic self-pollination, and control (unmanipulated individuals). We tested differences in seed production for statistical significance using Kruskal–Wallis analysis. Results Eriosyce subgibbosa showed a distinctive pollinator assemblage among the sympatric species that we studied (similarity ranged from 0% to 8%); it was visited by small bees and was the only species that was visited by the giant hummingbird Patagona gigas. Pollinator assemblages were similar between E. chilensis (year 2016 = 4 species; 2017 = 8) and E. chilensis var. albidiflora (2016 = 7; 2017 = 4); however, those of E. curvispina var. mutabilis (2016 = 7; 2017 = 6) were less similar to those of the aforementioned species. E. curvispina var. mutabilis showed the highest interannual variation in its pollinator assemblage (18% similarity). Reproduction in E. subgibbosa largely depends on pollinators, although it showed some degree of autogamy. Autonomous pollination was unfeasible in E. chilensis, which depended on flower visitors for its reproductive success. Both E. chilensis var. albidiflora and E. curvispina var. mutabilis showed some degree of autogamy. Discussion We observed differences in pollinator assemblages between E. subgibbosa and the remaining Eriosyce taxa, which depend on hymenopterans for pollen transfer. Pollinator assemblages showed considerable interannual variation, especially those of E. subgibbosa (ornithophilous syndrome) and E. curvispina var. mutabilis (melitophilous syndrome). Autogamous reproduction in these taxa may act as a reproductive assurance mechanism when pollinator availability is unpredictable. Our study contributes to improving our understanding of the reproductive systems of ecological interactions between threatened species in a Chilean mediterranean-type ecosystem.

scholarly journals The role of lateral and vertical herkogamy in the divergence of the blue- and red-flowered lineages of Lysimachia arvensis

2020 ◽  
Vol 125 (7) ◽  
pp. 1127-1135 ◽  
Author(s):  
F J Jiménez-López ◽  
P L Ortiz ◽  
M Talavera ◽  
J R Pannell ◽  
M Arista
Keyword(s):  
Pollen Limitation ◽  
Flower Colour ◽  
Reproductive Interference ◽  
Pollen Deposition ◽  
Potential Mechanism ◽  
Reproductive Assurance ◽  
Self Fertilization ◽  
Annual Herb ◽  
Mixed Populations

Abstract Background and Aims Herkogamy, or anther–stigma separation, is known to reduce self-pollen deposition, but little is known about the relative efficacy of different modes or conformations of herkogamy. We assessed the effectiveness of vertical versus lateral herkogamy in preventing or promoting self-pollen deposition in the annual herb Lysimachia arvensis, a plant with lineages that differ in flower colour, and in which flowers first display lateral and then vertical herkogamy. Because mating between the two lineages compromises fitness through the production of low-quality hybrid offspring, we tested the prediction that individuals sampled from sites occupied by both lineages should have flowers that promote autonomous self-pollen deposition and self-fertilization as a result of selection to reduce deleterious reproductive interference. Methods We characterized variation in herkogamy within and among 25 pure and mixed populations of L. arvensis in its European range and assessed the effectiveness of lateral versus vertical herkogamy in avoiding self-pollen deposition. Results Lateral herkogamy was more effective than vertical herkogamy in limiting self-pollen deposition. In the case of vertical herkogamy, only approach herkogamy was effective. Lineages showed consistent differences in herkogamy traits. In general, angles were smaller for blue than red flowers in most populations, and blue flowers showed approach herkogamy, while red flowers showed predominantly reverse herkogamy. In sympatry, the red lineage showed a reduction of both herkogamy traits while for the blue lineage only lateral herkogamy was reduced. Conclusions Our results demonstrate that pollen deposition is affected not only by the degree but also the spatial conformation of herkogamy. They also highlight reduced herkogamy as a potential mechanism for promoting reproductive assurance under pollen limitation, as well as for avoiding reproductive interference between genetically divergent lineages.

scholarly journals Experimental evidence of low-density liquid water upon rapid decompression

2018 ◽  
Vol 115 (9) ◽  
pp. 2010-2015 ◽  
Author(s):  
Chuanlong Lin ◽  
Jesse S. Smith ◽  
Stanislav V. Sinogeikin ◽  
Guoyin Shen
Keyword(s):  
Experimental Evidence ◽  
Liquid Water ◽  
Crystallization Rate ◽  
Supercooled Water ◽  
Bulk Water ◽  
Low Density ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffusion Controlled ◽  
Rapid Decompression

Water is an extraordinary liquid, having a number of anomalous properties which become strongly enhanced in the supercooled region. Due to rapid crystallization of supercooled water, there exists a region that has been experimentally inaccessible for studying deeply supercooled bulk water. Using a rapid decompression technique integrated with in situ X-ray diffraction, we show that a high-pressure ice phase transforms to a low-density noncrystalline (LDN) form upon rapid release of pressure at temperatures of 140–165 K. The LDN subsequently crystallizes into ice-Ic through a diffusion-controlled process. Together with the change in crystallization rate with temperature, the experimental evidence indicates that the LDN is a low-density liquid (LDL). The measured X-ray diffraction data show that the LDL is tetrahedrally coordinated with the tetrahedral network fully developed and clearly linked to low-density amorphous ices. On the other hand, there is a distinct difference in structure between the LDL and supercooled water or liquid water in terms of the tetrahedral order parameter.

scholarly journals Effect of Resource Reallocation on Pollen Limitation and Reproductive Assurance of Apocynum venetum L. in an Arid Region

2016 ◽  
Vol 8 (9) ◽  
pp. 95 ◽  
Author(s):  
Min Chen ◽  
Xue-yong Zhao ◽  
Xiao-an Zuo ◽  
Hao Qu ◽  
Wei Mao ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Pollen Limitation ◽  
Reproductive Assurance ◽  
Resource Reallocation ◽  
Strong Force ◽  
Whole Plant ◽  
Apocynum Venetum ◽  
Single Flower ◽  
Plant Pollen

<p>Pollen limitation is considered to be a strong force driving the evolution of reproductive strategies in flowering plants. However, resource reallocation may occur among seeds because of variation in the quantity or quality of pollen received. We performed single-flower and whole-plant pollen supplementation and emasculation of flowers of <em>Apocynum venetum</em> L. to estimate pollen limitation and reproductive assurance. In addition, we calculated the visiting patterns of the pollinators, frequency of pollinators to estimate the effect of pollinator activity and further on the reproductive success of <em>A. venetum</em>. Our results indicated estimates from single-flower manipulations were not biased, closely resembling those from whole-plant manipulations. We found<em> Apis mellifera</em> was the dominant pollinator during the pollination process. In addition, insect pollination played a more important role in the outcrossing system, which could explain the differences in reproductive success. Our results also showed that autonomous self-pollination eliminates pollen limitation and provides reproductive assurance.</p>

scholarly journals Constructing LDPC Codes with Any Desired Girth

Sensors ◽  
2021 ◽  
Vol 21 (6) ◽  
pp. 2012
Author(s):  
Chaohui Gao ◽  
Sen Liu ◽  
Dong Jiang ◽  
Lijun Chen
Keyword(s):  
Wireless Sensor Networks ◽  
Sensor Networks ◽  
Power Consumption ◽  
Experimental Evidence ◽  
Ldpc Codes ◽  
Wireless Sensor ◽  
Low Density ◽  
Parity Check ◽  
Optimal Input ◽  
Low Density Parity Check

In wireless sensor networks, the reliability of communication can be greatly improved by applying low-density parity-check (LDPC) codes. Algorithms based on progressive-edge-growth (PEG) pattern and quasi-cyclic (QC) pattern are the mainstream approaches to constructing LDPC codes with good performance. However, these algorithms are not guaranteed to remove all short cycles to achieve the desired girth, and their excellent inputs are difficult to obtain. Herein, we propose an algorithm, which must be able to construct LDPC codes with the girth desired. In addition, the optimal input to the proposed algorithm is easy to find. Theoretical and experimental evidence of this study shows that the LDPC codes we construct have better decoding performance and less power consumption than the PEG-based and QC-based codes.

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