Variation in sampling effort affects the observed richness of plant-plant interactions via heterospecific pollen transfer: implications for interpretation of pollen transfer networks

Studies that aim to understand the processes that generate and organize plant diversity in nature have a long history in Ecology. Among these, pollinator-mediated plant-plant interactions that occur by altering pollinator floral preferences have been at the forefront in this field. Current evidence however indicates that plants can interact directly via heterospecific pollen (HP) transfer, that these interactions are ubiquitous, and can have strong fitness effects with implications for floral evolution, speciation and community assembly. Hence, interest in understanding their role in the diversification and organization of plant communities is rapidly rising. The existence of geographic mosaics of species interactions and their role in shaping patterns of diversity is also well recognized. However, after 40 years of research, the importance of geographic mosaics in HP intensity and effects remain poorly known, thus ignoring its potential in shaping patterns of diversity at local and global scales. Here, I develop a conceptual framework and summarize existing evidence for the ecological and evolutionary consequences of geographic mosaics in HP transfer interactions and outline future directions in this field.

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Pollination success increases with plant diversity in high-Andean communities

Scientific Reports ◽

10.1038/s41598-021-01611-w ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sabrina S. Gavini ◽

Agustín Sáez ◽

Cristina Tur ◽

Marcelo A. Aizen

Keyword(s):

Plant Diversity ◽

Species Coexistence ◽

Pollen Grains ◽

Plant Interactions ◽

Pollination Success ◽

Heterospecific Pollen ◽

Biodiversity Maintenance ◽

Pollen Receipt ◽

Facilitative Interactions ◽

Plant Plant

AbstractPollinator-mediated plant–plant interactions have traditionally been viewed within the competition paradigm. However, facilitation via pollinator sharing might be the rule rather than the exception in harsh environments. Moreover, plant diversity could be playing a key role in fostering pollinator-mediated facilitation. Yet, the facilitative effect of plant diversity on pollination remains poorly understood, especially under natural conditions. By examining a total of 9371 stigmas of 88 species from nine high-Andean communities in NW Patagonia, we explored the prevalent sign of the relation between conspecific pollen receipt and heterospecific pollen diversity, and assessed whether the incidence of different outcomes varies with altitude and whether pollen receipt relates to plant diversity. Conspecific pollen receipt increased with heterospecific pollen diversity on stigmas. In all communities, species showed either positive or neutral but never negative relations between the number of heterospecific pollen donor species and conspecific pollen receipt. The incidence of species showing positive relations increased with altitude. Finally, stigmas collected from communities with more co-flowering species had richer heterospecific pollen loads and higher abundance of conspecific pollen grains. Our findings suggest that plant diversity enhances pollination success in high-Andean plant communities. This study emphasizes the importance of plant diversity in fostering indirect plant–plant facilitative interactions in alpine environments, which could promote species coexistence and biodiversity maintenance.

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ALLELOPATHIC EFFECTS OF PARTHENIUM HYSTEROPHORUS ON GERMINATION OF SORGHUM SEEDS

Scholarly Research Journal for Humanity Science & English Language ◽

10.21922/srjhsel.v6i26.11391 ◽

2018 ◽

Vol 6 (26) ◽

Author(s):

Jitendra Rajpoot

Keyword(s):

Biological System ◽

Growth And Development ◽

Plant Virus ◽

Evolutionary Origin ◽

Plant Interactions ◽

Biological Organization ◽

Plant Soil ◽

System A ◽

Allelopathic Effects ◽

Plant Plant

International Allelopathy Society has redefined Allelopathy as any process involving secondary metabolities produced by plants, algae, bacteria, fungi and viruses that influences the growth and development of agricultural and biological system; a study of the functions of secondary metabolities, their significance in biological organization, their evolutionary origin and elucidation of the mechanisms involving plant-plant, plant-microorganisms, plant-virus, plant-insect, plant-soil-plant interactions.

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Competition-free gaps are essential for the germination and recruitment of alpine species along an elevation gradient in the European Alps

Alpine Botany ◽

10.1007/s00035-021-00264-9 ◽

2021 ◽

Author(s):

Vera Margreiter ◽

Janette Walde ◽

Brigitta Erschbamer

Keyword(s):

Vegetation Cover ◽

Seedling Recruitment ◽

Environmental Control ◽

Elevation Gradient ◽

European Alps ◽

Plant Interactions ◽

Experimental Conditions ◽

Positive Effects ◽

Seed Sowing ◽

Plant Plant

AbstractSeed germination and seedling recruitment are key processes in the life cycle of plants. They enable populations to grow, migrate, or persist. Both processes are under environmental control and influenced by site conditions and plant–plant interactions. Here, we present the results of a seed-sowing experiment performed along an elevation gradient (2000–2900 m a.s.l.) in the European eastern Alps. We monitored the germination of seeds and seedling recruitment for 2 years. Three effects were investigated: effects of sites and home sites (seed origin), effects of gaps, and plant–plant interactions. Seeds of eight species originating from two home sites were transplanted to four sites (home site and ± in elevation). Seed sowing was performed in experimentally created gaps. These gap types (‘gap + roots’, ‘neighbor + roots’, and ‘no-comp’) provided different plant–plant interactions and competition intensities. We observed decreasing germination with increasing elevation, independent of the species home sites. Competition-released gaps favored recruitment, pointing out the important role of belowground competition and soil components in recruitment. In gaps with one neighboring species, neutral plant–plant interactions occurred (with one exception). However, considering the relative vegetation cover of each experimental site, high vegetation cover resulted in positive effects on recruitment at higher sites and neutral effects at lower sites. All tested species showed intraspecific variability when responding to the experimental conditions. We discuss our findings considering novel site and climatic conditions.

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Trichoderma Strains and Metabolites Selectively Increase the Production of Volatile Organic Compounds (VOCs) in Olive Trees

Metabolites ◽

10.3390/metabo11040213 ◽

2021 ◽

Vol 11 (4) ◽

pp. 213

Author(s):

Irene Dini ◽

Roberta Marra ◽

Pierpaolo Cavallo ◽

Angela Pironti ◽

Immacolata Sepe ◽

...

Keyword(s):

Volatile Organic Compounds ◽

Organic Compounds ◽

Gas Chromatography Mass Spectrometry ◽

Lipid Signaling ◽

Plant Interactions ◽

Growth Promoters ◽

Volatile Organic ◽

Trichoderma Fungi ◽

Olive Trees ◽

Plant Plant

Plants emit volatile organic compounds (VOCs) that induce metabolomic, transcriptomic, and behavioral reactions in receiver organisms, including insect pollinators and herbivores. VOCs’ composition and concentration may influence plant-insect or plant-plant interactions and affect soil microbes that may interfere in plant-plant communication. Many Trichoderma fungi act as biocontrol agents of phytopathogens and plant growth promoters. Moreover, they can stimulate plant defense mechanisms against insect pests. This study evaluated VOCs’ emission by olive trees (Olea europaea L.) when selected Trichoderma fungi or metabolites were used as soil treatments. Trichoderma harzianum strains M10, T22, and TH1, T. asperellum strain KV906, T. virens strain GV41, and their secondary metabolites harzianic acid (HA), and 6-pentyl-α-pyrone (6PP) were applied to olive trees. Charcoal cartridges were employed to adsorb olive VOCs, and gas chromatography mass spectrometry (GC-MS) analysis allowed their identification and quantification. A total of 45 volatile compounds were detected, and among these, twenty-five represented environmental pollutants and nineteen compounds were related to olive plant emission. Trichoderma strains and metabolites differentially enhanced VOCs production, affecting three biosynthetic pathways: methylerythritol 1-phosphate (MEP), lipid-signaling, and shikimate pathways. Multivariate analysis models showed a characteristic fingerprint of each plant-fungus/metabolite relationship, reflecting a different emission of VOCs by the treated plants. Specifically, strain M10 and the metabolites 6PP and HA enhanced the monoterpene syntheses by controlling the MEP pathway. Strains GV41, KV906, and the metabolite HA stimulated the hydrocarbon aldehyde formation (nonanal) by regulating the lipid-signaling pathway. Finally, Trichoderma strains GV41, M10, T22, TH1, and the metabolites HA and 6PP improve aromatic syntheses at different steps of the shikimate pathway.

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Mycorrhizosphere bacteria and plant-plant interactions facilitate maize P acquisition in an intercropping system

Journal of Cleaner Production ◽

10.1016/j.jclepro.2021.127993 ◽

2021 ◽

pp. 127993

Author(s):

Chun Song ◽

Clement Kyei Sarpong ◽

Xiaofeng Zhang ◽

Wenjing Wang ◽

Lingfeng Wang ◽

...

Keyword(s):

Plant Interactions ◽

P Acquisition ◽

Plant Plant

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Ecological field theory model: a mechanistic approach to simulate plant–plant interactions in southeastern forest ecosystems

Canadian Journal of Forest Research ◽

10.1139/x93-271 ◽

1993 ◽

Vol 23 (10) ◽

pp. 2180-2193 ◽

Cited By ~ 19

Author(s):

Pu Mou ◽

Robert J. Mitchell ◽

Robert H. Jones

Keyword(s):

Field Theory ◽

Loblolly Pine ◽

Vegetation Dynamics ◽

Plant Size ◽

Theory Model ◽

Plant Interactions ◽

Simulation Accuracy ◽

Individual Level ◽

The Individual ◽

Plant Plant

Ecological field theory, unlike many other vegetation modeling approaches, provides a basis to construct an individually based, spatially explicit, and resource-mediated model for mechanistic simulation of plant–plant interactions and vegetation dynamics. The model REGROW has been developed, based on ecological field theory principles, to simulate vegetation dynamics for northern hardwood forests. Using data from a current study of a southern pine system to calibrate a modified version of this model, SPGROW, we simulated growth of individuals for the first growing season in stands of loblolly pine (Pinustaeda L.) and sweetgum (Liquidambarstyraciflua L.) seedlings and loblolly pine seedling–sweetgum sprout mixtures. SPGROW accurately simulated stand development at population and stand levels. However, less agreement occurred at the individual level between simulated and field survey values, possibly owing to lack of data on site heterogeneity and genetic variation. Plant interactions, which altered resource availability (light, water, and nutrients) to individual plants, played a major role in differentiating plant size in the model. Given its unique model structure and simulation accuracy, SPGROW has the potential to provide very detailed insight into the mechanisms of plant–plant interactions.

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Unilateral incompatibility and the effects of interspecific pollination for Erythronium americanum and Erythronium albidum (Liliaceae)

Canadian Journal of Botany ◽

10.1139/b93-038 ◽

1993 ◽

Vol 71 (2) ◽

pp. 353-358 ◽

Cited By ~ 41

Author(s):

Lawrence D. Harder ◽

Mitchell B. Cruzan ◽

James D. Thomson

Keyword(s):

Seed Production ◽

Pollen Tubes ◽

The Self ◽

Pollen Transfer ◽

Interspecific Incompatibility ◽

Unilateral Incompatibility ◽

Heterospecific Pollen ◽

Interspecific Pollen Transfer ◽

Erythronium Americanum ◽

Incompatibility Reaction

To determine whether interspecific pollen transfer could reduce seed production by two sympatric lilies, Erythronium albidum and Erythronium americanum, we hand-pollinated flowers with mixtures of conspecific and heterospecific pollen. These species exhibited typical unilateral interspecific incompatibility, i.e., pollen tubes from the self-infertile species (E. americanum) grew apparently unimpeded in styles of the self-fertile species (E. albidum), whereas the reverse cross resulted in an incompatibility reaction. Because of this asymmetrical relation and faster growth by heterospecific pollen tubes in E. albidum stigmas than by conspecific tubes, pollination with abundant heterospecific pollen reduced fruit and seed production by E. albidum, but not by E. americanum, as long as the stigma also received some conspecific pollen. Unilateral incompatibility could benefit self-infertile species in reproductive interactions with closely related self-fertile species; however, this benefit remains to be demonstrated for naturally pollinated plants. Key words: Erythronium albidum, Erythronium americanum, interspecific pollen transfer, pollination, unilateral incompatibility.

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