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Wizenberg SB, Newburn LR, Pepinelli M, Conflitti IM, Richardson RT, Hoover SER, Currie RW, Giovenazzo P, Zayed A. Validating a multi-locus metabarcoding approach for characterizing mixed-pollen samples. Plant Methods 2023; 19:120. [PMID: 37925401 PMCID: PMC10625703 DOI: 10.1186/s13007-023-01097-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 10/21/2023] [Indexed: 11/06/2023]
Abstract
BACKGROUND The mutualistic interaction between entomophilous plants and pollinators is fundamental to the structure of most terrestrial ecosystems. The sensitive nature of this relationship has been disrupted by anthropogenic modifications to natural landscapes, warranting development of new methods for exploring this trophic interaction. Characterizing the composition of pollen collected by pollinators, e.g. Apis mellifera, is a common means of exploring this relationship, but traditional methods of microscopic pollen assessment are laborious and limited in their scope. The development of pollen metabarcoding as a method of rapidly characterizing the abundance and diversity of pollen within mixed samples presents a new frontier for this type of work, but metabarcoding may have limitations, and validation is warranted before any suite of primers can be confidently used in a research program. We set out to evaluate the utility of an integrative approach, using a set of established primers (ITS2 and rbcL) versus melissopalynological analysis for characterizing 27 mixed-pollen samples from agricultural sites across Canada. RESULTS Both individual markers performed well relative to melissopalynology at the family level with decreases in the strength of correlation and linear model fits at the genus level. Integrating data from both markers together via a multi-locus approach provided the best rank-based correlation between metagenetic and melissopalynological data at both the genus (ρ = 0.659; p < 0.001) and family level (ρ = 0.830; p < 0.001). Species accumulation curves indicated that, after controlling for sampling effort, melissopalynological characterization provides similar or higher species richness estimates than either marker. The higher number of plant species discovered via the metabarcoding approach simply reflects the vastly greater sampling effort in comparison to melissopalynology. CONCLUSIONS Pollen metabarcoding performed well at characterizing the composition of mixed pollen samples relative to a traditional melissopalynological approach. Limitations to the quantitative application of this method can be addressed by adopting a multi-locus approach that integrates information from multiple markers.
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Affiliation(s)
- Sydney B Wizenberg
- Department of Biology, York University, 4700 Keele St., Toronto, ON, M3J 1P3, Canada
| | - Laura R Newburn
- Department of Biology, York University, 4700 Keele St., Toronto, ON, M3J 1P3, Canada
| | - Mateus Pepinelli
- Department of Biology, York University, 4700 Keele St., Toronto, ON, M3J 1P3, Canada
| | - Ida M Conflitti
- Department of Biology, York University, 4700 Keele St., Toronto, ON, M3J 1P3, Canada
| | - Rodney T Richardson
- Appalachian Laboratory, University of Maryland Center for Environmental Science, Frostburg, MD, 21613, USA
| | - Shelley E R Hoover
- Department of Biological Sciences, University of Lethbridge, 4401 University Drive W, Lethbridge, AB, T1K3M4, Canada
| | - Robert W Currie
- Department of Entomology, University of Manitoba, 12 Dafoe Road, Winnipeg, MB, R3T2N2, Canada
| | - Pierre Giovenazzo
- Département de Biologie, Université Laval, 2325 Rue de l'Université, Québec City, Québec, G1V0A6, Canada
| | - Amro Zayed
- Department of Biology, York University, 4700 Keele St., Toronto, ON, M3J 1P3, Canada.
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Wizenberg SB, Newburn LR, Richardson RT, Pepinelli M, Conflitti IM, Moubony M, Borges D, Guarna MM, Guzman‐Novoa E, Foster LJ, Zayed A. Environmental metagenetics unveil novel plant-pollinator interactions. Ecol Evol 2023; 13:e10645. [PMID: 37941738 PMCID: PMC10630067 DOI: 10.1002/ece3.10645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 10/05/2023] [Accepted: 10/09/2023] [Indexed: 11/10/2023] Open
Abstract
Honey bees are efficient pollinators of flowering plants, aiding in the plant reproductive cycle and acting as vehicles for evolutionary processes. Their role as agents of selection and drivers of gene flow is instrumental to the structure of plant populations, but historically, our understanding of their influence has been limited to predominantly insect-dispersed flowering species. Recent metagenetic work has provided evidence that honey bees also forage on pollen from anemophilous species, suggesting that their role as vectors for transmission of plant genetic material is not confined to groups designated as entomophilous, and leading us to ask: could honey bees act as dispersal agents for non-flowering plant taxa? Using an extensive pollen metabarcoding dataset from Canada, we discovered that honey bees may serve as dispersal agents for an array of sporophytes (Anchistea, Claytosmunda, Dryopteris, Osmunda, Osmundastrum, Equisetum) and bryophytes (Funaria, Orthotrichum, Sphagnum, Ulota). Our findings also suggest that honey bees may occasionally act as vectors for the dispersal of aquatic phototrophs, specifically Coccomyxa and Protosiphon, species of green algae. Our work has shed light on the broad resource-access patterns that guide plant-pollinator interactions and suggests that bees could act as vectors of gene flow, and potentially even agents of selection, across Plantae.
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Affiliation(s)
| | | | - Rodney T. Richardson
- Appalachian LaboratoryUniversity of Maryland Center for Environmental ScienceFrostburgMarylandUSA
| | | | | | | | - Daniel Borges
- Ontario Beekeepers' AssociationTech‐Transfer Program, Orchard Park Office CentreGuelphOntarioCanada
| | - M. Marta Guarna
- Beaverlodge Research Farm, Agriculture and Agri‐Food CanadaBeaverlodgeAlbertaCanada
| | | | - Leonard J. Foster
- Department of Biochemistry & Molecular Biology and Michael Smith LaboratoriesVancouverBritish ColumbiaCanada
| | - Amro Zayed
- Department of BiologyYork UniversityTorontoOntarioCanada
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Wizenberg SB, Muir-Guarnaccia J, Campbell LG. Cosexuality Reduces Pollen Production and Fitness in Cannabis sativa L. Plants (Basel) 2023; 12:3731. [PMID: 37960087 PMCID: PMC10648298 DOI: 10.3390/plants12213731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 10/25/2023] [Accepted: 10/27/2023] [Indexed: 11/15/2023]
Abstract
Cannabis sativa L. is cultivated globally for its cannabinoid-dense inflorescences. Commercial preference for sinsemilla has led to the development of methods for producing feminized seeds through cross-pollination of cosexual (masculinized) female plants. Although the induction of cosexuality in Cannabis plants is common, to date, no work has empirically tested how masculinization of female Cannabis plants impacts male flowering, pollen production, pollen fitness, and related life-history trade-offs. Here, we cultivated a population of Cannabis plants (CFX-2) and explored how the route to cosexuality (drought vs. chemical induction) impacted flowering phenology, pollen production, and pollen fitness, relative to unsexual male plants. Unisexual males flowered earlier and longer than cosexual plants and produced 223% more total pollen (F2,28 = 74.41, p < 0.001), but per-flower pollen production did not differ across reproductive phenotypes (F2,21 = 0.887, p = 0.427). Pollen viability was 200% higher in unisexual males and drought-induced cosexuals (F2,36 = 189.70, p < 0.001). Pollen non-abortion rates only differed in a marginally significant way across reproductive phenotypes (F2,36 = 3.00, p = 0.06). Here, we demonstrate that masculinization of female plants impacts whole-plant pollen production and pollen fitness in Cannabis sativa.
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Affiliation(s)
- Sydney B. Wizenberg
- Department of Chemistry and Biology, Toronto Metropolitan University, 350 Victoria St, Toronto, ON M5B 2K3, Canada; (S.B.W.)
- Department of Biology, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada
| | - Jillian Muir-Guarnaccia
- Department of Chemistry and Biology, Toronto Metropolitan University, 350 Victoria St, Toronto, ON M5B 2K3, Canada; (S.B.W.)
| | - Lesley G. Campbell
- Department of Chemistry and Biology, Toronto Metropolitan University, 350 Victoria St, Toronto, ON M5B 2K3, Canada; (S.B.W.)
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Wizenberg SB, Dang M, Campbell LG. Methods for characterizing pollen fitness in Cannabis sativa L. PLoS One 2022; 17:e0270799. [PMID: 35797371 PMCID: PMC9262209 DOI: 10.1371/journal.pone.0270799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 06/17/2022] [Indexed: 11/22/2022] Open
Abstract
Pollen grains are male gametophytes, an ephemeral haploid generation of plants, that commonly engage in competition for a limited supply of ovules. Since variation in reproductive capabilities among male gametophytes may influence the direction and pace of evolution in populations, we must be able to quantify the relative fitness of gametophytes from different sires. To explore this, we estimated the relative fitness of groups of male gametophytes in a dioecious, wind-pollinated model system, Cannabis sativa, by characterizing the non-abortion rate (measured via chemical staining) and viability (measured via in vitro germination) of pollen from multiple sires. Pollen viability quickly declined within two weeks of anther dehiscence, and pollen stored under freezer conditions did not germinate regardless of storage time. In contrast, pollen non-abortion rates declined slowly and persisted longer than the lifetime of a sporophyte plant under both room temperature and freezer conditions. Pollen samples that underwent both viability and non-abortion rate analysis displayed no significant correlation, implying that researchers cannot predict pollen viability from non-abortion rates, nor infer male gametophytic fitness from a single measure. Our work demonstrates two independent, differential approaches to measure proxies of male fitness in C. sativa.
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Affiliation(s)
- Sydney B. Wizenberg
- Department of Chemistry and Biology, Toronto Metropolitan University (recently renamed), Toronto, Ontario, Canada
| | - Michelle Dang
- Department of Chemistry and Biology, Toronto Metropolitan University (recently renamed), Toronto, Ontario, Canada
| | - Lesley G. Campbell
- Department of Chemistry and Biology, Toronto Metropolitan University (recently renamed), Toronto, Ontario, Canada
- * E-mail:
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Wizenberg SB, Weis AE, Campbell LG. Comparing methods for controlled capture and quantification of pollen in Cannabis sativa. Appl Plant Sci 2020; 8:e11389. [PMID: 33014633 PMCID: PMC7526430 DOI: 10.1002/aps3.11389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 04/22/2020] [Indexed: 06/11/2023]
Abstract
PREMISE Precise pollen collection methods are necessary for crop breeding, but anemophilous pollen is notoriously difficult to capture and control. Here we compared a variety of methods for the controlled capture of cannabis pollen, intended to ease the process of cross-fertilization for breeding this wind-pollinated plant, and measured the utility of light spectroscopy for quantifying relative pollen yield. METHODS AND RESULTS In two independent trials, we compared a control method of pollen collection (hand collection) to either vacuum-, water-, or bag-collection methods. We used visible light spectroscopy to quantify relative pollen yield, and validated this approach using microscopic pollen counts. We determined that pollen yield was highest when using hand collection or vacuum collection, but efficiency did not differ significantly among methods. CONCLUSIONS To maximize yield, pollen should be collected by hand or vacuum, but all collection methods were equally efficient in a relative sense because yield increased with collection time. We also found that light spectroscopy is an accurate and rapid method of quantifying pollen abundance (R 2 = 0.86) in a liquid suspension.
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Affiliation(s)
| | - Arthur E. Weis
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoOntarioCanada
| | - Lesley G. Campbell
- Department of Chemistry and BiologyRyerson UniversityTorontoOntarioCanada
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