Pollen Quantity and Quality as Explanations for Low Seed Set in Small Populations Exemplified by Eupatorium (Asteraceae)

Byers, Diane L.

doi:10.2307/2446229

Cited by 116 publications

(80 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This has been invoked to explain the reduced fecundity in small endangered populations of self-incompatible plants (for example, Les et al 1991;Aspinwall and Christian 1992;Demauro 1993;Byers 1995). We found a quite high number of S-alleles in all populations except the smallest, Punta Calcina.…”

Section: Discussionmentioning

confidence: 54%

Balancing Selection in the Wild: Testing Population Genetics Theory of Self-Incompatibility in the Rare SpeciesBrassica insularis

Glémin¹,

et al. 2005

View full text Add to dashboard Cite

Self-incompatibility (SI) systems are widespread mechanisms that prevent self-fertilization in angiosperms. They are generally encoded by one genome region containing several multiallelic genes, usually called the S-locus. They involve a recognition step between the pollen and the pistil component and pollen is rejected when it shares alleles with the pistil. The direct consequence is that rare alleles are favored, such that the S-alleles are subject to negative frequency-dependent selection. Several theoretical articles have predicted the specific patterns of polymorphism, compared to neutral loci, expected for such genes under balancing selection. For instance, many more alleles should be maintained and populations should be less differentiated than for neutral loci. However, empirical tests of these predictions in natural populations have remained scarce. Here, we compare the genetic structure at the S-locus and microsatellite markers for five natural populations of the rare species Brassica insularis. As in other Brassica species, B. insularis has a sporophytic SI system for which molecular markers are available. Our results match well the theoretical predictions and constitute the first general comparison of S-allele and neutral polymorphism.H OMOMORPHIC self-incompatibility (SI) systems are widespread physiological mechanisms preventing self-fertilization in Angiosperms by controlling pollen germination or pollen tube growth (De Nettancourt 2001). Pollen and pistil are incompatible when they both express identical alleles. The recognition involves specificity molecules usually encoded by one genome region containing several multiallelic genes (De Nettancourt 2001). In gametophytic (GSI) systems, the pollen phenotype is encoded by its own haploid genome, whereas in sporophytic (SSI) systems, the pollen phenotype is determined by the sporophyte (diploid pollen parent) and can involve dominance interactions among alleles. For instance, two classes of alleles are known in Brassica oleracea (Nasrallah 1991). Class I alleles are dominant over the class II alleles in the pollen, while alleles within class I and class II are mutually codominant. In the pistil, all alleles are codominant. This scheme is also found in B. campestris, with the exception that alleles occur in three dominance levels in the pollen and a few alleles are recessive in the stigma (Hatakeyama et al. 1998). At the molecular level, the SSI system of the Brassicaceae is among the best known (for a recent review see Hiscock and McInnis 2003). Both pistil and pollen genes have been identified (Schopfer et al. 1999;Takayama et al. 2000). In this system, recognition proceeds through receptor-ligand interaction between S-locus cysteinerich protein (SCR), a small hypervariable ligand peptide, and S-locus receptor kinase (SRK), a transmembrane receptor with an intracellular kinase domain (Kachroo et al. 2001).SI evolutionary properties have also long aroused the population geneticist's interest because selection pressures are known a priori. C...

show abstract

Section: Discussionmentioning

confidence: 54%

Balancing Selection in the Wild: Testing Population Genetics Theory of Self-Incompatibility in the Rare SpeciesBrassica insularis

Glémin¹,

et al. 2005

View full text Add to dashboard Cite

show abstract

“…Lower fruit and seed set in plants of small habitat fragments have been observed for many species of tropical and temperate vegetation (e.g., Jennersten, 1988;Jennersten, & Nilsson, 1993;Aizen, & Feinsinger, 1994a;Byers, 1995;Oostermeijer, Altenburg, & den Nijs, 1995;Ågren, 1996;Cunningham, 2000;Quesada et al, 2003). Other species either do not show any different response in reproductive output between fragmented and continuous forest or present even higher reproductive output in smaller fragments and open areas than in continuous forest (e.g., Costin, Morgan, & Young, 2001;Dick, 2001;Lopes, & Buzato, 2007;Dunley et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

Reproductive success of Cabralea canjerana (Meliaceae) in Atlantic forest fragments, Brazil

Franceschinelli

Carmo

Neto

et al. 2015

RBT

View full text Add to dashboard Cite

Abstract:In Brazil, the Atlantic forest remnants have high biological diversity and a high level of endemism, but very little is known about the reproductive success of native species. Cabralea canjerana is a common tree in the Montane Atlantic forest, and its reproduction is highly dependent on pollinators. In order to contribute with the particular knowledge on this species, we collected data in three fragmented and three continuous forest sites, where the effects of fragmentation on both mutualistic (pollination) and antagonistic (seed predation) interactions were analysed. We determined fruit production and weight of 25 trees per site. The number of seeds and the percentage of predated and aborted seeds were also accessed for seven fruits of 10 trees per site. Pollinator visitation frequencies to flowers were recorded in two forest fragments and in two sites of the continuous forest. Our data showed that plants of C. canjerana produced more fruits (z-value=-8.24; p<0.0001) and seeds per fruit (z-value=-6.58; p=0.002) in the continuous than in the fragmented sites. This was likely due to differences in pollination, because the number of pollinator visits was higher in the continuous forest than in the fragments. Seed abortion (z-value=4.08, p<0.001) and predation (z-value=3.72, p=0.0002), on the other hand, were higher in the fragmented than in the continuous sites. Then, mutualistic and antagonistic interactions were affected by fragmentation, decreasing the reproductive success of the study tree. This study was the first to show a decrease in the reproductive output in forest fragments in an Atlantic forest tree species. This decrease may threaten the population structure and viability of C. canjerana in forest fragments. Rev. Biol. Trop. 63 (2): 515-524. Epub 2015 June 01.Key words: Cabralea canjerana, fruit production, habitat fragmentation, plant-pollinator interaction, moth pollination, reproductive success, pre-dispersal seed predation, seed set.Habitat fragmentation may disrupt plantpollinator interactions by changing the abundance and/or the identity of floral visitors (Lovejoy, 1980;Roubik, 1993;Aizen, & Feinsinger, 1994a;Aizen, & Feinsinger, 1994b;Matheson, Buchamann, O'Toole, Westrich, & Williams, 1996;Murcia, 1996;Prach, Pysek, & Smilauer, 1997). Because floral visitors can differ in their ability to transfer pollen, changes in the pollinator assemblages following fragmentation may affect plant reproductive success (Aizen, & Feinsinger, 1994b). Studies conducted during the past few decades show that fragmentation may affect the reproduction of various plant species in different ways. Most of these studies show decreases in the richness and abundance of pollinators and in the number of pollinator visits in response to fragmentation, leading to a decrease in the reproductive output of plants (Aizen, & Feinsinger, 1994a;Kolb, 2008). In contrast, other studies found no changes in the reproductive output of plants in fragmented habitats (e.g., Aldrich & Hamrick, 1998;Dick, 2001;Lopes, & Buzato, 2007;...

show abstract

“…In these pseudo self compatible (PSC) species SI operates as a quantitative, rather than a qualitative, trait due to the segregation of unlinked genes that modify the strength of SI (Good-Avila & al., 2008). Whether such intermediate strategies are widespread, artefactual or evolutionary labile is under debate (see Raduski & al., 2012 and references therein the path towards self-compatibility (Allen & Hiscock, 2008) particularly favored when mates are limiting (Busch & Schoen, 2008), for instance in small populations of endemic spe cies (e.g., Byers, 1995). Recent comparative analyses suggested that endemic species tend to evolve self-compatibility (SC) systems (Alonso & al., 2010) but PSC was not considered as a possible stage.…”

Section: Introductionmentioning

confidence: 99%

“…Recent comparative analyses suggested that endemic species tend to evolve self-compatibility (SC) systems (Alonso & al., 2010) but PSC was not considered as a possible stage. Interestingly, PSC has been found in several endemic species (e.g., Byers, 1995;Bush, 2005;Glemin & al., 2005, Ortiz & al., 2006Nielsen & al., 2007;Weber & Goodwillie, 2009;Crawford & al., 2010;Narbona & al., 2011) suggesting that endemics could be good species candidates for studying ongoing evolutionary changes in mating system. Endemic species frequently experience high pollen limitation in the characteristically diverse communities where they occur (Vamosi & al., 2006;Alonso & al., 2010).…”

Section: Introductionmentioning

confidence: 99%

Strong inbreeding depression and individually variable mating system in the narrow endemic <i>Erodium cazorlanum</i> (Geraniaceae)

Alonso¹,

García-Sevilla²

2013

Anal. Jard. Bot. Madr.

View full text Add to dashboard Cite

Alonso, C. & García-Sevilla, M. 2013. Strong inbreeding depression and individually variable mating system in the narrow endemic Erodium cazorlanum (Geraniaceae). Anales Jard. Bot. Madrid 70(1): 72-80.Angiosperms evolved different systems to attract effective pollinators while reducing selfing in hermaphroditic flowers. Selfing ability can be advantageous when pollinators and/or mates are scarce, although inbreeding depression may largely reduce those advantages. Recent comparative analyses suggested endemic species tend to evolve self-compatibility but a better understanding of the associated reproductive and genetic tradeoffs is required. Experimental hand-pollinations under greenhouse conditions were conducted to investigate the selfing ability and estimate inbreeding depression up to the offspring' first reproductive event in Ero dium cazorlanum, a narrow endemic species restricted to dolomite outcrops in SE Spanish mountains. We found autonomous selfing ineffective. Further, when experimentally applied, pollen of the same flower produced significantly fewer fruits and seeds compared to geitonogamous and cross pollinations. The number of seeds per fruit was significantly higher after cross pollinations and strong inbreeding depression accumulated through the life-cycle. Interestingly, individual plants exhibited broad variation in selfing ability with six out of 14 individuals producing no seed after geitonogamy. Understanding the consequences of individual variation in self compatibility deserves further investigation in the field now that we know that strong inbreeding depression may limit recruitment of selfed progeny.

show abstract

Pollen Quantity and Quality as Explanations for Low Seed Set in Small Populations Exemplified by Eupatorium (Asteraceae)

Cited by 116 publications

References 23 publications

Balancing Selection in the Wild: Testing Population Genetics Theory of Self-Incompatibility in the Rare SpeciesBrassica insularis

Balancing Selection in the Wild: Testing Population Genetics Theory of Self-Incompatibility in the Rare SpeciesBrassica insularis

Reproductive success of Cabralea canjerana (Meliaceae) in Atlantic forest fragments, Brazil

Strong inbreeding depression and individually variable mating system in the narrow endemic <i>Erodium cazorlanum</i> (Geraniaceae)

Contact Info

Product

Resources

About