Plant mating systems and assessing population persistence in fragmented landscapes

2007 ◽  
Vol 55 (3) ◽  
pp. 239 ◽  
Author(s):  
David J. Coates ◽  
Jane F. Sampson ◽  
Colin J. Yates
Keyword(s):  
Mating System ◽  
Population Size ◽  
Mating Systems ◽  
Habitat Disturbance ◽  
Population Persistence ◽  
Population Variation ◽  
Conservation Strategies ◽  
Valuable Insight ◽  
Mixed Mating ◽  
Fragmented Landscapes

Population size and habitat disturbance are key factors likely to shape the mating system of populations in disturbed and fragmented landscapes. They would be expected to influence the availability and behaviour of the pollinator, the ability to find mates in self-incompatible species, inbreeding in self-compatible species and the size of the pollen pool. These in turn might be expected to influence key variables critical for population persistence such as seed production, seed germination and seedling fitness. Here we investigate mating-system variation in six rare species, i.e. Banksia cuneata, B. oligantha, Lambertia orbifolia (Proteaceae), Verticordia fimbrilepis subsp. fimbrilepis, Eucalyptus rameliana (Myrtaceae), Acacia sciophanes (Mimosaceae), and two common species, i.e. Calothamnus quadrifidus (Myrtaceae) and Acacia anfractuosa. All seven species are animal-pollinated relatively long-lived woody shrubs with mixed-mating systems. Population variation in mating-system parameters was investigated in relation to population size and habitat disturbance. We show that although the mating system will vary depending on pollination biology and life-history, as populations get smaller and habitat disturbance increases there is a trend towards increased inbreeding, smaller effective sizes of paternal pollen pools and greater variation in outcrossing among plants. From the species investigated in this study we have found that changes in the mating system can be useful indicators of population processes and can give valuable insight into the development of conservation strategies for the persistence of plant species following anthropogenic disturbance and landscape fragmentation.

scholarly journals EVOLUTION OF INTERACTIONS IN FAMILY-STRUCTURED POPULATIONS: MIXED MATING MODELS

Genetics ◽  
1980 ◽  
Vol 96 (1) ◽  
pp. 275-296
Author(s):  
Richard E Michod
Keyword(s):  
Mating System ◽  
Mating Systems ◽  
Random Mating ◽  
Additive Model ◽  
Multiplicative Model ◽  
Structured Populations ◽  
Mixed Mating ◽  
Genotypic Distribution ◽  
Individual Fitness ◽  
Recessive Genes

ABSTRACT The effect of inbreeding on sociality is studied theoretically for the evolution of interactions between siblings in certain mixed mating systems that give rise to inbreeding: sib with random mating and selfing with random mating. Two approaches are taken. First, specific models of altruism are studied for the various mating systems. In the case of the additive model, inbreeding facilitates the evolution of altruistic genes. Likewise, for the multiplicative model this is usually the case, as long as the costs of altruism are not too great. Second, the case of total altruism, in which the gene has zero individual fitness but increases the fitness of associates, is studied for a general fitness formulation. In this case, inbreeding often retards the ability of such genes to increase when rare, and the equilibrium frequency of those recessive genes that can increase is totally independent of the mating system and, consequently, of the amount of inbreeding. It appears from the results presented that inbreeding facilitates most forms of altruism, but retards extreme altruism. These results stem from the fact that inbreeding increases the within-family relatedness by increasing the between-family variance in allele frequency. In most cases this facilitates altruism. However, in the case of total altruism, only heterozygotes can pass on the altruistic allele, and inbreeding tends to decrease this heterozygote class. In either case, the important effect of inbreeding lies in altering the genotypic distribution of the interactions.

Pollinator behaviour, mate choice and the realised mating systems of Grevillea mucronulata and Grevillea sphacelata

2000 ◽  
Vol 48 (3) ◽  
pp. 357 ◽  
Author(s):  
Matthew B. G. Richardson ◽  
David J. Ayre ◽  
Robert J. Whelan
Keyword(s):  
Mate Choice ◽  
Mating System ◽  
Mating Systems ◽  
Fruit Set ◽  
Electrophoretic Analysis ◽  
Population Variation ◽  
Pollinator Behaviour ◽  
High Level ◽  
Almost All ◽  
Pollination Systems

Successful long-term conservation and management of populations of plants requires successful management of the suite of factors that determine their ‘realised’ mating systems. Within the genus Grevillea, mating systems are potentially complex. They may vary among species and among populations within a species, reflecting variation in pollinator behaviour and diversity (‘potential’ mating systems) and in breeding system (the ‘preferred’ mating system). We used a combination of pollinator observations, pollination experiments and electrophoretic analysis of seed from open pollinations, to examine variation in potential and preferred mating systems in two populations of each of two ‘spider-flowered’ Grevillea species: G. mucronulata (visited by honeyeaters and honeybees, although only birds effected pollen removal and transfer) and G. sphacelata (visited only by honeybees, which made frequent contact with pollen and stigmas). Almost all observed bird and insect foraging bouts on either species involved movements among inflorescences within plants or among inflorescences on closely neighbouring plants. On the basis of these data, the mating system was predicted to involve a high level of selfing or inbreeding. However, the pollination experiment revealed that both species were highly self-incompatible and showed a clear preference for outcross pollen in mate-choice experiments. For both species, fruit set through autogamy was lower than 0.7% and fruit set from self-pollinations was always significantly lower than for outcross pollinations (0–11% cf. 25–33% for G. mucronulata and 0% cf. 4.2–8.8% for G. sphacelata). Allozyme studies revealed that genotypes in open-pollinated seeds on 20 G. mucronulata and 20 G. sphacelata plants were surprisingly uniform, best explained by outcrossed matings between close neighbours. We found little between-population variation in any aspect of the mating system for either species. These studies reveal that the preferred mating system of the plant and the pattern of pollinator behaviour interact to determine the mating system in a population, emphasising the need for a multifaceted investigation of mating systems, especially in predicting the fates of populations that have pollination systems altered by disturbance, small size, isolation and introduced species such as the honeybee.

Rates of inbreeding in the androdioecious clam shrimp Eulimnadia texana

1999 ◽  
Vol 77 (9) ◽  
pp. 1402-1408 ◽  
Author(s):  
S C Weeks ◽  
N Zucker
Keyword(s):  
Mating System ◽  
Mating Systems ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Clam Shrimp ◽  
Inbreeding Rate ◽  
Male Frequency ◽  
Relationship Of ◽  
The Relationship ◽  
Mixed Mating Strategy

Populations of the clam shrimp Eulimnadia texana exhibit androdioecy, which is a mixed mating system composed of males and self-compatible hermaphrodites. It has been suggested that such mating systems are evolutionarily unstable, and yet most populations of E. texana appear to exhibit both outcrossing and selfing (a mixed mating strategy). Genetic and sex-ratio features of seven populations of these clam shrimp confirm that the majority of these populations show a mixture of inbreeding and outcrossing modes of reproduction. Additionally, we suggest that the relationship of inbreeding rate with male frequency indicates that mating is not random, as was suggested in a previous model of the mating system of E. texana.

Limited impact of fragmentation and disturbance on the mating system of tuart (Eucalyptus gomphocephala, Myrtaceae): implications for seed-source quality in ecological restoration

2013 ◽  
Vol 61 (2) ◽  
pp. 148 ◽  
Author(s):  
Donna Bradbury ◽  
Siegfried L. Krauss
Keyword(s):  
Genetic Diversity ◽  
Mating System ◽  
Ecological Restoration ◽  
Habitat Disturbance ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Fragmented Population ◽  
Eucalyptus Gomphocephala ◽  
Multiple Trees ◽  
Seed Sourcing

Variation in patterns of mating within and among plant populations can be impacted by habitat disturbance and have significant implications for offspring fitness. An understanding of this variation will inform predictions of seed genetic quality, benefiting ecological restoration through better seed-sourcing guidelines. We assessed mating system variation in six populations of tuart (Eucalyptus gomphocephala DC.), an iconic tree of significance to ecological restoration in Western Australia. A mixed mating system was observed with predominant outcrossing (tm = 0.76 ± 0.05) and low biparental inbreeding (tm–ts = 0.03 ± 0.02). We detected some evidence of increased inbreeding in a naturally fragmented population (tm–ts = 0.10 ± 0.04) and in a disturbed urban remnant (tm = 0.52 ± 0.12), including a family with complete selfing. However, most variation in outcrossing rate occurred among individuals within populations (82%), rather than among populations (2.6%) or among groups of populations defined by fragmentation or disturbance (15.4%). Genetic diversity was not consistently lower in offspring from fragmented, smaller and/or disturbed populations. These data reinforce the importance of sourcing seeds from multiple trees for ecological restoration, and emphasise that tuart’s mating system and the genetic diversity of offspring is robust to some habitat disturbance and/or fragmentation.

scholarly journals Depicting the mating system and patterns of contemporary pollen flow in trees of the genus Anadenanthera (Fabaceae)

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10579
Author(s):  
Juliana Massimino Feres ◽  
Alison G. Nazareno ◽  
Leonardo M. Borges ◽  
Marcela Corbo Guidugli ◽  
Fernando Bonifacio-Anacleto ◽  
...  
Keyword(s):  
Gene Flow ◽  
Mating System ◽  
Management Practices ◽  
Pollen Dispersal ◽  
Paternity Analysis ◽  
Dispersal Distance ◽  
Conservation Strategies ◽  
Mixed Mating ◽  
Forest Fragments ◽  
Contemporary Gene Flow

Anadenanthera (Fabaceae) is endemic to the Neotropics and consists of two tree species: A. colubrina (Vell.) Brenan and A. peregrina (L.) Speg. This study examined the mating system and contemporary gene flow of A. colubrina (Acol) and A. peregrina (Aper) in a highly fragmented area of the Atlantic Forest to provide valuable information that informs conservation strategies. Reproductive adults from forest remnants [nA. colubrina = 30 (2.7 ha), nA. peregrina = 55 (4.0 ha)] and progeny-arrays (nA. colubrina = 322, nA. peregrina = 300) were genotyped for seven nuclear microsatellite markers. Mating system analyses revealed that A. colubrina is a mixed mating species (tm = 0.619) while A. peregrina is a predominantly outcrossing species (tm = 0.905). For both Anadenanthera species, high indices of biparental inbreeding were observed (Acol = 0.159, Aper = 0.216), resulting in low effective pollination neighborhood sizes. Categorical paternity analysis revealed different scales of pollen dispersal distance: the majority of crossings occurring locally (i.e., between nearby trees within the same population), with moderate pollen dispersal coming from outside the forest fragments boundaries (Acolmp = 30%, Apermp = 35%). Nevertheless, pollen immigration from trees outside the populations for both species suggests that the populations are not reproductively isolated. This study highlights the importance of evaluating both mating system and contemporary gene flow for a better understanding of the biology of Anadenanthera species. This information should be considered to ensure the effective conservation and management practices of these plant species.

scholarly journals Mixed mating system and variable mating patterns in tropical woody bamboos

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ning Xie ◽  
Ling-Na Chen ◽  
Yu-Ran Dong ◽  
Han-Qi Yang
Keyword(s):  
Mating System ◽  
Mating Systems ◽  
Pollen Dispersal ◽  
Germplasm Conservation ◽  
Paternity Analysis ◽  
Mixed Mating ◽  
Mixed Mating System ◽  
Mating Patterns ◽  
Woody Bamboos ◽  
Dispersal Distances

Abstract Background So far, little is known in detail about mating systems of woody bamboos. Paternity analysis of offspring improved our understanding of these systems, and contributed to their germplasm conservation and genetic improvement. Results In this study, a paternity analysis of offspring from two consecutive mass or sporadically flowering events of Dendrocalamus membranaceus and D. sinicus were conducted to determine their mating system and pollen dispersal using the program COLONY based on simple sequence repeat (SSR) markers. Two sporadically flowering populations of D. sinicus (C1, C2) obtained relatively high paternity assignments rates (69.0–71.4%). Meanwhile, among three populations of D. membranaceus, the sporadically flowering population A also had much higher paternity assignments rates (56.4%) than mass flowering populations B1(28.6%) and B2 (42.5%). Both D. membranaceus and D. sinicus had mixed mating systems while their mating patterns were variable depending on pollination conditions. The maximum pollen dispersal distances were 90 m and 4378 m for D. membranaceus and D. sinicus populations, respectively, and the mating distances of these two species focused on ranges of ca. 0–50 m and 0–1500 m, respectively. Conclusions These results revealed for the first time variable mating patterns in woody bamboos. This suggests half-sib seeds from the same bamboo clump may have different male parents and it is crucial to clarify genetic origin in woody bamboos’ breeding programs. The results also indicate the importance of pollinators in the mating systems of tropical woody bamboos.

scholarly journals Estimating Long-Term Mating Systems Using DNA Sequences

Genetics ◽  
1996 ◽  
Vol 142 (2) ◽  
pp. 619-627 ◽  
Author(s):  
Brook G Milligan
Keyword(s):  
Mating System ◽  
Population Size ◽  
Inbreeding Depression ◽  
Dna Sequences ◽  
Mating Systems ◽  
Natural Populations ◽  
Self Fertilization ◽  
Plant Mating Systems ◽  
The Relationship

Abstract Plant mating systems often involve a mixture of self fertilizations and outcross fertilizations. The degree of selfing has a large impact on the genetic composition of natural populations and on the evolution of the mating system itself in response to such factors as inbreeding depression. This paper describes a means of estimating the long-term rate of self-fertilization from samples of alleles taken from individuals in a population. Use is made of the genealogy of pairs of alleles at a locus within individuals and pairs between individuals. The degree of selfing is closely related to the extent to which the number of nucleotide sites differing within an individual is reduced relative to the number differing between individuals. Importantly, the estimate of long-term selfing is largely independent of population size and is not affected by historical fluctuations in population size; instead it responds directly to the mating system itself. The approach outlined here is most appropriate to evolutionary problems in which the long-term nature of the mating system is of interest, such as to determine the relationship between prior inbreeding and inbreeding depression.

Modified rescue and risk expectations for species with diverse mating systems and modes of inheritance

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Mating Systems ◽  
Outbreeding Depression ◽  
Mixed Mating ◽  
Genetic Rescue ◽  
Mode Of Inheritance

The risks of inbreeding and outbreeding depression, and the prospects for genetic rescue are often different in species with alternative mating systems and mode of inheritance (compared to outbreeding diploids), such as self-incompatible, self-fertilizing, mixed mating, non-diploid (haploid, haplodiploid and polyploid) and asexual.

Genetic diversity of the extremely rare Habenaria dentata and the rare Habenaria linearifolia (Orchidaceae) in South Korea: implications for population history and conservation

2018 ◽  
Vol 151 (1) ◽  
pp. 48-60
Author(s):  
Mi Yoon Chung ◽  
Hoa Thi Quynh Le ◽  
Sungwon Son ◽  
Huai Zhen Tian ◽  
Myong Gi Chung
Keyword(s):  
Genetic Diversity ◽  
Southern China ◽  
Geographic Location ◽  
Population History ◽  
Population Variation ◽  
Conservation Strategies ◽  
Ancestral Population ◽  
Allozyme Diversity ◽  
Glacial Origin

Background and aims – Since historical events often leave an indelible mark on levels of genetic diversity of plant populations, one may indirectly infer their evolutionary history with the help of current patterns of genetic diversity. The terrestrial orchid Habenaria dentata, an element of warm-temperate/subtropical vegetation, reaches its northernmost limits in the Korean Peninsula, and thus it is extremely rare there. As H. dentata was absent from the Peninsula during the Last Glacial Maximum (LGM), it is likely to be of post-glacial origin having arrived from either a single refugium or multiple refugia. However, its rare, temperate/boreal congener H. linearifolia might have persisted in situ in either macrorefugia or microrefugia on the Peninsula during the LGM.Methods – To test which hypothesis is most appropriate for each species, we investigated levels of allozyme-based (17 loci) genetic diversity and population genetic structure in the two only known populations of H. dentata and in 12 populations of H. linearifolia.Key results – No allozyme diversity was found in H. dentata (He = 0.000), whereas H. linearifolia exhibited low within-population variation (He = 0.060) and high among-population differentiation (FST = 0.237). We found little association between populations in relation to their geographic location; several populations presented individuals belonging to different clusters.Conclusions – Our results suggest that H. dentata likely originated from a single ancestral population (perhaps from southern Japan or southern China) through post-glacial dispersal, whereas H. linearifolia probably survived the LGM in situ in microrefugia situated at low to mid-elevated regions. We further suggest that separate conservation strategies for each species should be employed, given that the two taxa have different ecological and demographic traits and harbour different levels of genetic diversity.

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