Rates of inbreeding in the androdioecious clam shrimp Eulimnadia texana

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.

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Maintenance of androdioecy in the freshwater clam shrimp Eulimnadia texana: longevity of males relative to hermaphrodites

Canadian Journal of Zoology ◽

10.1139/z00-211 ◽

2001 ◽

Vol 79 (3) ◽

pp. 393-401 ◽

Cited By ~ 11

Author(s):

Naida Zucker ◽

Brian Stafki ◽

Stephen C Weeks

Keyword(s):

Sex Ratio ◽

Mating System ◽

Mixed Mating ◽

Mixed Mating System ◽

Freshwater Clam ◽

Behavioral Observations ◽

Clam Shrimp ◽

Rearing Conditions ◽

Mating Opportunities ◽

Males And Females

The clam shrimp Eulimnadia texana exhibits a rare mixed mating system known as androdioecy. In this ephemeral-pond branchiopod crustacean, males coexist with hermaphrodites, which can outcross with males or self-fertilize. We provide an estimate of the longevity of males relative to hermaphrodites (1 σ), an important parameter of a model that was developed to explain the conditions under which this system would be stable. Under both optimal rearing conditions and various sex-ratio treatments, hermaphrodites from two study populations lived significantly longer than males. Since various aspects of mating have been found to be costly to males and females/hermaphrodites in other taxa, we explored this possibility as well. Hermaphrodites showed no differences in longevity when kept in groups provided with different mating opportunities. Males, however, lived significantly longer when mating opportunities were increased, a result contrary to what we had expected. Behavioral observations, however, suggested that malemale interactions may have been deleterious to males living in groups with little opportunity to mate. This was confirmed by an additional study in which individual males were maintained in the presence and absence of hermaphrodites. Under these conditions we still detected no longevity cost of mating for males.

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Mixed mating system and variable mating patterns in tropical woody bamboos

BMC Plant Biology ◽

10.1186/s12870-019-2024-3 ◽

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.

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Mixed Mating System Are Regulated by Fecundity in Shorea curtisii (Dipterocarpaceae) as Revealed by Comparison under Different Pollen Limited Conditions

PLoS ONE ◽

10.1371/journal.pone.0123445 ◽

2015 ◽

Vol 10 (5) ◽

pp. e0123445 ◽

Cited By ~ 4

Author(s):

Naoki Tani ◽

Yoshihiko Tsumura ◽

Keita Fukasawa ◽

Tomoyuki Kado ◽

Yuriko Taguchi ◽

...

Keyword(s):

Mating System ◽

Mixed Mating ◽

Mixed Mating System

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Plant mating systems and assessing population persistence in fragmented landscapes

Australian Journal of Botany ◽

10.1071/bt06142 ◽

2007 ◽

Vol 55 (3) ◽

pp. 239 ◽

Cited By ~ 49

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.

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

Genetics ◽

10.1093/genetics/96.1.275 ◽

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.

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