Sex and Parthenogenesis: Evolutionary Ecology of Reproductive Modes in Non-Marine Ostracods

Guayule (Parthenium argentatum Gray, Asteraceae) is a latex-producing perennial desert shrub that is potentially of economic importance as an industrial crop for the desert Southwest. It is known to possess complex reproductive modes. Diploids are predominantly sexual and self-incompatible, while polyploids show a range of apomictic potential and self-compatibility. This paper describes the development of a relatively rapid and simple technique for characterizing reproductive modes of breeding lines of P. argentatum. Initial field experiments were based on an auxin test used successfully to characterize reproductive mode in the Poaceae. The application of 2,4-dichlorophenoxyacetic acid inhibited embryo formation in P. argentatum, but this was not the case with other auxins tested. Results of field experiments were ambiguous because: 1) the floral structure of P. argentatum is such that auxins might not have penetrated to the ovules, and 2) there was potential self-fertilization by pollen released within isolation bags. Therefore, in vitro culture of flower heads was tested because it provided much better control of environmental conditions, growth regulator application, and pollen release. Auxin alone, or in combination with gibberellic acid or kinetin, inhibited parthenogenesis in vitro. Embryo production did not vary using two substantially different nutrient media. In vitro flower head culture using a (Nitsch and Nitsch) liquid nutrient medium without growth regulators, enabled characterization of the reproductive mode of seven breeding lines, ranging from predominantly sexual to predominantly apomictic. The results of this technique were substantiated using RAPD analyzes of progeny arrays from controlled crosses.

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Supplemental Material: Fossilized reproductive modes reveal a protistan affinity of Chitinozoa

10.1130/geol.s.12735848.v1 ◽

2020 ◽

Author(s):

Yan Liang ◽

et al.

Keyword(s):

Reproductive Modes

Extended introduction to the materials and methods, Figures S1–S4, Tables S1 and S2, and supplemental movies (Movies S1–S3).<br>

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The Biology of Lakes and Ponds

10.1093/oso/9780198713593.001.0001 ◽

2017 ◽

Cited By ~ 5

Author(s):

Christer Brönmark ◽

Lars-Anders Hansson

Keyword(s):

Evolutionary Ecology ◽

Global Climate ◽

Biodiversity Loss ◽

Environmental Threats ◽

Freshwater Organisms ◽

Abiotic Constraints ◽

Abiotic And Biotic Factors ◽

The Individual ◽

Degraded Ecosystems ◽

Behavioural Adaptations

The Biology of Lakes and Ponds focuses on the interactions between the abiotic frame, such as turbulence, temperature, pH and nutrients, and the organisms, including interactions with and among organisms at the individual, population and community level. The book fills this niche between traditional limnology and evolutionary ecology by focusing on physiological, morphological and behavioural adaptations among organisms to abiotic and biotic factors and how interactions between biotic processes and abiotic constraints determine the structure and dynamics of lake and pond systems. In addition, the book describes and analyses the causes and consequences of human activities on freshwater organisms and ecosystems and covers longstanding environmental threats, such as eutrophication and acidification, as well as novel threats, such as biodiversity loss, use of everyday chemicals and global climate change. However, also signs of improvement and the possibilities to restore degraded ecosystems are discussed and provide hope for future generations.

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Introduction

10.1093/oso/9780199688678.003.0001 ◽

2018 ◽

Author(s):

Graeme D. Ruxton ◽

William L. Allen ◽

Thomas N. Sherratt ◽

Michael P. Speed

Keyword(s):

Evolutionary Ecology ◽

The State ◽

Warning Signals ◽

The Many

In 2004, the first edition of ‘Avoiding Attack: The Evolutionary Ecology of Crypsis, Warning Signals, and Mimicry’ by Ruxton et al. was published. The book aimed to provide a systematic and up-to-date review and synthesis of widespread anti-predator defences. In it, we focussed on sensorially mediated defences and the many factors that underpin these adaptations, aiming to set out the state-of-understanding in the fascinating world of anti-predator adaptations, and highlight which topics within the field seem most ripe for further investigation....

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