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Environmentally Controlled Sex Expression in Meloidodera floridensis.
Journal of Nematology
|March 26, 2009
Summary
Environmental factors, particularly starvation, control sex determination in Meloidodera floridensis. Larvae develop as females when feeding but shift to male development under starvation, indicating environmental influence on this thelytokous organism.
Area of Science:
- Nematology
- Developmental Biology
- Environmental Science
Background:
- Meloidodera floridensis is a plant-parasitic nematode.
- Environmental conditions are known to influence nematode development and reproduction.
Purpose of the Study:
- To investigate the role of environmental factors, specifically nutrition, in sex determination of Meloidodera floridensis larvae.
- To understand the mechanisms controlling female and male development in this nematode species.
Main Methods:
- Larvae were cultured in tap water, on pine roots, and in soil without host plants.
- Developmental stages and sex ratios were monitored over a four-month period.
- Hormonal solutions were tested for their effect on male development.
Main Results:
- Larvae in tap water (starvation) developed into males (70-80% molted, >50% adult males).
- Larvae feeding on pine roots predominantly developed into females (96%), with few males (4%).
- Hormonal treatments and soil without host plants did not significantly induce male development.
Conclusions:
- Sex expression in Meloidodera floridensis is largely controlled by environmental factors, primarily nutrition.
- Starvation triggers male development, likely through hormonal imbalance and altered gene expression.
- Under host-feeding conditions, larvae follow their genetic predisposition for female development (thelytoky).
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