Maternal effects on progeny in Thymelaea hirsuta

Area of Science:

• Plant reproductive biology
• Ecology
• Evolutionary botany

Background:

• Thymelaea hirsuta, an evergreen desert shrub, exhibits three primary gender variants: stable females, protandrous, and protogynous individuals.
• These gender variants influence reproductive strategies and potentially offspring development.
• Understanding the interplay between maternal phenotype, habitat, and progeny traits is crucial for desert plant ecology.

Purpose of the Study:

• To investigate the effects of maternal gender phenotype and desert habitat on seed and seedling traits in Thymelaea hirsuta.
• To determine if maternal habitat and gender influence seed mass, germination, emergence, growth, and survival.
• To explore potential differential selection pressures acting on the distinct maternal gender phenotypes.

Main Methods:

• Seed collection from three maternal gender phenotypes across six diverse Egyptian desert habitats.
• Laboratory and botanic garden experiments evaluating seed and seedling traits (mass, germination, emergence, growth, survival).
• Statistical analysis to assess the significant effects of maternal habitat, gender phenotype, and their interaction.

Main Results:

• Maternal habitat significantly affected most seed and seedling traits.
• Seedling height after 30 days varied significantly between habitats and maternal gender phenotypes.
• Progeny from stable females and plants originating from saline/non-saline depressions exhibited greater height.

Conclusions:

• Both maternal habitat and gender phenotype play significant roles in shaping progeny traits in Thymelaea hirsuta.
• A notable interaction between maternal habitat and gender phenotype was observed for progeny height and germination.
• The findings suggest that natural selection may differentially favor the three maternal gender phenotypes based on environmental conditions.