Maternal Temperature Imposes a Longer-Term Effect on Seedling Emergence Than Does Genetic Variation in Seed Dormancy

Area of Science:

• Plant Science
• Ecology
• Agronomy

Background:

• Seed dormancy is a key factor regulating plant germination timing.
• The interplay between genetic variation, maternal environment, and seed dormancy on germination timing requires further investigation.
• Weedy rice poses a significant agricultural challenge, making its emergence dynamics crucial to understand.

Purpose of the Study:

• To investigate the influence of maternal temperature during seed maturation and genetic variation on weedy rice seedling emergence.
• To assess the long-term effects of maternal factors and global warming on weedy rice emergence patterns.

Main Methods:

• Field experiments were conducted over four years using weedy rice seeds from groups with varying dormancy levels.
• Maternal temperature was assessed through yearly field temperature fluctuations.
• Seedling emergence was monitored in a field environment.

Main Results:

• Genetic variation significantly affected seedling emergence, particularly during unfavorable seasons.
• Higher maternal temperatures delayed seedling emergence in favorable seasons.
• Global warming has demonstrably impacted weedy rice seedling emergence over the past 15 years, with continued effects predicted.

Conclusions:

• Maternal effects, especially at higher temperatures, have lasting impacts on seedling emergence.
• Global warming, coupled with maternal effects, is likely to exacerbate challenges in managing weedy rice emergence.
• Understanding these factors is critical for developing effective weed management strategies under changing climate conditions.