PLANTING DENSITY INFLUENCES THE EXPRESSION OF GENETIC VARIATION IN SEED MASS IN WILD RADISH (RAPHANUS SATIVUS L.:...

Area of Science:

• Plant biology
• Evolutionary ecology
• Genetics

Background:

• Seed mass is a critical trait influencing plant establishment and fitness.
• Environmental factors, such as planting density, can interact with genetic factors to shape phenotypic variation.

Purpose of the Study:

• To investigate the effects of planting density, parental genotype, and their interaction on individual seed mass in Raphanus sativus L.
• To understand how environmental plasticity influences maternal and paternal effects on seed mass.

Main Methods:

• A nested breeding design was used in a greenhouse to produce seeds.
• Maternal and paternal families were grown in an experimental garden at two different planting densities.
• Individual seed mass was measured to assess the impact of density and genotype.

Main Results:

• Planting density had a strong negative effect on seed mass.
• At low density, maternal plant identity significantly affected seed mass, but this effect disappeared at high density.
• Significant genotype by density interactions were observed for both paternal and maternal families, indicating differential responses to density across genotypes.

Conclusions:

• Planting density is a major determinant of seed mass in Raphanus sativus.
• Density modulates the expression of maternal effects on seed mass.
• Genotype by density interactions contribute to the maintenance of genetic variation for seed mass in wild radish populations.