EMBRYO GROWTH AND SEED SIZE IN RAPHANUS SATIVUS: MATERNAL AND PATERNAL EFFECTS IN VIVO AND IN VITRO

Area of Science:

• Plant reproductive biology
• Developmental genetics
• Angiosperm evolution

Background:

• Theories on angiosperm seed evolution debate the influence of maternal and paternal tissues on embryo growth.
• Understanding genetic contributions is crucial for comprehending seed development and evolutionary trajectories.

Purpose of the Study:

• To investigate the relative contributions of maternal and paternal genes to embryo growth in wild radish (Raphanus sativus).
• To compare embryo performance in vivo (within fruit) versus in vitro (embryo culture).

Main Methods:

• Controlled crosses were performed in a greenhouse setting using wild radish plants.
• Maternal, paternal, and interaction effects on embryo development were analyzed.
• Embryo development was assessed both within the fruit and through embryo culture techniques.

Main Results:

• Maternal plant identity significantly influenced fruit set, seeds per fruit, embryo developmental stage, and seed weight.
• In embryo culture, maternal effects were observed for cotyledon size and embryo weight.
• Paternal effects were generally smaller in magnitude than maternal effects, influencing embryo developmental stage, seed weight, cotyledon size, and embryo weight.

Conclusions:

• Both maternal and paternal genetic factors significantly impact embryo growth in wild radish.
• Greater maternal influence in culture may stem from cytoplasmic factors or maternal nuclear genes.
• Embryo-maternal tissue interactions are complex and vary based on maternal plant and developmental stage.