Researchers used a method called triple testcross analysis to study how different genes interact to affect traits like plant height, flowering time, and yield in rice plants. They found that these traits are influenced by a combination of additive and dominance effects, with additive effects being more important for some traits like plant height and yield, while dominance effects play a bigger role in traits like grain weight. Overall, the study showed that genes working together (epistasis) have a significant impact on these important characteristics in rice plants.