The researchers studied 40 types of rice to see how they differ in yield and related factors. They found that there is a lot of variation among the rice types, meaning there is potential for selecting the best ones. The amount of grain produced per plant and the overall plant yield showed the most variation. These traits are mostly inherited, meaning they are passed down from parent to offspring. The number of tillers per plant and the weight of the seeds also showed high inheritance and potential for improvement. The time it takes for the rice to flower, the number of tillers, and the weight of the seeds can be improved with breeding. The researchers suggest focusing on these traits to increase rice yield.