The researchers studied how well two different types of beans, Vigna radiata and Vigna umbellata, can cross with each other. They used five types of each bean and found that some crosses were successful, with the best ones being Yellowmung × KBR-1, DGGV-2× RBL-35, Selection-4×KBR-1, Chinamung × KBR-1, and BGS-9× RBL-35. These successful crosses could be used to transfer useful genes between the two bean species. They also found that there were barriers to the crosses, both before and after fertilization, and that the growth of the hybrid plants was influenced by the parent plants.