Improvement of yam through breeding is difficult because

Improvement of yam through breeding is difficult because it possesses no sexual reproductive system. Unlike many other crops, yam does not produce flowers or seeds that can be used in conventional breeding techniques. Instead, yam is propagated vegetatively, which means that new plants are grown from sections of the tuber. This makes it difficult to introduce new genetic material into yam populations and to create new varieties with desirable traits. Additionally, yam plants are often heterozygous, which means that their genes do not segregate in a predictable manner, making it difficult to select for specific traits through breeding. Therefore, improving yam through breeding is a time-consuming and difficult process that requires a lot of expertise and resources.