Question

Interspecific crosses are rare in nature and intergeneric crosses almost unknown. Why?

Answer 1

Interbreeding is a major criterion for members of any species. If two individuals can not breed, they cannot be termed to belong to the same species. Hence, interspecific crosses are rare in nature. The same logic applies to intergeneric crosses. The main reason lies in the difference in the number of chromosomes in the cells of different organisms. Due to this, a viable zygote cannot be formed by two gametes having different numbers of chromosomes. But artificial hybridization is frequently used to produce interspecific and intergeneric crosses; especially for producing better varieties of plants.