Gene Pool

• Sum total of all genes present in a given population is known as gene pool.
• It is of following types:

a) Primary gene pool (GP-1): Varieties of same species that can intermate freely.

b) Secondary gene pool (GP-2): Closely related species that can intercross with GP-1 and produce at least some fertile hybrid.

c) Tertiary gene pool (GP-3): Distantly related species that can intercross with GP-1 and GP-2 but requires additional measure like endosperm rescuing to obtain offspring.

How can you transfer desirable gene from GP3 to GP1.

Ans: GP3 x GP2 —>  F1 x GP1 —–>   50% BC1 x GP1 —->   75% BC2 x GP1 —->  87.5 % BC3 x GP1 —–>  BC4 x GP1 —->  BC5 x GP1 —–>  BC7x GP1—->  99.9% BC8 ( having 99.9% character of GP1).