Fig. 16.11. Barred and black plumage in poultry.
In poultry, female individual is heterogametic having only one X-chromosome (XO condition) and male is homogametic having two X-chromosomes (XX). Therefore, inheritance pattern in relation to sex will be reversed in this case.
Barred plumage is a popular example of sex linked character in poultry. In an individual, which has
barred plumage, feathers are banded with bars of
black on a white background (Fig. 16.11). Reciprocal crosses using this character will be discussed in this section.
Fig. 16.11. Barred and black plumage in poultry.
Barred ♀x
black ♂. If
barred (
B-)female individual is crossed with
black male (
bb)individual, (barred is normal and dominant over black), only
barred males and
black females are obtained in F
1 generation. When these are intercrossed and F
2 progeny is raised,
barred and
black individuals appear in 1 : 1 ratio, among male as well as female populations (Fig. 16.12).
Fig. 16.12. Inheritance of plumage character in poultry in a cross barred ♀x black ♂
Fig. 16.13. Inheritance of plumage character in poultry in a cross black ♀ x barred ♂
Black ♀ x
barred ♂
. When black female individual (
b-) is crossed with barred male (
BB)
, all progeny (male as well as female) would be barred in F, generation. In F
2 generation barred and black individuals would be found in 1 : 1 ratio among female population. All F
2 male individuals would be barred (Fig. 16.13).
