[Relationship between the genetic polymorphism of alkaline phosphatase and the resistance of broiler poultry to Marek's disease virus].

Studied was the polymorphism of alkaline phosphatase in blood plasma samples taken from 507 poulets and cocks of lines 66 and 77 of the Cornish breed, and lines 88 and 99 of the White Plymouth Rock breed. The birds were divided into three groups to test their resistance to Marek's disease: (1) controls, (2) infected with the virus of Marek's disease with 3 subgroups--resistant birds, slightly susceptible ones, and strongly susceptible ones, and (3) contacts, with two subgroups--survivals and birds that died. The blood plasma alkaline phosphatase was determined through horizontal electrophoresis on a starch gel, employing the method of Gahne. It was found that the alkaline phosphatase genetype FF frequency was lower with lines 66 and 77 than with line 88 and especially with line 99 of the White Plymouth Rock breed which proved most susceptible to the virus of Marek's disease. In the homozygotic alkaline phosphatase genetype SS none of the investigated lines showed any mortality. The resistance of broiler birds to Marek's disease was governed by the Akps allele, while the susceptibility was governed by the Akpf one. The former could be used as a genetic marker in the selection of initial lines of broiler birds by resistance, and the latter could be used as a marker in the selection by susceptibility.