Alleles controlling apple skin colour and incompatibility in new Czech apple varieties with different degrees of resistance against Venturia inaequalis CKE.

Abstract

The skin colour of 21 varieties was assessed on a molecular level. Four varieties had yellow skin colour with the genotype constitution a1a1, a1a2 or a2a2. Seventeen varieties had dominant red colour. Homozygous A1A1 constitution was present in 7 varieties, and heterozygous constitution A1a1 or A1a2 was found in the rest of the assessed varieties. The S-alleles controlled the incompatibility system of the pistil. Their detection is possible by means of the PCR method on the basis of allele specific primers. Six S-alleles (S1, S2, S3, S5, S7 and S9) were studied in the same collection of 21 diploid Czech varieties. This paper brings new findings on S-allele characterization, because the Czech varieties have not yet been studied on a molecular level. Both types of S-allele were found in 12 varieties. Only one type of S-allele was described in 9 varieties. Simultaneously, the presence of the Vf gene was screened in the collection of 21 Czech apple varieties. Ten varieties with a field resistance against the scab had a heterozygous constitution of the Vf gene. All 11 susceptible varieties were recessive homozygous vfvf.

Keywords

• malus
• pcr
• vf gene
• incompatibility
• s-allele
• skin colour
• a-allele