Apple genetics resources and their molecular analysis

Breeding process of apple tree is a multiyear matter. The development of molecular markers linked to the important agronomic traits has already made it possible to improve and to speed up some selection process. The aim of this work was to distinguish a group of varieties by DNA markers and to verify functionality to these markers in MAS (marker assisted selection). The 131 apple tree varieties were chosen. The chosen markers describe softening of flesh, columnar growth habit, selfincompatibility, apple skin colour and resistance to scab (Venturia inaequalis CKE). The softening of flesh is the most critical criterion for storage life. Excessive softening (related to ethylene production) is considered undesirable in apple and can lead to lower sensory values. By means of the marker gene Md-ACS1 the 29 homozygous varieties of the gene Md-ACS1-2 with very low ethylene production were found. This gene was identified by variety McIntosh Wijcik. This variety is spontaneous spot of McIntosh with normal growth habit. Chosen marker of Co gene cant differentiate these two varieties. It was determined 22 varieties, which have this marker, but these had a normal growth habit. Apple trees are heterogamous. This trait is determined by the multi-allelic Slocus. There was device to detect these S-alleles: S1, S2, S3, S4, S5, S7, S9, S10, S16, S19, S22, S23, S24 in this work. Both alleles were found out in 88 varieties. Only one allele was found in 35 varieties. In 8 varieties no allele was found. Fruit skin colour in apple is produced by a blend of carotenoids, chlorophyll and anthocyanins. The colour is controlled by Rf (Red fruit) gene. Allele A1 or A2 determinates red colouration; yellow colour is associated with allele a1 and a2. From 131 varieties 108 were established red and 21 yellow skin colour varieties. Vf gene was also detected. The donor of this gene is botanic species of Malus floribunda Sieb. clone 821. This gene provides resistance to apple scab (Venturia inaequalis CKE). Varieties with this gene can provide the donor of resistance for other breeding. Key words: apple tree, cultivated variety, DNA markers, MAS, Md-ACS1 gene, Co gene, Vf gene, Pl1 gene, S-alleles, A-alleles.