Six zones of LAP activity were detected in apples, some of them tissue specific. Genetic studies in four of them revealed the presence of four genes
LAP-1, LAP-2, LAP-3 and
LAP-4 with 4, 5, 4 and 4 alleles respectively including two null alleles. There were no big differences in allelic frequency within cultivars, selections, rootstocks and
Malus species. Close linkage was found between
LAP-2 and resistance to mildew derived from
White Angel
.
Key words
Malus pumila Mill - Leucine aminopeptidase - Genes LAP-1, LAP-2, LAP-3, LAP-4
- Mildew resistance - Linkage - Breeding
Communicated by H. F. Linskens