Isozyme, randomly amplified polymorphic DNA (RAPD), and restriction fragment-length polymorphism (RFLP) markers used to deduce a putative parent for the 'Braeburn' apple

Information about a rare allele of phosphoglucomutase (PGM) that is shared by 'Braeburn' and 16% of cultivars in the New Zealand Cultivar Collection was combined with historical information about cultivar distribution to select a set of 15 cultivars for a more detailed genetic analysis of their relatedness to the key New Zealand apple (Malus domestica Borkh.) 'Braeburn'. DNA from all 16 cultivars was examined by RFLP analysis using 41 probe-enzyme combinations and also by RAPD analysis with 39 selected primers. The RFLP and RAPD data excluded a proposal that 'Lady Hamilton' and 'Braeburn' are genetically identical. All cultivars except 'Lady Hamilton' were excluded as potential parents for 'Braeburn' based on incompatible RFLP banding. Assessment of genetic distances between 'Braeburn' and the other 15 cultivars from RFLP and RAPD data demonstrated that 'Lady Hamilton' was more closely related to 'Braeburn' than all others. We conclude that there is a high likelihood that 'Lady Hamilton' is one of the parents of 'Braeburn'.