PEACH [PRUNUS PERSICA (L.) BATSCH] ROOTSTOCK SEEDLING IDENTIFICATION BY DNA-FINGERPRINTING WITH MICROSATELLITE (SSR) MARKERS
Peach rootstocks are usually propagated from seeds. Seedlings are difficult to distinguish morphologically, and once grafted, no above ground material is available for visual identification. To avoid misidentification and to protect plant cultivars and patents, DNA fingerprinting was investigated as a robust rootstock identification tool. The objective was to identify peach seedling rootstocks of Bailey, Guardian® BY520-9 selection 3-17-7, Halford, Kakamas, Lovell, Nemaguard, Nemared and S-37. Twenty-eight SSR markers were screened on the eight rootstocks, and 23 exhibited polymorphism. Ten SSR markers were found to amplify at least four patterns among the eight rootstocks. Each rootstock clone could be discriminated by as few as a single SSR marker (e.g., Lovell) or at most, nine markers (e.g., S-37). No single perfect marker was found that could differentiate all rootstocks from each other. Marker BPPCT008 had the highest identification potential because it amplified seven patterns and was capable of uniquely distinguishing six of the eight rootstocks directly. Seedling identification was conducted by screening seedlings of open-pollinated rootstock clones. It was more difficult than parent genotype identification because a heterozygous pattern for a rootstock clone segregated in its seedlings. However, unique segregated patterns were found in the rootstock seedlings. Seedlings of several rootstocks such as Bailey, Kakamas, Nemaguard and Nemared could be identified by single SSR markers. Seedlings of 3-17-7 and S-37 could be identified by marker combinations. Seedlings of Lovell and Halford were differentiated from the other rootstocks by single markers. However, there were no SSRs or marker combinations to differentiate Lovell seedlings from Halford seedlings. The SSR markers presented in this study could be used as a practical fingerprinting system for rootstock seedling identification. This technology will be useful to test rootstocks for trueness to type for nurseries and commercial peach growers, and also will be helpful in protecting seed propagated proprietary rights (i.e., PVP) for fruit tree breeders.
Liu, X., Reighard, G.L., Swire-Clark, G.A. and Baird, W.V. (2012). PEACH [PRUNUS PERSICA (L.) BATSCH] ROOTSTOCK SEEDLING IDENTIFICATION BY DNA-FINGERPRINTING WITH MICROSATELLITE (SSR) MARKERS. Acta Hortic. 962, 169-176
3-17-7, bailey, halford, kakamas, lovell, nemaguard, nemared, S-37