Liu, Xiaoyu , Reighard, Gregory , Swire-Clark, Ginger , Baird, Wm. Vance .
Identification of peach [Prunus persica (L.) Batsch] rootstock seedling using DNA-fingerprinting with microsatellite (SSR) markers.
DNA fingerprinting with microsatellite (simple sequence repeat/SSR) molecular markers was investigated as a robust tool for intra-species peach identification. Rootstocks, the belowground portion of commercial fruit trees, are usually propagated from seed. Seedlings can be very difficult to differentiate using morphological/phenotypic traits. In an attempt to avoid misidentification, this study used SSR markers to distinguish seedlings among seven common peach rootstocks: a new release 3-17-7 (GuardianTM, with tolerance to Peach Tree Short Life syndrome), its parental lines S-37 and Nemaguard, and Bailey, Halford, Lovell and Nemared. We initially screened 102 Prunus SSR markers on 3-17-7, Nemaguard, Lovell and Nemared. Seventy-five markers showed polymorphism among these four taxa. The polymorphic markers were then used to screen Bailey, Halford and S-37. Two additional seedlings from each rootstock were tested to confirm the patterns of amplified DNA. Eight SSR markers consistently distributed the seven rootstocks into as many as few as three and as five groupings. Thus, it was necessary to use a multiplex approach to uniquely identify each rootstock because no single SSR locus (evaluated thus far) was able to differentiate all seven. An additional ten independent accessions of each rootstock will be screened to confirm the reliability of the markers, and screening additional SSRs in a search for the single, perfect marker continues. To confirm the identity of the SSR markers, we cloned the polymorphic DNA fragments amplified by primer SSR-UDA014, which was developed for an AC-rich sequence originally isolated from almond [P. dulcis (Mill.) D.A. Webb]. DNA sequence analysis proved that the amplified fragments shared a common AC-enriched repeat with copy numbers ranging from 5 to 14 (sizes 133bp to 157bp). Taken together, these results demonstrate that a microsatellite-based DNA fingerprint system is capable of and has great potential for unambiguous peach rootstock identification.
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1 - Clemson University, Horticulture Department, Poole Agriculture Center, Clemson, SC, 29634-0319, U.S.A.
2 - Clemson University, Horticulture
Simple Sequence Repeats.
Presentation Type: Poster:Posters for Sections
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM