The fruit peach originated in China and has a history of domestication of more than 4000 years. Numerous local cultivars were selected during the long course of cultivation, and a great morphological diversity exists. To study the diversity and genetic background of local peach cultivars in China, a set of 158 accessions from different ecological regions, together with 27 modern varieties and 10 wild accessions, were evaluated using 49 simple sequence repeats (SSRs) covering the peach genome. Broad diversity was also observed in local cultivars at the SSR level.
In this study, 33 homeodomain-leucine zipper (HD-ZIP) genes were identified in peach using the HD-ZIP amino acid sequences of Arabidopsis thaliana as a probe. Based on the phylogenetic analysis and the individual gene or protein characteristics, the HD-ZIP gene family in peach can be classified into 4 subfamilies, HD-ZIP I, II, III, and IV, containing 14, 7, 4, and 8 members, respectively. The most closely related peach HD-ZIP members within the same subfamilies shared very similar gene structure in terms of either intron/exon numbers or lengths.
DNA markers have useful applications in cultivar identification. A novel analysis approach called cultivar identification diagram (CID) was developed using DNA markers in the separation of plant individuals. This new strategy is less time- and cost-consuming, has reliable results, and was constructed for fingerprinting. Ten 11-mer primers were used to amplify the genotypes; all 95 peach genotypes (from the National Peach Germplasm Repository, in Nanjing, China) were distinguished by a combination of 54 primers.
We identified 131 AP2/ERF (APETALA2/ethylene-responsive factor) genes in material from peach using the gene sequences of AP2/ERF amino acids of Arabidopsis thaliana (Brassicaceae) as probes. Based on the number of AP2/ERF domains and individual gene characteristics, the AP2/ERF superfamily gene in peach can be classified broadly into three families, ERF (ethylene-responsive factor), RAV (related to ABI3/VP1), and AP2 (APETALA2), containing 104, 5, and 21 members, respectively, along with a solo gene (ppa005376m).