Genetic Relationship Analysis And Cultivar Identification Of Blueberry Based On SSR Markers

In this study, a SSR-PCR protocol serving for blueberry{Vaccinium spp.) genetic relationship analysis and cultivar identification was established. Genetic relationship of22blueberry cultivars was analyzed using SSR (Simple Sequence Repeat) markers. A blueberry cultivar identification protocol was established. This approach would benefit for blueberry germplasm evaluation, identification and management as well as novel variety breeding.The established SSR-PCR protocol for blueberry was as follows:initial denaturation at94"C for4min;(denaturation at94℃for40s, annealing at the optimum annealing temperature of the primer pair for40s, elongation at72℃for40s) for35cycles; final elongation at72℃for8min. PCRs were performed in a20μL volume containing1.5U Taq,2.0nmol/uL Mg2+,0.25nmol/μL dNTP,0.25pmol/μL of each primer and40ng genomic DNA.15SSR markers which have unambiguous bands, high polymorphism and good reproducibility were screened.22accessions of blueberry cultivars were genotyped using these SSR markers. The amount of polymorphistic bands of each SSR marker ranged from3to13.15SSR markers produced115bands in total, of which113were polymorphistic. The polymorphistic ratio was98.26%. Genetic similarity coefficient of the22blueberry cultivars ranged from0.486to0.886. The similarity coefficient between Nui and Bluereka was the highest while the value between Jersey and Blomidon was the lowest. The dendrogram of the22cultivars was constructed using UPGMA method by NTSYSpc (2.10e). The22cultivars were clustered into2major groups. The lowbush cultivar Blomidon was seperated from the other21cultivars. The21cultivars were further clustered into2subgroups according to their ripen season. Late-season cultivar Dixi and Elliot were clustered into one subgroup while the other19early-mid season cultivars were clustered into one subgroup. This result is consistent with the pedigree and morphological characteristics of the22cultivars, which implied that the SSR marker can be used to guide cross-breeding.SSR marker NA961and NA1040were chosen as core markers for blueberry cultivar identification. These SSR markers could completely distinguish the22cultivars. The graph-fingerprint and digital-fingerprint of the22cultivars were established using these2core SSR markers. A convenient and stable blueberry cultivar identification protocol was founded.