Genetic diversity analysis using molecular markers and in vitro shoot regeneration of strawberry cultivars in Lam Dong

Abstract

In the present study, start codon targeted (SCoT) polymorphism and CAAT box-derived polymorphism (CBDP) molecular markers were used to study the genetic diversity of ten strawberry cultivars. In addition, shoot regeneration from in vitro leaf explants of ten commercial cultivars, i.e Aicyberry, Kayonoka, Tochiotome, Penchika, Amauo, Pajado, Selva, Monterey, Camarosa, and Albion, was also investigated. The result showed that a total of 9 SCoT primers and 9 CBDP primers detected genetic polymorphism among ten strawberry cultivars. Comparatively, SCoT markers proved to be more efficient than CBDP markers in terms of percentage polymorphism as the former detected an average of 74.49% and the latter at 71.15%. Meanwhile, the indices of genetic diversity from the aggregated data of two techniques SCoT and CBDP are as follows: expected heterozygosity (He) 0.2480, Shannon index (I) 0.3749, polymorphic band ratio 75.56%. The highest level of genetic similarity among the cultivars was 0.827 (between Aicyberry and Kayonoka varieties), the lowest was 0.586 (between Aicyberry and Selva varieties), and the average was 0.724. In addition, the results of shoot regeneration of strawberry varieties from leaf discs with different sizes were strongly dependent on the genotype and weakly on explant size. Leaf explants (3 mm in size) of Camarosa cultivar cultured on MS medium supplemented with 7 g/l agar, 30 g/l sucrose and 2 mg/l TDZ gave the best shoot regeneration.