Comparative study of the discriminating capacity of dna markers and their effectiveness in establishing genetic relationships in the genus tigridia

Abstract

Tigridia Jussieu is an endemic genus to Mexico and taxonomically difficult with limited information about its genetic variability. A diversity assessment conducted using different DNA markers as an inter simple sequence repeat (ISSR) and random amplified polymorphic DNA (RAPD) markers will be helpful in the establishment of a broad- based description for improved germplasm curation and the identification of germplasm for genome mapping and breeding of these species. Thus, the objective of this study was to characterize 15 wild species of Tigridia by using RAPD and ISSR molecular markers. This study was carried out in the laboratory of Plant Molecular Biology at the Faculty of Agricultural Sciences of the Universidad Autónoma del Estado de México between August and November of 2011. In this assay, 13 RAPD primers of 10, 15 and 20 b, and five ISSR primers of the anchored type (ASSR) of 17 b were used to assess the level of genetic variation among 15 wild species of Tigridia . With both markers there were 163 amplified bands of which 150 (92.02 %) were polymorphic. The RAPD primers of 10 b generated 12 specific bands with a polymorphism of 95.12 %, for 15 b primers those values were five and 82.93 %, and for 20 b primers eight and 94.59 %, respectively. The RAPD pooled primers presented a polymorphism of 90.76 %, the genetic distance (G D ) among the species ranged from 0.16 (between T. illecebrosa and T. huajuapanensis ) to 0.57 (between T. multiflora and T. augusta ). The ISSR primers showed more polymorphism(95.45 %) than RAPD primers. With ASSR primers the highest genetic association (G D = 0.89) was observed between T. mexicana ssp. mexicana and T. durangense , whereas the least related were T. vanhouttei spp. vanhouttei and T. multiflora (G D = 0.14). This study shows that 10 base random primers and 17 base anchored primers were more efficient to detect polymorphism and genetic differentiation among Tigridia species.