Fingerprinting the genetic variation and intergeneric hybrid dynamics in the family Asteraceae (genera Helianthus, Echinaceae, Tagetes and Verbesina) using iPBS markers

Abstract

Transposable elements constitute a large fraction of plant genomes and represent a powerful marker tool for genetic diversity studies. Here, the retrotransposon-based marker method inter primer binding sites (iPBS) was used to assess the genetic variation and intergeneric hybrid dynamics in the family Asteraceae by studying genera Helianthus, Echinaceae, Tagetes, Tithonia and Verbesina. Two selected iPBS primers (2222 and 2224) detected intergeneric polymorphism in the range 44.8% - 93.3% (mean 70%) and 85.7% - 100% (mean 89.5%) respectively. Moreover, iPBS markers allowed the genetic discrimination at within-species level between varieties of H. annuus (35.7% and 19.1%) but also between single cross’s segregating intergeneric hybrids (28.6% and 40%). The inheritance of iPBS markers and the parental genomes respectively in intergeneric hybrids of H. annuus has been manifested by the non-random elimination of markers mainly of origin of wild species and the preferential inheritance of markers unique to H. annuus. Such instability evidences genomic reconstruction involving LTR elements. In conclusion, the iPBS method stands as a reliable approach for the evaluation of genetic diversity of Asteraceae germplasms and perspective for use in the breeding practice of sunflower and related species.