The usefulness of random amplified polymorphic DNA (RAPD) in characterizing two perennial ryegrass (Lolium perenne L.) synthetic cultivars, `Accolade' and `Caravelle', was tested. Two out of 10 arbitrary primers produced three RAPD markers that distinguished bulk samples of 30 seedlings. Additional fragments were apparent when DNA from individual seedlings was amplified. Amplification products from bulk samples were not simply the sum of amplification products of individual seedlings and did not reflect all the diversity within or between the cultivars. The study illustrates the need to screen individuals to accurately evaluate the genotypic composition of a synthetic cultivar or heterogeneous population.
As the number of perennial ryegrass (Lolium perenne L.) cultivars increases, the development of reliable identification methods becomes more important. Randomly amplified polymorphic DNA (RAPD) markers show promise in cultivar identification. Since perennial ryegrass cultivars are composites of genotypes rather than a single genotype, finding markers that distinguish cultivars is difficult. The ideal cultivar identification procedure would use seed tissue as a DNA source and evaluate a single sample as representative of a cultivar. The objective of this research was to determine whether RAPD markers could be used to consistently distinguish bulk seed samples of perennial ryegrass cultivars. Two extraction protocols were evaluated. A quick, simple extraction resulted in the amplification of few consistent RAPD markers. The more labor-intensive extraction with hexadecyltrimethyl ammonium bromide (CTAB), however, produced more reliable RAPD markers. Eight of 11 cultivars were distinguished by using RAPD markers produced using bulk seed samples together with four of 30 primers that were screened. These results show the potential of RAPD markers to provide the turfgrass industry, breeders, and certification agencies additional options to ensure the genetic integrity of perennial ryegrass seed lots and cultivars.
This study examined the use of random amplified polymorphic DNA (RAPD) markers as a means to identify cultivars of petunia (Petunia hybrida Vilm) seedlings and cyclamen (Cyclamen persicum Mill.) seeds and to determine the genetic purity within cyclamen seeds. Bulked samples of six petunia and five cyclamen hybrid cultivars, respectively, produced consistent RAPD marker profiles. Evaluation of individual seeds from a single cyclamen hybrid produced polymorphic banding patterns that were attributed to genetic variability present in the female and male inbred parents. These results show that RAPD makers can be used to quickly assess the genetic purity of selected cultivars of these two flower seed crops.