RAPD and ISSR markers in the evaluation of genetic divergence among accessions of elephant grass

Genetic diversity of Poa pratensis L. depending on geographical origin and compared with genetic markers

BACKGROUND

Poa pratensis is one of the most common species of meadow grass in Europe. Most cultivars of the species found in Poland were originally derived from its ecotypes. We compared the effectiveness of the RAPD and ISSR methods in assessing the genetic diversity of the selected populations of P. pratensis. We examined whether these methods could be useful for detecting a possible link between the geographical origin of a given population and its assessed genetic variation.

METHODS

The molecular markers RAPD and ISSR were used and their efficiency compared using, inter alia, statistical multivariate methods (UPGMA and PCA).

RESULTS

The low value of Dice's coefficient (0.369) along with the significantly high percentage of polymorphic products indicates a substantial degree of genetic diversity among the studied populations. Our results found a correlation between the geographical origin of the studied populations and their genetic variations. For ISSR, which proved to be the more effective method in that respect, we selected primers with the greatest differentiating powers correlating to geographical origin.

DISCUSSION

The populations evaluated in this study were characterized by a high genetic diversity. This seems to confirm the hypothesis that ecotypes of P. pratensis originating from different regions of Central Europe with different terrain structures and habitat conditions can be a source of great genetic variability.

Application of ISSR markers for verification of F₁ hybrids in mungbean (Vigna radiata)

Mungbean improvement via hybridization requires the identification of true F(1) hybrids from controlled crosses before further generations of selfing/crossing and selection. We utilized inter-simple sequence repeat (ISSR) markers for identifying putative F(1) hybrids from six cross combinations whose morphological characteristics were very similar to those of their respective female parents and could not be visually discriminated from the self-pollinated progeny. Based on 10 ISSR primers, polymorphisms were found between female and male parents of all six cross combinations. The highest value of genetic differentiation (21.4%) was found between male and female parents of the SUT3 x M5-1 cross. These 10 ISSR primers gave 2.8-25.0% polymorphism between male and female parents, with a mean of 12.1%, and 0-13.0% polymorphism between F(1) hybrid and female parents, with a mean of 4.8%. F(1) hybrids of all six cross combinations could be differentiated from the self-pollinated progeny of their female parents by using only either ISSR 841 or 857 primers, together with the ISSR 835 primer. We conclude that ISSR markers are useful and efficient for identifying mungbean F(1) hybrids in controlled crosses from different genetic background.

Inter- and intra-specific genetic diversity of Iranian yarrow species Achillea santolina and Achillea tenuifolia based on ISSR and RAPD markers

Cultivation and preservation of yarrow has recently attracted wide attention due to its beneficial properties; however, genetic variation of Achillea species is still relatively unknown. We used RAPD and ISSR markers to assess genetic diversity in 16 accessions of yarrow belonging to two species native to Iran. Seven ISSR and nine RAPD primers generated 187 amplified fragments, of which 159 were polymorphic. The similarity coefficient among Achillea tenuifolia accessions ranged from 61 to 86%, and from 40 to 84% among A. santolina accessions. A low similarity was observed between these two species (mean similarity = 0.36%). This low similarity is consistent with their geographical distribution. According to the results of cluster and PCA analyses, the two species completely separated from each other. These markers will aid in the identification of elite genotypes for domestication and breeding programs.