Document Type : scientific research article
Authors
1
Department of Horticultural Sciences, Faculty of Agriculture, Ilam University. Ilam, Iran,
2
Ilam university
3
University of Guilan
Abstract
Background and objectives: Gladiolus (Gladiolus spp.) is used as a cut flower, garden ornamental plant and potted plant. Iran is one of the distribution centers of this ornamental plant. In breeding and release of new cultivars, access to diverse germplasm is a vital and essential resource for the production of new genotypes with desirable characteristics, that fortunately, the favorable distribution of Gladiolus in Iran has provided the basis for its breeding. Considering that sufficient knowledge about the amount and pattern of genetic diversity of Iran Gladiolus is necessary to understand the genetic differentiation of diverse populations, in the present research, ISSR and IRAP markers were used to evaluate genetic diversity and determine the degree of relatedness among native Gladiolus samples of Iran.
Materials and methods: In order to conduct the research, 76 samples of Gladiolus belonging to 14 populations were collected from the provinces of Ilam, Kermanshah, Hamedan and Kurdistan in the spring of 2019. The collected samples were related to two species, G. atroviolaceus and G. segetum. In order to evaluate the genetic diversity of the samples, five ISSR primers and three IRAP primers were used. After recording the genetic data, genetic diversity statistics, molecular variance analysis, cluster analysis and structure analysis were performed.
Results: Based on the results, the average of polymorphic information content (PIC), it was estimated to be 0.38 and 0.34 for ISSR and IRAP markers, respectively, and in the comparison between the used primers, ISSR5 and IRAP3 were able to show a higher potential in diversity. For the investigated populations, the Nei’s gene diversity index and Shannon's information index were 0.166 and 0.25, respectively, which showed that the populations have relatively high genetic diversity. The results of the analysis of molecular variance (AMOVA) showed that the diversity within the populations (81%) is more than the diversity between the Gladiolus populations (19%). Cluster analysis based on NJ (Nearest Neighbor) method and Jaccard similarity matrix assigned 76 Gladiolus samples into five separate groups. Also, based on structure analysis, Gladiolus samples were divided into two subpopulations.
Conclusion: The present study showed that the used markers despite were not able to separate two species from each other and there was no perfect match between genetic diversity and geographic diversity, had a significant potential in genetic differentiation of the samples. Among the primers, ISSR5 and IRAP3 showed higher efficiency based on all genetic diversity indices and are recommended for use in study and differentiating different Gladiolus samples. Also, due to the existence of significant genetic diversity within the populations, selection from within the populations is more desirable to perform crosses and achieve heterosis and is recommended for use in breeding programs.
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