Kentucky State University
Assessment of the Utility of ISSR Markers for Evaluating Genetic Diversity in Asimina and Annona Species
Institution
Kentucky State University
Faculty Advisor/ Mentor
Kirk Pomper; T.S. Kochhar
Abstract
The genus Asimina is the only temperate representative of the tropical Annonaceae, or Custard Apple family, and includes eight species that are indigenous to North America. The best-known species is Asimina triloba (L.) Dunal, the North American pawpaw, which has the largest edible fruit native to the United States. The USDA National Clonal Germplasm Repository for Asimina species is located at Kentucky State University (KSU); therefore, assessment of genetic diversity is an important research priority for KSU. The inter-simple sequence repeat PCR (ISSR-PCR) methodology has been used successfully to characterize genetic diversity within and among populations of many plant species. The objective of this study was to assess the utility of ISSR markers in evaluating genetic diversity in members of the Asimina genus, as well as closely related tropical relatives in the Annona genus. Leaf samples were collected from three plants each of Asimina longifolia, A. obovata, A. parviflora, A. reticulata, A. tetramera and A. triloba. Leaf samples were also collected from three plants each of Annona cherimola, A. squamosa, A. reticulata, A. muricata, A. glabra, A. diversifolia, and A. montana. DNA was extracted from leaf samples and subjected to ISSR-PCR using the REDExtract-NAmp™ Plant PCR Kit. DNA samples were screened with ISSR primers using the University of British Columbia microsatellite primer set #9. Three primers, UBC812, UBC841, and UBC873 were found to produce 84 scorable ISSR markers and allowed the determination of genetic relationships among Asimina and Annona members examined.
Assessment of the Utility of ISSR Markers for Evaluating Genetic Diversity in Asimina and Annona Species
The genus Asimina is the only temperate representative of the tropical Annonaceae, or Custard Apple family, and includes eight species that are indigenous to North America. The best-known species is Asimina triloba (L.) Dunal, the North American pawpaw, which has the largest edible fruit native to the United States. The USDA National Clonal Germplasm Repository for Asimina species is located at Kentucky State University (KSU); therefore, assessment of genetic diversity is an important research priority for KSU. The inter-simple sequence repeat PCR (ISSR-PCR) methodology has been used successfully to characterize genetic diversity within and among populations of many plant species. The objective of this study was to assess the utility of ISSR markers in evaluating genetic diversity in members of the Asimina genus, as well as closely related tropical relatives in the Annona genus. Leaf samples were collected from three plants each of Asimina longifolia, A. obovata, A. parviflora, A. reticulata, A. tetramera and A. triloba. Leaf samples were also collected from three plants each of Annona cherimola, A. squamosa, A. reticulata, A. muricata, A. glabra, A. diversifolia, and A. montana. DNA was extracted from leaf samples and subjected to ISSR-PCR using the REDExtract-NAmp™ Plant PCR Kit. DNA samples were screened with ISSR primers using the University of British Columbia microsatellite primer set #9. Three primers, UBC812, UBC841, and UBC873 were found to produce 84 scorable ISSR markers and allowed the determination of genetic relationships among Asimina and Annona members examined.