Assessing the genetic diversity of Portuguese maize germplasm using microsatellite markers
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A collection of Portuguese maize accessions representing a valuable source of genes for introduction into modern cultivars is stored at the Portuguese Plant Germplasm Bank (Banco Português de Germoplasma Vegetal—BPGV). To assess genetic diversity among inbreds, microsatellite analysis was carried out for 54 inbred lines representing the diversity of Portuguese dent and flint maize germplasm. Fifty American and other European elite inbreds were also analysed for comparison. Fifteen microsatellite loci distributed throughout the maize genome were chosen based on their repeat unit and base composition. A total of 80 alleles were detected with an average allele number of 5.33 per locus. Polymorphism information content (PIC) values and observed genetic distances showed the existence of large variability among inbreds. Cluster analysis indicated that almost all of the inbreds could be distinguished from each other and Portuguese inbreds were present in all clusters formed. These associations were consistent with the known pedigree records of the inbreds, confirming a mixed origin of Portuguese materials. Comparative analysis of microsatellite diversity among groups was established according to important traits for both breeding and line identification. This revealed that, although most of the genetic diversity (>95%) was attributable to differences among inbreds of different groups, the existence of phenotypic differentiation in endosperm colour, kernel type and cob colour could be suggested for grouping. These findings support the joint use of molecular and morphological traits in management of the germplasm collection. In this study, SSR markers proved to be effective to characterise and identify maize inbred lines, and demonstrate associations among them.
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- Excoffier, L., 1992. WinAMOVA ver. 1.55 – analysis of molecular variance – Graphical Windows 3.x Program for the analysis of population genetic structure from molecular or conventional ge-netic data. Available at: http://anthropologie.unige.ch/LGB/soft-ware/ win/amova/.Google Scholar
- Minch, E., A. Ruiz-Linares, D. Goldstein, M. Feldman & L.L. Cavalli-Sforza, 1997. MICROSAT: A Computer Program for Calculating Various Statistics on Microsatellite Allele Data, ver. 1.5d. Stanford University, Stanford, CA. Available at: http://hpgl.stanford.edu/projects/microsat/.Google Scholar
- Pêgo, S., 1997. Resistance or tolerance? Philosophy may be the answer. In: S. Pêgo & R. Martins (Eds.), Proc. XIX Conf. of the Internat. Working Group on Ostrinia nubilalis and other maize pests, pp. 303–341. Guimarães, Portugal.Google Scholar
- Rohlf, F.J., 2000. NTSYS-pc. Numerical Taxonomy and Multivariate Analysis System, Version 2.1. Exeter Publications, NY.Google Scholar
- Romero-Severson, J., 1998. Maize microsatellite – RFLP consensus map. MaizeDB (http://www.agron.missouri.edu).Google Scholar
- Smith, J.S.C., E.C.L. Chin, H. Shu, O.S. Smith, S.J. Wall, M.L. Senior, S.E. Mitchell, S. Kresovich & J. Zeigle, 1997. An evaluation of the utility of SSR loci as molecular markers in maize (Zea mays L.): Comparison with data from RFLPs and pedigree. Theor Appl Genet 95: 163–173.CrossRefGoogle Scholar