Molecular characterization of tropical maize inbred lines using microsatellite DNA markers
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Date
2014
Journal Title
Journal ISSN
Volume Title
Publisher
Maydica
Abstract
An insight on diversity and relationships among germplasm is important in any breeding program for crop improvement.
The main objectives of our study were to: (i) determine the level of genetic diversity within mid altitude maize
inbred lines resistant to weevils, aflatoxin accumulation and drought, (ii) to suggest potential heterotic groups using
their genetic structures and distance based on cluster analysis with the aim to generate broad based source germplasm
for mid altitude maize breeding program with combined traits of importance against Aflatoxin accumulation.
In this study, 25 SSR markers were used to finger print forty two maize inbred lines to assess the genetic diversity,
genetic relationships, and their population structure. A total of 184 alleles were identified at all the loci with an average
of 7.36 and a range between two and 19 alleles per locus. The major allele frequency varied from 0.17 to 0.90
with an average of 0.49 while the minor allele frequency varied from 0.10 to 0.83 with an average of 0.51. The gene
diversity values varied from 0.18 to 0.92 with an average of 0.65. Average heterozygosity percentage of the inbred
lines was 4%, ranging from 0% to 2%, indicating the low level of heterozygosity within the inbred lines. The average
polymorphism information content (PIC) was 0.61. A dendrogram constructed using unweighted Neighbour
Joining algorithm suggested three heterotic groups among the inbred lines. The three heterotic patterns based on
the SSR markers need to be verified by field testing to confirm what appears to be promising alternative heterotic
patterns. The fixed pattern detected using SSR markers could potentially contribute towards effective utilization of
the inbred lines for the exploitation of heterosis and formation of genetically diverse sources population.
Description
Keywords
Molecular characterization, Tropical maize inbred lines, Microsatellite DNA markers
Citation
Kim, H., Asea, G., Si-myung, L., Chemining’wa, G. N., Muthomi, J. W., Njoroge, K., ... & Sserumaga, J. P. (2014). Molecular characterization of tropical maize inbred lines using microsatellite DNA markers.