Abstract:
The maintenance of genetic diversity in the parental lines of the
Cytoplasmic Male Sterile (CMS) system is important in the development
of heterotic blocks that assures the production of high yielding hybrid rice.
The genetic diversity within the rice samples was investigated through
Hexadecyltrimethylammonium bromide (CTAB) DNA extraction,
Polymerase Chain Reaction (PCR) amplification of microsatellite markers,
Polyacrylamide gel electrophoresis (PAGE), and visualization by ethidium
bromide staining. A total of 305 alleles were detected and the
Polymorphism Information Content (PIC) ranged from 0.61 to 0.97 with
an average of 0.89. All the microsatellite markers utilized in the study
were polymorphic, however only 7 were highly informative. A graphical
genotype of the CMS lines was constructed based on the marker profiles,
which detected 34 unique alleles across 25 CMS lines with 21
microsatellite markers. Analysis of the genetic relationships among the
CMS lines produced two genetically diverse clusters separated by their
close relationship either with traditional varieties of diverse geographical
origins or International Rice Research Institute (IRRI) bred parental lines.
The results suggested that the 62 CMS lines of rice were genetically
diverse and the usefulness of microsatellites as molecular markers for
evaluating the genetic diversity of rice samples was reaffirmed. The
marker profiles presented in the form of graphical genotype aided in the
selection of appropriate markers and in the identification of selected CMS
lines through the detected unique alleles.
