Molecular Plant Breeding 2016, Vol.7, No.26, 1
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The separation of DNA amplification fragment by polyacrylamide gel electrophoresis (PAGE) shown in
Figure 3
revealed the polymorphism in the population studied. The primer ladder, which is a 100- base pairs marked out the
polymorphic bands within the genotypes in each of the three primer combinations. Primer combination E- AAC +
M- CAG produced the highest number of fragments amplified and number of polymorphic bands.
Figure 3 AFLP PAGE product revealing Amplified Fragments and Polymorphic Bands
Note: AFLP: Amplified Fragments Length Polymorphism; PAGE: Polyacrylamide Gel Electrophoresis.
Polymorphic information content (PIC) of
C. argentea
at 89.1% showed that the variability in this population
exists in the organism’s genome as similarly reported by Denton (2004). This indicates these genotypes could be
useful as breeding material in the improvement of this crop. Cluster analysis and dendrogram indicate that cluster
groups consist of genotype from different geographical background and such wide adaptability has been attributed
to population genetic architecture, selection history and approach under domestic cultivation and developmental
traits (Ganapathy et al., 2011; Olawuyi et al., 2015).
3 Materials and Methods
3.1 Germplasm collection of
C. argentea
seeds
Ten
C. argentea
genotypes sourced from National Institute of Horticultural Research (NIHORT) and National
Centre for Genetic Resources and Biotechnology (NACGRAB) in Ibadan, Nigeria were; NGB 01260,
NG/MA/MAY/09/015, NHGB/09/160, NIHORT/0001, NG/MAY/09/015, NG/SA/07/213 and NHGB/01260.
3.2 Experimental locations and planting procedure
The molecular studies were carried out in Bioscience Laboratory of International Institute of Tropical Agriculture
(IITA), Ibadan, while the field experiment was conducted at the research farm of the Department of Botany,
University of Ibadan. The cultivars were raised for 2 weeks in nursery bags; thereafter fresh young apical leaves
were collected into ice bags before transported to the laboratory for molecular studies.
3.3 DNA extraction
Extraction of DNA in young apical leaves was carried out using AFLP technique to assess genetic variability of
ten
C. argentea
genotypes. Total genomic DNA was extracted from frozen leaf tissue (50 - 100 mg) using the
procedure described in D2 Bio Technologies DNA X-Tract.
3.4 DNA quantization and AFLP protocol
DNA quantization kit was used to determine DNA concentration in the final preparation using nano drop DNA
quantization. Nano drop DNA quantization showed the extracts’ ratio of absorptions at 260/280 nm. This ratio is
used to validate purity of the nucleic acids in terms of the quality and quantity of total genomic DNA extracted
from the plant samples. The AFLP protocol initially described by Vos et al. (1995) was performed using
