Maize Genomics and Genetics 2015, Vol.6, No.2, 1-5
2
Figure 1 Dendrogram of maize inbred lines generated from the
genotyping result of 200 SNP markers
Table 1 Clustering of maize inbred lines based on diversity in
SNP markers
Cluster
Line
Cluster I
16 sub-
clusters
a
4001
b
88069
c
ATP S9 36Y-1
d
ATP S5 31Y-2
e
CLA 135
f
CLA 183
g
CML 332
h
CML 486
i
CML 534
j
Ku 1414
k
CML 435, CML 434
l
CML 304, CML 479
m
ATP S8 30Y-2, ATP S8 26Y-2
n
ATP 50, ATP S9 30Y-1,
D300-17, 9450, CML 533
o
CML 535, CML 439, CML 437,
CML 533
p
Cam Inb gp1 17, ATP 32, ATP S6
31Y-BB, Cam Inb gp1 17 (F)
Cluster II
ATP S6 31Y-1
ATP S6 20Y-1
the inbred lines used as heterotic testers in the next
chapter were colored in red (Figure 2).
1.2 Genetic distance among inbred lines
The genetic distance among the inbred lines varied
from 0.1 observed between CML 535 and CML 439 to
0.4 (Table 2). The genetic distance between inbred
88069 and most of the ATP lines (from number 4 to 13)
was 0.4. The genetic distance between 4001, 88069,
9450 and Cam Inb gp1 17 varied from 0.3 to 0.4.
2 Discussion
The description of maize inbred lines based on
molecular analysis is the one way of identify the little
difference between each of them. The molecular
markers were used to get more information on the
inbred lines of the study. The IRAD lines were
interspersed between the introduced inbred lines on
the dendogram. Two major groups were identified.
ATP S9 36Y-1 and ATP S5 31Y-2 were the only lines
in the main cluster II. They are local inbred lines from
IRAD. The main group I was subdivided into 16
sub-clusters. The genotypes in red are the lines used in
the next chapter as testers (Cam Inb gp1 17, 9450,
4001 and 88069). These were found to be in different
sub-clusters in group I. The genetic distance among
these testers varied from 0.3 to 0.4 indicating that they
were closely related. Genetic distance varied from 0.1
to 0.4 for the 30 inbred lines. The minimum distance
(0.1), indicating closely related inbred lines, was
between Cml 439 and Cml 535. Sserumaga et al.,
(2014) found that gene diversity ranged from 0. 18 to
0.92 between maize inbred lines with under adapted
regimes of water.
Tester 9450 was genetically similar to several
CIMMYT Cml lines and was closely related to Cam
Inb gp1-17 but the hybrid between these two testers
was the highest yielding in stressed plots in (Tandzi et
al., 2015). Testers 88069 and 4001 were in adjacent
sub-clusters suggesting that they are genetically very
close but their hybrid was the highest yielding under
control conditions (Tandzi et al., 2015) indicating that
they are in different heterotic groups. The results here
again demonstrate that genetic distance as measured
by molecular markers is not associated with heterosis.
The prediction of the heterosis effect of the crosses
between these inbred lines would have been in a
negative way. According to Warburton et al. (2002)
