Molecular Plant Breeding 2015, Vol.6, No.19, 1
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Table 1 The studied
Dracocephalum thymiflorum
populations, their geographical features and voucher number.
Province
Locality
Altitude (m)
Longitude
Latitude
Voucher number
1
Mazandran
Amol-Namarestaq
2370
520328.8
360328.8
HSBU- 2014370
2
Mazandran
Savad-kooh
2225
525550
355006
HSBU- 2014371
3
Mazandran
Kelardasht
3100
511667
365167
HSBU- 2014372
4
Mazandran
Siyah bishe
2200
511818
361304
HSBU- 2014373
5
Mazandran
Ramsar
21
503025
363430
HSBU- 2014374
Table 2 Genetic diversity parameters in
Dracocephalum thymiflorum
populations.
Pop
N
Na
Ne
I
He
UHe
%P
Hs
Pop1
12.000
1.478
1.400
0.369
0.243
0.253
73.91
0.294
Pop2
12.000
1.435
1.283
0.282
0.181
0.189
60.87
0.233
Pop3
12.000
0.957
1.187
0.201
0.125
0.131
47.83
0.195
Pop4
12.000
1.326
1.282
0.270
0.173
0.181
63.04
0.220
Pop5
7.000
0.957
1.179
0.195
0.120
0.130
47.83
0.195
Na = No. of alleles, Ne = No. of effective alleles, He = Gene diversity, Uhe = Unbiased gene diversity, %P = Percentage of
polymorphism, and Hs = Genetic diversity due to populations. Populations 1-5 are according to Table 1.
AMOVA test revealed significant molecular difference
(PhiPT = 0.27, P = 0.01) among the studied populations.
It showed that 25% of total genetic variability occurred
due to among populations genetic difference, while
75% due to within population genetic variability.
Pairwise Fst values obtained for the studied populations
were significant for most of the studied populations (P
= 0.01). This indicated genetic divergence of all
studied populations (Table 3). High Hickory theta B
value (0.35) obtained supported AMOVA result.
The population genetic differentiation analysis revealed
G'st_est = 0.283, P = 0.001, and D_est = 0.010, P =
0.001 and CVA plot separated each population based on
its genetic variance (Figure1). These results indicate
that the populations studied are genetically differentiated.
1.2 Populations’ genetic affinity
The grouping of the populations by NJ tree and Ward
clustering produced similar results. Therefore, the
Ward dendrogram is only presented here (Figure 2).
Almost all plants of each population were grouped
together in a distinct cluster. This result is in agreement
with AMOVA result and revealed the populations
,
genetic divergence in
Dracocephalum thymiflorum
.
Moreover, it showed the use of ISSR molecular markers
in population genetic studies of this species.
Two major clusters were formed. The populations 1
and 2 showed higher degree of genetic affinity and
were placed close to each other in the first major
cluster. The populations 3-5 were placed in the second
major cluster and showed some degrees of intermixture.
The PCoA plot is presented in Figure 3 The plants of
population 2 have been distributed in the left corner of
this plot, separated from the other studied populations.
This showed genetic difference of this population
from the other studied populations. Moreover, this
population showed a high level of within-population
genetic variability, and its plants are distributed from
top to down of the PCoA plot.
The plants of population 1 were placed close to the
population 2 as also revealed by Ward dendrogram.
However, some of its plants were placed far due to
genetic difference. The plants of population 1 also
revealed a good level of within-population genetic
variability.
Plants of population 3-5 were placed close to each other,
with plants of population 3 intermixed with the plants
of populations 4 and 5. This population also showed
high level of genetic variability as they were scattered
from left side to right side of the PCoA plot. In
general, PCoA plot revealed high within and between
population genetic variability in
Dracocephalum
thymiflorum
population, that is good from conservation
point of view.
