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Plant Gene and Trait 2012, Vol.3, No.7, 34
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(Zhang, 2004), genetic diversity studies (Been et al.,
2002). However, the molecular biology and genetics
of
Phalaenopsis
are still being poorly understood (Xu
et al., 2010), The genetic map and QTL analysis of
Phalaenopsis
have not been reported yet. We
constructed the molecular genetic maps of AFLP from
a hybrid population (Xu, 2010). In
Phalaenopsis
,
leaves conferring the shape and size of plant are the
most important organ of vegetative and nutrient
storage for lacking an obvious stem. In this study
three phenotypic traits of the leaves, the leaf length
(LL), leaf width (LW)
、
plant width (PW) of
Phalaenopsis
were calculated and used to establish a
QTLs mapping and to locate on the genetic linkages
of ALFP. We tried to explore a new way for the
genetic analysis of relevant functional genes, gene
cloning and marker-assisted breeding for genome
complex species.
1 Result and Analysis
1.1 The distribution of phenotypic values of
Phalaenopsis
LL, LW and PW
Statistical analysis indicated that the phenotypic
values showed a clear separation, and had a significant
reduction in variability (Table 1). The frequency
distribution further showed that they were normal
distribution (Figure 1), the distribution of the peak and
skewness were less than 2. Therefore, all these statistical
parameters showed that these three traits have typical
features of quantitative inheritance controlled by
equivalent polygenes.
Table 1 Segregation of LL, LW, and PW traits of
Phalaenopsis
progenies in the hybrid population
Traits
Parents
Mean of progenies
Variance
SD
Variation range
Kurtosis
Skewness
phal.462
phal.20
LL
25.50
13.50
16.84
5.87
2.41
8.2~23.8
1.63
0.22
LW
7.30
6.40
6.77
0.54
0.73
5.0~9.1
0.52
0.04
PW
44.50
25.50
31.95
19.81
4.42
23.2~43.6
-
0.21
0.29
Figure 1 Segregation of LL, LW, and PW traits of
Phalaenopsis
progenies in the hybrid population
1.2 Correlation analysis between the three phenotypic
traits
QTLs controlling relevant traits possibly be located in
the similar or close positions to the same linkage
group. Correlation analysis results showed that a highly
significant positive correlation was found between LL
and PW, but there were no significantly correlation
between LW and LL, LW and PW (Table 2).
1.3 QTLanalysis for LL, LWand PW in AFLP linkage
group of the paternal parent
Phalaenopsis
Total sixty QTLs conferring the three horticultural
traits LL, LW, PW were detected and they covered
eight AFLP linkage groups of the paternal parent
Phalaenopsis
(Table 3; Figure 2).
Twenty QTLs for the LL trait were detected in six linkage
groups, they were MLG
-
1, MLG
-
2, MLG
-
3, MLG
-
5,
Table 2 Correlation analysis among LL, LW, and PW traits of
Phalaenopsis
progenies
Traits
LL
LW
PW
LL
1
LW
0.08
1
PW
0.79**
0.12
1
Note: **: The correlation is significant at p< 0.01