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Dong et al., 2011, Preliminary mapping of soybean dominant locus
Hrcs7
conferring resistance to
Cerocospara sojina
race 7, Molecular Plant Breeding Vol.2
No.6 (doi: 10.5376/mpb.2011.02.0006)
38
race 1 and one RAPD marker OPS036 with resistance
gene against physiological race 7 (Zhou et al., 1998)
were identified. These DNA markers were insufficient
for assisted-select resistant breeding against FLS. The
main purpose of this research was to find new
molecular markers linked with resistance gene by
analyzing resistance genetic and mapping the
resistance locus against FLS.
1 Results
1.1 Inheritance of the resistance
After inoculation with
C. sojina
race 7, the FLS
reaction of the two parents, ‘Gang 95144-1’ and
‘Gongjiao 9723-6’ are significantly different. The
reaction of ‘Gongjiao 9723-6’ was susceptible and the
reaction of ‘Gang 95144-1’ was highly resistant.
Among the 184 F
2
individuals inoculated, 138
individuals were resistant and 46 individuals were
susceptible. A good fit to a 3:1 resistant:susceptible
ratio (χ
2
=1.15, P =0.868) was showed. It was
indicated that the resistance in ‘Gang 95144-1’ was
completely dominant and controlled by a single gene.
1.2 Identification of SSR markers
A total of 600 SSR primers were selected to survey
the polymorphisms between ‘Gang 95144-1’ and
‘Gongjiao 9723-6’. 24 primer pairs couldn’t obtain
amplified DNA bands, the remaining 363 primer pairs
couldn’t obtain polymorphism between the two
parents, and 213 primer pairs obtained polymorphic
bands that ranged from 100 bp to 300 bp in size.
These polymorphic primer pairs between parents were
used to detect the polymorphisms between the two
DNA bulks (Resistant and susceptible). Only 4 primer
pairs (Satt207, Satt411, Satt384 and Satt491)
exhibited polymorphisms between the two DNA bulks.
The results suggest that these markers were relevant
possibly to resistant locus to
Cerocospara sojina
race
7 in soybean.
1.3 Linkage analysis
The polymorphism markers between the two DNA
bulks were screened in the entire F
2
population to
analyze the resistance segregation. The χ
2
test was
used to analyze the genetic segregation of the 4
polymorphic primer pairs in F
2
population. The χ
2
value of the Satt411 and Satt384 marker were
respectively 1.570 and 2.562, and the P value were
respectively 0.473 and 0.317, indicating that their
maternal type
，
heterozygous type and paternal type
conformed significantly to 1:2:1 (Table 1, Figure 1
and Figure 2). The χ
2
value of the Satt207 and Satt491
marker were respectively 66.687 and 334.607, and the
P value were respectively 5.32×10
-15
and 2.19×10
-73
,
indicating that their maternal type, heterozygous type
and paternal type did not conform to 1:2:1 (Table 1).
Figure 1 DNA amplified products for the SSR marker Satt414
Note: P
1
: ‘Gang95144-1’; P
2
: ‘Gongjiao9723-6’; R: resistant
DNA bulk; S: susceptible DNA bulk; 1~30 some plants among
F
2
population derived from the cross of ‘Gang 95144-1’
בGongjiao 9723-6’
Table1 Genetic Segregation of Polymorphic SSR primer pairs between the two DNA bulk in F
2
population
Marker
Maternal type
Heterozygous type Paternal type
No band Total (plant)
χ2 (1
:
2
:
1)
P
Satt207
62
24
61
37
184
66.687
5.32×10
-15
Satt411
52
85
42
5
184
1.570
0.473
Satt384
50
75
44
15
184
2.562
0.317
Satt491
19
5
144
16
184
334.607
2. 19 ×10
- 73