Basic HTML Version
Molecular Plant Breeding 2011, Vol.2, No.6, 37
-
40
http://mpb.sophiapublisher.com
37
Research Report Open Access
Preliminary Mapping of Soybean Dominant Locus
Hrcs7
Conferring Resistance
to
Cerocospara sojina
Race 7
Zhimin Dong , Shuming Wang , Jia Liu , Zhi Li , Zhigang Yi
Soybean Centre, Jilin Academy of Agriculture Science, Changchun, 130124, P.R. China
Corresponding author email:
dongzhimin2005@126.com;
Author
Molecular Plant Breeding, 2011, Vol.2 No.6 doi: 10.5376/mpb.2011.02.0006
Received: 29, Dec., 2010
Accepted: 25, Feb., 2011
Published: 15, Apr.., 2011
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
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)
Abstract
Molecular marker-assisted selection can significantly improved resistance breeding efficiency. The soybean frogeye leaf
spot (FLS) is caused by the fungus
Cercospora sojina
Hara. In order to find the resistant markers linked to
C. sojina
race 7 in
soybean, we carried out the resistant genetic ananlysis and the resistant locus mapping. The F
2
population derived from the cross of
‘Gang 95144-1’ and ‘Gongjiao 9723-6’ was employed to analyze the resistance genetics. it was sure that the resistance conferring to
FLS was controlled by one major dominant gene.
.
Bulk Segregant Analysis (BSA) and Simple Sequence Repeat (SSR) method were
used to map the resistant locus. Among the 600 selected SSR primers, there were four primer pairs exhibiting the polymorphisms
between DNA bulk of resistant and susceptible as well as both parents. Segregation distribution of the SSR markers, satt 414 and
satt384, were conformed significantly to be as 1:2:1.of Mendel Segregation. The marker, satt411 and satt384 were assigned to link
with the resistant locus based on estimation of MAPMAKER/EXP 3.0 software. The linkage order and distance would be Satt384
-
5.7cM
-
Satt411
-
7.9cM
-
Hrcs7
. The resistant locus was integrated to soybean linkage group E based on the Cregen
’
s genetic
linkage map of soybean.
Keywords
Soybean
(
Glycine max); Cercospora leaf spot race 7; Resistant locus;
Hrcs7
; Genetic mapping
Background
Frogeye leaf spot (FLS) is an important disease of
soybean in the world for several years (Yorinori,
1997). It is caused by
Cercospora sojina
K. Hara.
There are several races of this fungal pathogen, which
are distinguished by their ability to infect soybean
varieties. There were 12 races in America, 20 races in
Brazil, 11 races in China. But only China race 4 and
America race 1, and China race 3 and Brazil race 2
exist in similar pathopoiesia (Hu et al., 1995). Among
11 races of the fungal pathogen in China, races 1 and
7 were identified as the dominant ones, whose
incidence rate were 50% and 22% respectively.
The main symptoms of FLS are small, spots like
frogeye on the leaves. The infection lesions can also
develop on stems, pods and seeds (Sinclair and
Backman, 1989). The disease incidence favored by
hot and humid environment and it brought about the
reduction of the productivity derived from the
reduction of the photosynthetic area, premature
defoliation. Susceptible cultivars were 12%~15% in
less at average case, 30% at severe case (Akem and
Dashiell, 1994). Germination ratio of susceptible
seeds were lower, and it
’
s quality fall off, 1.2% in
protein, 2.9% in fat, 2g in thousand seed weight.
The utilizing natural genetic resistance and breeding
resistant cultivar are the most economical and efficient
means to control FLS, because the chemical control
with fungicides, in addition to being expensive, hasn't
been shown to be effective. In the process of the
traditional resistance breeding, it was aimless to select
resistant parents and segregation offspring in terms of
resistance phenotype identification. Otherwise,
resistance identification was expertise-required,
time-consuming, laboursome and environmentally
sensitive. In order to solve these problems well, DNA
markers linked to resistant genes can be used. Among
11 races of
C. sojina
recognized in China, only the
three markers Satt565, SOYGPATR, Satt396 (Zhang
et al., 2004) linked with resistance gene physiological