Page 5 - Rice Genomics and Genetics

Rice Genomics and Genetics 2012, Vol.3, No.4, 19-24
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which was restricted the application of YS-type
Japonica CMS line.
Molecular marker-assisted selection, a tool for crop
improvement, makes up for the traditional selection
techniques for low accurate rate in crop breeding. The
basic principle is to screen the target gene or the
whole genome from the selected individuals by using
the molecule markers which was tightly linked or
co-separation. Consequently, it can reduce the chain
cumbersome to obtain the desired individual and to
improve the breeding efficiency. Using the restorer
gene linkage the target gene of candidate plant with
marker-assisted selection, we chose the plants with
these two restorer genes. In the case of existing these
two fertility restorer genes, molecular markers
detection showed that the offspring seed-setting rate is
highest, more than 60%; whereas, when these two
genes was absent, the offspring of seed-setting rate
was only 20%, the correlation between genotype and
phenotype was very high. Studies have shown that the
selection result was reliable by using SSR markers
RM10353 and RM6100 on Rf3, Rf4 (Qi et al., 2008).
Therefore, we employed the Japonica rice material
with wide compatibility and WA-type restorer line
crossing using molecular marker-assisted selection of
RM10353, RM6100 to breed Japonica rice restorer
lines, which can be the restorer lines of restor the
Japonica rice YS-CMS. In this paper, we discussed
the application of technique f molecular marker-assisted
selection for breeding restorer lines.
1 Result and Analysis
1.1 Results of molecular marker-assisted selection
Using molecular markers RM10353, RM6100 for the
homozygousp in Japonica rice wide compatibility
materials with Wanlun 422 and Indica WA-type
restorer line Shuhui 527, Miyang 42, Miyang 46, the
amplification product was about 180 bp and 160 bp,
respectively. Their hybrid offspring F2, F4 restorer
genes were detected by these two molecular markers
(Table 1; Figure 1). In accordance with the requirements
on the selection, the agronomic traits of plants were
investigated, when both were containing Rf3, Rf4 gene
markers. we selected the plant based on the plant type,
seed-setting rate, as well as took the reference
condition for the gametophyte generation resistance
the premature aging, disease and insect resistance. The
selected plants were crossed with the sterile lines
to carry out the fertility restoration in the field
experiments.
1.2 Detection results of testcross and the fertility of
pollen
The number of 113 pairs in testcross was obtained in
winter of 2008 in Hainan, and the gametophyte
generations F1 were planted in Shenyang in 2009. The
bagged selfing seed-seting rate of was more than 60%,
which was 26.6% in the total combinations (Table 2).
The pollen fertility was positive correlation with the
Figure 1 Two pairs of marker primers for PCR amplified
electrophoresis of restorer gene
Note: A: Primer RM6100 amplified 10 strains; B: Primer
RM10353 amplified 10 strains
Table 1 Marker test results of restorer genetic in F2, F4 groups
Crosses Groups Tested
plants
Contain Rf3 Contain Rf4 Contain Rf3,
Rf4
Not contain Rf3,
Rf4
Numbers of
harvesting
Wanlun422×Shuhui527 F2 69 8 13 41 7 15
Wanlun422×Miyang42 38 5 12 20 1 13
Wanlun422×Miyang46 56 29 21 5 1 4
Wanlun422×Shuhui527 F4 525 47 60 406 12 126
Wanlun422×Miyang42 382 36 51 287 8 97
Wanlun422×Miyang46 358 202 59 92 5 58
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