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Genomics and Applied Biology, 2011, Vol.2 No.6
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Research Report Open Access
Construction of the Near-Isogenic Lines of the MI CMS Restorer Gene in
Rapeseed (
Brassica napus
) and Allelic Analysis
Weihua Long , Maolong Hu , Jianqin Gao , Huiming Pu , Song Chen , Jiefu Zhang , Cunkou Qi
The Industry Crops Institute of Jiangsu Academy of Agriculture Science, Nanjing Branch of National Improvement Center of Rapeseed, Nanjing, 210014, P.R.
China
Corresponding author, puhuiming@126.com;
Authors
Genomics and Applied Biology 2011, Vol.2 No.6 doi: 10.5376/gab.2011.02.0006
Received: 20 Nov., 2011
Accepted: 09 Dec., 2011
Published: 16 Jan., 2012
This article was first published in Molecular Plant Breeding in Chinese, and here was authorized to translate and publish the paper in English under the terms of
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:
Long et al., 2011, Construction of the Near-Isogenic Lines of the MI CMS Restorer Gene in Rapeseed (
Brassica napus
) and Allelic Analysis, Genomics and
Applied Biology, 2011, Vol.2, No.6 34-41 (doi: 10.3969/gab.2011.02.0006)
Abstract
In this research, we employed Ning R7, an elite restorer for MI CMS, as the restorer gene donor to develop restorer gene
candidate near-isogenic lines (NILs) by using three elite germplasms, T78, T84 and ZS9, as recurrent parents based on the advanced
backcross approach. The characteristics of agronomic traits were phenotyped at the maturity stage and genetic similarity was
calculated based on the SSR data. The results showed most agronomic traits of the candidates had quite similar with that of recurrent
parents besides the trait of plant height and the height of the initiate branch based on t-test. Further, in order to figure out the
similarity of the genetic background, we used 75 SSR markers to generate total 157 SSR loci in the 21 candidate NILs. The average
genetic similarity coefficient of the candidate NIL background reached 0.86, 0.92 and 0.98 corresponding to their own recurrent
parent, respectively. With the comprehensive assessment, three candidate NILs, wh13
、
wh59 and wh118, were chosen as potential
restorer NILs, which might be used in our future breeding program.
Keywords
Rapeseed (
Brassica napus
L.); CMS; Restorer gene; Near-Isogenic Lines (NIL); Allelic analysis
Background
Cytoplasmic male sterility system (CMS) would be
the most important way for heterosis utilization at the
present in China. MI CMS system of
Brassica napus
type is a kind of three line breeding system developed
by Mr. Shou-Zhong Fu of Jiangsu Academy of
Agricultural Sciences with independent intellectual
property rights (Fu et al., 1989). Series of new varieties
of hybrid rapeseed, such as Ningza No1, Ningza No3
Suyou No5, Ningza No 15, Ningza No19 and Ningza
No21 were developed and released by using this
breeding system. The utilization of hybrid rapeseed in
China has been placed on the front ranks in the world
(Fu, 1999), but the genetic mechanism was just
beginning. This system of MI CMS, the restoration of
fertility was controlled by the single dominant gene
(Zhang et al., 2000), thus restoring gene should be one
of the most worthy to study in genetics. Scholars from
countries were very keen on studying restoring genes
of various Brassica napus type hybrid system by using
BC1 and or F
2
populations and DNA Bulk approach to
obtain molecular markers linked to restoring genes of
Pol CMS, Shaan 2A CMS and MI CMS systems (Jean
et al., 1997, 1998; Zeng et al., 2009; Liu et al., 2007;
Zhang et al., 2004; Zhang, 2005). It was obvious that
the researchers focused on using early separating
generations (such as BC1, F
2
) to map and clone the
genes, however, there was very little using near-isogenic
lines of the restoring gene to study the genes. Actually,
the near-isogenic lines were less utilized in the research
due to time consuming and low efficiency to building
near-isogenic lines. However, it became an unique tool
for studying the dominant genes of important traits in
crops because of near-isogenic lines with a single
genetic background, which might have more effective
to analyze genetic effects, gene fine mapping and cloning,
etc. Definitely, near-isogenic line would be the valuable
materials in the fields of molecular biology and
genetics, which were widely used in rice, corn and
other crops to have obtained the molecular markers
close linked to the target traits as well as to have
cloned the target genes (Toshiyuki et al., 2003; Zhang