Fine mapping of a recessive genic male sterility gene (Bnms3) in rapeseed (Brassica napus) with AFLP- and Arabidopsis-derived PCR markers

Abstract

9012AB, a recessive genic male sterility (RGMS) line developed from spontaneous mutation in Brassica napus (Chen et al. in Acta Agron Sin 24:431-438, 1998), has been playing an increasing role in hybrid cultivar development in China. The male sterility of 9012AB is controlled by two recessive genes (designated Bnms3 and Bnms4) interacting with one recessive epistatic suppressor gene (esp). Previous study has identified seven AFLP markers, six of which were co-segregated with the Bnms3 gene in a small population (Ke et al. in Plant Breed 124:367-370, 2005). By cloning these AFLP markers and their flanking sequences, five of the six co-segregated markers were successfully converted into sequence characterized amplified region (SCAR) markers. For fine mapping of the Bnms3 gene, these SCAR markers were analyzed in a NIL population of 4,136 individuals. The Bnms3 gene was then genetically mapped to a region of 0.56 cM, with 0.15 cM from marker SEP8 and 0.41 from marker SEP4, respectively. BLAST analysis with these SCAR marker sequences identified a collinear genomic region in Arabidopsis chromosome 5, from which two specific PCR markers further narrowed the Bnms3 locus from an interval of 0.56 to 0.14 cM. These results provide additional information for map-based cloning of the Bnms3 gene and will be helpful for marker-assisted selection (MAS) of elite RGMS lines and maintainers.

Exploiting comparative mapping among Brassica species to accelerate the physical delimitation of a genic male-sterile locus (BnRf) in Brassica napus

“…It was generated as follows: first, some F 2 fertile plants from the cross between 9012A and DH206 were backcrossed with 9012A. The BC1 families displaying a 1:1 fertility segregation were further genotyped with two BnMs3 tightly flanking markers (AR23 and AR28; He et al 2008). Only those families where both markers showed the recessive homozygosity at the BnMs3 locus were kept because the BnRf a allele is responsible for the fertility segregation in them.…”

“…Second, attempts toward final isolation of the genes responsible for male sterility in 9012AB have been carried out. For example, the genetic map of BnMs3 was gradually narrowed by continual efforts (Ke et al 2005;Huang et al 2007;He et al 2008). Now, the BnMs3 locus has been cloned and characterized as a member of the protein import complex responsible for the transport of nuclear-encoded proteins to the chloroplast stroma (Dun et al 2011).…”

AFLP and SSR markers linked to the yellow seed colour gene in Brassica juncea L.

“…So it is a promising strategy to use markers linked to these two alleles to increase the genetic map density, and to narrow the distance between markers of the target gene. In fact, there are many reports on a successful use of this method (Huang et al 2007;Wang et al 2007;He et al 2008).…”

Mapping of BnMs4 and BnRf to a common microsyntenic region of Arabidopsis thaliana chromosome 3 using intron polymorphism markers

“…17 ampliWed fragment length polymorphism (AFLP) markers linked to the BnMs3 gene are identiWed and conWrm the presence of two Xanking markers with their distance of 0.1 and 0.3 cM using a near-isogenic line (NIL)-derived population consisting of 2,000 plants (Huang et al 2007). Another NIL-derived population of 4,136 individuals was used to deWne BnMs3 gene to a genetical region of 0.56 cM (He et al 2008). Several AFLP and sequence characterized ampliWed region (SCAR) markers linked to BnRf have been identiWed (Xiao et al 2008).To our present knowledge, Wne mapping of BnRf and BnMs4 has not been reported yet.…”

“…Two trapezoids show an inversion of AT C3 in the 304 kb region were also used in mapping genes of Brassica species(Yi et al 2006;Lei et al 2007;He et al 2008; Fig. 4).…”