Allelism analysis of BrRfp locus in different restorer lines and map-based cloning of a fertility restorer gene, BrRfp1, for pol CMS in Chinese cabbage (Brassica rapa L.)

Abstract

In Chinese cabbage, there are two Rf loci for pol CMS and one of them was mapped to a 12.6-kb region containing a potential candidate gene encoding PPR protein. In Chinese cabbage (Brassica rapa), polima cytoplasmic male sterility (pol CMS) is an important CMS type and is widely used for hybrid breeding. By extensive test crossing in Chinese cabbage, four restorer lines (92s105, 01s325, 00s109, and 88s148) for pol CMS were screened. By analyzing the allelism of the four restorer lines, it was found that 92s105, 01s325, and 00s109 had the same "restorers of fertility" (Rf) locus (designated as BrRfp1), but 88s148 had a different Rf locus (designated as BrRfp2). For fine mapping the BrRfp1 locus of 92s105, a BCF population with 487 individuals and a BCF population with 2485 individuals were successively constructed. Using simple sequence repeat (SSR) markers developed from Brassica rapa reference genome and InDel markers derived from whole-genome resequencing data of 94c9 and 92s105, BrRfp1 was mapped to a 12.6-kb region containing a potential candidate gene encoding pentatricopeptide repeat-containing protein. Based on the nucleotide polymorphisms of the candidate gene sequence between the restoring and nonrestoring alleles, a co-segregating marker SC718 was developed, which would be helpful for hybrid breeding by marker-assisted screening and for detecting new restorer lines.

Fine mapping and candidate gene analysis of the white flower gene Brwf in Chinese cabbage (Brassica rapa L.)

“…Two DNA pools, yellow-flowered pool and white-flowered pool, were created by mixing equal amounts of DNA from 8 individuals with yellow flower and 8 individuals with white flower, respectively, which were randomly selected from F 2 population. The PCR reaction and separation of its products were performed as described by Zhang et al 31 .…”

“…The Brassica genus includes important oil crops and vegetables 15 with yellow flower color as the most common form, while there are other colors, such as pale yellow, white, orange, and tangerine [16][17][18][19][20][21][22] . Compared with the studies of other traits in Brassica genus, such as yield [23][24][25][26][27][28] , fertility [29][30][31][32] , disease resistance [33][34][35] , the genetic studies of flower colors have been conducted earlier 16,17,36 . However, only the molecular mechanisms of white flower formation were understood [11][12][13][14]37,38 .…”

Comparative Mapping Combined With Map-Based Cloning of the Brassica juncea Genome Reveals a Candidate Gene for Multilocular Rapeseed

“…Despite the collection and development of numerous markers, the Bjln2 locus interval remained very large. It was difficult to further narrow the positioning range and predict the candidate gene via map-based cloning (Lei et al, 2007 ; Zhang et al, 2017 ). Previous studies (Lagercrantz et al, 1996 ; Schranz et al, 2002 ; Suwabe et al, 2006 ) have shown that genes controlling the same trait share a high degree of homology and collinearity based on mapping comparisons between Brassica and Arabidopsis thaliana and between species of Brassica .…”

High resolution mapping of restoration of fertility (Rf) by combining large population and high density genetic map in pigeonpea [Cajanus cajan (L.) Millsp]

“…The importance of high resolution mapping and fine mapping has been realized in a number of crop species for several disease resistance and agronomic traits [3][4][5][6][7][8]. Moreover, QTLs/ genes associated with Rf have been isolated in few crops and vegetable species including barley [9], maize [10] and Chinese cabbage [11].…”