Mapping Of A Male Sterility Restorer Gene Rfp Of The Pol CMS In Brassica Napus L

Utilization of heterosis in rapeseed is an effective way to increase yield, solve thecontradiction between yield and quality; yield and disease resistance, and improve theadaptability. Polima (Pol) CMS is a main pollination controlling system, which has beenused widely for rapeseed hybrid breeding. How to select its appropriate restorer lines hasbeen a major task. The DNA markers linked to the fertility restorer gene (Rfp) canaccelerate the breeding of excellent restorer lines. In addition, a large number of markerstightly linked to the fertility restorer gene are necessary for map-based cloning. Theobjective of this study is mapping the Rfp, and then we can use the DNA markersexploited to assist the genetic improvement of restorer lines, and lay a good foundationfor cloning the Rfp gene. The main results are as follows:1. In order to map Rfp, a fertile individual from a backcross population were crossedwith the recurrent parent Wu108 to construct a NILs population. There were 125 fertileand 113 sterile plants in the population. The segregation ratio of fertility: sterility agreedwith expected 1:1. It showed the fertility of Pol CMS was controlled by a pair ofdominant genes.2. Bulked segregant analysis(BSA) was utilized to identify AFLP markers linked tothe Rfp. DNA bands amplified from 3072 pairs of AFLP primer combinations werescreened. Twenty-four AFLP markers were found linked to the Rfp locus, nine of whichwere mapped with the Rfp locus, spanning a genetic distance of 10.4 cM. The nearest twomarkers were found linked to the Rip locus at the same side, the distance between the twomarkers and the target locus were both 0.4 cM.3. The two AFLP fragments were sequenced and converted successfully to SCARmarkers. The SCAR markers (SCAP0612EM2å’ŒSCAP0612ST) were tested in a largerNILs (960 individuals) and Pol CMS restorer lines came from different genetic origin. Asa consequence, we ensured that the SCAR marker SCAP0612ST could be used foridentify hybrid purity and marker assisted selection.4. BLASTn analysis between the two markers' sequence and Arabidopsis genome onNCBI website can identify homologues of 87% and 91% respectively. Both of themdistribute on the short arm of Arabidopsis chromosome I.