Identification of a microsatellite marker linked to the fertility-restoring gene for a polima cytoplasmic male-sterile line in Brassica napus L.

摘要

Polima cytoplasmic male sterility (pol CMS) has been widely used for exploiting heterosis in rapeseed breeding. The dominant restorer gene of?pol CMS?(Rfp) is found in the nucleus and is a key component of hybrid production by achieving F1 progeny with complete fertility restoration. To identify the molecular markers associated with the?Rfp?gene, a?near isogenic line (NIL) population?of 2,000 individuals?segregating for the?Rfp?locus was generated by crossing?and backcrossing for 12 times. This NIL population was used to screen?Rfp?markers by AFLP technique. Based?on?the sequence information of AFLP markers that?havebeen identified in previous research, we identified a homologous region?of?Rfp?locusin chromosome 1 of?Arabidopsis.?Then,?six sequenced?Brassica rapa?BAC?clones corresponding to this target region were chosen?to design microsatellite (SSR) primer pairs.?Twenty-two?SSR markers?were designed and?one of them, KBrDP1,was verified in?the?2, 000 NILs population and proved?to be?strongly?linked to?Rfplocus.?The genetic distance between KBrDP1 and?Rfp?was 0.2 cM. KBrDP1 marker was found located on linkage group N9 of a published DH mapping population.?This SSR marker?was?useful in?marker assisted selection?breeding of the elite pol CMS restorer lines in rapeseed.