Molecular tagging of the male fertility restorer gene for the 501-8S cytoplasmic male sterility in rapeseed (Brassica napus L.)

2007 ◽  
Vol 58 (8) ◽  
pp. 753
Author(s):  
Haohua He ◽  
Liang Xu ◽  
Xiaosong Peng ◽  
Guangsheng Yang ◽  
Changlan Zhu ◽  
...  

The cytoplasmic male sterile (CMS) system has been successfully used to explore heterosis in rapeseed (Brassica napus L.). A newly developed male sterile line (501-8S) was characterised for its male fertility response to temperature and photoperiod, and the inheritance of fertility restoration. Segregation analysis using F1 and F2, BC1, and F3 populations of the crosses between the 501-8S and fertile lines of B. napus revealed that fertility restoration was conferred by a dominant nuclear gene (Rf). The F2 population of the cross 501-8S × Yuyou1 was used as a mapping population to map the Rf gene. A combination of bulked segregant analysis (BSA) and amplified fragment length polymorphism (AFLP) methodology was used to identify putative markers linked to the Rf gene. Twenty-nine of the 1280 primer combinations tested revealed polymorphism between the 2 extreme bulks. Further testing of these primer combinations in individual plants identified 5 AFLP markers tightly linked to the Rf gene with a map distance of less than 5.0 cM. All 5 markers were on one side of the restoration gene in the coupling phase. The closest marker, EA02MG03-260, is only 0.4 cM from the Rf gene. The EA02MG03-260 marker was converted to a dominant sequence characterised amplified region (SCAR) marker (SCARE2M3-214). Amplification using this locus-specific primer generated specific bands with male fertile plants when tested using the mapping population. Specific amplification of SCARE2M3-214 was also detected in all 3 male sterile plants and their F1 hybrids, with 5 restorer lines used for verification. Thus, SCARE2M3-214 will be very useful for the development of new restorer lines by the transfer of the Rf gene into other breeding lines. It can also be used for isolating the Rf gene by means of map-based cloning.

2016 ◽  
Vol 41 (3) ◽  
pp. 529-540
Author(s):  
MA Miah ◽  
MG Rasul ◽  
MAK Mian

Identification of male fertility restorer genotypes for rapeseed CMS lines towards hybrid development in spring habit rapeseed (Brassica napus L.) adapted for short day winter season was studied. The experiment was conducted at the experimental farm and laboratory of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Salna, Gazipur during October, 2008 to March, 2011. An exotic CMS-based F1 hybrid of rapeseed was selfed to get F2 generation with a view to resynthesizing restorer line. As a result a restorer line for Nap248A Z1 and Nap248A Z2 cytoplasmic male sterile lines was identified in the F3 generation of the exotic F1 rapeseed hybrid which appears as the first case so far reported as achievement in Bangladesh in this regard. Genetic analysis further revealed fertility restoration for Nap248A Z1 and Nap248A Z2 cytoplasmic male sterility was controlled by a single dominant nuclear gene as a simple genetic phenomenon.Bangladesh J. Agril. Res. 41(3): 529-540, September 2016


2021 ◽  
Author(s):  
Nari Yu ◽  
Sunggil Kim

Abstract Cytoplasmic male-sterility (CMS) has been exclusively used to produce F1 hybrid seeds of onion (Allium cepa L.). A single nuclear locus, Ms, is known to restore male-fertility of CMS in onions. Unstable male-sterile onions producing a small amount of pollen grains have been identified in a previous study. When such unstable male-sterile onions were crossed with stable male-sterile onions containing CMS-T cytoplasm, male-fertility was completely restored, although genotypes of the Ms locus were homozygous recessive. Inheritance patterns indicated that male-fertility restoration was controlled by a single locus designated as Ms2. A combined approach of bulked segregant analysis and RNA-seq was used to identify candidate genes for the Ms2 locus. High resolution melting (HRM) markers were developed based on single nucleotide polymorphisms (SNPs) detected by RNA-Seq. Comparative mapping of the Ms2 locus showed that Ms2 was positioned at the end of chromosome 2 with a distance of approximately 70 cM away from the Ms locus. Although 38 contigs containing reliable SNPs were analyzed using recombinants selected from 1,344 individuals, no contig showed perfect linkage to Ms2. Interestingly, transcription levels of orf725, a CMS-associated gene in onions, were significantly reduced in male-fertile individuals of segregating populations. However, no significant change in its transcription level was observed in individuals of a segregating population with male-fertility phenotypes determined by the Ms locus, suggesting that male-fertility restoration mechanism of Ms2 might be different from that of the Ms locus.


2021 ◽  
Vol 12 ◽  
Author(s):  
Qian Yang ◽  
Xiaoyi Nong ◽  
Jize Xu ◽  
Fan Huang ◽  
Fang Wang ◽  
...  

Crosses that lead to heterosis have been widely used in the rapeseed (Brassica napus L.) industry. Cytoplasmic male sterility (CMS)/restorer-of-fertility (Rf) systems represent one of the most useful tools for rapeseed production. Several CMS types and their restorer lines have been identified in rapeseed, but there are few studies on the mechanisms underlying fertility restoration. Here, we performed morphological observation, map-based cloning, and transcriptomic analysis of the F2 population developed by crossing the CMS line WNJ01A with its restorer line Hui01. Paraffin-embedded sections showed that the sporogenous cell stage was the critical pollen degeneration period, with major sporogenous cells displaying loose and irregular arrangement in sterile anthers. Most mitochondrial electron transport chain (mtETC) complex genes were upregulated in fertile compared to sterile buds. Using bulked segregant analysis (BSA)-seq to analyze mixed DNA pools from sterile and fertile F2 buds, respectively, we identified a 6.25 Mb candidate interval where Rfw is located. Using map-based cloning experiments combined with bacterial artificial chromosome (BAC) clone sequencing, the candidate interval was reduced to 99.75 kb and two pentatricopeptide repeat (PPR) genes were found among 28 predicted genes in this interval. Transcriptome sequencing showed that there were 1679 DEGs (1023 upregulated and 656 downregulated) in fertile compared to sterile F2 buds. The upregulated differentially expressed genes (DEGs) were enriched in the Kyoto Encyclopedia of Genes and Genomes (KEGG) lysine degradation pathway and phenylalanine metabolism, and the downregulated DEGs were enriched in cutin, suberine, and wax biosynthesis. Furthermore, 44 DEGs were involved in pollen and anther development, such as tapetum, microspores, and pollen wall development. All of them were upregulated except a few such as POE1 genes (which encode Pollen Ole e I allergen and extensin family proteins). There were 261 specifically expressed DEGs (9 and 252 in sterile and fertile buds, respectively). Regarding the fertile bud-specific upregulated DEGs, the ubiquitin–proteasome pathway was enriched. The top four hub genes in the protein–protein interaction network (BnaA09g56400D, BnaA10g18210D, BnaA10g18220D, and BnaC09g41740D) encode RAD23d proteins, which deliver ubiquitinated substrates to the 26S proteasome. These findings provide evidence on the pathways regulated by Rfw and improve our understanding of fertility restoration.


Genetics ◽  
1982 ◽  
Vol 102 (2) ◽  
pp. 285-295
Author(s):  
H Ahokas

ABSTRACT A new cytoplasmic male sterility in barley (Hordeum vulgare s.l.) is described and designated as msm2. The cytoplasm was derived from a selection of the wild progenitor of barley (H. vulgare ssp. spontaneum). This selection, 79BS14-3, originates from the Southern Coastal Plain of Israel. The selection 79BS14-3 has a normal spike fertility in Finland. When 79BS14-3 was crossed by cv. Adorra, the F1 displayed partial male fertility and progeny of recurrent backcrosses with cv. Adorra were completely male sterile. Evidently 79BS14-3 is a carrier of a recessive or semidominant restorer gene of fertility. The dominant restorer gene Rfm1a for another cytoplasmic male sterility, msm1, is also effective in msm2 cytoplasm. The different partial fertility restoration properties of msm2 and msm1 cause these cytoplasms to be regarded as being distinct. Seventy spontaneum accessions from Israel have been studied for their capacity to produce F1 restoration of male fertility both in msm1 and in msm2 cytoplasms with a cv. Adorra-like seed parent (nuclear gene) background. The msm2 cytoplasm shows partial restoration more commonly than msm1 in these F1 combinations. The mean restoration percentage per accession for msm2 is 28, and for msm1 4. Most of the F1 seed set differences of the two cytoplasms are statistically significant. When estimated with partially restored F1 combinations, msm2 cytoplasm appeared to be about 50 times more sensitive to the male fertility-promoting genes present in the spontaneum accessions. The spontaneum sample from Central and Western Negev, which has been found to be devoid of restoration ability in msm1 cytoplasm, had only low partial restoration ability in msm2 (mean 0.3%). The female fertility of msm2 appears normal. The new msm2 cytoplasm could be useful in producing hybrid barley.


Genome ◽  
2003 ◽  
Vol 46 (5) ◽  
pp. 792-797 ◽  
Author(s):  
H S Janeja ◽  
S K Banga ◽  
P B Bhaskar ◽  
S S Banga

A cytoplasmic male sterility (CMS) system for Brassica napus (2n = 38; AACC) was developed by backcross substitution of its nucleus into the cytoplasm of a wild crucifer, Enarthrocarpus lyratus. Male sterility was complete, stable, and expressed in small flowers with rudimentary anthers. Since the B. napus germplasm lines were complete or partial maintainers of male sterility, the required fertility restorer gene (Rfl) was introgressed from the cytoplasm donor species. Inheritance studies carried out on F1 and F2 populations derived from hybridizing cytoplasmic male sterile and male fertile near-isogenic (PNILs) lines of B. napus 'Westar', revealed a monogenic dominant control for fertility restoration. Bulked segregant analysis with 215 RAPD primers helped in the identification of putative primers associated with fertility restoration. Co-segregation analysis of eight such primers with Rfl gene revealed two markers, OPK 15700 and OPZ 061300, which flank the Rfl locus on either side at a distance of 8.2 and 2.5 cM, respectively. These DNA markers will be useful in marker-assisted selection for improving the commercial potential of this newly developed CMS-fertility-restorer system for hybrid seed production programs in rapeseed.Key words: oilseed rape, hybrids, cytoplasmic male sterility, fertility restoration, RAPD mapping.


Botany ◽  
2014 ◽  
Vol 92 (11) ◽  
pp. 847-853 ◽  
Author(s):  
Benjamin R. Montgomery ◽  
Maia F. Bailey ◽  
Gregory G. Brown ◽  
Lynda F. Delph

Gynodioecy frequently results from the interplay of mitochondrial cytoplasmic male sterility (CMS) and nuclear fertility-restoration genes. Models suggest that maintaining cytonuclear gynodioecy requires that restorer genes incur a cost to fitness because otherwise they would increase toward fixation. Direct tests of costs of restorer alleles require knowledge of the underlying genetics of sex determination. We use a well characterized CMS system in Brassica napus L. to measure aspects of fitness in four lineages that vary in whether they carry the pol CMS gene or male-fertile cytoplasm (cam), and whether they carry the Rfp restorer of pol or Rfn restorer of the nap CMS gene. As expected, plants with pol CMS and only the Rfn restorer experienced reduced flower size, stamen length, and pollen counts. Plants with pol and the Rfp restorer showed incomplete restoration with shorter stamens than both lines with cam cytoplasm and reduced pollen counts compared with plants with cam cytoplasm and the Rfp restorer. Among plants with cam cytoplasm, pollen counts were higher for those with the Rfp than Rfn restorer, indicating a greater cost of restoration associated with Rfn. These results demonstrate that costs of restoration differ for the Rfn and Rfp alleles in B. napus.


1986 ◽  
Vol 66 (2) ◽  
pp. 229-234 ◽  
Author(s):  
Z. Fan ◽  
B. R. STEFANSSON ◽  
J. L. SERNYK

The F1 progenies from crosses involving 32 Brassica napus L. strains (including named cultivars) and male-sterile plants carrying one of the three cytoplasms, ogu, nap, and pol were evaluated for male fertility. All strains were found to be maintainers for the ogu cytoplasm. The fertility of the nap male-sterile plants were fully restored by 30 strains. The cultivar Bronowski partially maintained the nap male sterility, and segregation for male fertility/sterility was observed in the F1 hybrid between nap male sterile plants and the cultivar Lergo. Lergo, therefore, appears to be heterogeneous for genes conditioning maintenance and restoration of this type of male sterility. Most strains were maintainers and the balance were partial maintainers for the pol cytoplasm. The F2 and backcross data obtained under a controlled environment suggest that both the cultivars Karat and Westar possess a single dominant gene for the restoration of fertility in nap cytoplasm. Fertility in the pol cytoplasm was restored in the F1 of crosses between pol B. napus and the B. juncea L. Czern. cultivar ZEM. Five male fertile lines of pol B. napus were selected from the ZEM crosses after five generations of backcrossing to B. napus cultivar Regent and three generations of self-pollination. Selection for fertility during backcrossing and self-pollination resulted in selection for an extra chromosome involved with male fertility restoration.Key words: Rape, Brassica napus L., CMS, maintainers, restorers


2021 ◽  
Vol 22 (22) ◽  
pp. 12450
Author(s):  
Qing Xiao ◽  
Huadong Wang ◽  
Hui Chen ◽  
Xiaohan Chen ◽  
Jing Wen ◽  
...  

Temperature-sensitive male sterility is a heritable agronomic trait affected by genotype-environment interactions. In rapeseed (Brassica napus), Polima (pol) temperature-sensitive cytoplasmic male sterility (TCMS) is commonly used for two-line breeding, as the fertility of pol TCMS lines can be partially restored at certain temperatures. However, little is known about the underlying molecular mechanism that controls fertility restoration. Therefore, we aimed to investigate the fertility conversion mechanism of the pol TCMS line at two different ambient temperatures (16 °C and 25 °C). Our results showed that the anthers developed and produced vigorous pollen at 16 °C but not at 25 °C. In addition, we identified a novel co-transcript of orf224-atp6 in the mitochondria that might lead to fertility conversion of the pol TCMS line. RNA-seq analysis showed that 1637 genes were significantly differentially expressed in the fertile flowers of 596-L when compared to the sterile flower of 1318 and 596-H. Detailed analysis revealed that differentially expressed genes were involved in temperature response, ROS accumulation, anther development, and mitochondrial function. Single-molecule long-read isoform sequencing combined with RNA sequencing revealed numerous genes produce alternative splicing transcripts at high temperatures. Here, we also found that alternative oxidase, type II NAD(P)H dehydrogenases, and transcription factor Hsfs might play a crucial role in male fertility under the low-temperature condition. RNA sequencing and bulked segregant analysis coupled with whole-genome sequencing identified the candidate genes involved in the post-transcriptional modification of orf224. Overall, our study described a putative mechanism of fertility restoration in a pol TCMS line controlled by ambient temperature that might help utilise TCMS in the two-line breeding of Brassica crops.


Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1367-1379 ◽  
Author(s):  
Carren L Dill ◽  
Roger P Wise ◽  
Patrick S Schnable

Rf8 is a newly described nuclear gene that can substitute for Rf1 to partially restore pollen fertility to male-sterile, T-cytoplasm maize. Families segregating for Rf8 were used to investigate the mechanism of this fertility restoration and to compare it to the restoration conditioned by Rf1. Although Rf8 is unlinked to the rf1 locus, it also alters T-urf13 mitochondrial transcript accumulation and reduces the accumulation of the URF13 protein. Like the 1.6- and 0.6-kilobase (kb) T-urf13 transcripts that accumulate in T-cytoplasm plants carrying Rf1, 1.42- and 0.42-kb transcripts accumulate in plants that are partially restored by Rf8. A survey of T-cytoplasm maize lines, inbreds, and F1 hybrids by mitochondrial RNA gel blot analyses revealed that Rf8, is rare in maize germplasm. These surveys revealed the presence of another rare, weak restorer factor, Rf*, which is uniquely associated with the accumulation of 1.4- and 0.4-kb T-urf13 transcripts. Primer extension analyses position the 5′ termini of the 1.42/0.42-kb and 1.4/0.4-kb transcripts at +137 and +159 nucleotides, respectively, 3′ of the AUG initiation codon of the T-urf13 reading frame. The conserved motif, 5′-CNACNNU-3′, overlaps the 5′ termini of the Rf1-, Rf8-, and Rf*-associated transcripts and the 380 nucleotide, Rf3-associated orf107 transcript from cytoplasmic male sterility sorghum. These results demonstrate that multiple unlinked, nuclear genes can have similar but distinct effects on the expression of the unique T-urf13 mitochondrial coding sequence to restore pollen fertility to T-cytoplasm maize.


2003 ◽  
Vol 83 (3) ◽  
pp. 515-518 ◽  
Author(s):  
T. C. Riungu ◽  
P. B. E. McVetty

The inheritance of Diplotaxis muralis (L) DC. mur cytoplasmic male sterile (CMS) system maintenance and restoration in summer rape (Brassica napus L.) was studied by crossing eight summer rape cultivars of diverse origin to a winter habit mur CMS A-line. The F1 progenies from all eight crosses were male fertile and were selfed to produce the F2 generation. The F2 generation was grown in the field and data on segregation for male fertility and sterility were recorded and analyzed. The F2 segregation data showed that mur CMS restoration in summer rape is controlled by dominant alleles at one to three restorer genes. The number of genes for the restoration of male fertility in mur CMS varied both among and, occasionally, within cultivars. Maintainer lines for mur CMS must carry recessive alleles in homozygous condition at all three restorer genes. The ready availability of summer rape restorers suggests that the mur CMS system has good potential for hybrid cultivar development and hybrid seed production in summer rape; however, maintainers in summer rape must first be discovered or developed. Key words: Cytoplasmic male sterility, canola, Brassica napus, male sterility


Sign in / Sign up

Export Citation Format

Share Document