scholarly journals The Dominant Ms Allele in Onion Shows Reduced Penetrance

2010 ◽  
Vol 135 (1) ◽  
pp. 49-52 ◽  
Author(s):  
Sergio Melgar ◽  
Michael J. Havey
Keyword(s):  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Male Fertility ◽  
Fertility Restoration ◽  
The Other ◽  
Normal Male ◽  
Male Sterile ◽  
Mean Values ◽  
Reduced Penetrance ◽  
Male Fertility Restoration

The most commonly used source of cytoplasmic male sterility in onion (Allium cepa) is controlled by the interaction of the cytoplasm [male-sterile (S) or normal male-fertile (N)] and one nuclear male-fertility-restoration locus (Ms). Scoring of genotypes at Ms is generally done by testcrossing male-fertile to male-sterile (S msms) plants, followed by scoring of testcross progenies for male-fertility restoration. We identified two N-cytoplasmic families, one that was homozygous dominant and the other segregating at Ms. Plants from each of these two families were individually testcrossed to male-sterile onion. Nuclear restoration of male fertility in testcross progenies was evaluated in the field over 4 years. For male plants homozygous dominant at Ms, we expected testcross families to show 100% male-fertility restoration, but observed mean values between 46% and 100%. For plants segregating at Ms, we again observed lower than expected frequencies of male-fertility restoration. These results demonstrate that the dominant Ms allele shows reduced penetrance, requiring that male-fertility restoration be scored over years to more confidently assign genotypes at Ms.

scholarly journals The Dynamics of Gynodioecy in Plantago lanceolatu L. II. Mode of Action and Frequencies of Restorer Alleles

Genetics ◽  
1997 ◽  
Vol 147 (3) ◽  
pp. 1317-1328
Author(s):  
Anita A de Haan ◽  
Hans P Koelewijn ◽  
Maria P J Hundscheid ◽  
Jos M M Van Damme
Keyword(s):  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Allele Frequency ◽  
Mode Of Action ◽  
Male Fertility ◽  
Fertility Restoration ◽  
Plantago Lanceolata ◽  
Allele Frequencies ◽  
Male Sterile ◽  
Male Fertility Restoration

Male fertility in Plantago lanceolata is controlled by the interaction of cytoplasmic and nuclear genes. Different cytoplasmic male sterility (CMS) types can be either male sterile or hermaphrodite, depending on the presence of nuclear restorer alleles. In three CMS types of P. lanceolata (CMSI, CMSIIa, and CMSIIb) the number of loci involved in male fertility restoration was determined. In each CMS type, male fertility was restored by multiple genes with either dominant or recessive action and capable either of restoring male fertility independently or in interaction with each other (epistasis). Restorer allele frequencies for CMSI, CMSIIa and CMSIIb were determined by crossing hermaphrodites with “standard” male steriles. Segregation of male steriles vs. non-male steriles was used to estimate overall restorer allele frequency. The frequency of restorer alleles was different for the CMS types: restorer alleles for CMSI were less frequent than for CMSIIa and CMSIIb. On the basis of the frequencies of male steriles and the CMS types an “expected” restorer allele frequency could be calculated. The correlation between estimated and expected restorer allele frequency was significant.

scholarly journals Identification of Ms2, a Novel Locus Controlling Male-fertility Restoration of Cytoplasmic Male-sterility in Onion (Allium Cepa L.), and Development of Tightly Linked Molecular Markers

2021 ◽  
Author(s):  
Nari Yu ◽  
Sunggil Kim
Keyword(s):  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Allium Cepa ◽  
Male Fertility ◽  
Bulked Segregant Analysis ◽  
Fertility Restoration ◽  
Chromosome 2 ◽  
Rna Seq ◽  
Male Sterile ◽  
Male Fertility Restoration

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.

scholarly journals Variable Penetrance among Different Sources of the Male Fertility Restoration Allele of Onion

HortScience ◽  
2020 ◽  
Vol 55 (4) ◽  
pp. 543-546
Author(s):  
Hsiang-I Lee ◽  
Michael J. Havey
Keyword(s):  
Molecular Markers ◽  
Male Sterility ◽  
Male Fertility ◽  
Fertility Restoration ◽  
Male Sterile ◽  
Stainable Pollen ◽  
Breeding Lines ◽  
Reduced Penetrance ◽  
Different Sources ◽  
Male Fertility Restoration

Hybrid onion (Allium cepa) seed is produced using cytoplasmic male sterility (CMS). For the most commonly used source of onion CMS, male fertile plants possess male sterile (S) cytoplasm and dominant allele(s) at one nuclear male fertility locus (Ms). Because male fertility restoration is not necessary for bulb production, it is desirable to purge dominant alleles at Ms from populations and breeding lines to facilitate the development of male sterile inbreds for hybrid production. In this research, we used molecular markers to establish the cytoplasms and genotypes at Ms in progenies from testcrosses of male sterile lines with plants from three populations [B2354, Ailsa Craig (AC), and Sapporo-Ki (Ski)] possessing the dominant Ms allele. We scored male fertility of testcross progenies by visual examination of flowers and acetocarmine staining of pollen. Different sources of the dominant Ms allele showed significantly different amounts of male fertility restoration and proportions of stainable pollen, complicating visual selection against the dominant Ms allele. For AC and Ski, molecular markers correctly predicted male sterility vs. male fertility of progenies in the greenhouse and field. However, for B2354, male fertility restoration was less clear and especially difficult to score under field conditions, consistent with reduced penetrance of male fertility restoration for this source of the dominant Ms allele. These results will be of interest to onion breeders selecting S-cytoplasmic male sterile lines for hybrid onion development.

scholarly journals CYTOPLASMIC MALE STERILITY IN BARLEY. XI. THE msm2 CYTOPLASM

Genetics ◽  
1982 ◽  
Vol 102 (2) ◽  
pp. 285-295
Author(s):  
H Ahokas
Keyword(s):  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Male Fertility ◽  
Fertility Restoration ◽  
Nuclear Gene ◽  
Restorer Gene ◽  
Male Sterile ◽  
Partial Restoration ◽  
Restoration Ability ◽  
Selection Of

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.

Inheritance of male fertility restoration and allelism of restorer genes for the Polima cytoplasmic male sterility system in oilseed rape

Genome ◽  
1989 ◽  
Vol 32 (6) ◽  
pp. 1044-1047 ◽  
Author(s):  
G. H. Fang ◽  
P. B. E. McVetty
Keyword(s):  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Male Fertility ◽  
Fertility Restoration ◽  
Restorer Gene ◽  
Fertility Restorer ◽  
Brassica Napus L ◽  
Restorer Genes ◽  
Segregation Ratios ◽  
Male Fertility Restoration

The inheritance of male fertility restoration for the pol cytoplasmic male sterility (CMS) system in summer rape (Brassica napus L.) was determined. Male fertility:sterility segregation ratios observed in F2 and backcross generations derived from crosses and backcrosses between two pol CMS A lines and the male fertility restorer gene(s) sources Italy and UM2353 were used in this study. Italy and UM2353 were found to possess a single Mendelian dominant gene with high male fertility restoration capabilities for the pol CMS system. Tests for allelism of the restorer genes were also conducted using male fertility:sterility segregation ratios observed in F3 families derived from crosses between F1 plants containing genes for male fertility restoration from the Italy and UM2353 restorer gene sources. The male fertility restorer gene from Italy (designated Rfp1) was found to be different (i.e., nonallelic) from the restorer gene possessed by UM2353 (designated Rfp2).Key words: Brassica napus L., oilseed rape, male fertility restoration, pol cytoplasmic male sterility.

scholarly journals Molecular Tagging of the Ms Locus in Onion

2002 ◽  
Vol 127 (4) ◽  
pp. 576-582 ◽  
Author(s):  
Ali Fuat Gökçe ◽  
John McCallum ◽  
Yutaka Sato ◽  
Michael J. Havey
Keyword(s):  
Male Sterility ◽  
Fragment Length ◽  
Male Fertility ◽  
Fertility Restoration ◽  
Genomic Variation ◽  
Male Sterile ◽  
Single Nucleotide ◽  
Group I ◽  
Length Polymorphisms ◽  
Male Fertility Restoration

Cytoplasmic-genic male sterility (CMS) is used to produce hybrid onion (Allium cepa L.) seed. For the most widely used source of onion CMS, male sterility is conditioned by the interaction of the male-sterile (S) cytoplasm and the homozygous recessive genotype at a nuclear male-fertility restoration locus (Ms). Maintainer lines are used to seed propagate male-sterile lines, possess normal (N) male-fertile cytoplasm, and are homozyous recessive at the Ms locus. Due to the biennial nature of onion, it takes 4 to 8 years of crossing and scoring of progeny phenotypes to establish if maintainer lines can be extracted from an uncharacterized population or family. Identification of nuclear markers tightly linked to the Ms locus would allow for molecular-facilitated selection of maintainer lines. We evaluated testcross progenies from a segregating family for nuclear restoration of male fertility over at least three environments. Although segregations in the F2 family fit the expected 1:2:1 ratio (P = 0.973), the proportion of male-sterile testcross progenies showed significant (P < 0.01) year effects and it is therefore imperative to score male-fertility restoration over environments. Too many male-sterile testcross progenies were often observed, indicating that the dominant allele conditioning male-fertility restoration for S cytoplasm may not show complete penetrance. Segregations of amplified fragment length polymorphisms and restriction fragment length polymorphisms (RFLPs) revealed RFLPs flanking the Ms locus at 0.9 and 8.6 cM. An onion cDNA showing highly significant homology to the aldehyde dehydrogenase conditioned by the rf2 locus of maize was identified and mapped to linkage group I, independent of the Ms locus. A sample of commercial onion germplasm was evaluated for putative allelic diversity at the RFLP loci linked to Ms. The genomic region corresponding to the cDNA (AOB272) revealing the closest RFLP to Ms was sequenced to reveal numerous single nucleotide polymorphisms. Single-stranded conformational polymorphisms and single nucleotide extensions were developed that revealed genomic variation at AOB272-EcoRI. The use of these molecular markers to select maintainer lines in onion is discussed.

Genetic analysis of male fertility restoration in wild cytoplasmic male sterility G of beet

2004 ◽  
Vol 109 (1) ◽  
pp. 240-247 ◽  
Author(s):  
Pascal Touzet ◽  
Nathalie Hueber ◽  
Alexandra Bürkholz ◽  
Stephen Barnes ◽  
Joël Cuguen
Keyword(s):  
Genetic Analysis ◽  
Cytoplasmic Male Sterility ◽  
Male Sterility ◽  
Male Fertility ◽  
Fertility Restoration ◽  
Male Fertility Restoration

scholarly journals Linkage Equilibrium among Tightly Linked RFLPs and the Ms Locus in Open-pollinated Onion Populations

2002 ◽  
Vol 127 (6) ◽  
pp. 944-946 ◽  
Author(s):  
Ali Fuat Gökçe ◽  
Michael J. Havey
Keyword(s):  
Molecular Markers ◽  
Cytoplasmic Male Sterility ◽  
Fragment Length ◽  
Male Fertility ◽  
Fertility Restoration ◽  
Linkage Equilibrium ◽  
Male Sterile ◽  
Length Polymorphisms ◽  
Male Fertility Restoration ◽  
Restriction Fragment Length

Cytoplasmic male sterility (CMS) in onion (Allium cepa L.) is conditioned by the interaction of the male-sterile (S) cytoplasm with recessive alleles at a single nuclear male-fertility restoration locus (Ms). In order to seed propagate male-sterile plants (S msms), onion breeders must identify maintainer lines possessing normal (N) male-fertile cytoplasm and homozygous recessive at the Ms locus (N msms). Molecular markers have been identified distinguishing N and S cytoplasms and closely linked to the nuclear Ms locus. In this study, we evaluated testcross progenies from randomly selected N-cytoplasmic plants from three open-pollinated populations for nuclear restoration of male fertility over at least three environments. The Ms locus and linked restriction fragment length polymorphisms (0.9 and 1.7 cM) were at linkage equilibrium in all three open-pollinated onion populations, indicating that these linked markers cannot be used to identify maintaining genotypes in open-pollinated onion populations. However, cytoplasmic evaluations were effective in reducing the number of testcrosses required to identify CMS-maintaining genotypes.

Sign in / Sign up

Export Citation Format

Share Document