scholarly journals Efficacy of Molecular Markers Jnurf13 and AcPms1 for Prediction of Genotypes at the Nuclear Ms Locus in Three Open-pollinated Populations of Onion from North America

HortScience ◽  
2017 ◽  
Vol 52 (8) ◽  
pp. 1052-1053 ◽  
Author(s):  
Michael J. Havey ◽  
Christopher von Kohn

Seed of hybrid onion (Allium cepa L.) is produced using cytoplasmic male sterility (CMS). For the most widely used source of onion CMS, male sterility is conditioned by the interaction of male sterile (S) cytoplasm and the homozygous recessive genotype at the nuclear male fertility locus Ms. Because of the biennial generation time of onion, classical crossing and segregation analyses take years to establish cytoplasms and genotypes at Ms. Numerous molecular markers have been developed to distinguish onion cytoplasms and estimate genotypes at Ms. Two nuclear markers (jnurf13 and AcPms1) have been reported to cosegregate with Ms and correctly predict genotypes in commercial breeding lines and diverse onion germplasm; however, these markers were less predictive for open-pollinated (OP) populations from India. We evaluated the efficacy of jnurf13 and AcPms1 to correctly classify genotypes at Ms using 144 random plants from three OP populations of long-day onion from North America. No recombination events were detected between AcPms1 and the Ms locus and three events occurred between jnurf13 and Ms. Our results support either marker as a useful tool to predict genotypes at Ms in North American populations of onion, with AcPms1 being the better of the two.

HortScience ◽  
2020 ◽  
Vol 55 (4) ◽  
pp. 543-546
Author(s):  
Hsiang-I Lee ◽  
Michael J. Havey

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.


HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 453B-453
Author(s):  
Ali Fuat Gokce ◽  
Michael J. Havey

Cytoplasmic-genic male sterility (CMS) is used to produce hybrid onion seed. For the most widely used source of CMS in onion, male sterility is conditioned by the interaction of sterile (S) cytoplasm and the homozygous recessive genotype at a single nuclear male-fertility restoration locus (Ms). Maintainer lines used to seed-propagate male-sterile lines possess normal fertile (N) cytoplasm and the homozyous recessive genotype at the Ms locus. Presently, it takes 4 to 8 years to establish if maintainer lines can be extracted from an uncharacterized population or family. We previously developed a PCR marker useful to distinguish N and S cytoplasms of onion. To tag the nuclear male-fertility restoration locus (Ms), we evaluated segregation at Ms over at least three environments. Segregations of AFLPs, RAPDs, and RFLPs revealed molecular markers flanking the Ms locus. We are working to convert these linked molecular markers to nonradioactive PCR-based detection. The organellar and nuclear markers were used to select plants from open-pollinated onion populations and determine if the number of test-crosses required to identify maintaining genotypes.


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

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.


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.


1994 ◽  
Vol 42 (2) ◽  
pp. 89-103 ◽  
Author(s):  
H.P. Comes

Two major findings relating to the breeding system of Senecio vernalis from Israel are reported. First, isolation experiments failed to confirm the existence of a widespread, truly self-compatible and predominantly self-pollinating breeding system in Israeli populations of S. vernalis. However, a single S. vernalis plant derived from a natural stand at Jerusalem was found to be self- compatible and strongly self-pollinating. In its progeny, there were signs of inbreeding depression commonly associated with selfed offspring of outbreeding species. Selfing ability ratios in this progeny indicate a single dominant gene for selfing ability in S. vernalis. The implications of these observations for the origin of S. vulgaris are briefly discussed. Second, the occurrence of gynodioecy in S. vernalis populations from Israel is reported. Although male sterile plants are recognizable by the complete absence of pollen on their exposed stigmas, there probably exists a large amount of variation within and between plants for pollen production. Infertile pollen grains of male steriles differ in size, shape, and sculpturing from those of hermaphrodites. At the Mt. of Olives, in Jerusalem, the frequency of male steriles was found to be 9.1%. There is some preliminary evidence for differences in floret (= ovule) number between the two gender types. Although the inheritance of male sterility appears to be predominantly cytoplasmically controlled, additional mechanisms restoring male fertility have to be postulated to account for the data observed in one of the crosses. The male sterility system in S. vernalis should therefore be referred to as “nuclear-cytoplasmic.”


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.


2010 ◽  
Vol 135 (1) ◽  
pp. 49-52 ◽  
Author(s):  
Sergio Melgar ◽  
Michael J. Havey

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.


Author(s):  
Maneechat Nikornpun ◽  
Danai Boonyakiat

Male fertility reactions of one hundred and forty-one accessions of chilies were classified. Three groups were found. Some accessions maintained male sterility and were determined to carry a non-sterile cytoplasm and to lack fertility restoration genes or N rfrf genotype. Some accessions segregated for the ability to restore male sterile cytoplasm and were determined to be heterozygous in restorer genes with genotype N/SRfrf. Some accessions restored fertility of CMS and had the genotype N/SRfRf. A few maintainers with good horticultural characteristics were selected. They were selfed and selected for a few generations and then their progeny were evaluated. There were differences in the genetic stability of cytoplasmic male-sterility among the selected lines. Some lines were good maintainers, but a few lines were discarded. The stable maintainers were distributed to 10 seed companies and the government of China. Some F1 hybrid chilies produced using these lines have been commercially sold both in China and Thailand. Fruit physio-chemical qualities of maintainer accessions, restorers and heterozygous accessions were also recorded. The level of capsaicin of the accessions varied from 3,250 to 8,850 Scoville units. The level of vitamin C showed a range of 4.43 to 103.16 mg./100g.fw. Horticultural characteristics of the accessions were recorded and the fruit physio-chemical qualities of the accessions were reported.


Genome ◽  
2009 ◽  
Vol 52 (1) ◽  
pp. 95-99 ◽  
Author(s):  
Wenguang Cao ◽  
Daryl J. Somers ◽  
George Fedak

A male sterile wheat mutant, Triticum aestivum L. ‘Taigu’, was found in a wheat field in China in 1972. The male sterility was controlled by a single dominant gene that was referred to as Ms2. Recently, this gene was found to be linked to a dwarfing gene through crossing Taigu with the short wheat T. aestivum ‘Ai-Bian 1’ carrying the dwarfing gene Rht-D1c. The objective of this study was to develop molecular markers linked to the male sterility Ms2 gene in common wheat. One hundred and twenty-two near-isogenic lines were developed through backcrossing and sib intercrossing and used as the mapping population for the development of molecular markers. Bulked segregant analysis was used to screen 48 pairs of SSR primers, and a marker, MS2-WMC617, was identified closely linked to the male sterile Ms2 gene that mapped at the distal position of chromosome arm 4DS. The use of the molecular marker MS2-WMC617 can facilitate recurrent selection in a wheat breeding program based on marker-assisted selection.


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