Identification of a novel haplotype of the Ms locus controlling restoration of male-fertility and its implication in origination of cytoplasmic male-sterility in onion (Allium cepa L.)

Author(s):  
Taeheon Kim ◽  
Sunggil Kim
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.


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.


1991 ◽  
Vol 71 (3) ◽  
pp. 655-661 ◽  
Author(s):  
D. R. Burns ◽  
R. Scarth ◽  
P. B. E. McVetty

The effect of high temperature treatment on the expression of cytoplasmic male sterility (CMS) was studied using inbred lines of four summer rape (Brassica napus L.) cultivars. The nuclear genotypes of inbred lines from each of the cultivars Karat, Lergo, Marnoo and Regent were evaluated for their ability to maintain pollen sterility in the pol cytoplasm. Seven days' exposure to day/night temperatures of 30/24 °C in a controlled environment led to increased pollen production in all of the F1 populations (F1's) in the study. Maximum reversion to male fertility occurred 6–13 d after removal from the high temperature treatment. There was a significant linear relationship between daily mean temperatures in the field and mean male sterility index (MSI). In Lergo, Marnoo and Regent F1's, the effect of high temperatures on male sterility expression in terms of days to maximum pollen production in the field was accurately predicted by the values obtained in the controlled environment study. For the Karat F1's, the maximum response in the field occurred later than in the controlled environment. Variation in the stability of male sterility was evident in the F1's, indicating the presence of different maintainer genes among the inbred lines of each cultivar. The absence of environment-by-line interactions in the F1's of three cultivars indicated a high degree of stability for this trait. Selection for maintenance of high levels of male sterility may therefore be possible. Key words: Brassica napus, male fertility reversion


Euphytica ◽  
1969 ◽  
Vol 18 (3) ◽  
pp. 389-394 ◽  
Author(s):  
Q. P. Van Der Meer ◽  
J. L. Van Bennekom

Sign in / Sign up

Export Citation Format

Share Document