Natural or induced nucleocytoplasmic heterogeneity in Triticum longissimum

Genome ◽  
1996 ◽  
Vol 39 (1) ◽  
pp. 71-76 ◽  
Author(s):  
S. S. Maan
Keyword(s):  
Durum Wheat ◽  
Common Wheat ◽  
Meiotic Chromosome ◽  
Nuclear Gene ◽  
Meiotic Pairing ◽  
Alien Chromosome ◽  
Male Sterile ◽  
Substitution Lines ◽  
Selfish Gene ◽  
Group 4

Alien cytoplasms produce a variety of phenotypes in durum wheat (Triticum turgidum) and common wheat (Triticum aestivum) cultivars, which indicate the prevalence of cytoplasmic variability in the subtribe Triticinae. Intraspecific cytoplasmic differences have been demonstrated between the subspecies of Triticum speltoides, Triticum dichasians, and Triticum comosum. In this study, durum wheat lines with cytoplasm from two accessions, B and C, of Triticum longissimum were compared, and meiotic chromosome pairing between the group 4 homoeologues from the same two accessions was examined in common wheat. First, monosomic addition or monosomic substitution lines of common wheat with cytoplasm and one chromosome (designated B) from accession B were crossed with those having cytoplasm and a chromosome designated C-1 or C-2 from accession C. In each substitution line, an alien chromosome substituted for a group 4 homoeologue. Each alien chromosome had a "selfish" (Sf) gene, which remained fixed in the wheat nucleus. The F1s had greatly reduced meiotic pairing between chromosomes B and C-1 and B and C-2, which indicated greatly reduced homology between the group 4 homoeologues from the two accessions. Second, by using Triticum timopheevii as a bridging species, chromosome B in a common wheat line was eliminated and an euploid durum line with cytoplasm from accession B was obtained. This line was fertile. In contrast, a similarly produced durum line with cytoplasm from accession C was male sterile and retained a species cytoplasm specific (scs) nuclear gene from T. timopheevii. In conclusion, nuclear and cytoplasmic heterogeneity pre-existed between accessions B and C and they represent varieties or incipient subspecies in T. longissimum. Alternatively, the Sf genes produced chromosomal heterogeneity and mutated cytoplasmic genes from one or both accessions. Key words : meiotic drive, selfish gene (Sf), gametocidal gene (Gc), Triticum, Aegilops.

Transfer of a species cytoplasm specific (scs) gene from Triticum timopheevii to T. turgidum

Genome ◽  
1992 ◽  
Vol 35 (2) ◽  
pp. 238-243 ◽  
Author(s):  
S. S. Maan
Keyword(s):  
Common Wheat ◽  
Triticum Turgidum ◽  
Seed Viability ◽  
Male Parent ◽  
Alien Chromosome ◽  
Male Sterile ◽  
Male Sterile Plant ◽  
B Genome ◽  
Aegilops Longissima ◽  
Genome Donor

Initial attempts to substitute euploid nuclei of Triticum turgidum L. or T. aestivum L. into Aegilops longissima S. &L. cytoplasm failed because an alien chromosome remained fixed in the Triticum nucleus. The alien chromosome had gene(s) conditioning sporophytic sterility (also known as the gameticidal or Cuckoo effect). Subsequently, an exceptional 29-chromosome, male-sterile plant with spontaneously improved female fertility was used as a source of Ae. longissima cytoplasm, and a fully fertile alloplasmic common wheat 'Selkirk' line was developed. However, alloplasmic 'Selkirk' crossed with durum wheat as a recurrent male parent did not produce euploid plants. Instead, chromosome 1D or telocentric 1DL of 'Selkirk' was retained and male-sterile plants with 29 chromosomes were obtained. They set two seed types: a few that were plump and viable (PVi) and a large number that were shrivelled and inviable (SIv). The 1DL was deleted by crossing these plants to T. timopheevii, backcrossing the F1's to T. timopheevii, and repeatedly backcrossing the timopheevii-like plants to durum as the recurrent male parent. The resulting euploid durum plants with Ae. longissima cytoplasm were male sterile and set a 1:1 ratio of PVi and SIv seeds. Thus, a species cytoplasm specific (scs) gene of T. timopheevii was transferred to durum and caused male sterility and abortion of embryos lacking this gene. In conclusion, (i) the scs gene was expressed as a dominant sterility gene, restored seed viability, and partial compatibility between the durum nucleus and Ae. longissima cytoplasm and (ii) a scs gene on 1DL also caused dominant sterility in durum but not in alloplasmic common wheat. Hence, alien scs homoeoallele(s) conditioned sterility and seed abortion in alloplasmic durum but not in T. aestivum and T. timopheevii.Key words: interspecific nucleocytoplasmic genetics, sporophytically controlled sterility, B-genome donor, scs gene.

MEIOTIC PAIRING BETWEEN SINGLE CHROMOSOMES OF DIPLOID AGROPYRON ELONGATUM AND DECAPLOID A. ELONGATUM IN TRITICUM AESTIVUM

1975 ◽  
Vol 17 (3) ◽  
pp. 329-336 ◽  
Author(s):  
J. Dvořák
Keyword(s):  
Triticum Aestivum ◽  
Common Wheat ◽  
Meiotic Pairing ◽  
Substitution Lines ◽  
Agropyron Elongatum

It is shown that meiotic pairing between single chromosomes of closely related taxa can be studied in hybrids between alien addition and substitution lines. Using this technique, two chromosomes of diploid A. elongatum which appear to be homoeologous with wheat chromosomes of groups 6 and 7 were shown to pair with chromosomes of decaploid A. elongatum which are also homoeologous with wheat chromosomes of groups 6 and 7. Hence, pairing of these chromosomes verified the suggested homoeology among these chromosomes.Meiotic pairing was also studied in 2 hybrid progenies which carried specific telosomes of diploid A. elongatum in addition to a set of 7 Agropyron chromosomes which came from decaploid A. elongatum. The telosomes paired with the decaploid A. elongatum chromosomes in these hybrids. Hence, four chromosomes of diploid A. elongatum were shown to pair in common wheat with chromosomes of decaploid A. elongatum. Since pairing between diploid A. elongatum and decaploid A. elongatum chromosomes was generally low, it is suggested that the chromosomes assigned to the same group are not homologous but rather closely homoeologous.

scholarly journals A nuclear gene modifying instability of fertility restoration in cytoplasmic male sterile rice

1992 ◽  
Vol 60 (3) ◽  
pp. 195-200 ◽  
Author(s):  
Yoshio Sano ◽  
Mitsugu Eiguchi ◽  
Hiro-Yuki Hirano ◽  
Masa-Aki Yamada
Keyword(s):  
Seed Set ◽  
Fertility Restoration ◽  
Dominant Gene ◽  
Nuclear Gene ◽  
Male Sterile ◽  
Substitution Lines ◽  
Seed Fertility ◽  
Cytoplasmic Male Sterile ◽  
Gametic Selection ◽  
Partial Fertility

SummaryThe present study was carried out to examine the genetic mechanism responsible for reversions to fertile phenotype detected in cytoplasmic male-sterile plants of rice. The cms-bo cytoplasm of Chinsurah boro II gave rise to male-sterility in plants without a gametophytic restorer gene (Rf1). Taichung 65 (T65A) was known to be the maintainer which carries no restorer; however, Taichun 65 preserved in our laboratory (T65B) showed partial fertility (about 8% seed set) when crossed with the male-sterile plants. Unexpectedly, the seed fertility gradually increased with repeated selfings and almost fully fertile plants were obtained in the F6 generation. The cytoplasmic substitution lines revealed that reversions to fertile phenotype resulted from mutational events at the nuclear level. The genetic experiments indicated that the partial fertility observed in the F1 hybrid was controlled by a dominant gene, Ifr1, which was carried by T65B. The results obtained suggested that Ifr1 itself was associated with instability of fertility restoration in the presence of cms-bo cytoplasm since partially fertile plants carrying Ifr1 always showed a tendency for gradual increase in fertility in the later generations. The results are also discussed in relation to a rapid genetic change through intensified gametic selection combined with instability.

Effect of algae Ecklonia maxima extract (Kelpak SL) on yields of common wheat, durum wheat and spelt wheat

2019 ◽  
Vol 74 (1) ◽  
pp. 5-14
Author(s):  
GRZEGORZ SZUMIŁO ◽  
LESZEK RACHOŃ ◽  
BARBARA KROCHMAL-MARCZAK
Keyword(s):  
Triticum Aestivum ◽  
Durum Wheat ◽  
Common Wheat ◽  
Yield Components ◽  
Grain Quality ◽  
Foliar Application ◽  
Control Treatment ◽  
Favourable Effect ◽  
Ecklonia Maxima ◽  
Spelt Wheat

The 3-year experiment was concerned with the response of spring forms of common wheat (Triticum aestivum L. subsp. aestivum), durum wheat (Triticum durum Desf.) and spelt wheat (Triticum aestivum subsp. spelta L. em. Thell.) to the foliar application of a plant growth stimulant (extract from marine algae Ecklonia maxima), with the commercial name of Kelpak SL (GS), as compared to control treatment (C). The following parameters were analysed: yield of grain, yield components (number of ears, weight of 1000 kernels, number and weight of kernels per ear) and physical indicators of grain quality (test weight, uniformity and vitreosity of grain). The study showed that the level of yielding and the yield components were related primarily with the wheat genotype, but they depended also on the agro-climatic conditions and on the algae extract and control experimental treatments. The application of algae extract, compared to the control, caused a significant increase in the yields of the spring wheat species under study, on average by 7.0%. Canopy spraying with algae extract had a favourable effect on the number of ears, on he number and weight of kernels per ear, but it had no effect on the weight of 1000 kernels. The grain quality of durum wheat, spelt wheat and common wheat was affected more strongly by the weather conditions in the successive years of the study and by the genotype than by the foliar application of algae extract. The spelt genotypes were characterised by lower yields and lower grain quality than common wheat and the durum wheat genotypes.

scholarly journals Development and validation of a method for quantification of common wheat, durum wheat, rye and barley by droplet digital PCR

2021 ◽  
Author(s):  
Christian Schulze ◽  
Anne-Catrin Geuthner ◽  
Dietrich Mäde
Keyword(s):  
Durum Wheat ◽  
Real Time ◽  
Bread Wheat ◽  
Common Wheat ◽  
Real Time Pcr ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Food Fraud ◽  
Single Genome ◽  
Cereal Species

AbstractFood fraud is becoming a prominent topic in the food industry. Thus, valid methods for detecting potential adulterations are necessary to identify instances of food fraud in cereal products, a significant component of human diet. In this work, primer–probe systems for real-time PCR and droplet digital PCR (ddPCR) for the detection of these cereal species: bread wheat (together with spelt), durum wheat, rye and barley for real-time PCR and ddPCR were established, optimized and validated. In addition, it was projected to validate a molecular system for differentiation of bread wheat and spelt; however, attempts for molecular differentiation between common wheat and spelt based on the gene GAG56D failed because of the genetic variability of the molecular target. Primer–probe systems were further developed and optimized on the basis of alignments of DNA sequences, as well as already developed PCR systems. The specificity of each system was demonstrated on 10 (spelt), 11 (durum wheat and rye) and 12 (bread wheat) reference samples. Specificity of the barley system was already proved in previous work. The calculated limits of detection (LOD95%) were between 2.43 and 4.07 single genome copies in real-time PCR. Based on the “three droplet rule”, the LOD95% in ddPCR was calculated to be 9.07–13.26 single genome copies. The systems were tested in mixtures of flours (rye and common wheat) and of semolina (durum and common wheat). The methods proved to be robust with regard to the tested conditions in the ddPCR. The developed primer–probe systems for ddPCR proved to be effective in quantitatively detecting the investigated cereal species rye and common wheat in mixtures by taking into account the haploid genome weight and the degree of milling of a flour. This method can correctly detect proportions of 50%, 60% and 90% wholemeal rye flour in a mixture of wholemeal common wheat flour. Quantitative results depend on the DNA content, on ploidy of cereal species and are also influenced by comminution. Hence, the proportion of less processed rye is overestimated in higher processed bread wheat and adulteration of durum wheat by common wheat by 1–5% resulted in underestimation of common wheat.

scholarly journals Cosegregation of Single Genes Associated with Fertility Restoration and Transcript Processing of Sorghum Mitochondrial orf107 and urf209

Genetics ◽  
1998 ◽  
Vol 150 (1) ◽  
pp. 383-391 ◽  
Author(s):  
Hoang V Tang ◽  
Ruying Chang ◽  
Daryl R Pring
Keyword(s):  
Fertility Restoration ◽  
Mitochondrial Gene ◽  
Pollen Viability ◽  
Single Gene ◽  
Dominant Gene ◽  
Nuclear Gene ◽  
Male Sterile ◽  
Reading Frame ◽  
Transcript Processing ◽  
Backcross Populations

Abstract Defective nuclear-cytoplasmic interactions leading to aberrant microgametogenesis in sorghum carrying the IS1112C male-sterile cytoplasm occur very late in pollen maturation. Amelioration of this condition, the restoration of pollen viability, involves a novel two-gene gametophytic system, wherein genes designated Rf3 and Rf4 are required for viability of individual gametes. Rf3 is tightly linked to, or represents, a single gene that regulates a transcript processing activity that cleaves transcriptsof orf107, a chimeric mitochondrial open reading frame specific to IS1112C. The mitochondrial gene urf 209 is also subject to nucleus-specific enhanced transcript processing, 5′ to the gene, conferred by a single dominant gene designated Mmt1. Examinations of transcript patterns in F2 and two backcross populations indicated cosegregation of the augmented orf107 and urf209 processing activities in IS1112C. Several sorghum lines that do not restore fertility or confer orf107 transcript processing do exhibit urf209 transcript processing, indicating that the activities are distinguishable. We conclude that the nuclear gene(s) conferring enhanced orf107 and urf209 processing activities are tightly linked in IS1112C. Alternatively, the similarity in apparent regulatory action of the genes may indicate allelic differences wherein the IS1112C Rf3 allele may differ from alleles of maintainer lines by the capability to regulate both orf107 and urf209 processing activities.

Effect of the Pairing Gene Ph1 and Premeiotic Colchicine Treatment on Intra- and Interchromosome Pairing of Isochromosomes in Common Wheat

Genetics ◽  
1998 ◽  
Vol 150 (3) ◽  
pp. 1199-1208 ◽  
Author(s):  
Juan M Vega ◽  
Moshe Feldman
Keyword(s):  
Common Wheat ◽  
Homologous Chromosome ◽  
Colchicine Treatment ◽  
Crossing Over ◽  
Meiotic Pairing ◽  
Factors Affecting ◽  
Homologous Chromosomes ◽  
Polyploid Wheat ◽  
Main Gene ◽  
Ph1 Gene

Abstract The analysis of the pattern of isochromosome pairing allows one to distinguish factors affecting presynaptic alignment of homologous chromosomes from those affecting synapsis and crossing-over. Because the two homologous arms in an isochromosome are invariably associated by a common centromere, the suppression of pairing between these arms (intrachromosome pairing) would indicate that synaptic or postsynaptic events were impaired. In contrast, the suppression of pairing between an isochromosome and its homologous chromosome (interchromosome pairing), without affecting intrachromosome pairing, would suggest that homologous presynaptic alignment was impaired. We used such an isochromosome system to determine which of the processes associated with chromosome pairing was affected by the Ph1 gene of common wheat—the main gene that restricts pairing to homologues. Ph1 reduced the frequency of interchromosome pairing without affecting intrachromosome pairing. In contrast, intrachromosome pairing was strongly reduced in the absence of the synaptic gene Syn-B1. Premeiotic colchicine treatment, which drastically decreased pairing of conventional chromosomes, reduced interchromosome but not intrachromosome pairing. The results support the hypothesis that premeiotic alignment is a necessary stage for the regularity of meiotic pairing and that Ph1 relaxes this alignment. We suggest that Ph1 acts on premeiotic alignment of homologues and homeologues as a means of ensuring diploid-like meiotic behavior in polyploid wheat.

scholarly journals Development of cytoplasmic male sterile lines and restorer lines of various elite Indica Group rice cultivars using CW-CMS/Rf17 system

Rice ◽  
2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Kinya Toriyama ◽  
Tomohiko Kazama ◽  
Tadashi Sato ◽  
Yoshimichi Fukuta ◽  
Masaaki Oka
Keyword(s):  
Nuclear Gene ◽  
Oryza Rufipogon ◽  
Rice Cultivars ◽  
Male Sterile ◽  
Cytoplasmic Male Sterile ◽  
Cms Line

Abstract Background A cytoplasm of CW-type cytoplasmic male sterile (CMS) line is derived from Oryza rufipogon strain W1 and fertility is restored by a single nuclear gene, Rf17. We have previously reported that CW-CMS were effective for breeding CMS lines of Indica Group rice cultivars, IR 24 and IR 64. The applicability of this CW-CMS/Rf17 system to produce other elite Indica Group rice cultivars with CMS was explored. Findings Out of seven elite Indica Group rice cultivars, complete CMS lines were obtained for six cultivars: NSIC Rc 160, NSIC Rc 240, Ciherang, BRRI dhan 29, NERICA-L-19, and Pusa Basmati. The fertility of these six lines was restored when Rf17 was present. A CMS line was not obtained for the cultivar Samba Mahsuri. Conclusions The CW-CMS/Rf17 system will be useful to produce CMS lines and restorer lines of various elite Indica Group rice cultivars.

Inferences from genetical evidence on the course of meiotic chromosome pairing in plants

1977 ◽  
Vol 277 (955) ◽  
pp. 313-326 ◽  
Keyword(s):  
Chromosome Pairing ◽  
Developmental Stages ◽  
Meiotic Chromosome ◽  
Critical Assessment ◽  
Gene Control ◽  
Meiotic Pairing ◽  
Homologous Chromosomes ◽  
Meiotic Chromosome Pairing ◽  
Combined Use ◽  
Or Gene

Meiotic chromosome pairing is a process that is amenable to genetic and experimental analysis. The combined use of these two approaches allows for the process to be dissected into several finite periods of time in which the developmental stages of pairing can be precisely located. Evidence is now available, in particular in plants, that shows that the pairing of homologous chromosomes, as observed at metaphase I, is affected by events occurring as early as the last premeiotic mitosis; and that the maintenance of this early determined state is subsequently maintained by constituents (presumably proteins) that are sensitive to either colchicine, temperature or gene control. A critical assessment of this evidence in wheat and a comparison of the process of pairing in wheat with the course of meiotic pairing in other plants and animals is presented.

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