scholarly journals DIFFERENTIAL ALLELIC EXPRESSION AT A LOCUS ENCODING AN ENDOSPERM PROTEIN IN TETRAPLOID WHEAT (TRITICUM TURGIDUM)

Genetics ◽  
1978 ◽  
Vol 89 (1) ◽  
pp. 147-156
Author(s):  
G Salcedo ◽  
C Aragoncillo ◽  
M A Rodriguez-Loperena ◽  
P Carbonero ◽  
F Garcia-Olmedo

ABSTRACT Two hydrophobic endosperm proteins, designated CM3 and CM3′, have been purified from appropriate cultivars of tetraploid wheat (T. turgidum) and characterized. They are inherited as though encoded by alleles at a single locus, designated Cm3a and Cm3b, respectively. The net amount of protein molecules has been measured for each of the alleles at one, two and three doses. The amount of CM3′ is 50%-65% of that found for CM3. For both, there is a linear gene dosage response. These effects were observed not only in the parental material and the reciprocal F1 generations, but also in the segregating F2 generation, indicating that the quantitative difference depends on differences in the structural gene or is controlled by regulatory or modifier gene(s) linked to it.

2021 ◽  
Author(s):  
Baljeet K. Gill ◽  
Daryl L. Klindworth ◽  
Matthew N. Rouse ◽  
Jinglun Zhang ◽  
Qijun Zhang ◽  
...  

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 338
Author(s):  
Moran Nave ◽  
Mihriban Taş ◽  
John Raupp ◽  
Vijay K. Tiwari ◽  
Hakan Ozkan ◽  
...  

Triticum turgidum and T. timopheevii are two tetraploid wheat species sharing T. urartu as a common ancestor, and domesticated accessions from both of these allopolyploids exhibit nonbrittle rachis (i.e., nonshattering spikes). We previously described the loss-of-function mutations in the Brittle Rachis 1 genes BTR1-A and BTR1-B in the A and B subgenomes, respectively, that are responsible for this most visible domestication trait in T. turgidum. Resequencing of a large panel of wild and domesticated T. turgidum accessions subsequently led to the identification of the two progenitor haplotypes of the btr1-A and btr1-B domesticated alleles. Here, we extended the haplotype analysis to other T. turgidum subspecies and to the BTR1 homologues in the related T. timopheevii species. Our results showed that all the domesticated wheat subspecies within T. turgidum share common BTR1-A and BTR1-B haplotypes, confirming their common origin. In T. timopheevii, however, we identified a novel loss-of-function btr1-A allele underlying a partially brittle spike phenotype. This novel recessive allele appeared fixed within the pool of domesticated Timopheev’s wheat but was also carried by one wild timopheevii accession exhibiting partial brittleness. The promoter region for BTR1-B could not be amplified in any T. timopheevii accessions with any T. turgidum primer combination, exemplifying the gene-level distance between the two species. Altogether, our results support the concept of independent domestication processes for the two polyploid, wheat-related species.


Genome ◽  
2006 ◽  
Vol 49 (12) ◽  
pp. 1545-1554 ◽  
Author(s):  
J. Li ◽  
D.L. Klindworth ◽  
F. Shireen ◽  
X. Cai ◽  
J. Hu ◽  
...  

The aneuploid stocks of durum wheat ( Triticum turgidum L. subsp. durum (Desf.) Husnot) and common wheat ( T. aestivum L.) have been developed mainly in ‘Langdon’ (LDN) and ‘Chinese Spring’ (CS) cultivars, respectively. The LDN-CS D-genome chromosome disomic substitution (LDN-DS) lines, where a pair of CS D-genome chromosomes substitute for a corresponding homoeologous A- or B-genome chromosome pair of LDN, have been widely used to determine the chromosomal locations of genes in tetraploid wheat. The LDN-DS lines were originally developed by crossing CS nulli-tetrasomics with LDN, followed by 6 backcrosses with LDN. They have subsequently been improved with 5 additional backcrosses with LDN. The objectives of this study were to characterize a set of the 14 most recent LDN-DS lines and to develop chromosome-specific markers, using the newly developed TRAP (target region amplification polymorphism)-marker technique. A total of 307 polymorphic DNA fragments were amplified from LDN and CS, and 302 of them were assigned to individual chromosomes. Most of the markers (95.5%) were present on a single chromosome as chromosome-specific markers, but 4.5% of the markers mapped to 2 or more chromosomes. The number of markers per chromosome varied, from a low of 10 (chromosomes 1A and 6D) to a high of 24 (chromosome 3A). There was an average of 16.6, 16.6, and 15.9 markers per chromosome assigned to the A-, B-, and D-genome chromosomes, respectively, suggesting that TRAP markers were detected at a nearly equal frequency on the 3 genomes. A comparison of the source of the expressed sequence tags (ESTs), used to derive the fixed primers, with the chromosomal location of markers revealed that 15.5% of the TRAP markers were located on the same chromosomes as the ESTs used to generate the fixed primers. A fixed primer designed from an EST mapped on a chromosome or a homoeologous group amplified at least 1 fragment specific to that chromosome or group, suggesting that the fixed primers might generate markers from target regions. TRAP-marker analysis verified the retention of at least 13 pairs of A- or B-genome chromosomes from LDN and 1 pair of D-genome chromosomes from CS in each of the LDN-DS lines. The chromosome-specific markers developed in this study provide an identity for each of the chromosomes, and they will facilitate molecular and genetic characterization of the individual chromosomes, including genetic mapping and gene identification.


2018 ◽  
Vol 69 (2) ◽  
pp. 121 ◽  
Author(s):  
Sriram Padmanaban ◽  
Peng Zhang ◽  
Mark W. Sutherland ◽  
Noel L. Knight ◽  
Anke Martin

Both hexaploid bread wheat (AABBDD) (Triticum aestivum L.) and tetraploid durum wheat (AABB) (T. turgidum spp. durum) are highly significant global food crops. Crossing these two wheats with different ploidy levels results in pentaploid (AABBD) F1 lines. This study investigated the differences in the retention of D chromosomes between different hexaploid × tetraploid crosses in subsequent generations by using molecular and cytological techniques. Significant differences (P < 0.05) were observed in the retention of D chromosomes in the F2 generation depending on the parents of the original cross. One of the crosses, 2WE25 × 950329, retained at least one copy of each D chromosome in 48% of its F2 lines. For this cross, the retention or elimination of D chromosomes was determined through several subsequent self-fertilised generations. Cytological analysis indicated that D chromosomes were still being eliminated at the F5 generation, suggesting that in some hexaploid × tetraploid crosses, D chromosomes are unstable for many generations. This study provides information on the variation in D chromosome retention in different hexaploid × tetraploid wheat crosses and suggests efficient strategies for utilising D genome retention or elimination to improve bread and durum wheat, respectively.


Genetics ◽  
1981 ◽  
Vol 97 (3-4) ◽  
pp. 625-637 ◽  
Author(s):  
James A Birchler

ABSTRACT The levels of alcohol dehydrogenase (ADH) do not exhibit a structural gene-dosage effect in a one to four dosage series of the long arm of chromosome one (1L) (BIRCHLER19 79). This phenomenon, termed dosage compensation, has been studied in more detail. Experiments are described in which individuals aneuploid for shorter segments were examined for the level of ADH in order to characterize the genetic nature of the compensation. The relative ADH expression in segmental trisomics and tetrasomics of region IL 0.72–0.90, which includes the Adh locus, approaches the level expected from a strict gene dosage effect. Region IL 0.20–0.72 produces a negative effect upon ADH in a similar manner to that observed with other enzyme levels when IL as a whole is varied (BIRCHLEF1I9 79). These and other comparisons have led to the concept that the compensation of ADH results from the cancellation of the structural gene effect by the negative aneuploid effect. The example of ADH is discussed as a model for certain other cases of dosage compensation in higher eukaryotes.


1970 ◽  
Vol 35 (3) ◽  
pp. 413-422 ◽  
Author(s):  
M Tuhina-Khatun ◽  
MAA Bari ◽  
MA Zaman ◽  
H Begum ◽  
S Akter

Spring wheat (Triticum aestivum L.) varieties Gaurab, Kanchan, Balaka, Sonora, Protiva, Pavon, and Anza were used as parent materials to estimate heterosis in a set of 7 × 7 diallel crosses. The diallel trial was carried out for seven parental material and their 21 F2 progenies under two contrasting cultural conditions for different yield and yield contributing characters. Cultural conditions I is provided by the BARI recommended doses of fertilizer and irrigation, and 2 have no fertilizer but two irrigations once at crown root initiation stage and twice at panicle initiation stage. Heterosis was measured as i) Relative heterosis and ii) Heterobeltiosis. The result of relative heterosis revealed cross Sonora × Anza exhibited superior performance for grain yield/plot in environment-i. Desirable negative heterosis was observed in cross Balaka × Anza in environment-I and Pavon x Anza in environment-2 for days to 50% heading character. For days to maturity, desirable negative heterosis was found in cross Pavon x Anza in both cultural environments. Estimate of heterobeltiosis for different yield contributing characters showed that cross Sonora x Anza exhibited highest heterosis for grain yield/plant in environment-1 and Kanchan x Balaka in environment-2. Cross Pavon x Anza exhibited superior relative heterosis and heterobeltiosis for 100-grain weight in both cultural environments. By comparing two cultural conditions, it was found that 1 is better than 2 for all the characters. Keywords: Relative heterosis; heterobeltiosis; spring wheat; F2 generation; GxE interaction. DOI: 10.3329/bjar.v35i3.6448Bangladesh J. Agril. Res. 35(3) : 413-422


Genome ◽  
2020 ◽  
Vol 63 (5) ◽  
pp. 263-273
Author(s):  
Yuanyuan Zuo ◽  
Qin Xiang ◽  
Shoufen Dai ◽  
Zhongping Song ◽  
Tingyu Bao ◽  
...  

Aegilops comosa and Ae. markgrafii are diploid progenitors of polyploidy species of Aegilops sharing M and C genomes, respectively. Transferring valuable genes/traits from Aegilops into wheat is an alternative strategy for wheat genetic improvement. The amphidiploids between diploid species of Aegilops and tetraploid wheat can act as bridges to overcome obstacles from direct hybridization and can be developed by the union of unreduced gametes. In this study, we developed seven Triticum turgidum – Ae. comosa and two T. turgidum – Ae. markgrafii amphidiploids. The unreduced gametes mechanisms, including first-division restitution (FDR) and single-division meiosis (SDM), were observed in triploid F1 hybrids of T. turgidum – Ae. comosa (STM) and T. turgidum – Ae. markgrafii (STC). Only FDR was observed in STC hybrids, whereas FDR or both FDR and SDM were detected in the STM hybrids. All seven pairs of M chromosomes of Ae. comosa and C chromosomes of Ae. markgrafii were distinguished by fluorescent in situ hybridization (FISH) probes pSc119.2 and pTa71 combinations with pTa-535 and (CTT)12/(ACT)7, respectively. Meanwhile, the chromosomes of tetraploid wheat and diploid Aegilops parents were distinguished by the same FISH probes. The amphidiploids possessed specific valuable traits such as multiple tillers, large seed size related traits, and stripe rust resistance that could be utilized in the genetic improvement of wheat.


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