A gene for embryo–endosperm compatibility and seed viability in alloplasmic Triticum turgidum

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 772-779 ◽  
Author(s):  
S. S. Maan
Keyword(s):  
Triticum Turgidum ◽  
Fertility Restoration ◽  
Seed Viability ◽  
Hybrid Progeny ◽  
Genome Chromosome ◽  
D Genome ◽  
Aegilops Cylindrica ◽  
Cytoplasmic Effects ◽  
Complex Inheritance ◽  
Donor Species

Alien cytoplasms have more deleterious effect on Triticum turgidum L. var. durum (2n = 28; 14 II; AABB) than on T. aestivum L. (2n = 42; 21 II; AABBDD). The species cytoplasm specific (scs) nuclear genes from the cytoplasm donor species and scs homoeoalleles ameliorate cytoplasmic effects in alloplasmic wheats. The D-genome chromosome(s) of T. aestivum must have a scs gene(s) that is absent in T. turgidum. Also, the dosage of scs homoeoalleles must be more favorable for nucleocytoplasmic compatibility (NCC) in 6x than 4x wheats. This paper reports that two genes, scs on 1DL telosome from T. aestivum 'Selkirk' and a vitality (Vi) gene from (Aegilops cylindrica) T. aestivum 'Selkirk', restored nucleocytoplasmic and embryo–endosperm compatibility, fertility, seed viability, and plant vigor in Ae. squarrosa and Ae. cylindrica 29-chromosome durum plants. In the absence of Vi, 29-chromosome plants set a few sporadic plump seed in selfed spikes but a few plump (about same number as in selfed spikes) and a large number of shrivelled seed in spikes crossed with euplasmic durum. Seed with Vi embryos were viable and those without Vi were nonviable. Similarly, Vi restored fertility to spontaneous aneuploids in the progeny of Ae. squarrosa 29-chromosome plants. Euploid sibs with Vi, but without 1DL telosome, had greatly reduced vigor. The control 'Selkirk' and durum wheats did not have Vi. Hence, Vi may have originated by mutation in Ae. cylindrica 'Selkirk' or Ae. cylindrica durum. Similar spontaneous changes may improve fertility in interspecific hybrid progeny and condition complex inheritance of fertility restoration in alloplasmic wheats.Key words: T. aestivum, Vi and scs genes, xenia effect, zygotic sterility, seed viability, nucleocytoplasmic compatibility, syndrome of cytoplasmic effects.

Interactions between the scs and Vi genes in alloplasmic durum wheat

Genome ◽  
1994 ◽  
Vol 37 (2) ◽  
pp. 210-216 ◽  
Author(s):  
S. S. Maan
Keyword(s):  
Male Sterility ◽  
Chromosomal Location ◽  
Triticum Turgidum ◽  
Meiotic Chromosome ◽  
Seed Viability ◽  
Triticum Aestivum L ◽  
Male Sterile ◽  
Genome Chromosome ◽  
D Genome ◽  
Alien Cytoplasm

Two nuclear genes, vitality (Vi) on an A- or B-genome chromosome and species cytoplasm specific (scs) on a 1DL telosome from Triticum aestivum L. or a telosome from Aegilops uniaristata Vis. (un telosome), improved compatibility between the nucleus of Triticum turgidum L. var. durum and the cytoplasm of Ae. longissima S. &M. or Ae. uniaristata. To study interactions between Vi and scs and to determine the chromosomal location of Vi, 29-chromosome fertile plants were crossed with 13 D-genome disomic-substitution (d-sub) lines [except 5D(5A)] of 'Langdon' durum. F1 and backcross progenies were examined for meiotic chromosome number and pairing, fertility, and plant vigor. In 11 crosses, Vi restored seed viability but produced double-monosomics (d-monos) with greatly reduced growth and vigor. In contrast, crosses involving 1D(1A) and 1D(1B) d-sub lines produced d-monos with normal vigor and anthesis but nonfunctional pollen. A backcross of 1D + 1A d-mono F1 and 1D(1A) d-sub lines produced 11 male steriles; 3 had 13 II + 1 II 1D + 1 I 1A, 2 had 13 II + 2 I, 1 had 13 II + 1 II 1D(1A), and 5 were not examined. Crosses of 1D + 1A d-mono F1 with control durum, lo durum (with 1DL), and un durum (with un telosome) lines produced 16 male-sterile d-monos and 14 fertiles with 14 II + 1 I 1D, showing that 15-chromosome female gametes transmitted monosomes 1A and 1D. However, BC2F1's from 1D + 1B d-mono × fertile line with un telosome included 20 male-sterile d-monos, 6 fertile triple monosomics (13 II + 1 I 1D + 1 I 1B + t I un telosome), and 1 fertile plant with a 1B/1D translocation. Unlike d-mono 1A + 1D, d-mono 1B + 1D did not transmit 15-chromosome female gametes with monosomes 1D and 1B. Additional backcrosses also indicated that homozygous scs caused male sterility in 1D(1A) and 1D(1B) d-subs and that the procedure used was not suitable for the chromosomal location of Vi.Key words: alien cytoplasm, nucleocytoplasmic interactions, 1B/1D translocation, aneuploidy, cytoplasmic male sterility.

Molecular characterization and chromosome-specific TRAP-marker development for Langdon durum D-genome disomic substitution lines

Genome ◽  
2006 ◽  
Vol 49 (12) ◽  
pp. 1545-1554 ◽  
Author(s):  
J. Li ◽  
D.L. Klindworth ◽  
F. Shireen ◽  
X. Cai ◽  
J. Hu ◽  
...  
Keyword(s):  
Triticum Turgidum ◽  
Tetraploid Wheat ◽  
Substitution Lines ◽  
Genome Chromosome ◽  
D Genome ◽  
Single Chromosome ◽  
B Genome ◽  
The Individual ◽  
Trap Marker

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.

The scs and Vi genes correct a syndrome of cytoplasmic effects in alloplasmic durum wheat

Genome ◽  
1992 ◽  
Vol 35 (5) ◽  
pp. 780-787 ◽  
Author(s):  
S. S. Maan
Keyword(s):  
Durum Wheat ◽  
Triticum Turgidum ◽  
Seed Viability ◽  
Male Sterile ◽  
Selfed Progeny ◽  
Alloplasmic Lines ◽  
Preferential Transmission ◽  
Cytoplasmic Effects ◽  
True Breeding ◽  
Aegilops Squarrosa

The nucleus of Triticum turgidum L. var. durum is incompatible with cytoplasms of Aegilops squarrosa L., Ae. cylindrica Host, Ae. uniaristata Vis., and Ae. longissima S. &M. However, durum lines with these cytoplasms were obtained by adding a telosome from Ae. uniaristata (un telosome) or a 1DL telosome from T. aestivum L. 'Selkirk'. The Ae. squarrosa and Ae. cylindrica 29-chromosome plants with 1DL telosome were partially fertile. While Ae. uniaristata or Ae. longissima 29-chromosome plants with 1DL or un telosome were male sterile. The four alloplasmic lines set a few plump and a large number of shrivelled seed from crosses with euploid durum. Only plump seed germinated and produced 29-chromosome plants in successive backcrosses. The telosomes must have a species cytoplasm specific (scs) gene(s) that improved nucleocytoplasmic (NCC) and embryo–endosperm compatibility (EEC), but scs was not transferred to a durum chromosome because telosomes remained meiotically unpaired in 29-chromosome plants. However, a scs gene with similar effects was transferred from T. timopheevii Zhuk. to Ae. longissima euploid durum. The resulting plants were male sterile and set a 1:1 ratio of plump and shrivelled seed. This paper reports that a vitality gene (Vi) restored NCC, EEC, seed viability, fertility, and vigor to Ae. longissima euploid F1's with scs from T. timopheevii. F1 progeny had a 1:1 ratio of fertile plants of normal vigor and low vigor plants (LVP). Thus, Vi had xenia effect, improved EEC, and corrected a syndrome of cytoplasmic effects in 50% of the F1's where Vi was epistatic or dominant to scs. The F2 and sucessive selfed progeny segregated for LVP but true breeding fertile plants were not obtained. Either scs and Vi were alleles, heterosexual gametes with scs and Vi were incompatible, scs had preferential transmission through the heterosexual gametophytes, or Vi was inactivated or remained unexpressed. Thus, scs and Vi had an unorthodox manner of inheritance and expression.Key words: Triticum, dfs, xenia effect, zygotic sterility, embryo–endosperm compatibility.

Production of durum wheat substitution haploids from durum × maize crosses and their cytological characterization

Genome ◽  
2001 ◽  
Vol 44 (1) ◽  
pp. 137-142 ◽  
Author(s):  
M Dogramac1-Altuntepe ◽  
P P Jauhar
Keyword(s):  
In Situ Hybridization ◽  
Durum Wheat ◽  
Triticum Turgidum ◽  
Genomic In Situ Hybridization ◽  
Substitution Lines ◽  
Genome Chromosome ◽  
D Genome ◽  
Maize Pollen ◽  
A Genome

The objective of this study was to investigate the effect of individual durum wheat (Triticum turgidum L.) chromosomes on crossability with maize (Zea mays L.) and to cytologically characterize the haploids recovered. Fourteen 'Langdon' (LDN) D-genome disomic substitution lines, a LDN Ph mutant (Ph1b ph1b), and normal 'Langdon' were pollinated with maize pollen. After pollination, hormonal treatment was given daily for up to 14 days. Haploid embryos were obtained from all lines and were aseptically cultured. From a total of 55 358 pollinated florets, 895 embryos were obtained. Only 14 of the embryos germinated and developed into healthy plants. Different substitution lines showed varying degrees of success. The most successful was the substitution 5D(5B) for both embryo formation and haploid plantlet production. These results indicate that the substitution of 5D for 5B confers on durum wheat a greater ability to produce haploids. Fluorescent genomic in situ hybridization (GISH) showed that the substitution haploids consisted of 7 A-genome chromosomes, 6 B-genome chromosomes, and 1 D-genome chromosome. Triticum urartu Tum. genomic DNA was efficient in probing the 7 A-genome chromosomes, although the D-genome chromosome also showed intermediate hybridization. This shows a close affinity between the A genome and D genome. We also elucidated the evolutionary translocation involving the chromosomes 4A and 7B that occurred at the time of evolution of durum wheat. We found that the distal segment translocated from chromosome 7B constitutes about 24% of the long arm of 4A.Key words: cyclic translocation 4A·5A·7B, crossability, disomic substitution, fluorescent genomic in situ hybridization (GISH), Triticum turgidum.

A cytological and molecular analysis of D-genome chromosome retention following F2–F6 generations of hexaploid×tetraploid wheat crosses

2018 ◽  
Vol 69 (2) ◽  
pp. 121 ◽  
Author(s):  
Sriram Padmanaban ◽  
Peng Zhang ◽  
Mark W. Sutherland ◽  
Noel L. Knight ◽  
Anke Martin
Keyword(s):  
Durum Wheat ◽  
Tetraploid Wheat ◽  
Triticum Aestivum L ◽  
Food Crops ◽  
Cytological Analysis ◽  
Genome Chromosome ◽  
D Genome ◽  
Ploidy Levels ◽  
F2 Generation ◽  
Global Food

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.

Potential for gene transfer between wheat (Triticum aestivum) and jointed goatgrass (Aegilops cylindrica)

Weed Science ◽  
1998 ◽  
Vol 46 (3) ◽  
pp. 313-317 ◽  
Author(s):  
R. S. Zemetra ◽  
J. Hansen ◽  
C. A. Mallory-Smith
Keyword(s):  
Seed Set ◽  
Management Plan ◽  
Female Fertility ◽  
Recurrent Parent ◽  
D Genome ◽  
Aegilops Cylindrica ◽  
Herbicide Resistant ◽  
Jointed Goatgrass ◽  
Transfer Genes ◽  
Parent Female

Jointed goatgrass is a major weed in the wheat-producing areas of the western U.S. It shares the D genome with wheat, and interspecific hybrids between the two species occur in the field. The objective of this research was to determine if wheat X jointed goatgrass hybrids could serve to transfer genes from wheat to jointed goatgrass. A backcrossing program was initiated in the greenhouse between wheat X jointed goatgrass hybrids and either jointed goatgrass or wheat to determine the potential for seed set and the restoration of self-fertility. Seed was set by backcrossing with either species as the recurrent parent. Female fertility increased from 2% in the hybrid to 37% in the BC2 plants with jointed goatgrass as the recurrent parent. Partial self-fertility was restored in the second backcross (BC2) generation using jointed goatgrass as the recurrent parent. This indicates that genes could be transferred between wheat and jointed goatgrass after only two backcrosses. The number of bivalents observed in the plants during meiosis appeared to be key to increasing female fertility and self-fertility. Based on the results of this study, it is possible for genes to move from wheat to jointed goatgrass. Any release of a herbicide-resistant wheat should be accompanied by a management plan that would minimize the potential for gene movement between these species.

The inheritance and chromosomal location of a gene for chocolate chaff in durum wheat

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 229-233 ◽  
Author(s):  
C. F. Konzak ◽  
L. R. Joppa
Keyword(s):  
Durum Wheat ◽  
Chromosomal Location ◽  
Triticum Turgidum ◽  
Recessive Gene ◽  
Single Recessive Gene ◽  
Chromosome Substitution ◽  
Substitution Lines ◽  
D Genome ◽  
B Genome ◽  
Aneuploid Chromosome

The durum wheat (Triticum turgidum L. var. durum) cultivar 'Vic' was treated with the chemical mutagen N-methyl-N′-nitrosourea and among the M2 progeny a mutant with "chocolate chaff" (designated cc) was identified. Genetic analyses indicated that chocolate chaff is due to a single recessive gene mutation. The penetrance of the gene for chocolate chaff was environmentally influenced and varied from dark blotches on the glumes to complete coloration of culms as well as spikes. To determine the chromosomal location of the gene, the mutant was crossed with a set of 'Langdon' durum disomic substitution lines in which each of the 14 A- and B-genome chromosomes of durum wheat were replaced by their respective D-genome homoeologues. The segregation of cc was normal in all of the crosses except for those with the 7D(7A) and 7D(7B) lines. Cytogenetic analysis indicated that the gene was located on chromosome 7B, and that chromosome 7D has a gene that prevents the expression of cc when present in one or more copies. It was shown that the 'Langdon' D-genome disomic substitution lines can be used to determine the chromosomal location of genes in tetraploid wheat.Key words: Triticum turgidum, aneuploid, chromosome substitution, monosomic, cytogenetics.

INHERITANCE OF THE TYPE OF SOLID STEM IN GOLDEN BALL (TRITICUM DURUM): II. CYTOGENETICS OF THE RELATION BETWEEN SOLID STEM AND OTHER MORPHOLOGICAL CHARACTERS IN HEXAPLOID F5 LINES OF A HYBRID WITH RESCUE (T. AESTIVUM)

1959 ◽  
Vol 37 (6) ◽  
pp. 1207-1216 ◽  
Author(s):  
Ruby I. Larson
Keyword(s):  
Triticum Aestivum ◽  
Triticum Durum ◽  
Triticum Aestivum L ◽  
Morphological Characters ◽  
Genome Chromosome ◽  
D Genome ◽  
Stem Solidness ◽  
Pentaploid Hybrid ◽  
Golden Ball ◽  
Solid Stem

Cytogenetic analysis of selected F5 lines of the pentaploid hybrid, Rescue (Triticum aestivum L. emend. Thell.) × Golden Ball (T. durum Desf.) showed that chromosome XVI is the member of the D genome of Rescue that prevents transfer of the more solid top culm internode of Golden Ball to hexaploid segregates. It also produces a lax spike. Chromosome XX, which is the D-genome chromosome mainly responsible for the hollowness of hollow-stemmed hexaploids, probably has little effect in Rescue. Long awns were associated with low chromosome number but not with stem solidness or dense spike; therefore, the chromosome that suppresses awn development is probably not XVI.Three 42-chromosome segregates from the cross were more solid in the top internode than Rescue, presumably because of segregation of genes in the A and B genomes. It is unlikely, however, that a fully hexaploid segregate with a top internode as solid as that of Golden Ball can be selected from this hybrid.

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