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

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.

Genome ◽  
1990 ◽  
Vol 33 (1) ◽  
pp. 30-39 ◽  
Author(s):  
J. Dvořák ◽  
P. Resta ◽  
R. S. Kota

The genome allocation of the Triticum aestivum L. chromosomes denoted 4A and 4B was based on an erroneous inference. Since neither chromosome pairs with the chromosomes of putative ancestors of wheat, molecular tools were employed to clarify the origin of the two chromosomes. Disomic substitutions for T. aestivum chromosomes 4A or 4B by chromosomes 4 from T. speltoides (Tausch) Gren., a putative ancestor of the wheat B genome, T. longissimum (Schweinf. et Muschl.) Bowden (a close relative of T. speltoides), or T. monococcum L. ssp. aegilopoides (Link) Thell., a close relative of the ancestor of the wheat A genome, were produced. The ability of the substituted chromosome to compensate in the disomic substitution lines, the C-banding patterns of the chromosomes, electrophoretic alleles at the Adh-1 and Lpx-1 loci, and in situ hybridization with an interspersed repeated sequence all were consistent in showing that the chromosome previously denoted as 4A belongs to the B genome and the chromosome previously denoted as 4B is a rearranged chromosome of the A genome. Chromosome 4A is consequently reallocated to the B genome and chromosome 4B to the A genome in T. turgidum L. em. Morris et Sears and T. aestivum. To reflect the fact that the chromosome previously denoted as 4B has only a homoeologous relationship to chromosome 4A of T. urartu (the ancestor of the A genome in polyploid wheats), the chromosome is designated 4Aa.Key words: repeated nucleotide sequence, alcohol dehydrogenase, lipoxygenase, in situ hybridization, chromosome evolution.


Genome ◽  
1999 ◽  
Vol 42 (4) ◽  
pp. 706-713 ◽  
Author(s):  
Concha Linares ◽  
Antonio Serna ◽  
Araceli Fominaya

A repetitive sequence, pAs17, was isolated from Avena strigosa (As genome) and characterized. The insert was 646 bp in length and showed 54% AT content. Databank searches revealed its high homology to the long terminal repeat (LTR) sequences of the specific family of Ty1-copia retrotransposons represented by WIS2-1A and Bare. It was also found to be 70% identical to the LTR domain of the WIS2-1A retroelement of wheat and 67% identical to the Bare-1 retroelement of barley. Southern hybridizations of pAs17 to diploid (A or C genomes), tetraploid (AC genomes), and hexaploid (ACD genomes) oat species revealed that it was absent in the C diploid species. Slot-blot analysis suggested that both diploid and tetraploid oat species contained 1.3 × 104 copies, indicating that they are a component of the A-genome chromosomes. The hexaploid species contained 2.4 × 104 copies, indicating that they are a component of both A- and D-genome chromosomes. This was confirmed by fluorescent in situ hybridization analyses using pAs17, two ribosomal sequences, and a C-genome specific sequence as probes. Further, the chromosomes involved in three C-A and three C-D intergenomic translocations in Avena murphyi (AC genomes) and Avena sativa cv. Extra Klock (ACD genomes), respectively, were identified. Based on its physical distribution and Southern hybridization patterns, a parental retrotransposon represented by pAs17 appears to have been active at least once during the evolution of the A genome in species of the Avena genus.Key words: chromosomal organization, in situ hybridization, intergenomic translocations, LTR sequence, oats.


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.


Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 229-233 ◽  
Author(s):  
C. F. Konzak ◽  
L. R. Joppa

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.


Genome ◽  
2004 ◽  
Vol 47 (1) ◽  
pp. 206-214 ◽  
Author(s):  
Khwaja G Hossain ◽  
Oscar Riera-Lizarazu ◽  
Venugopal Kalavacharla ◽  
M Isabel Vales ◽  
Jamie L Rust ◽  
...  

Triticum aestivum (2n = 6x = 42, AABBDD) with Triticum longissimum (2n = 2x = 14; S1S1) cytoplasm ((lo) cytoplasm) has normal fertility and plant vigor. However, the nucleus of durum wheat (Triticum turgidum (2n = 4x = 28, AABB)) is incompatible with the T. longissimum cytoplasm, producing non-viable progeny. This incompatibility is alleviated by scsae, a species cytoplasm-specific (scs) gene, on the long arm of chromosome 1D (1DL) of common wheat. The hemizygous (lo) durum scsae line is male sterile and is maintained by crossing to normal durum wheat. After pollination, the seeds produced are either plump and viable (with scsae) or shriveled and inviable (without scsae). Thus, the chromosome with scsae is inherited as a whole without recombination. The objectives of this study were to characterize the chromosome carrying scsae and to determine the process through which this gene was introgressed into the (lo) durum background. Molecular marker analysis with 27 probes and primers mapped to homoeologous group 1 and genomic in situ hybridization using differentially labeled total genomic DNA of durum wheat and Aegilops tauschii suggest the presence of a 1AL segment in place of the distal region of 1DL. Owing to the absence of any detectable duplications or deletions, homoeologous recombination is the most likely mechanism by which this introgression occurred.Key words: homoeologous recombination, in situ hybridization, nuclear-cytoplasmic interaction, species cytoplasm specific gene


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 513B-513
Author(s):  
Anfu Hou ◽  
Ellen B. Peffley

Introgression of genes in species crosses can be observed morphologically in backcrossed or selfed progenies, but the phenotype does not give information about the movement of DNAs. Cytogenetic markers allow for visualization of specific DNAs in a genome. Few cytogenetic markers are available in onion to monitor the introgression of DNA in species crosses. Genomic in situ hybridization (GISH) provides a way to locate unique DNA sequences contributed by parents. We are using GISH to monitor the movement of DNAs from A. fistulosum into A. cepa. Results of experiments using A. fistulosum as probe DNA, and A. cepa as blocking DNA will be reported. Also presented are hybridization sites observed in F1BC3 progeny of the GISH.


Genome ◽  
1995 ◽  
Vol 38 (3) ◽  
pp. 548-557 ◽  
Author(s):  
Araceli Fominaya ◽  
Gregorio Hueros ◽  
Yolanda Loarce ◽  
Esther Ferrer

Satellite DNA specific to the oat C genome was sequenced and located on chromosomes of diploid, tetraploid, and hexaploid Avena ssp. using in situ hybridization. The sequence was present on all seven C genome chromosome pairs and hybridized to the entire length of each chromosome, with the exception of the terminal segments of some chromosome pairs. Three chromosome pairs belonging to the A genome showed hybridization signals near the telomeres of their long arms. The existence of intergenomic chromosome rearrangements and the deletions of the repeated units are deduced from these observations. The number of rDNA loci (18S–5.8S–26S rDNA) was determined for the tetraploid and hexaploid oat species. Simultaneous in situ hybridization with the satellite and rDNA probes was used to assign the SAT chromosomes of these species to their correct genomes.Key words: oats, satellite DNA, rDNA, in situ hybridization, genome evolution.


Genome ◽  
2002 ◽  
Vol 45 (6) ◽  
pp. 1230-1237 ◽  
Author(s):  
M L Irigoyen ◽  
C Linares ◽  
E Ferrer ◽  
A Fominaya

Fluorescent in situ hybridization (FISH) employing multiple probes was used with mitotic or meiotic chromosome spreads of Avena sativa L. cv. SunII and its monosomic lines to produce physical chromosome maps. The probes used were Avena strigosa pAs120a (which hybridizes exclusively to A-genome chromosomes), Avena murphyi pAm1 (which hybridizes exclusively to C-genome chromosomes), A. strigosa pAs121 (which hybridizes exclusively to A- and D-genome chromosomes), and the wheat rDNA probes pTa71 and pTa794. Simultaneous and sequential FISH employing two-by-two combinations of these probes allowed the unequivocal identification and genome assignation of all chromosomes. Ten pairs were found carrying intergenomic translocations: (i) between the A and C genomes (chromosome pair 5A); (ii) between the C and D genomes (pairs 1C, 2C, 4C, 10C, and 16C); and (iii) between the D and C genomes (pairs 9D, 11D, 13D, and 14D). The existence of a reciprocal intergenomic translocation (10C–14D) is also proposed. Comparing these results with those of other hexaploids, three intergenomic translocations (10C, 9D, and 14D) were found to be unique to A. sativa cv. SunII, supporting the view that 'SunII' is genetically distinct from other hexaploid Avena species and from cultivars of the A. sativa species. FISH mapping using meiotic and mitotic metaphases facilitated the genomic and chromosomal identification of the aneuploid chromosome in each monosomic line. Of the 18 analyzed, only 11 distinct monosomic lines were actually found, corresponding to 5 lines of the A genome, 2 lines of the C genome, and 4 lines of the D genome. The presence or absence of the 10C–14D interchange was also monitored in these lines.Key words: Avena sativa, monosomics, FISH mapping, genomic identification, intergenomic translocations.


Genome ◽  
2012 ◽  
Vol 55 (6) ◽  
pp. 407-415 ◽  
Author(s):  
Galina Pendinen ◽  
David M. Spooner ◽  
Jiming Jiang ◽  
Tatjana Gavrilenko

Wild potato ( Solanum L. sect. Petota Dumort.) species contain diploids (2n = 2x = 24) to hexaploids (2n = 6x = 72). J.G. Hawkes classified all hexaploid Mexican species in series Demissa Bukasov and, according to a classic five-genome hypothesis of M. Matsubayashi in 1991, all members of series Demissa are allopolyploids. We investigated the genome composition of members of Hawkes’s series Demissa with genomic in situ hybridization (GISH), using labeled DNA of their putative progenitors having diploid AA, BB, or PP genome species or with DNA of tetraploid species having AABB or AAAaAa genomes. GISH analyses support S. hougasii Correll as an allopolyploid with one AA component genome and another BB component genome. Our results also indicate that the third genome of S. hougasii is more closely related to P or a P genome-related species. Solanum demissum Lindl., in contrast, has all three chromosome sets related to the basic A genome, similar to the GISH results of polyploid species of series Acaulia Juz. Our results support a more recent taxonomic division of the Mexican hexaploid species into two groups: the allopolyploid Iopetala group containing S. hougasii, and an autopolyploid Acaulia group containing S. demissum with South American species S. acaule Bitter and S. albicans (Ochoa) Ochoa.


Genome ◽  
2013 ◽  
Vol 56 (5) ◽  
pp. 303-305 ◽  
Author(s):  
Ming Hao ◽  
Jiangtao Luo ◽  
Lianquan Zhang ◽  
Zhongwei Yuan ◽  
Youliang Zheng ◽  
...  

The important cyclic translocation 4AL–5AL–7BS is an evolutionary signature of polyploidy in wheat. This study aimed to determine its distribution within the subspecies of Triticum turgidum L., using genomic in situ hybridization and fluorescence in situ hybridization. As it exists in all eight subspecies, this translocation appeared before the differentiation of the subspecies of T. turgidum. This translocation probably first appeared in T. turgidum subsp. dicoccoides and was then transmitted into the other subspecies. Its existence in all of the analyzed subspecies suggests that this translocation may confer an adaptive advantage during the course of evolution.


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