NONSTRUCTURAL CHROMOSOME DIFFERENTIATION AMONG WHEAT CULTIVARS, WITH SPECIAL REFERENCE TO DIFFERENTIATION OF CHROMOSOMES IN RELATED SPECIES

Genetics ◽  
1981 ◽  
Vol 97 (2) ◽  
pp. 391-414
Author(s):  
Jan Dvořák ◽  
Patrick E McGuire

ABSTRACT Wheat cultivar Chinese Spring (Triticum aestivum L. em. Thell.) was crossed with cultivars Hope, Cheyenne and Timstein. In all three hybrids, the frequencies of pollen mother cells (PMCs) with univalents at metaphase I (MI) were higher than those in the parental cultivars. No multivalents were observed in the hybrids, indicating that the cultivars do not differ by translocations. Thirty-one Chinese Spring telosomic lines were then crossed with substitution lines in which single chromosomes of the three cultivars were substituted for their Chinese Spring homologues. The telosomic lines were also crossed with Chinese Spring. Data were collected on the frequencies (% of PMCs) of pairing of the telesomes with their homologues at MI and the regularity of pairing of the remaining 20 pairs of Chinese Spring chromosomes in the monotelodisomics obtained from these crosses. The reduced MI pairing in the intercultivar hybrids was caused primarily by chromosome differentiation, rather than by specific genes. Because the differentiation involved a large part of the chromosome complement in each hybrid, it was concluded that it could not be caused by structural changes such as inversions or translocations. In each case, the differentiation appeared to be unevenly distributed among the three wheat genomes. It is proposed that the same kind of differentiation, although of greater magnitude, differentiates homoeologous chromosomes and is responsible, together with structural differentiation, for poor chromosome pairing in interspecific hybrids.

1981 ◽  
Vol 23 (2) ◽  
pp. 287-303 ◽  
Author(s):  
J. Dvořák

Triticum aestivum L. em Thell ditelosomics 7AL and 7DS and T. aestivum-Elytrigia elongata (Host) Holub (2n = 2x = 14) ditelosomic additions were crossed with "E. elongata 4x" (2n = 4x = 28), E. caespitosa (C. Koch) Nevski (2n = 4x = 28), and E. intermedia (Host) Nevski (2n = 6x = 42). The effect of each Elytrigia genotype on homoeologous (heterogenetic) chromosome pairing was assessed by comparing the pairing frequencies of T. aestivum cv. Chinese Spring telosomes 7AL and 7DS in the hybrids with the pairing frequency of telosome 7AL in haploid Chinese Spring. The genotype of "E. elongata 4x" had no effect on heterogenetic pairing in the hybrids. Although some genotypes of E. caespitosa and E. intermedia promoted heterogenetic pairing in the hybrids, others had no effect. Telosome VS of E. elongata interacted in a complementary fashion with the genotype of "E. elongata 4x," but not with the genotypes of Chinese Spring and E. caespitosa, and it promoted heterogenetic pairing. In hybrids in which the wheat diploidizing genes were active at the normal level, the E. elongata telosomes paired with chromosomes of "E. elongata 4x" in 5.8% to 24.6% of the cells, with chromosomes of E. caespitosa in 0.0% to 1.0% of the cells, and with chromosomes of E. intermedia in 0.0% to 2.8% of the cells. A model of chromosome differentiation is discussed and special attention is devoted to the origin of diploid-like pairing in polyploid species.


Genome ◽  
1991 ◽  
Vol 34 (5) ◽  
pp. 727-732 ◽  
Author(s):  
Zheng-Qiang Ma ◽  
Yin-Hai Zhao ◽  
Da-Jun Liu

Six 'Chinese Spring' – Aegilops umbellulata Zhuk. addition lines (UAD, UBD, UCD, UDD, UED, and UFM) were assayed for their effects on the fertility of timopheevi cytoplasm male sterile lines (T-type). Chromosome 6U of disomic addition line UAD was found to be able to restore the fertility of T-type male sterility and 'Chinese Spring' was verified to lack restoring genes, indicating that 6U carries at least one fertility restoration gene. From about 200 plants with 42 somatic chromosomes derived from the progeny of crosses Qu Xian Early A × UAD and Sumai No. 3 A × UAD, eight self-fertile plants were selected. Their self-fertility in timopheevi cytoplasm implies that they carry the restoring gene(s) from 6U. Cytological analysis was conducted on the hybrid F1 of the selected fertile plants (040-5, 060-1, and 061-4) as female parents crossed with 'Chinese Spring'. The self-fertility segregation and the chromosome pairing of pollen mother cells of F1 fertile plants from 040-5, 060-1, and 061-4 × 'Chinese Spring' during meiosis suggested that they were heterozygous translocation lines with restoring gene(s) from 6U.Key words: Aegilops umbellulata Zhuk., restoring genes, alien gene transfer, timopheevi cytoplasmic male sterile fertility, Triticum aestivum L.


1986 ◽  
Vol 28 (1) ◽  
pp. 12-16
Author(s):  
D. R. Knott

Studies were done in an attempt to determine the inheritance of adult plant resistance to stem rust (Puccinia graminis f. sp. tritici Eriks. and E. Henn.) in the wheat (Triticum aestivum L.) cultivars 'Hope' and 'Thatcher'. 'Chinese Spring' substitution lines carrying individual chromosomes from 'Hope' and 'Thatcher' were tested in field rust nurseries, three times each with races 15B-1 and 56, and twice with multirace mixtures. In 1976 it was found that the date of heading often had a significant effect on rust severity, with early lines showing less rust. In 1977 and 1984 the lines were divided into three groups based on maturity and were planted on three dates about 10 days apart to make heading dates more uniform. The data indicate that 'Hope' has genes for resistance to race 56 on chromosomes 3B (Sr2) and 4D, and to a multirace mixture on 1B, 3B, and 7B. 'Thatcher' possibly has genes for resistance to race 56 on chromosomes 6A and 3B (Sr12). The results show that the resistance of both cultivars is complex and most genes have only small effects.Key words: Triticum, Puccinia, rust resistance, substitution lines.


1986 ◽  
Vol 28 (5) ◽  
pp. 696-700 ◽  
Author(s):  
Nicolás Jouve ◽  
Benito Giorgi

The meiotic behaviour of three hexaploid triticale × Triticum aestivum L. hybrids having different doses of ph1 mutant alleles was investigated using C-band staining of pollen mother cells at first metaphase. D-genome chromosomes that were clearly distinguished by their small size and unbanded response to Giemsa staining were increasingly promoted to pair with the homoeologous chromosomes of the A and B genomes in the absence of Ph1 genes. However, the wheat–rye associations were not enhanced when one or two ph1 alleles were present. The distribution of meiotic configurations was significantly different for each chromosome in the ph1/ph1 hybrid. Thus, 1B did not form multivalents in this hybrid, and the remaining identified chromosomes differed significantly in the level of involvement in tri-, quadri-, or quinque-valents. The hybrids should be of value for hexaploid and wheat breeding programs.Key words: Triticale, Triticum aestivum, C-banding, ph1 mutants.


Genome ◽  
1993 ◽  
Vol 36 (5) ◽  
pp. 913-918 ◽  
Author(s):  
Michael E. Devey ◽  
Gary E. Hart

Hybridization of radiolabeled wheat DNA probes to genomic DNA digests of compensating nullisomic-tetrasomic lines and ditelosomic lines of hexaploid wheat (Triticum aestivum L. cv. Chinese Spring) can be used to identify intergenomic RFLPs. Sixty-three PstI/BamHI genomic DNA probes and eight cDNA probes were used to determine the chromosomal locations of 223 DNA fragments that define a minimum of 189 RFLP loci. Eighty-four percent of the genomic DNA clones hybridize to fragments located in homoeologous chromosomes and 16% hybridize to fragments located in one chromosome only or to fragments located in nonhomoeologous chromosomes. All of the cDNA probes hybridize to fragments located in homoeologous chromosomes.Key words: aneuploids, genetic mapping.


Genome ◽  
2014 ◽  
Vol 57 (2) ◽  
pp. 61-67 ◽  
Author(s):  
András Farkas ◽  
István Molnár ◽  
Sándor Dulai ◽  
Sándor Rapi ◽  
Vince Oldal ◽  
...  

3MbTriticum aestivum L. (Mv9kr1) – Aegilops biuncialis Vis. (MvGB642) addition lines were crossed with the Chinese Spring ph1b mutant genotype (CSph1b) to produce 3Mb–wheat chromosome rearrangements. In the F3generation, 3Mb(4B) substitution lines and 3Mb.4BS centric fusions were identified with in situ hybridization using repetitive and genomic DNA probes, and with SSR markers. Grain micronutrient analysis showed that the investigated Ae. biuncialis accession MvGB382 and the parental line MvGB642 are suitable gene sources for improving the grain micronutrient content of wheat, as they have higher K, Zn, Fe, and Mn contents. The results suggested that the Ae. biuncialis chromosome 3Mbcarries genes determining the grain micronutrient content, as the 3Mb.4BS centric fusion had significantly higher Zn and Mn contents compared with the recipient wheat cultivar. As yield-related traits, such as the number of tillers, the length of main spike, and spikelets per main spike, were similar in the 3Mb.4BS centric fusion and the parental wheat genotype, it can be concluded that this line could be used in pre-breeding programs aimed at enriching elite wheat cultivars with essential micronutrients.


Genetics ◽  
1983 ◽  
Vol 103 (2) ◽  
pp. 313-321
Author(s):  
Paula R Neuman ◽  
J G Waines ◽  
K W Hilu ◽  
D Barnhart

ABSTRACT Two-dimensional paper chromatography was performed on methanol extracts of leaves of hexaploid bread wheat, Triticum aestivum L. em. Thell. cultivar Chinese Spring, and of the available nullisomic-tetrasomic compensating lines, the tetrasomic lines and the ditelocentric lines. The chromatograms had 27 spots identified as flavonoids and six representing phenolic acids. Some of the areas were complex and contained more than one compound. Four flavonoids were identified as under the control of gene(s) on chromosome arms 1DS, 4DL, 5AS and 6BS. A phenolic glycoside was concluded to be controlled by a gene(s) on chromosome arm 7BL. Gene(s) on chromosome arm 4DL affected the amount of compounds in two other spots, and gene(s) on chromosome arm 4BS reduced the level of all flavonoid compounds. The individual compounds in some of the complex spots may be under the control of gene(s) on homoeologous chromosomes.


1982 ◽  
Vol 24 (2) ◽  
pp. 227-233 ◽  
Author(s):  
George Fedak ◽  
Perry Y. Jui

Chromosome substitution lines of the variety Hope in Chinese Spring (Triticum aestivum L.) were crossed onto Betzes barley (Hordeum vulgare L. emend. Lam.). Three substitution lines of Hope involving chromosomes 5A, 5B, 5D gave no seed-set indicating that their counterparts in Chinese Spring were responsible for crossability with barley and that they function in complementary fashion. Other chromosomes of Hope had minor effects on crossability with barley.


Sign in / Sign up

Export Citation Format

Share Document