The inheritance of genetic variation in Triticum speltoides affecting heterogenetic chromosome pairing in hybrids with Triticum aestivum

1984 ◽  
Vol 26 (3) ◽  
pp. 279-287 ◽  
Author(s):  
K. C. Chen ◽  
J. Dvořák
Keyword(s):  
Triticum Aestivum ◽  
Genetic Variation ◽  
Chromosome Pairing ◽  
Major Gene ◽  
Diploid Species ◽  
Duplicate Gene ◽  
The Other ◽  
Major Genes ◽  
Minor Genes

Triticum speltoides (Tausch) Gren. ex Richter plants which differed in the ability to promote heterogenetic chromosome pairing in hybrids T. aestivum L. × T. speltoides were crossed and a single F1 plant from each cross was hybridized with T. aestivum. The segregation among the hybrids for mean number of chiasmata per cell showed that two gene systems in T. speltoides genotypes were involved in the promotion of heterogenetic pairing. One system was composed of two duplicate gene loci segregating independently of each other. Variation at these loci determined two basic levels of heterogenetic pairing. The other system was composed of several minor genes extensively modifying the effects of the major genes. The minor genes interacted mostly in an additive fashion. Triticum speltoides inbred plants were then crossed with diploid species. T. tauschii (Coss.) Schmal and T. dichasians (Zhuk.) Bowden. Consistent differences in the levels of chromosome pairing were found in these hybrids. However, this variation in chromosome pairing did not coincide with the variation at the major gene loci. This indicated that the major genes were ineffective in the diploid hybrids.Key words: Triticum, pairing regulation, homeologous pairing, heterogenetic pairing.

Inheritance of resistance to stem rust in 'Bonza', 'Chris', 'FKN-II-50-17', 'MRFY', 'Thatcher', 'Marquillo', and 'Hope' wheats

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 269-276
Author(s):  
M. Padidam ◽  
D. R. Knott
Keyword(s):  
Triticum Aestivum ◽  
Plant Resistance ◽  
Stem Rust ◽  
Adult Plant Resistance ◽  
Major Gene ◽  
Triticum Aestivum L ◽  
Adult Plant ◽  
Puccinia Graminis ◽  
Seedling Resistance ◽  
Minor Genes

Resistance to stem rust (Puccinia graminis Pers. f. sp. tritici Eriks, and Henn.), particularly adult plant resisitance to race 15B-1, was studied in seven wheat (Triticum aestivum L.) cultivars or lines: 'Bonza', 'Chris', 'FKN-II-50-17', 'MRFY', 'Thatcher', 'Marquillo', and 'Hope'. Each of the seven was crossed with a susceptible parent and either F4- or F5-derived lines developed by single seed descent. All of the lines were tested with race 15B-1 in field nurseries. Lines derived from parents carrying seedling resistance to race 15B-1 were also tested as seedlings in the greenhouse with race 15B-1, and in some cases races 56, 29, and C65. The data indicated that 'Bonza' carries Sr6, probably Sr5, an unidentified gene giving resistance to race 56, two unidentified genes for resistance to race C65, and two minor genes that combine to produce intermediate adult plant resistance. 'Chris' carries Sr5, Sr7a, Sr8a, and Sr12. In addition, it may have three minor genes for adult plant resistance. 'FKN-II-50-17' carries Sr6 and may have four minor genes that combine to produce moderate adult plant resistance. 'MRFY', which is seedling susceptible to race 15B-1, carries Sr9b, possibly Sr5, plus an unidentified gene for resistance to C65. In addition, it appears to have one major gene for adult plant resistance plus two or more minor genes. 'Thatcher', 'Marquillo', and 'Hope' had only limited resistance to race 15B-1 in the field and no genetic analysis of their crosses was possible. The four parents that had good resistance to race 15B-1 in the field, 'Bonza', 'Chris', 'FKN-II-50-17', and 'MRFY', all carry minor genes for adult plant resistance that had little effect individually but produced moderate resistance when combined. The genes Sr5 and Sr9b, which have no effect on resistance to 15B-1 is seedlings, were found to significantly increase resistance in adult plants in the field.Key words: stem rust, Puccinia graminis tritici, wheat, Triticum aestivum, adult plant rust resistance.

GENETIC VARIATION IN TRITICUM AFFECTING THE LEVEL OF CHROMOSOME PAIRING IN INTERGENERIC HYBRIDS

1970 ◽  
Vol 12 (2) ◽  
pp. 278-282 ◽  
Author(s):  
C. J. Driscoll ◽  
C. J. Quinn
Keyword(s):  
Triticum Aestivum ◽  
Genetic Variation ◽  
Natural Selection ◽  
Chromosome Pairing ◽  
Chinese Spring ◽  
Chiasma Frequency ◽  
Intergeneric Hybrids ◽  
Homoeologous Chromosome ◽  
Homoeologous Chromosome Pairing ◽  
Aegilops Variabilis

Genetic differences which affect the extent of homoeologous chromosome pairing in intergeneric hybrids have been demonstrated between varieties of Triticum aestivum. Each of seven varieties of Triticum was crossed with the same strain of Aegilops variabilis. Significant differences in chiasma frequencies between varieties were found. Varieties Eureka, Gamut and Chinese Spring constitute one group with a relatively low chiasma frequency and varieties A. R. Falcon, Federation and Poso constitute a distinct second group with a relatively high chiasma frequency. The variety Bearded Yalta is intermediate to the two groups. Thus, this genetic variation appears to be common among varieties of Triticum. Presumably this variation does not become subject to natural selection as long as chromosome pairing in the parental varieties remains strictly homologous.

Assessment of chromosome associations in haploids and their parental accessions in Hordeum

Genome ◽  
1988 ◽  
Vol 30 (2) ◽  
pp. 204-210 ◽  
Author(s):  
R. von Bothmer ◽  
N. C. Subrahmanyam
Keyword(s):  
Genetic Variation ◽  
Chromosome Pairing ◽  
Diploid Species ◽  
Meiotic Behaviour ◽  
Meiotic Pairing ◽  
Homoeologous Pairing ◽  
Homoeologous Chromosome ◽  
Homologous Pairing ◽  
Homoeologous Chromosome Pairing ◽  
Chromosome Associations

Meiotic pairing was studied in the following species and their haploid derivatives: Hordeum cordobense 2x, H. marinum 2x and 4x, H. secalinum 4x, H. capense 4x, H. jubatum 4x, H. brachyantherum 4x and 6x, H. lechleri 6x, and H. procerum 6x. The study revealed (i) homologous pairing in diploid species and very little nonhomologous associations in their mono-haploids; (ii) the alloploid nature of the polyploid taxa; (iii) a certain degree of homoeologous pairing in polyhaploids despite the diploid-like meiotic behaviour of the polyploids; (iv) genetic variation in the suppression of homoeologous chromosome pairing in different Hordeum species.Key words: Hordeum, meiotic pairing, haploids.

MAJOR AND MINOR GENES IN WHEAT FOR RESISTANCE TO PUCCINIA STRIIFORMIS AND THEIR RESPONSES TO TEMPERATURE CHANGES

1967 ◽  
Vol 45 (11) ◽  
pp. 2155-2172 ◽  
Author(s):  
R. T. Lewellen ◽  
E. L. Sharp ◽  
E. R. Hehn
Keyword(s):  
Temperature Profile ◽  
Puccinia Striiformis ◽  
Major Gene ◽  
Wheat Varieties ◽  
Major Genes ◽  
Temperature Changes ◽  
Minor Genes ◽  
Higher Temperature ◽  
Lower Temperature ◽  
Moderate Resistance

The wheat varieties, 'P.I. 178383' and 'Chinese 166' (Triticum aestivum), were each found to carry an incompletely dominant major gene for resistance to a single pathogenic type of Puccinia striiformis. In addition, an undetermined number of minor genes segregated in such a way that in certain combinations they conferred moderate resistance and modified the action of the major genes. The rust readings were made on seedling plants grown in strictly controlled-environment chambers that simulated natural conditions. The action of the major genes was not affected by different temperature profiles, but the minor genes gave better resistance at a higher temperature profile than at a lower temperature profile.

The inheritance of genetic variation in rye (Secale cereale) affecting homoeologous chromosome pairing in hybrids with bread wheat (Triticum aestivum)

1986 ◽  
Vol 28 (5) ◽  
pp. 844-851 ◽  
Author(s):  
P. K. Gupta ◽  
George Fedak
Keyword(s):  
Triticum Aestivum ◽  
Genetic Variation ◽  
Chromosome Pairing ◽  
Secale Cereale ◽  
Chinese Spring ◽  
Continuous Distribution ◽  
Genetic System ◽  
Aegilops Speltoides ◽  
Homoeologous Chromosome ◽  
Homoeologous Chromosome Pairing

Chiasmata frequencies ranging from 0.07 to 10.40 per cell were recorded in 125 hybrid plants derived from wheat × F1 rye crosses. These included 89 plants belonging to 28 families from the Triticum aestivum 'Chinese Spring' × Secale cereale F1 ('Petkus' × 'Prolific') cross and 36 plants belonging to 11 families from the 'Chinese Spring' × F1 ('Prolific' × 'Puma') cross. The data were analyzed to study the inheritance of genetic variation in rye affecting homoeologous chromosome pairing. The results were particularly interesting in the former case where segregation for major genes was evident. First, in this cross, a bimodal distribution was observed and second, chiasmata frequencies ranging from 6.11 to 10.40 per cell were observed in three families but without any hybrid falling in either the range of 3.0 to 6.0 or in the range of 6.11 to 9.82, showing discontinuous distribution. It was concluded that the genetic system in 'Petkus' differs from that in 'Prolific', and that genes both with major effects and minor effects may be present, the major effects possibly resulting from complementary gene action. In the second cross involving F1 rye plants derived from 'Prolific' × 'Puma', a smaller sample gave a continuous distribution with a single mode, the chiasmata frequency never exceeding 2.70 per cell. This could be due to a difference in genetic systems found in 'Puma' and 'Petkus' since 'Prolific' was a common parent in both crosses. The genetic variation in rye observed in the present study has been compared with that known in Aegilops speltoides and it was concluded that these may be of a similar nature.Key words: Triticum, Secale, pairing regulation, homoeologous pairing.

Genetic and cytogenetic analyses of the A genome of Triticum monococcum. II. The mode of inheritance of spring versus winter growth habit

1986 ◽  
Vol 28 (1) ◽  
pp. 88-95 ◽  
Author(s):  
J. Kuspira ◽  
J. Maclagan ◽  
K. Kerby ◽  
R. N. Bhambhani
Keyword(s):  
Triticum Aestivum ◽  
Growth Habit ◽  
Major Gene ◽  
Diploid Species ◽  
Triticum Monococcum ◽  
Allelic Series ◽  
A Genome ◽  
Multiple Allelic Series ◽  
Winter Growth Habit ◽  
Mode Of Inheritance

The study on the mode of inheritance of spring versus winter growth habit in Triticum monococcum is the first in a diploid wheat species. The results are discussed in light of the information available on the genetics and cytogenetics of this character in Triticum aestivum. Two spring habit and six winter habit lines were used in these investigations. Statistical analyses of progenies in each of these lines clearly established the true-breeding nature of all eight lines with respect to days to heading. Analysis of F1 and F2 results of crosses between the two spring habit lines 68 and 293 showed the following: (i) neither line carries winter habit alleles at any of the major gene loci determining growth habit; and (ii) four of five minor allele pairs determine the phenotypic differences between them. Monohybrid F2 and testcross ratios in crosses between spring habit line 68 and each of the six winter lines lead to the following conclusions: (i) differences between spring and winter growth habit in each cross are due to alleles of one major gene; (ii) the allele for spring habit is completely dominant to that for winter habit in each cross; and (iii) all these lines are genotypically identical or very similar at all modifying gene loci. These results imply that only one major gene determines growth habit in this species. Diallel (critical) crosses among the six recessive lines indicate that complementation does not occur in any of the F1's. Therefore, all these recessive genes represent mutations in the same gene. If these results are characteristic of all winter lines in Triticum monococcum, they permit the initial conclusion that only one major gene determines growth habit in this diploid species. This locus is in all likelihood the VrnI locus since it is the only one of the five major genes identified for growth habit, that is present in the A genome of Triticum aestivum. All six recessive lines respond to natural vernalization. This lends further support to our initial conclusion. Because the six recessive lines head at five different times we conclude that a multiple allelic series occurs at this locus. Specifically, at least three and probably five recessive alleles responsible for different heading dates among the winter lines, and at least one dominant allele for spring habit, occur at this locus.Key words: Triticum, complementation, quantitative, vernalization, alleles, multiple.

THE GENIC BASIS FOR DIFFERENCES IN SEDIMENTATION VALUE AND PROTEIN CONTENT BETWEEN TWO CULTIVARS OF TRITICUM AESTIVUM

1975 ◽  
Vol 17 (3) ◽  
pp. 433-439 ◽  
Author(s):  
K. K. Wu ◽  
F. W. Sosulski ◽  
C. F. Wehrhahn
Keyword(s):  
Triticum Aestivum ◽  
Genetic Variation ◽  
Protein Content ◽  
Genetic Relationship ◽  
Wheat Cultivars ◽  
Major Genes ◽  
Inbred Backcross Lines ◽  
Present Technique ◽  
Sedimentation Value ◽  
Inbred Backcross

Genie analysis was used to study the inheritance of sedimentation value and protein content in two sets of reciprocal inbred backcross lines. Three loci containing genes with major effects were responsible for most of the differences in sedimentation value between two wheat cultivars, Baart and Ramona, grown in two years. These loci accounted for 84% to 93% of genetic variation, while environmental variances were relatively low. However, the differences in protein content between the two parents were too small for the present technique to detect the presence of any major genes. No genetic relationship was found between protein content and sedimentation value.

Different genetic systems in rye affecting homoeologous pairing in wheat – rye combinations

Genome ◽  
1988 ◽  
Vol 30 (5) ◽  
pp. 793-796 ◽  
Author(s):  
M. C. Cuadrado ◽  
C. Romero
Keyword(s):  
Triticum Aestivum ◽  
Secale Cereale ◽  
Chinese Spring ◽  
Genetic System ◽  
The Other ◽  
Meiotic Pairing ◽  
Homoeologous Pairing ◽  
Major Genes ◽  
Genetic Systems ◽  
Polygenic System

The present study analyzed meiotic pairing in wheat – rye hybrids obtained by crossing of Triticum aestivum cv. Chinese Spring with allogamous ryes, two cultivars of Secale cereale ('Don Enrique' and 'Selectión') and Secale cereale ssp. segetale. The results indicate that each rye type has different behaviour on hybrid meiotic pairing because they contain distinct genetic systems affecting meiotic pairing. In the case of 'Don Enrique' and 'Selección,' a polygenic system could be present, but not identical in both cultivars. On the other hand, Secale cereale ssp. segetale contained genes that strongly affect the genetic system controlling homoeologous pairing in wheat.Key words: homoeologous pairing, wheat – rye hybrids, polygenic system, major genes.

INHERITANCE OF BUNT REACTION IN A REDMAN × S-615 WHEAT CROSS

1964 ◽  
Vol 44 (6) ◽  
pp. 561-567 ◽  
Author(s):  
Hugh McKenzie
Keyword(s):  
Triticum Aestivum ◽  
High Resistance ◽  
Major Gene ◽  
Heading Date ◽  
Triticum Aestivum L ◽  
Moderate Degree ◽  
Tilletia Caries ◽  
Wheat Stem Sawfly ◽  
Minor Genes ◽  
Stem Solidness

Inheritance of reaction to race T-2 of Tilletia caries (DC.) Tul. was studied in populations of F3 and B2 lines from the cross Redman × S-615 (Triticum aestivum L.) and the respective backcrosses. Redman and S-615 were found to differ by three genes for bunt reaction. Redman possesses a major gene recessive for resistance, and two minor genes. Each of the minor genes is capable of conditioning a moderate degree of resistance alone but together they are capable of conditioning high resistance as a result of geometric gene actionCorrelation coefficients show that bunt reaction to race T-2 is not associated with wheat stem sawfly (Cephus cinctus Nort.) reaction, total stem solidness, solidness in each internode, awn type, glume color, plant height, or heading date.

The differentiation between chromosome 7D of Triticum aestivum cv. Canthatch and Triticum tauschii as measured by chromosome pairing

1986 ◽  
Vol 28 (3) ◽  
pp. 385-389 ◽  
Author(s):  
G. A. Penner ◽  
E. R. Kerber ◽  
E. N. Larter
Keyword(s):  
Triticum Aestivum ◽  
Chromosome Pairing ◽  
Homologous Chromosome ◽  
The Other ◽  
Chromosome Substitution ◽  
Genome Chromosome ◽  
D Genome ◽  
Triticum Tauschii ◽  
Intraspecific Divergence ◽  
Degree Of Differentiation

Disomic substitution stocks in which chromosome 7D of Triticum aestivum cv. Canthatch was replaced by the corresponding homologous chromosome of each of four varieties of Triticum tauschii were crossed with 'Canthatch' to investigate the degree of differentiation for this chromosome between these two species. These disomic substitutions were also crossed with a 'Canthatch' plant double monotelosomic for chromosome 7D. Three double telotrisomics were produced, one of which had the complete 7D chromosome derived from 'Canthatch', one had 7D derived from the T. tauschii var. typica, and one had 7D from T. tauschii var. strangulata. Analysis of chromosome pairing demonstrated that chromosome 7D from var. typica formed fewer bound arms with 'Canthatch' 7D than did the corresponding chromosome from the other three tauschii varieties. The reduction in pairing between chromosomes 7D of var. typica and 'Canthatch' is greater than that previously reported from intraspecific D-genome chromosome pairing studies within T. aestivum. It is suggested that intraspecific divergence for at least chromosome 7D occurred between var. typica and these other three tauschii varieties before the synthesis of common hexaploid wheat.Key words: Triticum, aneuploidy, chromosome pairing, chromosome substitution.

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