RAPD-Based Analysis of Introgression of Barley Genetic Material into the Genome of Alloplasmic Wheat Lines (Hordeum geniculatumAll./Triticum aestivum L.)

Genomes of three alloplasmic wheat lines obtained on the basis of barley–wheat hybrid Hordeum geniculatumAll. (2n = 28) ×Triticum aestivumL. (2n = 42)(Pyrotrix 28) were examined using random amplified polymorphic DNA (RAPD) analysis. Line L-29 was obtained after first backcross of the initial hybrid with the wheat variety Pyrotrix 28 and ten subsequent self-pollinating generations. This line was represented by euploid plants with typical to the common wheat chromosome number (2n = 42), as well as by aneuploids, which contained an additional telocentric chromosome in the main karyotype (2n = 42 + t). Lines L-26 and L-27 were obtained by two backcrosses of one BC₁ plant with the wheat variety Novosibirskaya 67 and one subsequent self-polination of one BC₃ plant. Chromosome number in all these plants corresponded to 2n = 40 + 4t. RAPD analysis was carried out using seven primers, which were previously proved to be effective for identification of the barley genome fragments within hybrid genomes of alloplasmic lines. The presence of barley genome fragments in line L-29 was revealed by use of five primers, while in lines L-26 and L-27 these fragments were detected by use of one primer. The significant difference in the number of barley RAPD fragments in the genomes of alloplasmic lines obtained at different backcrossing stages suggests more intense displacement of barley genome during backcrossing compared to self-pollination in BC₁ plants.     

Study of the backcross progeny of barley-wheat hybrids by the RAPD and RAMPO methods

The genomes of alloplasmic wheat lines were analyzed by PCR-based methods: random amplified polymorphic DNA (RAPD) and random amplified microsatellite polymorphism (RAMPO). Lines L-16(1) and L-17(2) were obtained by three backcrosses and line L-79(10), by four backcrosses of the barely-wheat hybrid Hordeum vulgare (2n = 14) (variety Nepolegayuschii) x Triticum aestivum (2n = 42) (variety Saratovskaya 29) with different common wheat varieties. These lines proved to be euploid (2n = 42). The aneuploid line L-9 (2n = 43 + t) was obtained after a second backcross of the hybrid H. geniculatum All. (2n = 28) x T. aestivum (2n = 42) (Pyrotrix 28) with the variety Pyrotrix 28. The RAPD patterns of L-16(1) and L-17(1) contained fragments present only in the patterns of the parental wheat varieties and, in addition, fragments absent from the latter. This fragment from the pattern of L-16(1) was cloned. Analysis of its primary structure showed that the difference between L-16(1) and the parental wheat genotypes may be related to a mutation that had occurred during the development of the alloplasmic line at the binding site of an arbitrary primer. The genomes of plants of the lines L-79(10) and L-9 contain, in addition to the RAPD fragments of wheat, those characteristic of barley. RAMPO revealed higher polymorphism level among wheat varieties than that detected by RAPD. The hybridization patterns of the lines L-16(1), L-17(1), and L-79(10) contained fragments specific for wheat, and the patterns of L-9 contained both wheat and barley fragments.     

Investigation of the Backcross Progeny of Barley–Wheat Hybrids by the RAPD and RAMPO Methods

The genomes of alloplasmic wheat lines were analyzed by PCR-based methods: random amplified polymorphic DNA (RAPD) and random amplified microsatellite polymorphism (RAMPO). Lines L-16(1) and L-17(2) were obtained by three backcrosses and line L-79(10), by four backcrosses of the barley–wheat hybrid Hordeum vulgare (2n = 14) (variety Nepolegayushchii) × Triticum aestivum (2n = 42) (variety Saratovskaya 29) with different common wheat varieties. These lines proved to be euploid (2n= 42). The aneuploid line L-9 (2n = 43 +t) was obtained after a second backcross of the hybridH. geniculatum All. (2n = 28) × T. aestivum (2n = 42) (Pyrotrix 28) with the variety Pyrotrix 28. The RAPD patterns of L-16(1) and L-17(1) contained fragments present only in the patterns of the parental wheat varieties and, in addition, fragments absent from the latter. This fragment from the pattern of L-16(1) was cloned. Analysis of its primary structure showed that the difference between L-16(1) and the parental wheat genotypes may be related to a mutation that had occurred during the development of the alloplasmic line at the binding site of an arbitrary primer. The genomes of plants of the lines L-79(10) and L-9 contain, in addition to the RAPD fragments of wheat, those characteristic of barley. RAMPO revealed higher polymorphism level among wheat varieties than that detected by RAPD. The hybridization patterns of the lines L-16(1), L-17(1), and L-79(10) contained fragments specific for wheat, and the patterns of L-9 contained both wheat and barley fragments.     

Features of the formation of self-fertile euploid lines (2n = 42) by self-pollination of the 46-chromosome barley-wheat BC1 hybrid Hordeum marinum subsp. gussoneanum Hudson (= H. geniculatum All.) (2n = 28) x Triticum aestivum L. (2n = 42)

We studied some features of the development of self-fertile 42-chromosome lines on the base of self-pollination progeny of 46-chromosome plants obtained by backcrossing of barley--wheat hybrids Hordeum marinum subsp. gussoneanum Hudson (= H. geniculatum All.) (2n = 28) x Triticum aestivum L. (2n = 42). The stabilization of karyotypes, resulting in 42-chromosome plants of the wheat type was generally completed by generation BC1F10. The plants of all self-pollination progenies, including BC1F10, showed some phenotypic traits characteristic of wild barley. Plants of BC1F10 with the chromosome sets 2n = 42 and 2n = 42 + t were analyzed by RAPD with a set of 115 primers. Fragments of the wild barley genome were detected in RAPD patterns with 19 primers. Cross-hybridization confirmed that these fragments belonged to the wild barley genome. We raised four phenotypically different 42-chromosome lines from grains obtained from plants of generation BC1F10, and these lines proved to be cytogenetically stable and self-fertile when grown in the field.     

Production of alloplasmic and euplasmic wheat-barley ditelosomic substitution lines 7H<Superscript>1</Superscript>L<Superscript>mar</Superscript>(7D) and analysis of the 18S/5S mitochondrial repeat in these lines

Alloplasmic lines of common wheat with disomic substitution of chromosome 7D for telocentric chromosome 7H¹L^mar of barley H. marinum subsp. gussoneanum Hudson were isolated from the plants of generation BC₃, produced as a result of backcrossing of barley-wheat hybrids H. marinum subsp. gussoneanum (2n = 28) × T. aestivum (2n = 42), Pyrotrix, cultivar, with 28 common wheat cultivars Pyrotrix 28 and Novosibirskaya 67. Chromosome substitution pattern was determined using SSR analysis and C-banding. In preliminary genomic in situ hybridization experiments, telocentric chromosomes were assigned to wild barley was established. In the BC₃F₈ generations of three alloplasmic lines with the 7H¹L^mar(7D) substitution type the differences in fertility manifestation were observed: most of the L-32(1) plants were sterile, in line L-32(2) only sporadic plants were sterile, and line L-32(3) was fertile. Simultaneously with these experiments, using selfpollinated progeny of the hybrids obtained in crosses of common wheat cultivar Saratovskaya 29 (2n = 41), monosomic for chromosome 7D, with common wheat cultivar Pyrotrix 28 with addition of pair of telocentric chromosomes 7H¹L^mar (7D) of barley H. marinum subsp. gussoneanum, euplasmic wheat-barley ditelosomic substitution 7H¹L^mar (7D) lines were isolated. The lines obtained had normal fertility. PCR analysis of the 18S/5S mitochondrial repeat (hereafter, mtDNA sequence) in alloplasmic and euplasmic ditelosomic substitution lines 7H¹L^mar(7D) was performed. In the plants from alloplasmic sterile line L-32(1), the sequences only of the barley (maternal) type were revealed, while the plants from alloplasmic fertile lines L-32(2) and L-32(3) demonstrated heteroplasmy (the presence of barley- and wheat-like sequences within one individual). In euplasmic ditelosomic substitution lines the presence of only wheat-like 18S/5S mitochondrial repeat sequences was observed. The results indicate that the presence of barley-like mtDNA sequences in alloplasmic substitution lines was not associated with the presence of barley chromosomes in their nuclear genomes.     

Molecular study and C-banding of chromosomes in common wheat alloplasmic lines obtained from the backcross progeny of barley-wheat hybrids Hordeum vulgare L. (2n = 14) x Triticum aestivum L. (2n = 42) and differing in fertility

We studied common wheat alloplasmic lines differing in fertility traits, which had been obtained from the backcross progeny of barley-wheat hybrids Hordeum vulgare L. (2n = 14) x Triticum aestivum L. (2n = 42), using molecular analysis and chromosome C-banding. It was found that the nuclei of all alloplasmic lines studied, regardless of their fertility traits, contained only the common wheat chromosomes (2n = 42). The formation of line L-79(10)(3)F6, stable for self-fertility, from line L-79(10)(3)F6 was accompanied by changes of the proportions of simple sequence repeats of the parental common wheat varieties in the nuclear genome. The presence of barley genome fragments in line accessions with incomplete self-fertility was shown by RAPD. Heteroplasmy for mitochondrial genome loci was detected in these lines with the use of primers specific to the tMet-18S-5S repeat of mitochondrial ribosomal genes.     

Construction and molecular and cytogenetic analyses of euploid (2n = 42) and telocentric addition (2n = 42 + 2t) alloplasmic lines (Hordeum marinum subsp gussoneanum)-Triticum aestivum

Individual plants from the BC1F5 and BC1F6 backcross progenies of barley--wheat (= H. geniculatum All.) (2n = 28) x T. aestivum L. (2n = 42)] and the BC1F6 progeny of their amphiploids were used to obtain alloplasmic euploid (2n = 42) lines L-28, L-29, and L-49 and alloplasmic telocentric addition (2n = 42 + 2t) lines L-37, L-38, and L-50. The lines were examined by genomic in situ hybridization (GISH), microsatellite analysis, chromosome C-banding, and PCR analysis of the mitochondrial 18S/5S repeat. Lines L-29 and L-49 were characterized by substitution of wild barley chromosome 7H1 for common wheat chromosome 7D. In line L-49, common wheat chromosomes 1B, 5D, and 7D were substituted with homeologous barley chromosomes. Lines L-37, L-38, and L-50 each contained a pair of telocentric chromosomes, which corresponded to barley chromosome arm 7H'L. All lines displayed heteroplasmy for the mitochondrial 18S/5S locus; i.e., both barley and wheat sequences were found.     

Features of recombination of nuclear genome in back crossed offspring of barley-wheat hybrids Hordeum vulgare L. (2n=14) x Triticum aestivum L. (2n+42) with the use of SSR-analysis

The backcross progenies of the barley-wheat hybrids Hordeum vulgare L. (2n = 14) x Triticum aestivum L. (2n = 42) and two alloplasmic lines derived from them were studied using microsatellite markers of barley and wheat. The F1 hybrids and first backcross plants BC1 contained the genetic material of both cultivated barley and the cultivars of common wheat involved in developing of these hybrid genotypes. The genomes of BC3, BC4, and alloplasmic lines contained no microsatellite markers of the cultivated barley, whereas chromosomes of each homeologous group of common wheat were identified. In chromosomes of backcross progenies BC3, BC4, and alloplasmic lines yielded by backcrosses of hybrids and various common wheat cultivars, microsatellite markers of the parental wheat cultivars were shown to undergo recombination.     

Molecular-genetic analysis of wheat (T. aestivum L.) genome with introgression of Ae. cylindrica Host genetic elements

Wheat-aegilops hybrid plants Triticum aestivum L. (2n = 42) x Aegilops cylindrica Host (2n = 28) were investigated with using microsatellite markers. In two BC1F9 lines some genome modifications connected with losing DNA fragments of initial variety or appearing of Aegilops genome elements were detected. In some investigated hybrids new amplicons lacking in parental plants were found. Substitution of wheat chromosomes for aegilops chromosomes was not revealed. Analysis of microsatellite loci in BC2F5 plants showed stable introgression of aegilops genetic elements into wheat; elimination of some transferred aegilops DNA fragments in the course of backcrossing; decreasing size of introgressive elements after backcrossing. Introgressive lines were classified according to genome changes.     

Characterization of fertility restoration in alloplasmic lines derived from hybridization of self-fertilized offspring of barley-wheat (Hordeum vulgare L. × Triticum aestivum L.) amphiploid with common wheat varieties Saratovskaya 29 and Pyrotrix 28

The problems of fertility restoration in the progeny of barley-wheat hybrids (H. vulgare × T. aestivum) are explained by incompatibility between the cytoplasm of cultivated barley and the nuclear genome of common wheat. Appropriate models for studying these problems are alloplasmic lines that combine the cytoplasm of barley and the nuclear genome of wheat. In this work, the differences of fertility restoration in alloplasmic common wheat lines (H. vulgare)-T. aestivum were studied depending on the influence of wheat varieties Saratovskaya 29 (Sar29) and Pyrotrix 28 (Pyr28) used to produce these lines. The alloplasmic lines were created using hybrids between the 48-chromosome offspring (Amph₁) of the barley-wheat amphiploid H. vulgare (ya-319) × T. aestivum (Sar29) and these wheat varieties. Backcrossing of the Amph₁ (2n = 48) × Sar29 hybrid with the wheat variety Sar29 resulted in the complete sterility in the (H. vulgare)-Sar29 line, which suggests the incompatibility of the nuclear genome of the common wheat variety Sar29 with the cytoplasm of H. vulgare. Crossing of Amph₁ (2n = 48) with Pyr28 resulted in the restoration of self-fertility in the hybrid with 2n = 44. In the alloplasmic lines (2n = 42) formed based on plants of the self-fertilized generations of this hybrid, the barley chromosomes were eliminated, and recombination between the nuclear genomes of the parental wheat varieties Sar29 and Pyr28 took place. Alloplasmic recombinant lines (H. vulgare)-T. aestivum with different levels of fertility were isolated. As was shown by the SSR analysis, differences in the fertility between these lines are determined by differences in the content of the genetic material from the wheat varieties Sar29 and Pyr28. The complete restoration of fertility in these alloplasmic recombinant lines is accompanied by the formation of a nuclear genome in which the genetic material of Pyr28 significantly prevails. The conclusion is made that the common wheat variety Pyrotrix 28 is a carrier of a gene (or genes), which determines the restoration of common wheat fertility on the cytoplasm of cultivated barley.     

Study of mitochondrial genomes of allopllasmic recombinant wheat lines constructed on the basis of barley-wheat hybrids Hordeum geniculatum all. (= H. marinum subsp. gussoneanum) (2n = 28) x x Triticum aestivum L. (2n = 42) with using of RELP and PCR analyses

Using RELP analysis with three probes homologous to specific regions of mitochondrial DNA genes and PCR analysis of the mitochondrial recombining-repeat-sequence 18S/5S region of cereals, five alloplasmic wheat lines of different origin and fertility expression were studied. These lines are self-pollinated progeny of BC1-BC4 generations of barley-wheat hybrids Hordeum geniculatum All. (2n = 28) x Triticum aestivum L. (2n = 42). It was found that recombinant alloplasmic lines characterized by partial fertility contain either maternal (barley) DNA fragments or maternal and paternal (wheat) DNA fragments simultaneously (heteroplasmy). In lines with stable expression of self-fertility, fragments of only paternal mitochondrial DNA were detected. It is assumed that in alloplasmic lines, there is the interrelation between the presence of definite fragments of the mitochondrial genome belonging to either parental type and fertility expression.     

Features of the formation of self-fertile euploid lines (2n = 42) by self-pollination of the 46-chromosome barley-wheat BC1 hybrid Hordeum marinum subsp. gussoneanum Hudson (= H. geniculatum All.) (2n = 28) × Triticum aestivum L. (2n = 42)

We studied some features of the development of self-fertile 42-chromosome lines on the base of self-pollination progeny of 46-chromosome plants obtained by backcrossing of barley-wheat hybrids Hordeum marinum subsp. gussoneanum Hudson (= H. geniculatum All.) (2n = 28) × Triticum aestivum L. (2n = 42). The stabilization of karyotypes, resulting in 42-chromosome plants of the wheat type was generally completed by generation BC₁F₁₀. The plants of all self-pollination progenies, including BC₁F₁₀, showed some phenotypic traits characteristic of wild barley. Plants of BC₁F₁₀ with the chromosome sets 2n = 42 and 2n = 42 + t were analyzed by RAPD with a set of 115 primers. Fragments of the wild barley genome were detected in RAPD patterns with 19 primers. Cross-hybridization confirmed that these fragments belonged to the wild barley genome. We raised four phenotypically different 42-chromosome lines from grains obtained from plants of generation BC₁F₁₀, and these lines proved to be cytogenetically stable and self-fertile when grown in the field.     

Expression of fertility during morphogenesis in self-pollinated backcrossed progenies of barley-wheat amphiploids

The fertility characteristics expressed during morphogenesis in first-generation self-pollinated backcrossed progenies (BC1) obtained from amphiploid barley-wheat hybrids [Hordeum geniculatum All. (2n = 28) x Triticum aestivum L. (2n = 42)] (2n = 70) backcrossed with common wheat were studied. It was found that, in the case of self-pollination of BC1 plants, karyotype stabilization leads to the formation of alloplasmic euploid (2n = 42), telocentric substitution (2n = 40 + 2t), and telocentric addition (2n = 42 + 2t), (2n = 42 + 2t) plant forms, which may serve as the sources of the respective alloplasmic lines of common wheat. That the expression of fertility characters in BC1F8 plants was shown to depend on growth conditions. The main mechanism of hybrid incompatibility of BC1F1-BC1F8 plants was expressed as grass-clump dwarfism.     

Barley chromosome identification using genomic in situ hybridization in the genome of backcrossed progeny of barley-wheat amphiploids [H. geniculatum All. (2n = 28) x T. aestivum L. (2n = 42)] (2n = 70)

Genomic in situ hybridization (GISH) has been used to study characteristics of the formation of alloplasmic lines detected among self-pollinated backcrossed progeny (BC1F5-BC1F8) of barley--wheat amphiploids [Hordeum geniculatum All. (2n = 28) x Triticum aestivum L. (2n = 42)] (2n = 70). The chromosome material of the wild barley H. geniculatum has been shown to contribute to these lines. For example, fifth-generation plants (BC1F5) had genotypes (2n = 42w + 2g), (2n = 42w + 1g + 1tg), and (2n = 41w + 1g), where w is common wheat chromosomes, g is barley (H. geniculatum) chromosomes, and tg is the telocentric chromosome of wild barley. Beginning from the BC1F6 generation, alloplasmic telocentric addition lines (2n = 42 + 2tg) and (2n = 42 + 1tg) appear. This lines has been found cytogenetically unstable. The progeny of each of these cytological types include not only the (2n = 42 + 2tg) and (2n = 42 + 2tg) addition plants, but also plants with the monosomic (2n = 41 + 1tg) and the disomic (2n = 40 + 2tg) substitutions, as well as the (2n = 41 + 2tg) plants, which lack one wheat chromosome and have two telocentric barley chromosomes. It has been demonstrated that the selection for well-filled grains favors the segregation of telocentric addition lines (2n = 42 = 2tg) and (2n = = 42 + 1tg).     

Molecular study and C-banding of chromosomes in common wheat alloplasmic lines obtained from the backcross progeny of barley–wheat hybrids Hordeum vulgare L. (2n = 14) × Triticum aestivum L. (2n = 42) and differing in fertility

We studied common wheat alloplasmic lines differing in fertility traits, which had been obtained from the backcross progeny of barley—wheat hybrids Hordeum vulgare L. (2n = 14) × Triticum aestivum L. (2n = 42), using molecular analysis and chromosome C-banding. It was found that the nuclei of all alloplasmic lines studied, regardless of their fertility traits, contained only the common wheat chromosomes (2n = 42). The formation of line L-79(10)(3)F₆, stable for self-fertility, from line L-79(10)F₃ was accompanied by changes of the proportions of simple sequence repeats of the parental common wheat varieties in the nuclear genome. The presence of barley genome fragments in line accessions with incomplete self-fertility was shown by RAPD. Heteroplasmy for mitochondrial genome loci was detected in these lines with the use of primers specific to the tMet-18S-5S repeat of mitochondrial ribosomal genes.Translated from Genetika, Vol. 40, No. 12, 2004, pp. 1668–1677.Original Russian Text Copyright © 2004 by Bildanova, Badaeva, Pershina, Salina.     

Features of alloplasmic wheat-barley substitution and addition lines (<Emphasis Type="Italic">Hordeum marinum</Emphasis> subsp. <Emphasis Type="Italic">gussoneanum</Emphasis>)-<Emphasis Type="Italic">Triticum aestivum</Emphasis>

Two alloplasmic wheat-barley substitution lines were studied: a line replaced at three pairs of chromosomes 1H ^mar (1B), 5H ^mar (5D), and 7H ^mar (7D), and the disomic-substituted line 7H ^mar (7D). The lines were constructed on the basis of individual plants from BC₁F₈ and BC₂F₆ progeny of barley-wheat hybrids (H. marinum subsp. gussoneanum Hudson (= H. geniculatum All.) (2n = 28) × T. aestivum L.) (2n = 42) (Pyrotrix 28), respectively. Moreover, the alloplasmic wheat-barley ditelosomic addition line 7HL ^mar isolated among plants from the BC₁F₆ progeny of a barley-wheat amphiploid was studied, which in this work corresponds to BC₂F₁₀ and BC₂F₁₁ progeny. It was ascertained that when grown in the field, these alloplasmic lines manifest stable self-fertility. Plants of the given lines are characterized by low height, shortened ears, the fewer number of stems and ears, and of spikelets in the ear, by decreased grain productivity and weight of 1000 grains, in comparison with the common wheat cultivar Pyrotrix 28. The inhibition of trait expression in alloplasmic wheat-barley substitution and addition lines may be connected not only with the influence of wild barley chromosomes functioning in the genotypic environment of common wheat, but also with the effect of the barley cytoplasm. The alloplasmic line with substitution of chromosomes 1H ^mar (1B), 5H ^mar (5D), and 7H ^mar (7D) or the alloplasmic line 5HL ^mar with ditelosomic addition have, in comparison with the common wheat cultivar Pyrotrix 28, an increased grain protein content, which is explained by the effect of wild barley H. marinum subsp. gussoneanum chromosomes.     

Nuclear-cytoplasmic compatibility and the state of mitochondrial and chloroplast DNA regions in alloplasmic recombinant and introgressive lines (H. vulgare)-T. aestivum

Alloplasmic lines combining alien nuclear and cytoplasmic genomes are convenient models for studying the mechanisms of nuclear-cytoplasmic compatibility/incompatibility. In the present study, we have investigated the correlation between the characters and state of mitochondrial (mt) and chloroplast (cp) DNA regions in alloplasmic recombinant common wheat lines with barley cytoplasm characterized by partial or total fertility. Fertility restoration in the studied lines (Hordeum vulgare)-Triticum aestivum is determined by different ratios of the genetic material of common wheat variety Pyrotrix 28, which is a fertility restorer in the cytoplasm of barley, and variety Saratovskaya 29, which is a fixer of sterility. In partially fertile lines with nuclear genomes dominated by the genetic material of Saratovskaya 29, plant growth and development are suppressed. In these lines we have identified the barley homoplasmy of cpDNA regions infA and rpoB and the heteroplasmy of the 18S/5S mt repeat and the cpDNA ycf5 region. Nuclear-cytoplasmic compatibility in lines with reduced fertility (the genetic material of Pyrotrix 28 predominates in their nuclear genomes) is associated with restoration of normal plant growth and development and the changes in the state of the studied cpDNA and mtDNA regions towards the wheat type. Thus, in fertile lines, the cpDNA regions (infA, rpoB) and the 18S/5S mt repeat were identified in the homoplasmic wheat state; though the cpDNA ycf5 region was in the heteroplasmic state, it was dominated by the wheat type of the copies. The nuclear-cytoplasmic compatibility is not broken as a result of introgression of the alien genetic material into the nuclear genome of one of the fertile lines; the plants of introgressive lines are fertile and normally developed, and the states of the cpDNA and mtDNA regions correspond to their states in fertile recombinant lines.     

Specific Features of the Nuclear Genome Recombination in Backcross Progenies of Barley–Wheat Hybrids Hordeum vulgare L. (2n = 14) × Triticum aestivum L. (2n = 42)

The backcross progenies of the barley–wheat hybrids Hordeum vulgare L. (2n = 14) × Triticum aestivum L. (2n= 42) and two alloplasmic lines derived from them were studied using microsatellite markers of barley and wheat. The F₁ hybrids and first backcross plants BC₁ contained the genetic material of both cultivated barley and the cultivars of common wheat involved in developing of these hybrid genotypes. The genomes of BC₃, BC₄, and alloplasmic lines contained no microsatellite markers of the cultivated barley, whereas chromosomes of each homeologous group of common wheat were identified. In chromosomes of backcross progenies BC₃, BC₄, and alloplasmic lines yielded by backcrosses of hybrids and various common wheat cultivars, microsatellite markers of the parental wheat cultivars were shown to undergo recombination.     

Production and molecular and cytogenetic analyses of euploid (2n = 42) and telocentric addition (2n = 42 + 2t) alloplasmic lines (Hordeum marinum subsp. gussoneanum)-Triticum aestivum

Individual plants from the BC₁F₆ and BC₁F₈ backcross progenies of barley-wheat [H. marinum subsp. gussoneanum Hudson (=H. geniculatum All.) (2n = 28) × T. aestivum L. (2n = 42)] and the BC₁F₆ progeny of their amphiploids were used to obtain alloplasmic euploid (2n = 42) lines L-28, L-29, and L-49 and alloplasmic telocentric addition (2n = 42 + 2t) lines L-37, L-38, and L-50. The lines were examined by genomic in situ hybridization (GISH), microsatellite analysis, chromosome C-banding, and PCR analysis of the mitochondrial 18S/5S repeat. Lines L-29 and L-49 were characterized by substitution of wild barley chromosome 7H¹ for common wheat chromosome 7D. In line L-49, common wheat chromosomes 1B, 5D, and 7D were substituted with homeologous barley chromosomes. Lines L-37, L-38, and L-50 each contained a pair of telocentric chromosomes, which corresponded to barley chromosome arm 7H¹L. All lines displayed heteroplasmy for the mitochondrial 18S/5S locus; i.e., both barley and wheat sequences were found. Original Russian Text ? N.V. Trubacheeva, E.D. Badaeva, I.G. Adonina, L.I. Belova, E.P. Devyatkina, L.A. Pershina, 2008, published in Genetika, 2008, Vol. 44, No. 1, pp. 81–89.     

Study of mitochondrial genomes of allopllasmic recombinant wheat lines constructed on the basis of barley-wheat hybrids

Using RFLP analysis with three probes homologous to specific regions of mitochondrial DNA genes and PCR analysis of the mitochondrial recombining-repeat-sequence 18S/5S region of cereals, five alloplasmic wheat lines of different origin and fertility expression were studied. These lines are self-pollinated progeny of BC₁-BC₄ generations of barley–wheat hybrids Hordeum geniculatum All. (2n = 28) × Triticum aestivum L. (2n = 42). It was found that recombinant alloplasmic lines characterized by partial fertility contain either maternal (barley) DNA fragments or maternal and paternal (wheat) DNA fragments simultaneously (heteroplasmy). In lines with stable expression of self-fertility, fragments of only paternal mitochondrial DNA were detected. It is assumed that in alloplasmic lines, there is the interrelation between the presence of definite fragments of the mitochondrial genome belonging to either parental type and fertility expression.Translated from Genetika, Vol. 41, No. 3, 2005, pp. 349–355.Original Russian Text Copyright © 2005 by Trubacheeva, Salina, Pershina.