1022-7954/03/3906- $25.00 © 2003 MAIK “Nauka /Interperiodica” 0656 Russian Journal of Genetics, Vol. 39, No. 6, 2003, pp. 656–660. Translated from Genetika, Vol. 39, No. 6, 2003, pp. 791–795. Original Russian Text Copyright © 2003 by Troubacheeva, Salina, Numerova, Pershina. INTRODUCTION Generation of hybrid forms of higher plants on the basis of distant hybridization enables to solve the prob- lems related to diversification [1], phylogenetic rela- tionships between plants of different taxonomic groups [2], and the effect of foreign cytoplasm on the nuclear genome functioning [3]. Practical significance of dis- tant hybridization lies in the enhancement of genetic diversity of agricultural plants, specifically, by produc- tion of amphiploids [4], or as a result of introgression of the genes for commercially important traits from wild plants to the cultivated ones [4–6]. The spectrum of artificial distant hybrids among the Triticale Dum. tribe is mostly represented by the geno- types generated by interspecific or intergeneric hybrid- ization of Triticum L. species [7]. With the advent of the methods permitting to over- come incompatibility, it has become possible to involve wheat species also in the intersubtribal crosses, in particu- lar, with barley species [8], and thus to create new models for basic research and the starting material for selec- tion. For instance, using wheat–barley hybrid Triticum aestivum L. × Hordeum vulgare All. the lines of com- mon wheat supplemented with the chromosome pairs of cultivated barley [8], as well as the lines, containing wheat–barley recombinant chromosomes were created [9]. Backcrossing of wheat–barley hybrids H. vul- gare All. × T. aestivum L. resulted in the development of alloplasmic wheat lines with the combination of cytoplasm from cultivated barley and recombinant nuclear genome from wheat [10]. Amphiploids of bar- ley–wheat hybrids H. cholense Roem. et Schulz. × T. turgidum conv. durum Desf. Em M.K. served as a basis for the creation of a new cereal crops, Tritodeum [5]. Distant hybridization is a strong stress factor capa- ble of inducing structural changes of hybrid genome during its stabilization [11, 12]. In our previous studies the methods promoting the creation of barley–wheat hybrids H. geniculatum All. × T. aestivum L. and restoration of their fertility were designed [13]. It was shown that while hybrid fertility could be restored after the first backcross with common wheat variety (BC 1 ), the process of karyotype stabiliza- tion in the hybrid progeny was very long [13]. Prelimi- nary studies of a line isolated among the BC 2 progeny revealed a tendency towards inclusion of the fragments of barley nuclear genome into the developing genome of alloplasmic lines. Effectiveness of RAPD analysis for identification of such fragments was also demon- strated [14]. The present study was focused on comprehensive investigation of the H. geniculatum All. × T. aestivum L. hybrid genome transformation during restoration and maintenance of fertility in the backcross progeny at the development of alloplasmic lines. We attempted to detect introgression of barley H. geniculatum genetic RAPD-Based Analysis of Introgression of Barley Genetic Material into the Genome of Alloplasmic Wheat Lines (Hordeum geniculatum All./Triticum aestivum L.) N. V. Troubacheeva, E. A. Salina, O. M. Numerova, and L. A. Pershina Institute of Cytology and Genetics, Russian Academy of Sciences, Novosibirsk, 630090 Russia; fax: (3832)33-12-78; e-mail: natas@bionet.nsc.ru Received June 5, 2002 Abstract—Genomes of three alloplasmic wheat lines obtained on the basis of barley–wheat hybrid Hordeum geniculatum All. (2n = 28) × Triticum aestivum L. (2n = 42)(Pyrotrix 28) were examined using random ampli- fied 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 eup- loid 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 BC 1 plant with the wheat variety Novosibirskaya 67 and one subsequent self-polination of one BC 3 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 frag- ments 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 BC 1 plants. PLANT GENETICS