The aim of the programme started at ARDI-Fundulea in 1999 is to improve the pest and disease resistance of cultivated barley (H. vulgare L.) by introgressing valuable genes from the wild species H. bulbosum L. The paper presents results on the development and cytogenetical characterization of primary genetic stocks represented by diploid, triploid and tetraploid interspecific hybrids and first backcrossed generation descendants. several sterile diploid hybrids were found during the phenotypic screening and cytological analysis of haploid progeny from H. vulgare 2x × H. bulbosum 2x crosses. These hybrids were treated with colchicine and fertile tetraploid hybrids were obtained. Significant improvements in the seed setting and in vitro triploid hybrid regeneration were obtained using doubled haploid lines (DHLs), previously selected for high interspecific crossability, in crosses with a tetraploid cytotype of H. bulbosum. Meiosis analysis of triploid hybrids provided compelling evidence that relatively high intergenomic allosyndetic pairing had occurred in some of the triploids with increased potential for crossing over and genetic recombination. High mean values for hybrid stability, multivalent associations in MI, higher chiasma frequency per PMC and partial pollen fertility were considered by far the most important criteria in the cytogenetic selection of triploid hybrids. Selected triploids were backcrossed to barley DHLs. Among the in vitro regenerated backcrossed progeny several putative substitution lines (SLs) were identified by preliminary cytological screening. The complete phenotypic and cytogenetic characterization and disease resistance tests of tetraploid hybrids and putative SLs or RLs are now in progress.
Pickering, R. A. (1988): The production of fertile triploid hybrids between Hordeum vulgare L. (2n = 2x = 14) and H. bulbosum L. (2n = 4x = 28). Barley Genet. Newsl., 18, 25-29.
'The production of fertile triploid hybrids between Hordeum vulgare L. (2n = 2x = 14) and H. bulbosum L. (2n = 4x = 28) ' () 18 Barley Genet. Newsl. : 25 -29 .
Pickering, R. A. (1991): The production of fertile triploid hybrids from crosses between Hordeum vulgare L. (2n = 4x = 28) and H. bulbosum L. (2n = 2x = 14). Hereditas, 114, 227-236.
'The production of fertile triploid hybrids from crosses between Hordeum vulgare L. (2n = 4x = 28) and H. bulbosum L. (2n = 2x = 14) ' () 114 Hereditas : 227 -236 .
Pickering, R. A. (1992): Monosomic and double monosomic substitution of Hordeum bulbosum L. chromosomes into H. vulgare L. Theor. Appl. Genet., 84, 466-472.
'Monosomic and double monosomic substitution of Hordeum bulbosum L. chromosomes into H. vulgare L ' () 84 Theor. Appl. Genet. : 466 -472 .
Pickering, R. A., Johnston, P. A., Timmerman Vaughan, G. H., Cromey, M. B., Forbes, E. M., Steffenson., B. J., et al. (2000): Hordeum bulbosum - A new source of disease and pest resistance genes for use in barley breeding programmes. Barley Genet. Newsl., 30, 7-10.
'Hordeum bulbosum - A new source of disease and pest resistance genes for use in barley breeding programmes ' () 30 Barley Genet. Newsl. : 7 -10 .
Xu, J., Kasha, K. J. (1992): Transfer of a dominant gene for powdery mildew resistance and DNA from Hordeum bulbosum into cultivated barley (H. vulgare). Theor. Appl. Genet., 84, 771-777.
'Transfer of a dominant gene for powdery mildew resistance and DNA from Hordeum bulbosum into cultivated barley ' () 84 (H. vulgare). Theor. Appl. Genet. : 771 -777 .
Walther, U., Hebekus, A., Kopahnke, D., Proesler, G., Schliphake, E. (1999): Evaluation of IPK's barley germplasm for disease resistance. Rep. of Working Group on Barley of ECP/GR, Germany, pp. 93-103.
Ho, K. M., Kasha, K. J. (1975): Genetic control of chromosome elimination during haploid formation in barley. Genetics, 81, 263-275.
'Genetic control of chromosome elimination during haploid formation in barley ' () 81 Genetics : 263 -275 .
Lange, W. (1971): Crosses between Hordeum vulgare L. and Hordeum bulbosum L. 1. Production, morphology and meiosis of hybrids, haploids and dihaploids. Euphytica, 20, 14-29.
'Crosses between Hordeum vulgare L. and Hordeum bulbosum L. 1. Production, morphology and meiosis of hybrids, haploids and dihaploids ' () 20 Euphytica : 14 -29 .
Lehmann, L. C. (1991): The use of genetic resources for isolating disease resistance for barley cultivar development. In: Barley Genetics VI, pp. 650-652.
Mihãilescu, A., Giura, A. (1999a): Hybrid and triploid progenies from Hordeum vulgare L. (2 n = 14) x Hordeum bulbosum L. (2 n = 14 and 2 n = 28) interspecific crosses. In: COST 824, "Wide crosses in cereals - problems and applications". Krakow, Poland, pp. 21-22.
Mihãilescu, A., Giura, A. (1999b): Production of barley doubled haploid lines by Bulbosum system. In: Proc. 2nd Balkan Symp. on Field Crops, 16-20 June, 1998, Novi-Sad, Yugoslavia, pp. 287-290.
Mihãilescu, A., Giura A. (2000): Use of the wild species Hordeum bulbosum L. in Romanian barley breeding programmes. In: Proc. XVI EUCARPIA, Genetic Resources Section, Poland, pp. 343-347.
Xu, J., Snape, J. W. (1987): Crossabilities of barley varieties with diploid and tetraploid clones of Hordeum bulbosum. Barley Genet. Newsl., 17, 40-43.
'Crossabilities of barley varieties with diploid and tetraploid clones of ' () 17 Hordeum bulbosum. Barley Genet. Newsl. : 40 -43 .
Xu, J., Snape, J. W. (1988): The cytology of hybrids between H. vulgare and H. bulbosum revisited. Genome, 30, 486-494.
'The cytology of hybrids between H. vulgare and H. bulbosum revisited ' () 30 Genome : 486 -494 .
Zeller, F. J. (1998): Improving cultivated barley (Hordeum vulgare L.) by making use of the genetic potential of wild Hordeum species. Angewandte Botanik, 75, 162-167.
'Improving cultivated barley (Hordeum vulgare L.) by making use of the genetic potential of wild Hordeum species ' () 75 Angewandte Botanik : 162 -167 .
Bothmer, R. von, Jacobsen, N., Baden, C., Jorgensen, R. B., Linde-Laursen, I. (1995): An Ecogeographical Study of the Genus Hordeum. IPGRI, Rome, 129 pp.
Gilpin, M. J., Pickering, R. A., Fautrier, A. G., Mc Neil, D. L., Szigat, G., Hill, A. M., Kynast, R. G. (1997): Morphological and molecular analysis of androgenetic selfed and backcrossed plants produced from a Hordeum vulgare x Hordeum bulbosum hybrid. Plant Breed., 116, 505-510.
'Morphological and molecular analysis of androgenetic selfed and backcrossed plants produced from a Hordeum vulgare x Hordeum bulbosum hybrid ' () 116 Plant Breed. : 505 -510 .