Japanese indigenous Elymus species is one of the potential genetic resources for Triticeae crops because of their high adaptability for Japanese moist climate and close relationship to the important crops. In spite of such potential importance, the genetic information about these species is very little. To provide the basic genetic information on these species, I conducted preliminary genetic variation analysis of two hexaploidElymus species, E. tsukushiensis and E.humidus, using several SSR markers and CAPS of a chloroplast region. Samples were collected from four sympatric populations of these two species at Kanagawa, Gifu, Okayama and Miyazaki. With SSR markers intrapopulational variation was detected for both species. The chloroplast CAPS suggested the possibility of introgression between the two Elymus species.

P-5 S. Konishi, Y. Nemoto, T. Sasanuma, T. Sasakuma (Kihara Institute for Biological Research, Graduate School of Integrated Science, Yokohama City University)
The structure and expression of Mlo genes in wheat

The Mlo gene is encoding a plant specific protein containing seven trans-membrane domains. By searching on the database, seven Mlo genes of wheat including known gene TaMlo1 were identified as ESTs. The phylogenetic analysis of the Mlo family members originated from several monocot and dicot species revealed that the Mlo genes had been generated aomnd diverged at least earlier than monocot-dicot diversification. Gene specific RT-PCR revealed differential expression of TaMlo genes in response to treatments with salt or mannitol, in root and shoot. These observations indicate that the expression of the Mlo family is regulated by differential mechanisms for each gene and suggest that each of the MLO proteins in wheat may function differently depending on tissues or environmental stresses.

P-6 S. Kadosumi¹, T. Sasanuma¹, T. Kawahara²,T. Sasakuma¹ (¹Kihara Institute for Biological Research, Yokohama City University, ²Graduate School of Agriculture, Kyoto University)
Multiple origin of tetraploid species based on U genome-specific CAPS marker U31

Polyploidization is important for plants. To elucidate the relationship of polyploidization with speciation, we revealed the intra- and interspecific variation of the four UUMM genome tetraploid Aegibops species (Ae. ovata, Ae. columnaris, Ae. triaristata and Ae. biuncialis) and the UU genome diploid Ae. umbellulata. Among the 30 primers tested to construct genome specific marker, U31 demonstrated the U genome-specific amplification. The size polymorphism and RFLP with MspI indicated that the U31 locus had four alleles in all the 264 accessions studied. Among them, the major allele and the allele with a 123bp deletion were detected in both the diploid and two of the tetraploid (Ae. columnaris and Ae. triaristata). This result indicates multiple origin of these two tetraploid species.

P-7 M. Okuda, J. Kimbara, S. Nasuda, T.R. Endo
(Laboratory of Plant Genetics, Graduate School of Agriculture, Kyoto University)
Chromosomal localization patterns of a heterochromatin protein HP1 in wheat and related species

Heterochromatin is a chromosomal region where chromatin is highly condensed. In yeast, fly, and vertebrates, heterochromatin protein 1 (HP1) plays a key role in heterochromatin formation. In order to characterize the function of the HP1 in plants, we isolated genes encoding for HP1 homologues from hexaploid wheat Triticum aestivum. We prepared antibodies against wheat HP1 homologues and investigated localization patterns of the HP1 proteins in mitotic chromosomes of hexaploid wheat and related species by the immunofluorescence microscopy. In diploids, barley, rye, and T. monococcum, and in tetraploid T. durum, HP1 mainly localized to centromeres. In hexaploid wheat, however, HP1 signals were observed along the length of every chromosome. Our observations suggest that the relocation of HP1 has possibly occurred through polyploidization.