Molecular Cytogenetic Studies On Derivatives Of Wheat-Leymus Mollis

Leymus mollis(2n = 28, NsNsXmXm), a allotetraploid perennial wild plants(Leymus Hochst., Hordeinae, tribe Triticeae, family Poaceae). It has lots of excellent agronomic traits, i.e., long spike with more spikelet, tolerance to drought and salt, resistance to stripe rust and mildew powder. so it is an important genetic resources for wheat improvement. Chromosome engineering can transfer genes of L. mollis to wheat, from which can get new germplasm such as addition lines, substitution lines, translocation lines. Derivatives of wheat-L. mollis M13063-3-3 and M11005-1-2-7-10 were studied by aid of morphologic, cytological, in situ hybridization, SSR, EST-STS, PLUG molecular markers and A-PAGE. Results are as follows:(1) M13063-3-3 was no significant differences with 7182 in plant height, spike length, kernel number per spikelet, spikelet number per spike and awn shape. There were obvious differences between M13063-3-3 and L. mollis in plant height and spike length. M13063-3-3 was also no significant differences with L. mollis in spikelet number per spike and ear shape. The disease resistance indicated that L. mollis was immune to stripe rust and M13063-3-3 exhibited high resistance to stripe rust. By analysis of cytology, it was showed that the configuration was 2n=44=22Ⅱ. Genomic in situ hybridization(GISH) analysis showed that M13063-3-3 has a pair of alien chromosomes with blue-green signals. Select 70 pairs of SSR, 70 pairs of EST-STS and 56 pairs of PLUG markers which distributed seven wheat homoeologous groups to identify M13063-3-3, results showed that 8 pairs of markers which respectively mapped on homoeologous group 6 chromosomes could amplify specific bands of L. mollis in it. A-PAGE indicated that α region of M13063-3-3 had the specific band of L. mollis. The above results indicated that M13063-3-3 was a common wheat material with the resistance to stripe rust and the additioned chromosomes belong to the homoeologous group 6 chromosomes of L. mollis. It provided a new germplasm resource for wheat resistance breeding.(2) The plant type of M11005-1-2-7-10 was compact, which was similar to 7182; M11005-1-2-7-10 plant length was 55 cm, characterized by dwarf; Ear shape of M11005-1-2-7-10 was spindled, which was different from 7182; Awn shape of M11005-1-2-7-10 was short, which was different from 7182 and L. mollis. The disease resistance indicated that the reaction type of L. mollis was 0, which showed the immunity to stripe rust; the reaction type of M11005-1-2-7-10 was 2, which showed the middle resistance to stripe rust. By analysis of cytology, M11005-1-2-7-10 was showed that the configuration was 2n=44=22Ⅱ. Genomic in situ hybridization(GISH) analysis showed that M11005-1-2-7-10 has a pair of alien chromosomes with blue-green signals. EST-STS and PLUG markers results showed that 8 pairs of EST-STS markers and 3 pairs of PLUG markers which respectively mapped on homoeologous group 3 chromosomes could amplify specific bands of L. mollis in M11005-1-2-7-10. These suggest that dwarf materials M11005-1-2-7-10 was a stable wheat-L. mollis disomic alien addition line, which provides new germplasm resources for wheat disease resistance and dwarf breeding.