Cytological, Biochemical, Molecular Identification Of Alien Germplasm From Wheat-Rye Hybrids

Wild relatives of wheat in Triticeae have contained a great number of such valuable genes as resistant genes and so on, the introduction of alien genetic germplasm from related species was an important method for improving genetic base of wheat. In order to reach the target, wheat line A42912 with high yield characters, and rye inbred line R3 derived from Weiyuan area in China,were used as parents, alien germplasm of the progenies from wheat-rye hybrids was studied in the present paper. Results were shown as following:1. The karyotype of materials tested was primarily analyzed by the method of Feulgen counting and meiosis pairing. The results indicated that genetic composition of all materials tested was stable, and these materials could be divided into two groups according to chromosome numbers: 2n=44=22ll, including 98—917—19, 98—917—25,9&—917—26; 2n=42=21 II, including other materials except above.2. Using the improved Giemsa—C banding technique, materials 98—1104—9, 98—917—15, 98—917—29 were identified as 1RS/1BL interarm translocation lines.3. Materials 98—1104—9, 98—917—15, 98—917—29, 98—917—27 were tested to be 1RS/1BL translocation lines by using A—PAGE, therein the first three materials were also identified as 1RS/1BL translocation lines by Giemsa—C banding technique.4. HMW—GS compositions at Glu—1 loci were analyzed in 25 materials by SDS—PAGE. From the glutenin patterns, it was concluded that materials 98₁104—9(1, 7+9, 2+12), 98—917—15(1, 7+8 and 20, 2+12), 98—917—27 (N, 7+8, 5+10), 98—917—29(1, 14+15, 2+12), 98—917—24(1, 7+8, 2+12) were different from parent A42912(l, 7+8, 5+10) at Glu—1 loci, therein the first four materials were 1RS/1BL translocation lines identified by A—PAGE, so 1RS/1BLtranslocation had a significant effect on the HMW—GS compositions of wheat.5. Alien germplasm from wheat—rye hybrids was identified by molecular marker SSR. The results showed that materials 98—1104—9, 98—917—15, 98—917—27, 98—917—29 possessed IRS of rye chromosome; materials 98—917—17, 98—917—19, 98—917—23, 98—917—24, 98—917—25 possessed possibly partial 5RS of rye chromosome; materials 98—1104—10, 98—917—27,98—917—29 possessed partial 6RS of rye chromosome.6. Disease resistance of materials tested was investigated in field. It was concluded that most materials having alien rye germplasm appeared the ideal resistant response to powdery mildew, yellow rust. In addition, it was deduced that materials 98—917—20, 98—917—21 possessed potentially rye germplasm which was not identified in the present experiment.7. Seven materials containing alien rye germplasm were indentified comprehensively by cytological, biochemical and molecular analysis. The results indicated that:(1) three new 1RS/1BL interarm transolcation lines(98—1104—9, 98—917—15, 98—917—29), the chromosome composition of them was respectively: 2n=42=20x/W + 1" 1RS/1BL, 2n=42=20 " W+l " 1RS/1BL, 2n=42=19x/W+l" 1RS/1BL +1" IDS- 1DL—6RS(2) two disomic addition lines containing partial 5RS fragment (98-917—19,98—917—25; 2n=44=21//W+l//W—5RS)(3) one small segment transolcation line of 5RS(98—917—24, 2n=20/x W+l^lDS-lDL—5RS)(4) one double transolcation line of IRS and 6RS(98—917—27, 2n=42=19WllBL-lBS—IRS +11AS-1AL—6RS)Finally, some questions about the utilization of 1RS/1BL translocation lines containing new resistant genes, the flexible application of multiple identification approachs for alien germplasms and the potential interests of multiple translocation lines so on were also discussed in this paper.