| Thinopyrum intermedium (2n= 42, StJJs) carries many useful agronomic traits for wheat improvement, such as disease resistance, tolerance to salt, drought and cold and so on. It also possesses great potential in processing quality of wheat including high protein content and some superior subimits comparative to other relatives, such as rye, of wheat In this study, the high molecular weight glutenin subunits (HWM-GS) among a total of 602 Th. intermedium-derived wheat-alien introgression lines was analysed using SDS-PAGE method, and the superior HWM-GSs predent in 100 lines randomly selected from above-mentioned lines were further confirmed molecularly using specific PCR marker. The following results were obtained:(1)602 wheat-alien introgression lines from Th. intermedium were screened for their reactions to stripe rust using the most widely virulent and predominant pathotypes CYR32, CYR33 and v26 of Puccinia striiformis f. sp. tritici. The disease evaluation showed that 414 lines were completely resistant (immune or hypersensitive flecks) to all or two of race tested, accounting for 70%. The excellent resistance specified by these resistant lines and high proportion in all tested lines provided rich diversity for breeding of wheat cultivars conferring stripe rust resistance.(2)On Glu-1 loci, the genetic composition of 480 lines tested was stable and 122 lines appears to be separating. There are 16 kinds of of allelic variation on Glu-1 loci present in 480 lines. Among these allelic variation 1, 2*, Null were present at Glu-Al locus, with 1 and 2 * subunits being 61.7% of the proportion in 480 lines. There were 8 kinds of allelic variations for 7, 13+16,13+19,14+15,17+18,7+9,7+8 and 6+8 at Glu-Bl locus, At Glu-Dl locus, there were 5 kinds of allelic variation, including 2+10,2+12,4+12, 5+10 and 5+12, with the types of superior subunit 5+10 and 5+12 accounting for 26.9% and for 10.2%,respectively In a word, a total of 42 kinds of HMW-GS combination were found among 480 stable wheat introgression lines, and of these lines,140 had superior subunit compositions with high quality scores of 8 to 10, including 1,17+18,5+10; 1,17+18,5+12; N, 14+15,5+10, accounting for 30% in 480 stable lines.(3)100 were picked out randomly from 480 homozygous lines for further testing accuracy of the composition of HMW-GS alleles by using PCR molecular markers. The results showed that when using UMN19, the specific primers for Glu-Al locus, the 344 bp and 362 bp segments were amplified, respectively, confirming the presence of Ax2* subunit and Ax1/Ax-null subunit genes in lines tested and the proportion of Ax2* being 34%. UMN25 and UMN26 are the specific primers for Glu-D1 locus. When using UMN25 for detecting,281 bp and 299 bp segments were amplified, and when using UMN26 for detecting,397 bp and 415 bp segments were amplified. Thesesuggested that Dx5 and Dx2, Dy10 and Dy12 subunit genes were, respectively, present at Glu-Dl locus in the tested lines. The specific primers, cauBx642 and cauBx752, were used for detecting allelic variations at the Glu-B1 locus. The segments of 642 bp,534 bp,752 bp, and 337 bp were amplified, showing that the alleles of Bx14 and Bx17 subunits were respectively present at Glu-B1 locus in these lines, with the proportions of Bxl4 and Bx17 being 4% and is 27%. In addition, ZSBy9aFl/R3 marker was used for testing of the Glu-B1 locus, and the segments 662 bp and 707 bp were amplified, demonstrating the presence or absence of By9 subunit gene in some lines. The obtained results are basically the same as the SDS-PAGE electrophoresis. The result is accurate and reliable and can provide theoretical guidance. |
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