Abstract:

【Objective】 Characterization of genes Lr34/Yr18, Rht-B1b (Rht1) and Rht-D1b (Rht2) in 263 CIMMYT wheat cultivars and advanced lines will benefit the improvement of rust resistance and plant height in Chinese wheat breeding program. 【Method】 A total of 263 CIMMYT wheat cultivars and advanced lines were tested by STS markers to understand the distribution of resistance genes Lr34/Yr18 and dwarfing genes Rht-B1b and Rht-D1b. 【Result】 The marker csLV34 could amplify a 150 bp fragment in the lines with Lr34/Yr18, and a 229 bp fragment in those lines without Lr34/Yr18. Two complementary markers, NH-BF.2/WR1.2 and NH-BF.2/MR1, were used to investigate the alleles Rht-B1a and Rht-B1b, respectively. They could amplify a 400 bp fragment in the genotypes with Rht-B1a and Rht-B1b, respectively. The marker DF/MR2 could generate a 280 bp fragment in the genotype with Rht-D1b. Of the 263 lines, 57 generated a 150 bp fragment with the marker csLV34, indicating the presence of Lr34/Yr18 in these lines, with a frequency of 21.7%. Two hundred and sixteen lines (82.1%) were detected to have the allele Rht-B1b, and 38 lines (14.4%) contained the allele Rht-D1b. Twenty-one lines were detected to possess both the wild-type alleles Rht-B1a and Rht-D1a, while 12 had two dwarfing genes Rht-B1b and Rht-D1b. 【Conclusion】 These STS markers could be useful to detect the genes Lr34/Yr18, Rht-B1b and Rht-D1b. The frequency of Rht-B1b was much higher than that of Rht-D1b in CIMMYT lines.

Key words: Triticum aestivum L., slow rusting resistance, dwarfing gene, molecular marker