Identification and evaluation of disease resistance and HMW-GS composition of Aegilops geniculata Roth

Abstract

Aegilops geniculata Roth is an important germplasm resource for the transfer of beneficial genes from alien species of wheat into common wheat (Triticum aestivum L.). In this study, we identified and evaluated agronomic characters, powdery mildew resistance, stripe rust resistance, and high molecular weight glutenin subunit (HMW-GS) compositions of 44 Ae.geniculata accessions. The average growth period (254 days) was longer than that of common wheat (240 days). Coefficients of variation (CVs) of all examined agronomic characters except growth period were >10 %. The largest CV, 23.80 %, was that of 1,000-grain weight. An assay for disease resistance revealed that 37 Ae.geniculata accessions (85.09 %) were resistant to powdery mildew, of which 33 were immune, 1 was highly resistant, and 3 were moderately resistant. This assay also indicated that 33 of the accessions (75 %) were resistant to stripe rust, with 25 showing immunity, 4 highly resistant, and 4 moderately resistant. Additionally, 19 accessions (43.18 %) were immune to both powdery mildew and stripe rust. HMW-GSs in the 44 accessions were analyzed by SDS polyacrylamide-gel electrophoresis, which indicated rich germplasm diversity. A total of 21 different HMW-GS alleles were identified at Glu-1 loci. The most frequent subunits were 1Dx2, 1Dx1.1, 1Dx2.2, 1Dx1.5, 1Bx20, 1Bx22, 1Dy10, and 1Dy12, found in 36.36, 54.55, 40.91, 34.09, 38.64, 25.00, 47.73, and 20.45 % of accessions, respectively. The data uncovered for the 44 accessions should facilitate their use as beneficial germplasm donors in wheat breeding.