Development and Molecular Cytogenetic Identification of Two Wheat-Aegilops geniculata Roth 7Mg Chromosome Substitution Lines with Resistance to Fusarium Head Blight, Powdery Mildew and Stripe Rust

Abstract

Fusarium head blight (Fhb), powdery mildew, and stripe rust are major wheat diseases globally. Aegilops geniculata Roth (UgUgMgMg, 2n = 4x = 28), a wild relative of common wheat, is valuable germplasm of disease resistance for wheat improvement and breeding. Here, we report the development and characterization of two substitution accessions with high resistance to powdery mildew, stripe rust and Fhb (W623 and W637) derived from hybrid progenies between Ae. geniculata and hexaploid wheat Chinese Spring (CS). Fluorescence in situ hybridization (FISH), Genomic in situ hybridizations (GISH), and sequential FISH-GISH studies indicated that the two substitution lines possess 40 wheat chromosomes and 2 Ae. geniculata chromosomes. Furthermore, compared that the wheat addition line parent W166, the 2 alien chromosomes from W623 and W637 belong to the 7Mg chromosomes of Ae. geniculata via sequential FISH-GISH and molecular marker analysis. Nullisomic-tetrasomic analysis for homoeologous group-7 of wheat and FISH revealed that the common wheat chromosomes 7A and 7B were replaced in W623 and W637, respectively. Consequently, lines W623, in which wheat chromosomes 7A were replaced by a pair of Ae. geniculata 7Mg chromosomes, and W637, which chromosomes 7B were substituted by chromosomes 7Mg, with resistance to Fhb, powdery mildew, and stripe rust. This study has determined that the chromosome 7Mg from Ae. geniculata exists genes resistant to Fhb and powdery mildew.

Transcriptome analysis revealed the potential mechanism of a wheat-Th. elongatum translocation line YNM158 against Fusarium head blight

“…In addition, the 1Y c and 3S c chromosomes of Roegneria ciliaris [21], the 1E, 7E chromosome of diploid Th. elongatum, the chromosome 3St of Elymus repens [22], and the 7M g chromosome of Aegilops geniculata [23] also possessed the FHB resistance genes. Although the introduction of alien chromosomes can improve the resistance to FHB, it also brings some genetic encumbrance, which makes the agronomic characters of most foreign germplasm poor and di cultly to be directly used in wheat breeding for FHB resistance.…”

Meta-Analysis and Multiomics of a Chromosome Segment Substitution Line Reveal Candidate Genes Associated with Seed Hardness in Soybean

“…CSSL populations have been widely used to map QTLs in crops such as maize, 22 rice, 23 and wheat. 24 Recently, high-throughput transcriptomics and TMT-based quantitative proteomics were performed on dry seeds from soybean CSSLs and parental lines, 14 and 665 DEGs and 83 differentially accumulated proteins (DAPs) were identified. In the present study, the seed hardness of each CCSL in the population was determined in 2019 and 2020, and materials with sufficiently stable hardness phenotypes were identified, enabling research into the genetic basis of this trait.…”

“…Therefore, the analysis of the introduced fragments can be used to screen for candidate genes associated with the seed coat hardness trait. CSSL populations have been widely used to map QTLs in crops such as maize, rice, and wheat . Recently, high-throughput transcriptomics and TMT-based quantitative proteomics were performed on dry seeds from soybean CSSLs and parental lines, and 665 DEGs and 83 differentially accumulated proteins (DAPs) were identified.…”

Comparative genomic analysis of 5Mg chromosome of Aegilops geniculata and 5Uu chromosome of Aegilops umbellulata reveal genic diversity in the tertiary gene pool

“…( Mena et al., 1993 ). Researchers have reported substitution lines where 7A and 7B were replaced by 7M providing resistance to Fusarium head blight (fhb), powdery mildew, and stripe rust ( Yang et al., 2022 ). The significant number of mutations observed with the Chinese Spring provide distinction to the genomes.…”