Characterization and Evaluation of Resistance to Powdery Mildew of Wheat–Aegilops geniculata Roth 7Mg (7A) Alien Disomic Substitution Line W16998

Abstract

Aegilops geniculata Roth has been used as a donor of disease-resistance genes, to enrich the gene pool for wheat (Triticum aestivum) improvement through distant hybridization. In this study, the wheat–Ae. geniculata alien disomic substitution line W16998 was obtained from the BC1F8 progeny of a cross between the common wheat ‘Chinese Spring’ (CS) and Ae. geniculata Roth (serial number: SY159//CS). This line was identified using cytogenetic techniques, analysis of genomic in situ hybridization (GISH), functional molecular markers (Expressed sequence tag-sequence-tagged site (EST–STS) and PCR-based landmark unique gene (PLUG), fluorescence in situ hybridization (FISH), sequential fluorescence in situ hybridization–genomic in situ hybridization (sequential FISH–GISH), and assessment of agronomic traits and powdery mildew resistance. During the anaphase of meiosis, these were evenly distributed on both sides of the equatorial plate, and they exhibited high cytological stability during the meiotic metaphase and anaphase. GISH analysis indicated that W16998 contained a pair of Ae. geniculata alien chromosomes and 40 common wheat chromosomes. One EST–STS marker and seven PLUG marker results showed that the introduced chromosomes of Ae. geniculata belonged to homoeologous group 7. Nullisomic–tetrasomic analyses suggested that the common wheat chromosome, 7A, was absent in W16998. FISH and sequential FISH–GISH analyses confirmed that the introduced Ae. geniculata chromosome was 7Mg. Therefore, W16998 was a wheat–Ae. geniculata 7Mg (7A) alien disomic substitution line. Inoculation of isolate E09 (Blumeria graminis f. sp. tritici) in the seedling stage showed that SY159 and W16998 were resistant to powdery mildew, indeed nearly immune, whereas CS was highly susceptible. Compared to CS, W16998 exhibited increased grain weight and more spikelets, and a greater number of superior agronomic traits. Consequently, W16998 was potentially useful. Germplasms transfer new disease-resistance genes and prominent agronomic traits into common wheat, giving the latter some fine properties for breeding.

Identification and Characterization of Wheat - Aegilops Comosa 7M/7A Disomic Substitution Lines with Stripe Rust Resistance

“…geniculata (Kuraparthy et al 2007;Liu et al 2011), respectively, and a powdery mildew gene was derived from 7M g of Ae. geniculata (Wang et al 2020). Because stripe rust resistance in the 7M/7A substitution line was a little weaker than that of the diploid Ae.…”

“…geniculata (Wang et al 2020). Because stripe rust resistance in the 7M/7A substitution line was a little weaker than that of the diploid Ae.…”

“…A 7M g disomic addition line and a 7M g /7A disomic substitution line W 16998 derived from Ae. geniculata were found to be resistant to powdery mildew (Wang et al 2016(Wang et al , 2020. There are no other reports describing the 7M/7A substitution derived from diploid Ae.…”

Chromosome Karyotype and Stability Identification of New Synthetic Hexaploid Wheat

“…In previous studies, wheat of aneuploids was widely used for gene location, molecular marker development and genetic analysis (Endo et al 1996;Klindworth et al 2007;Zhang et al 2020;Pshenichnikova et al 2020). China spring monomer and durum wheat Langdon chromosome substitution lines are commonly used for gene mapping as tool materials (Sears 1953;Shimelis et al 2011;Wang et al 2020). Based on the durum wheat-Langdon substitution lines and Abbondanza monosomic system, the crossability related genes were located in chromosome 1A, 6A and 7A by Liu (1999).…”

Genome-wide identification, evolution, and expression of the SNARE gene family in wheat resistance to powdery mildew

“…The leaves were used for the next step of RNA extraction and q-PCR experiments. The method by Wang et al, (2020) was used for CS (Chinese Spring), 7M CH (NA0973-5-4-1-2-9-1), 7M US (TA7661) and ‘Shaanyou 225’ to identify powdery mildew.…”