Leymus mollis (2n = Ultrasonic 4x = 28, NsNsXmXm) possesses novel and important genes for resistance against multi-fungal diseases.The development of new wheat-L.mollis introgression lines is of great significance for wheat disease resistance breeding.M11003-3-1-15-8, a novel disomic substitution line of common wheat cv.
7182 -L.mollis, developed and selected from the BC1F5 progeny between wheat cv.7182 and octoploid Tritileymus M47 (2n = 8x = 56, AABBDDNsNs), was characterized by morphological and cytogenetic identification, analysis of functional molecular markers, genomic in situ hybridization (GISH), sequential fluorescence in situ hybridization (FISH)-genomic in situ hybridization (GISH) and disease resistance evaluation.Cytological observations suggested that M11003-3-1-15-8 contained 42 chromosomes and formed 21 bivalents at meiotic metaphase I.
The GISH investigations showed that line contained 40 wheat chromosomes and a pair of L.mollis chromosomes.EST-STS multiple loci markers and PLUG (PCR-based Landmark Unique Gene) markers confirmed that the introduced L.mollis chromosomes belonged to homoeologous group 7, it was designated as Lm#7Ns.
While nulli-tetrasomic and sequential FISH-GISH analysis using the oligonucleotide Oligo-pSc119.2 and Oligo-pTa535 as probes revealed that the wheat 7D chromosomes were Mini Funnel absent in M11003-3-1-15-8.Therefore, it was deduced that M11003-3-1-15-8 was a wheat-L.mollis Lm#7Ns (7D) disomic substitution line.
Field disease resistance demonstrated that the introduced L.mollis chromosomes Lm#7Ns were responsible for the stripe rust resistance at the adult stage.Moreover, M11003-3-1-15-8 had a superior numbers of florets.The novel disomic substitution line M11003-3-1-15-8, could be exploited as an important genetic material in wheat resistance breeding programs and genetic resources.