Isolate Virulence and Cultivar Response in the Winter Wheat: Pyrenophora tritici-repentis (Tan Spot) Pathosystem in Oklahoma.

Prevalence of tan spot of wheat caused by the fungus Pyrenophora tritici-repentis has become more prevalent in Oklahoma as no-till cultivation in wheat has increased. Hence, developing wheat varieties resistant to tan spot has been emphasized, and selecting pathogen isolates to screen for resistance to this disease is critical. Twelve isolates of P.

Development and deployment of KASP markers for multiple alleles of Lr34 in wheat.

Heterogeneous Lr34 genes for leaf rust in winter wheat cultivar 'Duster' and KASP markers for allelic variation in exon 11 and exon 22 of Lr34. Wheat, Triticum aestivum (2n = 6x = 42, AABBDD), is a hexaploid species, and each of three homoeologous genomes A, B, and D should have one copy for a gene in its ancestral form if the gene has no duplication. Previously reported leaf rust resistance gene Lr34 has one copy on the short arm of chromosome 7D in hexaploid wheat, and allelic variation in Lr34 is in intron 4, exon 11, exon 12, or exon 22.

Mis-Spliced Lr34 Transcript Events in Winter Wheat.

Lr34 in wheat is a non-race-specific gene that confers resistance against multiple fungal pathogens. The resistant allele Lr34 and the susceptible allele Lr34s can be distinguished by three polymorphisms that cause alternation of deduced amino acid sequences of Lr34 at the protein level. In seedlings of a cultivar carrying the resistant Lr34r allele, only a portion (35%) of its transcripts was correctly spliced and the majority (65%) of its transcripts were incorrectly spliced due to multiple mis-splicing events.

Association study of resistance to Soilborne wheat mosaic virus in U.S. winter wheat.

Soilborne wheat mosaic virus (SBWMV) is one of the most important winter wheat pathogens worldwide. To identify genes for resistance to the virus in U.S.

A single-nucleotide polymorphism that accounts for allelic variation in the Lr34 gene and leaf rust reaction in hard winter wheat.

Leaf rust, caused by Puccinia triticina Eriks, is one of the most common and persistent wheat diseases in the US Great Plains. We report that the Lr34 gene was mapped in the center of a QTL for leaf rust reaction and explained 18-35% of the total phenotypic variation in disease severity of adult plants in a Jagger x 2174 population of recombinant inbred lines (RILs) field-tested for 3 years. The sequence of the complete Lr34 gene was determined for the susceptible Jagger allele and for the resistant 2174 allele.

Response of Hard Red Winter Wheat to Soilborne wheat mosaic virus Using Novel Inoculation Methods.

ABSTRACT Soilborne wheat mosaic virus (SBWMV) is an agronomically important pathogen of wheat that is transmitted by the soilborne plasmodiophorid vector Polymyxa graminis. In the laboratory, attempts to generate SBWMV-infected plants are often hampered by poor infectivity of the virus. To analyze the mechanism for virus resistance in wheat cultivars, we developed novel inoculation techniques.