Evaluation of a Pyrenophora teres f. teres mapping population reveals multiple independent interactions with a region of barley chromosome 6H

Authors: SHJERVE, RACHEL - North Dakota State University; Faris, Justin; BRUEGGEMAN, ROBERT - North Dakota State University; YAN, CHANGHUI - North Dakota State University; ZHU, YA - North Dakota State University; KOLADIA, VAIDEHI - North Dakota State University; Friesen, Timothy

Submitted to: Fungal Genetics and Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/25/2014
Publication Date: 8/2/2014
Publication URL: http://handle.nal.usda.gov/10113/59508
Citation: Shjerve, R.A., Faris, J.D., Brueggeman, R.S., Yan, C., Zhu, Y., Koladia, V., Friesen, T.L. 2014. Evaluation of a Pyrenophora teres f. teres mapping population reveals multiple independent interactions with a region of barley chromosome 6H. Fungal Genetics and Biology. 70:104-112.

Interpretive Summary: Net form net blotch (NFNB) is a destructive disease of barley and is caused by the fungal pathogen Pyrenophora teres f. teres. To investigate the genetics of virulence in the barley- P. teres f. teres pathosystem, we evaluated a cross between P. teres f. teres pathotypes that were opposite for their virulence on the two barley lines Rika and Kombar. Genetic maps generated from various types of molecular markers that covered the P. teres f. teres genome were used to identify regions associated with virulence important in NFNB disease. Two major loci, VR1 and VR2, were associated with virulence on Rika barley, accounting for 35 and 20% of the disease reaction type variation, respectively. Two different loci, VK1 and VK2, were associated with virulence to Kombar barley accounting for 26 and 19% of the disease reaction type variation, respectively. The susceptibility induced by each pathogen locus corresponded to the same region on barley chromosome 6H as that identified for the parental isolates 15A and 6A. The data presented here indicate that the P. teres f. teres – barley interaction can at least partially be explained by pathogen-produced necrotrophic effectors (NEs) that interact with dominant barley susceptibility genes resulting in NE triggered susceptibility (NETS).

Technical Abstract: The necrotrophic fungal pathogen Pyrenophora teres f. teres causes the foliar disease net form net blotch (NFNB) on barley. To investigate the genetics of virulence in the barley- P. teres f. teres pathosystem, we evaluated 118 progeny derived from a cross between the California isolates 15A and 6A on two barley lines Rika and Kombar, which were chosen based on their differential reactions to P. teres f. teres isolates 15A and 6A for NFNB disease. Genetic maps generated with SNP, SSR, and AFLP markers were scanned for quantitative trait loci (QTL) associated with virulence in P. teres f. teres. Loci underlying two major QTL, VR1 and VR2, were associated with virulence on Rika barley, accounting for 35 and 20% of the disease reaction type variation, respectively. Two different loci, VK1 and VK2, were shown to underlie two major QTL associated with virulence on Kombar barley accounting for 26 and 19% of the disease reaction type variation, respectively. Progeny isolates harboring VK1, VK2, or VR2 alone were inoculated onto a Rika × Kombar recombinant inbred line mapping population and the susceptibility induced by each pathogen genotype corresponded to the same region on barley chromosome 6H as that identified for the parental isolates 15A and 6A. The data presented here indicate that the P. teres f. teres – barley interaction can at least partially be explained by pathogen-produced necrotrophic effectors (NEs) that interact with dominant barley susceptibility genes resulting in NE triggered susceptibility (NETS).