BGS 237, Reaction to Pyrenophora teres 2, Rpt2

Resistance to Pyrenophora teres 2c = Rpt2c (3).

Monofactorial incomplete dominant (3, 5).
Located in chromosome 1HS (3); Rpt2.c is associated with 1HS based on molecular markers (8).

The seedling reactions of CIho 9819 to Pyrenophora teres f. teres (Ptt) isolates was described as 1 on a scale where 0 = very resistant and 4 = susceptible (3, 4); however, some (Ptt) isolates produced susceptible seedling reactions (2, 3). Two genes conferring resistance to Ptt were reported to be present in CIho 9819 (5). One gene was associated with chromosome 3H and named Rpt1.b and another gene was associated with chromosome 1H and named Rpt2.c (3). Using different Ptt isolates, CIho 9819 was reported by Manninen et al. (8) to have another Rpt gene (Rpt5) with a major effect in chromosome 6H, but a minor effect QTL was reported in 1HS. Using several Ptt isolates, two dominant and one recessive resistance genes were found in CIho 9819 by Afanasenko et al. (2). A QTL for Ptt resistance from Steptoe was found in 1H (9), but other reports of QTL for Ptt reaction in 1H are rare (7). CIho 9819 was reported to show resistant seedling responses to Ptt isolates from many countries (1).

Natural occurrence in CIho 9819 (PI 195985) collected from Welo, Ethiopia (3, 4).

Rpt2.c from CIho 9819 (PI 195985) collected from Welo, Ethiopia (3, 4); a possible allele present as a QTL in Arapiles (PI 591926) (6).

Rpt2.c from CIho 9819 (PI 195985).

1. Afanasenko, O.S., M. Jalli, H.O. Pinnschmidt, O. Filatova, and G.J. Platz. 2009. Development of an international standard set of barley differential genotypes for Pyrenophora teres f. teres. Plant Pathol. 58:665-676.
2. Afanasenko, O.S., I.G. Makarova, and A.A. Zubkovich. 1999. The number of genes controlling resistance to Pyrenophora teres Drechs. strains in barley. Russ. J. Genet. 35:274-283.
3. Bockelman, H.E., E.L. Sharp, and R.F. Eslick. 1977. Trisomic analysis of genes for resistance to scald and net blotch in several barley cultivars. Can. J. Bot. 55:2142-2148.
4. Buchannon, K.W., and W.C. McDonald. 1965. Sources of resistance in barley to Pyrenophora teres. Can. J. Plant Sci. 45:189-193.
5. Khan, T.N., and W.J.R. Boyd. 1969. Inheritance of resistance to net blotch in barley II. Genes conditioning resistance against race W.A.-2. Can. J. Genet. Cytol. 11:592-597.
6. Lehmensiek, A., G.J. Platz, E. Mace, D. Poulsen, and M.W. Sutherland. 2007. Mapping of adult plant resistance to net form of net blotch in three Australian barley populations. Aust. J. Agric. Res. 58:1191-1197.
7. Liu, Z., S.R. Ellwood, R.P. Oliver, and T.L. Friesen. 2011. Pyrenophora teres: profile of an increasingly damaging barley pathogen. Mol. Plant Pathol. 12:1-19.
8. Manninen, O.M., M. Jalli, R. Kalendar, A. Schulman, O. Afanasenko, and J. Robinson. 2006. Mapping of major spot-type and net-type net-blotch resistance genes in Ethiopian barley line CI 9819. Genome 49: 1564-1571.
9. Steffenson, B.J., Hayes, P.M., and Kleinhofs, A. 1996. Genetics of seedling and adult plant resistance to net blotch (Pyrenophora teres f. teres) and spot blotch (Cochliobolus sativus) in barley. Theor. Appl. Genet. 92:552-558.

J.D. Franckowiak and G.J. Platz. 2013. Barley Genet. Newsl. 43:110-111.