Monday, November 13, 2006

Investigating the Genetics of Resistance to Net Blotch and Septoria Speckled Leaf Blotch in Barley.

Summer Kluck, Univ of Minnesota, Crops & Soils, 5120 Chicago Avenue, Minneapolis, MN 55417 and Kevin Smith, University of Minnesota, 411 Borlaug Hall Univ. of MN, 1991 Upper Buford Circle, St. Paul, MN 55108.

Septoria Speckled Leaf Blotch (SSLB), caused by Septoria passerinii and Net Blotch (NB), caused by Pyrenophora teres, are fungal diseases that decrease the yields of barley in Minnesota and the Upper Midwest.  A promising way to manage these diseases is breeding new varieties with genetic resistance.  To characterize the genetics of resistance to both pathogens, two barley advanced breeding lines: one resistant to NB (M120) and another resistant to SSLB (Sep2-72) were crossed.  The F1 was self-pollinated to produce a segregating F2 population which was advanced by single seed decent to the F4 generation creating a population of 115 inbred lines.  The lines, parents and controls were then grown in the greenhouse and inoculated in two separate experiments with Septoria passerinii and Pyrenophora teres to evaluate resistance to these pathogens.  Simple sequence repeat (SSR) markers that were shown in previous studies to be linked to resistance were evaluated on the parents and population.  Thus far, three regions are associated with resistance to SSLB.  These regions have not been associated with SSLB in previous studies.  No markers tested thus far are associated with resistance to Net Blotch.   This suggests that the resistances segregating in this population are due to genes not previously detected.  We will continue to map additional markers to attempt to locate new genes for resistance. 

Handout (.pdf format, 80.0 kb)