Seedling Response of Iranian Barley Landraces to Pyrenophora teres f. teres and Pyrenophora teres f. maculata

Abstract

Net blotch caused by Pyrenophora teres is an important pathogen of barley plants worldwide. There are two biotypesof the fungus. Pyrenophora teres f. teres (Ptt) causes the net form of the disease and Pyrenophora teres f. maculata(Ptm) causes the spot form of the disease. Barley landraces are good sources of disease resistance. In this study, seedlingresponse of 25 barley landraces obtained from diffrent regions of northwest Iran to 3 single spore isolates of Pttand 3 single spore isolates of Ptm were determined under greenhouse conditions. Diffrences in virulence among theisolates were evident. Some landraces showed diffrent responses to diffrent isolates. Landraces # 9 and # 16 showedmoderately resistant reactions to one isolate of Ptt and showed moderately resistant-moderately susceptible reactionsto 2 isolates of Ptt. Landraces # 7, # 11, # 15, # 17, # 21, # 22, # 23 and # 25 showed moderately resistant-moderatelysusceptible reactions to all 3 isolates of Ptt. Landrace # 23 showed resistant-moderately resistant reaction to one isolateof Ptm and showed moderately resistant reactions to 2 isolates of Ptm. Landrace # 16 showed moderately resistantreactions to all isolates of Ptm. Landraces # 11, # 15, # 21 and # 25 showed moderately resistant reaction to one isolateof Ptm and showed moderately resistant-moderately susceptible reactions to 2 isolates of Ptm. Landraces that exhibitedreactions between resistant and moderately resistant-moderately susceptible range could be used as a direct seedingmaterial to the fild or could be used as breeding materials.