نمط الضراوة لعشائر مسبب مرض الصدأ الأصفر Puccinia striiformis Westend. على المدخلات المتماثلة وراثيا في القمح في منطقة بغداد

pulation Pzccin ia stfiifomis Westend. on Near lsogenic Lines in Baghdad Area. Arab J. Pl. Prot.20t 24-28. Yirulence of Puccinia srrifo/,,rb Westend. population on 15 Yr genes ofNear Isogenic Lines undcr artificial inoculation in Baghdad area was investigated. The Yr genes which were individually transfen€d to Australian spring wheat cultivar Avocet are Yrl, Yr5, Yr6, Yr7, Yr8. Yr9, Yrlo, Yrl l, Yrl2, Yrl5, Yrl7, Yrl8, YrA, YrSp and YrSk. Avocct cultivar and wheat strain (lR ?22) were used as a chcck and spreader respectively. Results indicated that the pathogen did successfully ovcrcome the following genes Yr6, Yr7, YI9, Yrll,YrlS, YrA and YrSk. Data ofdisease responses on these Yr genes ranged from 25 MS to 100 S. Yrl, Yr5, Yr8, Yrl0, Yrl2, Yrl5, Yrl7, and YrSp proved to be effecti\e ag inst P. stridotmis in Baghdad area. Plants of the lines carrying these Yr genes showed rcsistant reaction (0 to 5 R) against the pathogen population