Assessment of the Seedling Resistance of Spring Wheat Lines to Fusarium culmorum

Abstract

Wheat diseases are one of the constraints limiting wheat  yields wherever the crop is grown. Fusarium crown rot,  incited by Fusarium culmorum, is one of the most important  diseases limiting wheat yields especially in dryland areas.  Although there are no wheat varieties which are fully  resistant to crown rot, the use of varieties showing some  degree of resistance is the most reliable and cost effective  method to control this disease. In this study, seedling  reactions of 165 spring wheat breeding lines (Triticum  aestivum L.) obtained from CIMMYT, Mexico were  determined under growth room conditions using an  aggressive isolate of Fusarium culmorum. Crown rot severity  was assessed using a 1-5 scale. The mean disease severity  scores for the lines tested ranged from 1.4 to 4.4. Two out of  the 165 lines tested (lines 147 and 158) were resistant (R) in  their reaction and had scores of 1.4. Twenty lines showed  moderately resistant (MR) reaction and had scores ranging  from 1.6 to 2.4. The scores of both the R and MR lines were  not significantly different from scores of MR control  cultivars. Sixty-three percent of the lines were moderately  susceptible (MS). Out of the 165 lines tested, 39 were  susceptible (S) in their reaction. The promising wheat lines  that showed some degree of resistance to Fusarium  culmorum in the present study can serve as useful sources of  genetic resistance in breeding for Fusarium crown rot.