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

Abstract

Wheat diseases are one of the constraints limiting wheatyields wherever the crop is grown. Fusarium crown rot,incited by Fusarium culmorum, is one of the most importantdiseases limiting wheat yields especially in dryland areas.Although there are no wheat varieties which are fullyresistant to crown rot, the use of varieties showing somedegree of resistance is the most reliable and cost effectivemethod to control this disease. In this study, seedlingreactions of 165 spring wheat breeding lines (Triticumaestivum L.) obtained from CIMMYT, Mexico weredetermined under growth room conditions using anaggressive isolate of Fusarium culmorum. Crown rot severitywas assessed using a 1-5 scale. The mean disease severityscores for the lines tested ranged from 1.4 to 4.4. Two out ofthe 165 lines tested (lines 147 and 158) were resistant (R) intheir reaction and had scores of 1.4. Twenty lines showedmoderately resistant (MR) reaction and had scores rangingfrom 1.6 to 2.4. The scores of both the R and MR lines werenot significantly different from scores of MR controlcultivars. Sixty-three percent of the lines were moderatelysusceptible (MS). Out of the 165 lines tested, 39 weresusceptible (S) in their reaction. The promising wheat linesthat showed some degree of resistance to Fusariumculmorum in the present study can serve as useful sources ofgenetic resistance in breeding for Fusarium crown rot.