Host Susceptibility of CIMMYT's International Spring Wheat Lines to Crown and Root Rot Caused by Fusarium culmorum and F. pseudograminearum.

The destructive soilborne Fusarium species is one of the most serious challenges facing agriculture. Mycotoxins produced by Fusarium spp. can induce both acute and chronic toxic effects on humans and animals. Massive investments have been made in the last few decades to develop an appropriate management strategy to control Fusarium species in cereals, particularly in wheat, using genetic resistance and other practices, with varied outcomes. The purpose of this research was to find new sources of resistance to both Fusarium culmorum and F. pseudograminearum, which are wheat's most destructive pathogens in seedlings and adult plants stages. In this study, 26 lines were selected and promoted from a total of 200 spring wheat germplasm received from CIMMYT Mexico plus 6 local check lines. The 32 lines were screened for their resistance reactions to both Fusarium species under different environmental conditions. The discriminant factorial analysis indicated that 7, 12, and 5 were resistant lines against F. culmorum under field, greenhouse, and growth room conditions, respectively. Four lines, L12, L19, L21, and L26, were found to be jointly resistant at the adult and seedling stages in the field and greenhouse. On the other hand, only moderately resistant lines were found for F. pseudograminearum but not completely resistant, which was limited to growth room conditions. Interestingly, five lines (L10, L13, L17, L25, and L28) have shown resistant properties to both Fusarium species. To further evaluate the yield performance of the best-selected 26 lines plus 6 check lines, field trials were conducted under ± F. culmorum inoculum. The highest yield values were obtained from three check lines, as well as the L26, which showed consistency in its reaction to F. culmorum under both field and greenhouse conditions, and produced a high yield (5342 kg/ha). Based on the result obtained, L26 showed a high potential to improve wheat yield and resistance to F. culmorum-caused root and crown rot; therefore, it should be used in wheat crossing programs. Having Fusarium-resistant varieties will ultimately reduce crown rot symptoms and increase grain quality by reducing mycotoxin levels. [ABSTRACT FROM AUTHOR]