Selecting Resistance to Bipolaris sorokiniana and Fusarium graminearum in Intermediate Wheatgrass

Forage yield and persistence of intermediate wheatgrass and pubescent intermediate wheatgrass can be adversely affected by foot rot caused by Fusarium graminearum, Bipolaris sorokiniana, or both. Putative B. sorokiniana- and F. graminearum-resistant plants were selected from both Reliant and Manska cultivars of intermediate wheatgrass to produce four populations. When plants from half-sib families that were selected for resistance were intercrossed and progeny subjected to subsequent selection cycles for B. sorokiniana and F. graminearum resistance, progressively higher percentages of putative resistant seedlings were found for three of the four selected populations compared to the original base populations. In cycle 3 of three populations, 7 to 91% of half-sib families with statistically higher seedling survival rates than the base populations were considered more resistant than the base populations. Thus, progressive improvement in seedling survival was realized for three populations selected for resistance using three cycles of recurrent phenotypic selection among and within half-sib families.