Assessment of elite wheat germplasm for resistance to Fusarium head blight -a threat to wheat production in north-west Pakistan

Abstract

Fusarium head blight (FHB), caused by Fusarium graminearum, affects both quality and quantity of wheat produce. In Pakistan, due to favorable environmental conditions during spring, FHB can cause significant losses to wheat. Recently, we observed FHB in wheat fields, having 34-84% incidence, along river Swat, Northwest Pakistan. Therefore, elite wheat cultivars and candidate lines in Pakistan as well as exotic-near isogenic lines were screened for FHB resistance using molecular markers, specific for Fhb-1, 2 and 3. Furthermore, all the germplasm was screened for 2NS Translocation - from Triticum ventricosum segment containing cluster of resistance genes for many diseases including FHB. Among Pakistani wheat varieties, Marvi-2000 showed presence of Fhb-2 and 3 specific bands while wheat cv. Saleem-2000 displayed presence of Fhb-1 and 2 specific bands. However, among the candidate lines, L-112, L-105, L-106, L-103 and L-129 exhibited Fhb-1 and 2 specific bands while L-111 alone amplified bands specific to Fhb-1 and Fhb-3. Moreover, 2NS translocation was validated in 2NS near isogenic lines (NILs) obtained from Kansas State University using 2-NS specific marker VENTRIUP and LN2, however, no 2-NS translocation was found in Pakistani varieties as well as candidate lines. In conclusion, none of the Pakistani varieties or candidate lines possessed all sources of FHB resistance in altogether; however, one aliens NIL (Yaccora-Rojo-2NS) surprisingly not only exhibited 2NS translocation but also Fhb-1, 2 and 3 resistant genes.