Delineating a locus conferring Fusarium crown rot resistance on chromosome arm 1HL in barley by developing and analysing a large population derived from near isogenic lines

Fusarium crown rot (FCR), a chronic and severe disease caused by various Fusarium species, is prevalent in semi-arid cropping regions worldwide. One of the major QTL conferring FCR resistance was detected on chromosome arm 1HL (Qcrs.cpi-1H) in barley. To develop markers that can be reliably used to incorporate the resistance locus into breeding programs, we developed and assessed a near-isogenic line-derived population consisting of 1180 recombinant inbred lines targeting the locus. Using this population, we delineated Qcrs.cpi-1H into an interval of 0.4 cM covering a physical length of about 487 kb. Six markers co-segregating with this locus were generated. Co-linearity for genes located in this interval between the genome of barley and those of either rice or Brachypodium distachyon is poor. Three genes with non-synonymous variations between the resistant and susceptible lines were identified within the interval. The results reported in this study not only provide markers for integrating Qcrs.cpi-1H into breeding programs, but also form a solid foundation for cloning the causal gene(s) underlying this locus. (C) 2020 Crop Science Society of China and Institute of Crop Science, CAAS. Production and hosting by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.