Abstract：
Higher levels of ergot (Claviceps purpurea (Fr.)) Tul. were reported in North Dakota hard red spring wheat (HRSW) in 2018, leading to questions pertaining to management and cultivar resistance. To better understand pathogen and HRSW cultivar responses, greenhouse experiments were conducted from 2020 to 2021 to evaluate aggressiveness of nine C. purpurea isolates and ergot resistance in 21 HRSW cultivars. Results from the aggressiveness assay indicated significant cultivar by isolate interactions for total weight of sclerotia produced and ergot incidence. Mean data across all cultivar by isolate combinations suggested isolates CC-3 and IA-Tim were the most aggressive and subsequently used in ergot resistance experiments. Results from ergot resistance screening indicated none of the HRSW cultivars were immune to C. purpurea as all cultivars produced sclerotia. However, differences in ergot incidence, kernel incidence, aborted kernel incidence, total sclerotia weight, sclerotia length, and sclerotia width occurred among cultivars. Both \'ND-Frohberg\' and \'TCG-Spitfire\' had the lowest ergot incidence values and were among the lowest in total sclerotia weight. \'Waldron\' and \'LCS-Trigger\' had the highest ergot incidence and the highest total sclerotia weight. Given that most concerns with ergot occur post-harvest, we suggest two categories to describe ergot resistance: host resistance (fate of inoculation for a stigma) and logistical resistance (size characteristics of a sclerotium that influence its ability to remain with a seed lot after harvest and cleaning). This research provides a strong foundation on our understanding of HRSW resistance to ergot that will influence variety decisions in ergot-prone areas in North Dakota.
摘要：
麦角含量较高（紫癜（Fr。))图尔。2018年在北达科他州硬红春小麦（HRSW）报道，导致与管理和品种抗性有关的问题。为了更好地了解病原体和HRSW品种的反应，从2020年到2021年进行了温室实验，以评估21个HRSW品种中9个紫癜分离株的侵袭性和麦角抗性。侵袭性测定的结果表明，通过分离出的相互作用对产生的菌核的总重量和麦角发生率具有重要意义。所有品种按分离物组合的平均数据表明，分离物CC-3和IA-Tim最具侵略性，随后用于麦角抗性实验。麦角抗性筛选的结果表明，由于所有品种都产生菌核，因此没有一个HRSW品种对紫菜C.purpurea免疫。然而,麦角发病率的差异，内核发生率，中止的内核发生率，总菌核重量，菌核长度,菌核宽度发生在品种之间。“ND-Frohberg”和“TCG-Spitfire”均具有最低的麦角发生率，并且是总菌核重量最低的。“Waldron”和“LCS-Trigger”的麦角发病率最高，总菌核重量最高。考虑到麦角的大部分问题发生在收获后，我们建议将麦角抗性分为两类：寄主抗性（柱头接种的命运）和后勤抗性（菌核的大小特征会影响其在收获和清洁后保留种子的能力）。这项研究为我们理解HRSW对麦角的抗性奠定了坚实的基础，这将影响北达科他州麦角易发地区的品种决策。
