Abstract：
Paspalum L. is a genus of the Poaceae family, with many species serving as well-adapted forage plants in subtropical climates and continuous grazing systems. However, Claviceps paspali, an ascomycete of the order Hypocreales, represents a major threat to Paspalum species. This fungus induces ergot disease, characterized by the replacement of infected flower seeds with sclerotia, which adversely affects seed production and animal health through mycotoxin production. Although ergot disease is reported in many countries, no totally resistant Paspalum cultivars have been reported for commercial use. This study comparatively evaluated disease development in six Paspalum species under greenhouse conditions with three specific isolates of C. paspali, along with field trials. In addition, field isolates of C. paspali were analyzed for phenotypic characteristics and phylogenetic relationships. Greenhouse evaluation revealed variable susceptibility among Paspalum species, with P. malacophyllum,P. notatum and P. umbrosum being the most resistant. In field trials P. dilatatum showed the highest severity index, while P. umbrosum and P. malacophyllum were less affected. Phenotypic characterization of 22 C. paspali isolates showed variability in pigmentation and growth rates, with PDA being the culture medium where the highest growth rate was observed. Phylogenetic analysis of the isolates identified two well-supported lineages between C. paspali species. This research reports an ergot resistance gradient among Paspalum species, identifying genuine sources of resistance. In addition, virulent isolates of C. paspali potentially useful for rapid screening of accessions or crosses in Paspalum breeding programs were identified.
摘要：
PaspalumL.是禾本科科的一个属，在亚热带气候和连续放牧系统中，许多物种都是适应良好的饲草植物。然而,ClavicepsPaspali,Hypocreales命令的子囊，对Paspalum物种构成重大威胁。这种真菌会诱发麦角病，其特点是用菌核代替受感染的花籽，通过生产霉菌毒素对种子生产和动物健康产生不利影响。尽管许多国家都报道了麦角病，没有报道完全抗性的Paspalum品种用于商业用途。这项研究在温室条件下使用三种特定的C.paspali分离株比较了六种Paspalum物种的疾病发展。以及田间试验。此外,分析了C.paspali的田间分离株的表型特征和系统发育关系。温室评估揭示了Paspalum物种之间的可变易感性，与P.malacophylum，P.notatum和P.umbrosum是最有抵抗力的。在田间试验中，P.dilatatum显示出最高的严重程度指数，而甘草和甘草则受影响较小。22C.paspali分离株的表型特征显示色素沉着和生长速率的变异性，PDA是观察到最高生长速率的培养基。分离株的系统发育分析鉴定了C.paspali物种之间的两个良好支持的谱系。这项研究报告了Paspalum物种之间的麦角抗性梯度，找出真正的抵抗来源。此外,鉴定了C.paspali的毒力分离株，该分离株可能可用于快速筛选Paspalum育种计划中的种质或杂交。
