Powdery mildew infections are among the most severe foliar biotrophic fungal diseases in grain legumes. Several accessions of Lathyrus cicera (chickling pea) show levels of partial resistance to Erysiphe pisi, the causal agent of pea powdery mildew, and to E. trifolii, a powdery mildew pathogen recently confirmed to infect pea and Lathyrus spp. Nevertheless, the underlying L. cicera resistance mechanisms against powdery mildews are poorly understood. To unveil the genetic control of resistance against powdery mildews in L. cicera, a recombinant inbred line population segregating for response to both species was used in resistance linkage analysis. An improved L. cicera genetic linkage map was used in this analysis. The new higher-density linkage map contains 1,468 polymorphic loci mapped on seven major and two minor linkage groups, covering a total of 712.4 cM. The percentage of the leaf area affected by either E. pisi or E. trifolii was recorded in independent screenings of the recombinant inbred line population, identifying a continuous range of resistance-susceptibility responses. Distinct quantitative trait loci (QTLs) for partial resistance against each pathogen were identified, suggesting different genetic bases are involved in the response to E. pisi and E. trifolii in L. cicera. Moreover, through comparative mapping of L. cicera QTL regions with the pea reference genome, candidate genes and pathways involved in resistance against powdery mildews were identified. This study extended the previously available genetic and genomic tools in Lathyrus species, providing clues about diverse powdery mildew resistance mechanisms useful for future resistance breeding of L. cicera and related species.

白粉病是谷物中豆类中最严重的叶片生物营养真菌病。数种山thy豆（小豌豆）显示出对豌豆白粉病的病原体Erysiphe pisi和最近被证实可感染豌豆和山thy豆属的白粉病病原体E. trifolii的部分抗性水平。然而，对白粉病的潜在的L. cicera抗药性机制了解甚少。为了揭示对L. cicera的白粉病抗性的遗传控制，在抗性连锁分析中使用了分离的自交系以重组对这两种物种的重组。改良的L. cicera遗传连锁图谱用于该分析。新的更高密度的连锁图谱包含映射到七个主要和两个次要连锁基团上的1,468个多态位点，覆盖总计712.4 cM。受任一叶面积的百分比E.皮丝或E.蚜被记录在重组自交系人口的独立放映，识别的电阻敏感性响应的连续范围。鉴定了针对每种病原体的部分抗性的不同数量性状基因座（QTL），表明在L. cicera中对E. pisi和E. trifolii的反应涉及不同的遗传基础。此外，通过比较作图L. cicera鉴定了具有豌豆参考基因组，候选基因和抗白粉病的途径的QTL区域。这项研究扩展了山La豆属物种的先前可用的遗传和基因组学工具，提供了有关多种白粉病抗性机制的线索，这些机制可用于今后对蝉毛及相关物种的抗性育种。