Table_2.XLSX

Verticillium wilt and leaf mottle of sunflower, caused by the fungus Verticillium dahliae (Vd) has become a major constraint to sunflower oil production in temperate European countries. Information about Vd from sunflower is very scarce despite genetics, molecular traits and pathogenic abilities of fungal strains affecting many other crops being widely known. Understanding and characterizing the diversity of Vd populations in those countries where sunflowers are frequent and severely affected by the fungus are essential for efficient breeding for resistance. In this study, we have analyzed genetic, molecular and pathogenic traits of Vd isolates affecting sunflower in European countries. When their genetics was investigated, almost all the isolates from France, Italy, Spain, Argentina, and Ukraine were assigned to vegetative compatibility group (VCG) 2B. In Bulgaria, Turkey, Romania, and Ukraine, some isolates were assigned to VCG6, but some others could not be assigned to any VCG. Genotyping markers used for Vd affecting crops other than sunflower showed that all the isolates were molecularly identified as race 2 and that markers of defoliating (D) and non-defoliating (ND) pathotypes distinguished two well-differentiated clusters, one (E) grouping those isolates from Eastern Europe and the other (W) all those from the Western Europe and Argentina. All the isolates in cluster W were VCG2B, while the isolates in cluster E belonged to an unknown VCG or to VCG6. When the host range was investigated in the greenhouse, the fungus was highly pathogenic to artichoke, showing the importance of farming alternatives in the management of Verticillium attacks. Sunflower genotypes were inoculated with a selection of isolates in two experiments. Two groups were identified, one including the isolates from Western Europe, Argentina, and Ukraine, and the other including isolates from Bulgaria, Romania, and Turkey. Three pathogenic races were differentiated: V1, V2-EE (Eastern Europe) and V2-WE (Western Europe). Similarly, three differentials are proposed for race identification: HA 458 (universal susceptible), HA 89 (resistant to V2-EE, susceptible to V2-WE) and INRA2603 (susceptible to V2-EE, resistant to V2-WE). The diversity found in Vd affecting sunflower must be taken into account in the search for resistance to the pathogen for European environments of sunflower production.

由大丽轮枝菌（Verticillium dahliae, Vd）引发的向日葵黄萎病与叶斑驳病，已成为欧洲温带地区向日葵油料生产的主要限制因素。尽管学界已对侵染多种其他作物的该真菌菌株的遗传学、分子特征及致病能力开展了广泛研究，但针对向日葵来源的大丽轮枝菌的相关信息仍极为匮乏。明确并解析那些向日葵频繁且严重受该真菌侵染的欧洲国家境内的大丽轮枝菌种群多样性，是开展高效抗病育种的核心前提。本研究对欧洲国家境内侵染向日葵的大丽轮枝菌分离物的遗传学、分子特征与致病性状展开了分析。遗传学分析结果显示，来自法国、意大利、西班牙、阿根廷与乌克兰的几乎所有分离物均被归为营养亲和群（vegetative compatibility group, VCG）2B。在保加利亚、土耳其、罗马尼亚与乌克兰境内，部分分离物被归为VCG6，另有部分分离物无法归属于任何已知营养亲和群。针对非向日葵作物的大丽轮枝菌开发的基因分型标记显示，所有受试分离物经分子鉴定均为生理小种（race）2；且落叶型（defoliating, D）与非落叶型（non-defoliating, ND）致病型的标记可将分离物划分为两个分化显著的类群：类群E聚集了所有东欧来源的分离物，类群W则涵盖了西欧与阿根廷来源的全部分离物。类群W内的所有分离物均属于VCG2B，而类群E内的分离物则隶属于未知营养亲和群或VCG6。温室寄主范围测定结果表明，该真菌对菊芋具有极强的致病性，这提示种植替代作物在黄萎病防控中具有重要价值。研究团队通过两组试验，利用筛选得到的分离物对接不同向日葵基因型进行接种鉴定，最终划分出两个分离物类群：一类涵盖西欧、阿根廷与乌克兰来源的分离物，另一类则包含保加利亚、罗马尼亚与土耳其来源的分离物。本研究共区分出三类致病生理小种：V1、V2-EE（东欧型）与V2-WE（西欧型）。同时，本研究提出了用于该菌生理小种鉴定的三套鉴别品种：HA 458（广谱感病）、HA 89（对V2-EE表现抗病、对V2-WE感病）以及INRA2603（对V2-EE感病、对V2-WE表现抗病）。在针对欧洲向日葵种植环境开展抗病种质筛选时，必须充分考虑侵染向日葵的大丽轮枝菌所存在的种群多样性。