Department of Plant Pathology, The Ohio State University, Ohio Agricultural Research and Development Center, Wooster 44691.
Plant Dis. 2018 Jul;102(7):1326-1333. doi: 10.1094/PDIS-11-17-1786-RE. Epub 2018 May 4.
Germplasm screening programs have primarily relied on inoculation with mycelia to determine the resistance reaction of soybean genotypes to Sclerotinia sclerotiorum. However, under field conditions, ascospores are the primary source of inoculum. Therefore, the objective of this study was to determine which components most accurately differentiate the resistance reaction of soybean genotypes inoculated with ascospores of S. sclerotiorum. Ascospores were produced in the laboratory and all of the experiments were carried out under controlled conditions with inoculations at flowering stage. Initially, inoculum densities of 1 × 10, 1 × 10 and 1 × 10 ascospores ml were compared on six soybean genotypes with known resistance reactions. Disease symptoms developed on all genotypes and at all inoculum densities. The highest ascospore concentration increased infection efficiency but it was not correlated with an increase in lesion length. Components of resistance were then measured on a set of 17 cultivars with known resistance reactions at 1 × 10 ascospores ml. Resistance reactions could be differentiated based on the level of infection efficiency and lesion length on the main stem. Although inoculation with ascospores presents some limitations such as the time required for inoculum production as well as the time and space required for plant growth, it has the potential to be used to complement other methods for the characterization of resistance of soybean genotypes.
种质筛选计划主要依赖于接种菌丝来确定大豆基因型对核盘菌的抗性反应。然而，在田间条件下，子囊孢子是主要的接种体来源。因此，本研究的目的是确定哪些成分最能准确区分接种核盘菌子囊孢子的大豆基因型的抗性反应。在实验室中产生了子囊孢子，所有实验均在开花期接种的受控条件下进行。最初，在六个具有已知抗性反应的大豆基因型上比较了 1×10、1×10 和 1×10 子囊孢子 ml 的接种体密度。所有基因型和所有接种体密度都出现了病症。最高的子囊孢子浓度提高了感染效率，但与病变长度的增加无关。然后，在 1×10 个子囊孢子 ml 的条件下，用一组具有已知抗性反应的 17 个品种测量抗性成分。根据主茎上的感染效率和病变长度，可以区分抗性反应。虽然接种子囊孢子存在一些限制，例如接种体生产所需的时间以及植物生长所需的时间和空间，但它有可能被用来补充其他方法来描述大豆基因型的抗性。
