The root lesion nematode (RLN) species Pratylenchus thornei and P. neglectus are widely distributed within cropping regions of Australia and have been shown to limit grain production. Field experiments conducted to compare the performance of cultivars in the presence of RLNs investigate management options for growers by identifying cultivars with resistance, by limiting nematode reproduction, and tolerance, by yielding well in the presence of nematodes. A novel experimental design approach for RLN experiments is proposed where the observed RLN density, measured prior to sowing, is used to condition the randomization of cultivars to field plots. This approach ensured that all cultivars were exposed to consistent ranges of RLN in order to derive valid assessments of relative cultivar tolerance and resistance. Using data from a field experiment designed using the conditioned randomization approach and conducted in Formartin, Australia, the analysis of tolerance and resistance was undertaken in a linear mixed model framework. Yield response curves were derived using a random regression approach and curves modeling change in RLN densities between sowing and harvest were derived using splines to account for nonlinearity. Groups of cultivars sharing similar resistance levels could be identified. A comparison of slopes of yield response curves of cultivars belonging to the same resistance class identified differing tolerance levels for cultivars with equivalent exposures to both presowing and postharvest RLN densities. As such, the proposed design and analysis approach allowed tolerance to be assessed independently of resistance.

根病变线虫（RLN）种Pratylenchus thornei和P. neglectus在澳大利亚的种植地区广泛分布，并已显示出限制谷物产量的作用。进行的田间实验用于比较存在RLN的品种的性能，通过鉴定具有抗性，限制线虫繁殖和耐受性的品种（在存在线虫的情况下表现良好）来研究种植者的管理选择。提出了一种用于RLN实验的新颖实验设计方法，其中在播种之前测量的观测RLN密度用于调节品种到田间的随机性。这种方法确保所有品种都暴露在恒定的RLN范围内，以便得出相对品种耐性和抗性的有效评估。使用来自使用条件随机化方法设计并在Formartin中进行的现场实验的数据，在澳大利亚，对耐受性和抗性的分析是在线性混合模型框架中进行的。使用随机回归方法得出产量响应曲线，并使用样条曲线得出播种和收获之间RLN密度变化的曲线模型，以说明非线性。可以鉴定出具有相似抗性水平的品种。对属于相同抗性类别的品种的产量响应曲线的斜率进行比较，可以确定在播种前和收获后RLN密度相同的情况下，对品种的耐受水平不同。因此，建议的设计和分析方法允许独立于电阻来评估公差。使用随机回归方法得出产量响应曲线，并使用样条曲线得出播种和收获之间RLN密度变化的曲线模型，以说明非线性。可以鉴定出具有相似抗性水平的品种。对属于相同抗性类别的品种的产量响应曲线的斜率进行比较，可以确定在播种前和收获后RLN密度相同的情况下，对品种的耐受水平不同。因此，建议的设计和分析方法允许独立于电阻来评估公差。使用随机回归方法得出产量响应曲线，并使用样条曲线得出播种和收获之间RLN密度变化的曲线模型，以说明非线性。可以鉴定出具有相似抗性水平的品种。对属于相同抗性类别的品种的产量响应曲线的斜率进行比较，可以确定在播种前和收获后RLN密度相同的情况下，对品种的耐受水平不同。因此，建议的设计和分析方法允许独立于电阻来评估公差。对属于相同抗性类别的品种的产量响应曲线的斜率进行比较，可以确定在播种前和收获后RLN密度相同的情况下，对品种的耐受水平不同。因此，建议的设计和分析方法允许独立于电阻来评估公差。对属于相同抗性类别的品种的产量响应曲线的斜率进行比较，可以确定在播种前和收获后RLN密度相同的情况下，对品种的耐受水平不同。因此，建议的设计和分析方法允许独立于电阻来评估公差。