Fusarium wilt, caused by Fusarium oxysporum f. sp. vasinfectum race 4 (FOV4), is an early season vascular disease with symptoms including seedling wilt and mortality. The objectives of this study were to investigate the relationship between mortality rate (MR) and disease severity rating (DSR) based on root vascular staining (RVS)-DSR and stem vascular discoloration (SVD)-DSR in the field and the relationship of MR in controlled conditions with MR and DSR in the field. Results from two field tests and two greenhouse tests each with a Latin square design for eight cultivars of cotton (Gossypium spp.) and two field progeny-row tests were analyzed. In the field, MR at the square stage was significantly correlated with both DSR (RVS) and DSR (SVD) at crop maturity, and they were also significantly correlated with DSR based on both MR and RVS-DSR (MR+RVS) and both MR and SVD-DSR (MR+SVD). The results show that DSR (MR+RVS) was the most accurate in assessing FOV4 resistance, and DSR (SVD) and DSR (MR+SVD) can be used in combination with DSR (RVS) and DSR (MR+RVS), or as the substitutes for RVS. Mortality rate in the greenhouse was significantly correlated with MR and DSR (MR+RVS) and DSR (MR+SVD) in the field, indicating consistency between evaluations under both conditions. Furthermore, foliar symptoms-based MR and DSR under controlled-conditions were significantly correlated, with coefficients of variation at 20 to 30% in other related studies. The results confirm the validity of using the two parameters in greenhouse evaluations for FOV4 resistance in cotton.

中文翻译：

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枯萎病菌小种4（Fusarium oxysporum f. sp. vasinfectum）棉花抗枯萎病性评价参数研究

枯萎病，由尖孢镰刀菌引起。sp。vasinfectum race 4 (FOV4) 是一种早期的血管疾病，症状包括幼苗枯萎和死亡。本研究的目的是基于现场根管染色（RVS）-DSR和茎血管变色（SVD）-DSR，探讨死亡率（MR）与疾病严重程度等级（DSR）之间的关系以及MR的关系。在现场使用 MR 和 DSR 的受控条件下。两个田间试验和两个温室试验的结果，每个试验都采用拉丁方设计，用于八个棉花品种（Gossypiumspp。）和两个现场后代行测试进行了分析。在田间，方形阶段的 MR 与作物成熟时的 DSR (RVS) 和 DSR (SVD) 均显着相关，并且它们也与基于 MR 和 RVS-DSR (MR+RVS) 的 DSR 和两者均显着相关MR 和 SVD-DSR (MR+SVD)。结果表明，DSR (MR+RVS) 在评估 FOV4 阻力时最准确，并且 DSR (SVD) 和 DSR (MR+SVD) 可以与 DSR (RVS) 和 DSR (MR+RVS) 结合使用，或作为RVS的替代品。温室中的死亡率与田间的 MR 和 DSR (MR+RVS) 和 DSR (MR+SVD) 显着相关，表明两种条件下的评估具有一致性。此外，在受控条件下，基于叶面症状的 MR 和 DSR 显着相关，在其他相关研究中，变异系数为 20% 至 30%。结果证实了在温室评价中使用这两个参数对棉花 FOV4 抗性进行评估的有效性。