Holmes crossed two compatible races of ceratocystis ulmi, the causal agent of Dutch elm disease.

霍姆斯曾把荷兰榆病害的致病因子，长喙壳的两个亲和小种杂交。

Xanthomonas oryzae pv. oryzae is the causal agent of rice bacterial blight, a destructive rice disease worldwide.

由水稻黄单胞菌引起的白叶枯病是世界上对水稻生长最具破坏性的病害。

The results are as follows:1. The causal agent was identified as Fusarium proliferatum for the first time in China.

研究结果如下：1、首次明确层出镰刀菌为芒果畸形病病原菌。

Dual infections are common, and all possible causes should be excluded before accepting that the first virus identified is the causal agent.

双重感染很常见，在接受第一种确定的病毒为病原体之前应该排除所有的可能原因。

[2] Vincent v. Lake Erie Transport was a superb decision, for there the court was careful to investigate the causal agent at work—in this case, the boat, which clearly slammed against the dock.

【注2】文森特诉伊利湖运输公司案是一个极好的判决，因为法院仔细调查了真正的肇因，此案中显然是船猛撞了船坞。