Bacterial leaf streak (BLS), caused Xanthomonas vasicola pv. vasculorum (Xvv), has become a major concern for maize production, mainly in the United States and South America. Therefore, this study aimed to establish a protocol for Xvv inoculation in young maize plants under controlled conditions and to develop and validate a diagrammatic scale for evaluation of maize hybrids in regard to BLS resistance. The study was carried out in three steps: the establishment of a protocol for inoculation of Xvv in young maize plants under controlled conditions; the development and validation of a diagrammatic scale for BLS severity evaluation; and the screening for BLS resistance of 45 hybrids using the proposed protocol for bacterial inoculation and the diagrammatic scale developed in this study. Besides reproducing a more natural Xvv infection, the bacterial suspension spraying without injury inoculation method induced higher disease incidence and severity, as well as reproducibility of results under the experimental conditions established in this study. The proposed diagrammatic scale allowed evaluating BLS severity with up to 97.49% of the leaf area affected by the disease. Further, the use of the diagrammatic scale resulted in an increase of accuracy from 0.909 up to 0.992. The reaction of 45 maize hybrids to BLS allowed establishing six major groups of susceptibility to the disease. The most resistant maize hybrids to BLS formed a group of 13 hybrids, with disease severity below 5%.

细菌叶片条纹（BLS），引起黄单胞菌黄单胞菌PV。vasculorum（Xvv）已成为玉米生产的主要关注点，主要在美国和南美。因此，本研究旨在建立在受控条件下在玉米幼芽中接种Xvv的方案，并开发和验证用于评估玉米杂交种抗BLS的图解量表。这项研究分三个步骤进行：建立Xvv接种协议在控制条件下的年轻玉米植株中；开发和验证用于BLS严重性评估的图表规模；并使用拟议的细菌接种方案和本研究开发的图解规模筛选45个杂种的BLS抗性。除了再现更自然的Xvv在本研究建立的实验条件下，无损伤接种的细菌悬浮液喷洒无损伤接种方法可引起更高的疾病发生率和严重程度，以及结果的可重复性。拟议的图表比例尺可以评估BLS严重程度，其中高达97.49％的叶面积受该病影响。此外，使用图表比例尺可以将精度从0.909提高到0.992。45种玉米杂交种与BLS的反应可以建立六种主要的对该病的易感性。对BLS抗性最高的玉米杂种形成了13个杂种，其病情严重程度低于5％。