In an effort to control aflatoxin contamination in food and/or feed grains, a segment of research has focused on host resistance to eliminate aflatoxin from susceptible crops, including maize. To this end, screening tools are key to identifying resistant maize genotypes. The traditional field screening techniques, the kernel screening laboratory assay (KSA), and analytical methods (e.g., ELISA) used for evaluating corn lines for resistance to fungal invasion, all ultimately require sample destruction. A technological advancement on the basic BGYF presumptive screening test, fluorescence hyperspectral imaging offers an option for non-destructive and rapid image-based screening. The present study aimed to differentiate fluorescence spectral signatures of representative resistant and susceptible corn hybrids infected by a toxigenic (SRRC-AF13) and an atoxigenic (SRRC-AF36) strain of Aspergillus flavus, at several time points (5, 7, 10, and 14 days), in order to evaluate fluorescence hyperspectral imaging as a viable technique for early, non-invasive aflatoxin screening in resistant and susceptible corn lines. The study utilized the KSA to promote fungal growth and aflatoxin production in corn kernels inoculated under laboratory conditions and to provide actual aflatoxin values to relate with the imaging data. Each time point consisted of 78 kernels divided into four groups (30-susceptible, 30-resistant, 9-susceptible control, and 9-resistant control), per inoculum. On specified days, kernels were removed from the incubator and dried at 60°C to terminate fungal growth. Dry kernels were imaged with a VNIR hyperspectral sensor (image spectral range of 400-1000 nm), under UV excitation centered at 365 nm. Following imaging, kernels were submitted for the chemical AflaTest assay (VICAM). Fluorescence emissions were compared for all samples over 14 days. Analysis of strain differences separating the fluorescence emission peaks of resistant from the susceptible strain indicated that the emission peaks of the resistant strain and the susceptible strains differed significantly (p < 0.01) from each other, and there was a significant difference in fluorescence intensity between the treated and control kernels of both strains. These results indicate a viable role of fluorescence hyperspectral imaging for non-invasive screening of maize lines with divergent resistance to invasion by aflatoxigenic fungi.

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基于光谱的筛选方法评估了两种不同的黄曲霉毒素真菌入侵抵抗力的特定玉米品系。

为了控制食品和/或饲料谷物中的黄曲霉毒素污染，研究的一部分集中在宿主抗性上，以从包括玉米在内的易感作物中消除黄曲霉毒素。为此，筛选工具是鉴定抗性玉米基因型的关键。传统的田间筛选技术，核仁筛选实验室测定法（KSA）和用于评估玉米品系对真菌入侵的抗性的分析方法（例如ELISA）最终都需要破坏样品。荧光高光谱成像是基本BGYF推定性筛查测试的一项技术进步，它为非破坏性和基于图像的快速筛查提供了一种选择。本研究旨在在几个时间点（5、7、10和10）区分代表性的抗性和易感玉米杂种的荧光光谱特征，这些玉米杂种被黄曲霉的产毒力（SRRC-AF13）和产毒力（SRRC-AF36）菌株感染。 （第14天），以评估荧光高光谱成像作为在抗性和易感玉米品系中进行早期，非侵入性黄曲霉毒素筛查的可行技术。这项研究利用KSA促进了在实验室条件下接种的玉米粒中真菌的生长和黄曲霉毒素的产生，并提供了与成像数据相关的实际黄曲霉毒素值。每个时间点由每个接种物的78个籽粒组成，分为四个组（30个敏感菌，30个抗药性，9个敏感药性对照和9个抗药性对照）。在指定日期，从培养箱中取出谷粒并在60℃下干燥以终止真菌生长。在以365 nm为中心的UV激发下，用VNIR高光谱传感器（图像光谱范围为400-1000 nm）对干粒进行成像。成像后，将籽粒提交进行化学AflaTest分析（VICAM）。比较了14天内所有样品的荧光发射。通过将菌株的荧光发射峰与敏感菌株分离开来的差异分析表明，耐药菌株和敏感菌株的发射峰之间存在显着差异（p <0.01），并且两个菌株之间的荧光强度存在显着差异。处理和控制两种菌株的籽粒。