Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29631.
O&A Enterprises, Maricopa, AZ 85139.
Plant Dis. 2022 Mar;106(3):990-995. doi: 10.1094/PDIS-08-21-1743-RE. Epub 2022 Mar 7.
f. sp. race 4 (FOV4) is a devastating fungus pathogen that causes Fusarium wilt in both domesticated cotton species, (Upland) and (Pima). Greenhouse and field-based pathogenicity assays can be a challenge because of nonuniform inoculum levels, the presence of endophytes, and varying environmental factors. Therefore, an in vitro coculture system was designed to support the growth of both domesticated cotton species and FOV4 via an inert polyphenolic foam substrate with a liquid medium. A Fusarium wilt-susceptible Pima cotton cultivar, 'GB1031'; a highly resistant Pima cotton cultivar, 'DP348RF'; and a susceptible Upland cotton cultivar, 'TM-1', were evaluated for 30 days during coculture with FOV4 in this foam-based system. Thirty days after inoculation, disease symptoms were more severe in both susceptible cultivars, which displayed higher percentages of foliar damage, and greater plant mortality than observed in 'DP348RF', the resistant Pima cotton cultivar. This foam-based in vitro system may be useful for screening cotton germplasm for resistance to a variety of fungus pathogens and may facilitate the study of biotic interactions in domesticated cotton species under controlled environmental conditions.
f. sp. race 4（FOV4）是一种毁灭性的真菌病原体，可引起陆地棉（Upland）和皮马棉（Pima）两种栽培棉种的枯萎病。由于接种物水平不均匀、内生菌的存在以及环境因素的变化，温室和田间致病性测定可能具有挑战性。因此，设计了一种体外共培养系统，通过惰性多酚泡沫基质和液体培养基来支持两种栽培棉种和 FOV4 的生长。在该泡沫基系统中，对枯萎病敏感的皮马棉品种'GB1031'、高度抗枯萎病的皮马棉品种'DP348RF'和易感的陆地棉品种'TM-1'进行了 30 天的共培养评估。接种后 30 天，在易感品种中观察到更严重的病害症状，叶片损伤百分比和植株死亡率均高于抗性皮马棉品种'DP348RF'。这种基于泡沫的体外系统可能有助于筛选棉花种质对各种真菌病原体的抗性，并且可以在受控环境条件下促进对栽培棉种中生物相互作用的研究。
