North Florida Research and Education Center, University of Florida, Quincy, 32351, USA.
Curr Microbiol. 2010 Aug;61(2):79-84. doi: 10.1007/s00284-009-9578-5. Epub 2010 Jan 6.
Boll rots of cotton (Gossypium hirsutum L.) are common in the humid areas of the Southeastern US. One type of boll damage that may be differentiated from others is hardlock, with symptoms that include compression of the fibers within individual locules of mature, open cotton bolls without further obvious disintegration of the lint or damage to the carpel wall. The principal economic effect is that the boll's lint is unharvestable by mechanical cotton pickers. This disease is endemic to the Southeast and can cause severe yield losses up to 70% in some fields. Scanning electron microscopy images of fibers from hardlocked bolls showed flattened and twisted tissue compared to fibers from healthy bolls. Fusarium verticillioides (Saccardo) Nirenberg was the fungus most commonly isolated from seeds of developing cotton bolls. Flowers inoculated with F. verticillioides on the day of bloom by spraying a spore suspension onto the flowers developed significantly (P < 0.05) more hardlock symptoms compared to untreated controls. The infection process was analyzed using a F. verticillioides isolate tagged with green fluorescent protein (GFP). When it was applied to cotton flowers on the day of bloom, the GFP-tagged F. verticillioides strain was detected in the stigma and style by 2 days after bloom (DAB) and in developing seeds at 4, 6, 8, 10, 16, 20, 40, and 60 (open bolls) DAB. By 8 DAB, the GFP F. verticillioides was isolated from over 80% of developing seeds.
棉花铃腐病（Gossypium hirsutum L.）在美国东南部的潮湿地区很常见。一种可能与其他类型区别开来的棉铃损伤是硬锁病，其症状包括成熟、开放棉铃的单个室腔内纤维的压缩，而纤维绒没有进一步明显的解体或心皮壁的损伤。主要的经济影响是机械采棉机无法收获棉铃的纤维。这种疾病在东南部地区流行，在某些地区可导致高达 70%的严重减产。硬锁棉铃纤维的扫描电子显微镜图像显示，与健康棉铃的纤维相比，组织扁平化和扭曲。从发育中的棉铃种子中最常分离出的真菌是尖孢镰刀菌（Saccardo）Nirenberg。在开花当天通过将孢子悬浮液喷洒到花朵上来接种 F. verticillioides 的花朵与未处理的对照相比，明显（P < 0.05）发展出更多的硬锁症状。使用带有绿色荧光蛋白（GFP）标记的 F. verticillioides 分离株分析感染过程。当在开花当天应用于棉花花朵时，GFP 标记的 F. verticillioides 菌株在开花后 2 天（DAB）在柱头和花柱中以及在发育中的种子中被检测到，在 4、6、8、10、16、20、40 和 60（开放棉铃）DAB 中。到 8 DAB 时，从超过 80%的发育种子中分离出 GFP F. verticillioides。
