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采用浸胚根法和浸根法对京欣一号西瓜种壳分离得到的尖孢镰刀菌(Fusarium oxysporum)进行致病性试验。结果表明:从接种后发病幼苗上分离得到的分离物与最初接种所用的镰刀菌菌落形态和生长速率等性状基本相同,采用相同的引物对rDNA进行PCR扩增获得的核苷酸序列完全相同,说明这二者为同一种菌,从而证明西瓜种子上所携带的尖孢镰刀菌具有致病性,在国内首次报道了西瓜种传尖孢镰刀菌具有致病性。西瓜种传尖孢镰刀菌培养滤液和粗毒素提取物处理西瓜种子后,种子的发芽势、发芽率和发芽指数均显著降低,其中发芽势下降了16.7%~29.0%,发芽率下降了14.4%~22.3%,发芽指数下降了19.1%~37.1%,说明培养滤液和粗毒素提取物可影响西瓜种子发芽。
Pathogenicity test was carried out on Fusarium oxysporum isolated from Jingxin-1 watermelon seed-hull by dip radicle method and immersion root method. The results showed that the isolates isolated from the inoculated seedlings were basically the same in morphology and growth rate as those used for the initial inoculation. The nucleotide sequences of the rDNA amplified by the same primers were the same, Indicating that the two are the same species of bacteria, which proves that Fusarium oxysporum carried on watermelon seeds is pathogenic, the first report in the country watermelon seedling Fusarium oxysporum has pathogenicity. Watermelon seeds Fusarium oxysporum culture filtrate and crude toxin extract treatment of watermelon seeds, seed germination potential, germination rate and germination index were significantly reduced, of which the germination potential decreased by 16.7% to 29.0%, the germination rate decreased by 14.4% ~ 22.3%, germination index decreased 19.1% ~ 37.1%, indicating that the culture filtrate and crude toxin extract can affect watermelon seed germination.