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作 者 ：张茂星 张明超 陈鹏 阮云泽 朱毅勇 沈其荣

期 刊 ：植物营养与肥料学报 2013年 19卷 5期 页码：1241-1247

关键词：硝态氮/铵态氮比；香蕉枯萎病；尖孢镰刀菌；

Keywords:nitrate/ ammonium ratio, banana wilt disease, Fusarium oxysporum f. sp. Cubense,

摘 要 ：通过水培试验，研究了不同硝/铵配比对香蕉生长及其根际尖孢镰刀菌侵染的影响。结果表明， 1）铵硝混合营养对香蕉生长的效果优于单一营养，尤其是在75%硝态氮+25%铵态氮处理下香蕉生长最好，叶片中氮、磷、钾含量也最高； 2）香蕉根际pH在100%铵态氮处理时最低，随着硝态氮比例的增加，pH逐渐上升； 3）接种尖孢镰刀菌后，根际病原菌数量在100% 铵态氮处理时最多，但是在根系细胞内却没有检测到，相反，随着硝态氮比例的增加，虽然在根际中检测到的病菌数量有所降低，但是在根系内均发现存在病原菌。本研究结果说明，相对于铵硝混合营养，全铵营养会导致香蕉生长受到一定的影响，但是却能够防止香蕉尖孢镰刀菌侵染进植物根系。由于在离体培养时，全铵可以抑制尖孢镰刀菌穿透植物细胞壁的过程，因此全铵培养植物时，其根部质外体及细胞中铵态氮浓度高很可能是抑制病原菌侵染的主要原因。

Abstract:Hydroponics experiments were conducted to investigate the effects of nitrate/ammonium ratio on the growth of banana plants and invasion of banana Fusarium oxysporum f. sp. Cubense. The results showed that, 1) In comparison with the treatments of sole nitrogen source, under the treatment of 75% nitrate + 25% ammonium (75% N + 25% A), the biomass of banana plants and the content of N, P, K in plants were the highest amongst all the treatments. 2) The rhizospheric pH was decreased strongly under the 100% ammonium treatment, while the pH increased with the addition of nitrate in the root medium. 3) After inoculation of Fusarium oxysporum f. sp. Cubense, the population of pathogen in rhizosphere was increased by the application of ammonium nutrition, but the number of pathogen in root tissue was reduced especially when the ammonium ratio reached 100%, no pathogen was detected in the root. In conclusion, sole ammonium nutrition could depress the growth of banana plants, but it can inhibit Fusarium oxysporum f. sp. Cubense penetration into the root cells. In combination with our previous experiments in vitro, that 100% ammonium inhibited Fusarium oxysporum f. sp. Cubense penetration process through the host plant cell wall. Our results suggested that the high concentration of ammonium in root cytoplast and cytosol could play an important role in the inhibition of invasion of this pathogen.

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