铵硝配比对巴西香蕉生长和氮素营养的影响

Effects of NH_4^+/NO_3^- Ratios on Growth and Nitrogen Nutrition in Brazil Banana

采用水培法,在等氮条件下设置5种不同铵硝配比处理,探讨不同铵硝配比对巴西香蕉幼苗生长及其氮素营养特性的影响。结果表明,等氮条件下,适当地提高铵态氮比例可以提高香蕉的生物量;铵硝比为10∶90最适合香蕉的生长;增铵促进根系的生长,根系中铵、硝含量分别与培养液中铵态氮和硝态氮的含量有关。香蕉幼苗中氮的含量、累积量与铵硝配比有关,增加铵的比例地上部分氮含量和累积量高于全硝处理,促进氮的吸收和利用;铵硝配比影响香蕉叶绿素含量、光合速率以及硝酸还原酶活性,光合速率与叶绿素含量、硝酸盐含量与硝酸还原酶活性没有明显的正相关关系。在香蕉生长早期适当增加铵态氮供应可以促进香蕉根系的生长,有利于香蕉的早发、稳长。

Study on growth and nitrogen nutrition physiological characteristics in Brazil Banana seedling by hydroponic culture experiment with five ratio of ammonium to nitrate at equal nitrogen concentration condition. These results were showed that： At this condition, banana biomass increased with suited ammonium concentration and the ratio of NH4^＋/NO3^- 10：90 was the most suitable to its growth. Increasing ammonium ratio promoted banana root development, and concentration of ammonium and nitrate in its body related to the concentration of ammonium and nitrate in culture solution respectively. In banana nitrogen concentration and content related to the ratio of NH4^＋/NO3^-; amd increasing ammonium ratio shoot nitrogen concentration and content with higher ratio of utilization and absorption was higher than that of 100% nitrate treatment. Ahhough there were no distinct linearity relation between chlorophyll concentration and photosynthesis rate, or nitrate concentration and nitrate reductive enzyme activity, ratio of NH4^＋/NO3^- influenced these physiological characteristics. Therefore, increasing supply of suited ammonium in banana seedling stage will promote root growth, thus this make it growth fleetly and steadily.