Effects Of Silicon Combination With Ammonium Nitrate Ratio On Banana Growth,Nutrient Uptake And Fusarium Wilt Physiological

Banana,as the second-largest fruit crop in the world,is an important economic crop,but the Fusarium wilt has seriously affected the development of the industry in Hainan province.The ratio of ammonium-nitrate and silicon affected the physiological and metabolic changes of banana,thus affected the resistance of banana to Fusarium wilt.The absorption and accumulation of silicon by banana were affected by banana variety and the ratio of ammonium-nitrate.In this paper,through the research methods of hydroponic culture and soil culture,the effects of different ammonium-nitrate ratio on banana silicon absorption kinetics were analyzed.the effects of silicon fertilizer on banana growth,nutrient absorption,accumulation,distribution and disease resistance were studied,in order to find the suitable ammonium-nitrate ratio and silicon supply level for banana growth,and provide scientific basis for rational application of nitrogen fertilizer and silicon in the field.The main conclusions were as follows:1.Under the experimental conditions,the kinetics of silicon absorption in banana seedling stage under four ammonium-nitrate ratio conformed to the kinetic model of Michaelis-Menten enzyme.Ammonium nitrate ratio significantly affected the silicon absorption rate of Brazil banana and Baodao.Under the ammonium-nitrate ratio of 1:1,the silicon absorption rate of Brazil increased gradually,while the silicon absorption rate of Brazil decreased gradually under the ammonium-nitrate ratio of 1:14.The silicon absorption rate of Baodao decreased gradually under the four ratios of ammonium to nitrate.Ammonium nitrate ratio significantly affected the changes of the maximum capacity(Vmax),nutrient transport efficiency(Km)of silicon and the rate of silicon flowing into roots(α)in Brazil and Baodao.The Km and Vmax absorbed by silicon of Brazil were the highest at ammonium nitrate ratio at 1:1,which was suitable for high silicon concentration,while Baodao was suitable for medium silicon concentration.2.Soil environment affected the growth of banana.Under the condition of sterilization,the correlation between aboveground dry weight and root dry weight of banana was not significant,but under unsterilized condition,there was a significant positive correlation between aboveground dry weight and root dry weight of banana.Under the condition of silicon-supplied 0.6g/kg,the dry weight of aboveground part of Morado decreased significantly with the increase of the ratio of nitrate to nitrogen in both sterilized soil and unsterilized soil.Under the condition of unsterilized soil,the root and aboveground part of Morado increased significantly by 46% and 76.7% under ammonium nitrate ratio at 3:1,and decreased by 45.8% and 40.4% under ammonium nitrate ratio at 1:1.Under sterilized soil,increase the level of silicon supply and promote the growth of aboveground part of banana.3.There was a significant negative correlation between nitrate reductase activity((NR)and nitrate content in banana pseudostem under two kinds of soil conditions.Under the condition of sterilized soil,silicon-supplied0.3g/kg and 0.6g/kg,the NR activity of ammonium-nitrate than 3:1 banana pseudostem was significantly higher than that of 1:3;under unsterilized soil with silicon-supplied 0.6g/kg,the NR activity of 1:1 Morado pseudostem was significantly lower than that of 3:1,and the nitrate content of pseudostem was significantly increased by 21.5%.Under the condition of sterilized soil,increasing the level of silicon supply significantly decreased the NR activity of pseudostem,and the content of nitrate nitrogen in pseudostem increased significantly4.Ammonium nitrate ratio,the level of silicon supply and soil environment affected the lignin content,total phenol content,polyphenol oxidase(PPO),peroxidase(POD)activity and the number of Fusarium oxysporum in rhizosphere soil.Under the condition of sterilized soil,different levels of silicon supply had different effects on the contents of lignin and total phenol in the pseudostem of Morado.When the silicon supply level was increased to 0.6g/kg,the total phenol content of unsterilized Morado pseudostem decreased and the lignin content increased.Under the condition of sterilized soil,the POD enzyme activity of Morado pseudostem decreased with the increase of silicon supply level,under the silicon supplied0.6g/kg,increasing the proportion of nitrate nitrogen would cause the PPO enzyme activity of Morado pseudostem to increased and decreased the POD enzyme activity.Under the unsterilized soil and ammonium-nitrate ratio at1:1,with the increase of silicon concentration,the PPO enzyme activity decreased by 22.1% and the POD enzyme activity increased by 41.9%,and the ammonium-nitrate ratio had no significant effect on PPO enzyme activity.Increase the level of silicon supply and significantly reduce the number of Fusarium oxysporum in the rhizosphere soil of unsterilized red banana.5.Ammonium nitrate ratio and the level of silicon supply in different soil environments affect the absorption and accumulation of nitrogen,phosphorus,potassium and silicon in different parts of banana.No matter whether the soil was sterilized or not,the potassium content of Morado root was the lowest under ammonium nitrate ratio at 3:1.Under the condition of sterilized soil,the level of silicon supply had no significant effect on the content of nitrogen 、 potassium in roots and potassium in leaves.In unsterilized soil,ammonium nitrate ratio had no significant effect on the content of nitrogen in leaves,and ammonium nitrate ratio did not affect the content of phosphorus in roots.With the increase of silicon supply,the silicon content of roots and leaves increased significantly under unsterilized soil.