Influence of Crosslinked Poluacrylate Amine and AM Fungi on Growth,Nutrient Uptake and Physiological Indices of Flue-cured Tobacco Seedlings

The culture boxes were floated on nutrient solution with crosslinked polyacrylate amine(CPA) added and arbuscular fungi(AM fungi) inoculated into culture medium,respectively,to study their influence on growth,nutrient uptake and some physiological indices of flue-cured tobacco seedlings.The results suggested the growth promotion of no-mycorrhizal tobacco seedlings due to the improvement of nitrogen nutrition,and concomitant increment of nutrient absorption such as nitrogen,phosphorus and potassium by both no-mycorrhizal and mycorrhizal ones by CPA addition.In the same case,however,no obvious changes in the growth and activities of nitrate reductase of mycorrhizal seedlings but reduction of fungal infection rates were detected.Moreover,the biomass of mycorrhizal seedlings fluctuated little if any irrespective of CPA addition and fungal inoculation.In the medium without CPA,the biomass,absorption of phosphorus and potassium,and nitrate reductase activity of tobacco seedlings were increased by fungal inoculation,as compared with the fungi free treatment.In the medium with CPA,however,the biomass of mycorrhizal seedlings was similar to no-mycorrhizal ones,and nutrient absorption and activities of nitrate reductase,chitinase and roots varied diversely according to fungal strains inoculated and the contents of CPA added into culture mediums.Taking into account of the decrease in fungal infection rate,no further growth improvement even possible excess of mycorrhizal seedlings by CPA,it was better to choose one of the two measurements,the CPA addition and the AM fungus inoculation,to promote the growth of the seedlings in practice.