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In this paper, the wealth dish ( Gynuradivaricata ( L. ) DC . ) , Talinum (Talinum paniculatum (Jacq.) Gaert.), Spirodela dishes ( Gynurabicolor ( ROXB. ) DC . ) Of much the Hunan Changsha commercially Welcome the common Diet plant for the material , using the hydroponic method , from the point of view of plant mineral nutrition and plant physiology and biochemistry of different nitrogen forms on the physiological effects of the three medicated plants , and made ??the following main findings : 1 , the most appropriate three kinds of medicated plant growth , nitrogen levels 12mmol · L-1. With the reduction of the ratio of ammonium to nitrate nitrogen levels three medicated plant aboveground fresh weight was a growing trend . Wealth dishes , Talinum ammonium to nitrate ratio of 25:75, seasonal weighing maximum Spirodela dish weighing ammonium to nitrate than 0:100 seasonal maximum ; the Talinum purple back dish of ammonium to nitrate ratio of 25:75 when dry matter weighing up to maximum , rich dishes of ammonium to nitrate than 0:100 when weighing up to a maximum of dry matter . 2 , With the reduction of the ratio of ammonium to nitrate , the three medicated plant stems and leaves of nitrate , nitrite content gradually increases, a downward trend in the total amount of free amino acids ; properly enhanced facilities ammonium nitrogen helps reduce medicated plant nitrate , nitrite salt content. Full ammonium nutrition , the major component of the free amino acids in the leaves and stems of three medicated plants serine , arginine , proline ; full nitrate nutrition , the the three medicated plant leaves and stems of free amino acids aspartic acid , glutamic main . Increase the proportion of the nitrate in the nutrient solution , can significantly increase the activity of NR medicated plant stems and leaves , and at the same time reduce the activity of GDH . 3 , in the same nitrogen treatment under GS activity is much higher than the GDH activity play a key role in the GS in the the ammonia assimilation process in three medicated plants . At the same time , the total amount of free amino acids and GS activity was positively correlated negatively correlated with NR activity , the GDH activity changes in trends in general and GS activity trends . Suitable for the three medicated plant growth nitrogen level of ammonium nitrogen ratio should not be less than 50 % of the total nitrogen .
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