介质转换对平邑甜茶生物量、根系特征及氮代谢的影响

以盆栽平邑甜茶实生苗为试材,研究了介质转换对其生物量、根系特征及氮代谢的影响。结果表明：平邑甜茶根系由粘土转入壤土后,其生物量增加,外层根系大量发生,也有利于侧根的水平发展,根系活力增强,根系的硝酸还原酶（NR）和谷氨酰胺合酶（GS）活性得到促进,但不利于侧根数量的增加,且根系总表面积下降;当平邑甜茶根系由壤土转入粘土后,根系发生及代谢活动均受到抑制,NR、GS活性下降;在粘土中生长有利于平邑甜茶根系氮素积累,当根系发生介质转换后,无论转入壤土还是粘土,其氮素积累均受到抑制。平邑甜茶根系由一种介质进入另一种介质会打破其原有的生态适应,需通过一系列生理生化过程和新的形态建造过程建立新的生态适应型。

Effect of Soil Changing on the Biomass, Root Characteristics and Nitrogen Metabolism of Malus Hupehensis

A pot culture experiment is conducted to investigate the effects of soil changing on the biomass,root characteristics and nitrogen metabolism of Malus hupehensis seedlings.The results show that when the seedlings are changed from clay to loam,the root biomass increases,outer root substantially induced and NR and GS activities of outer fine roots enhanced,the lateral root developing to the horizontal;however,the number of lateral roots and total surface area of root decreases.When the growing soil is changed from loam to clay,both the root development and metabolism are inhibited,NR and GS activities decreasing,but it is beneficial to nitrogen accumulation.Nevertheless,the soil changing（from clay to clay or from clay to loam） shows that the nitrogen accumulation is inhibited.In conclusion,the ecological adaptation of Malus hupehensis roots alters when the seedling is changed from one medium to another,and the root system has to establish a new root architecture to adapt new environment through a series of physiological and biochemical process.