| Gtycyirhiza uralensis Fisch. is widely used in many industries and its wild resource becoming deficient, in the same time cultured glycyrrhiza can’t meet the quality standard of Chinese pharmacopoeia, so it is becoming important to enhance the amount of active chemical compounds in cultivated glycyrrhiza to meet the tremendous need. We study one-year-old and two-year-old glycyrrhiza materials through environment-control-experiment, whole glycyrrhiza plant nitrogen-ion-absorption-experiment, nitrogen-supply-experiment to learn the law of root respiration of glycyrrhiza, the regular pattern of nitrogen absorption of glycyrrhiza and the respond of root respiration and active chemical compounds of glycyrrhiza by nitrogen supply to reveal the correlation between root respiration and quality of glycyrrhiza. Through this study we could find the possible pathway of impacting the synthetizing and accumulating of ative chemical compounds of glycyrrhiza and provide theory basis for the study of enhancing the quality of cultivated glycyrrhiza. Through this study we find out these:(1) During the observation, the volume root respiration of both0-class and1-class root of one-year-old and two-year-old glycyrrhiza got significant seasonal dynamic change and present a single curve while July got significant highest peak and November got significant lowest peak. The dynamic change of active chemical compounds got no pattern law, and the correlation between volume root respiration and the five active chemical compounds respectively are liquiritin-0.304, glycyrrhizin-0.129, glycyrrhizic acid-0.441*, isoliquiritin-0.471*, isoliquititigenin0.148.(2)The rate of NO3-absorption of one-year-old and two-year-old glycyrrhiza descending by the time and got stabilized absorption rate at eight hours and the average absorption rate of one-year-old glycyrrhiza is1.85times than two-year-old. The rate of NH4+absorption of one-year-old and two-year-old glycyrrhiza both falling off and then ascended slowly finally got stabilized absorption rate at eight hours and the average absorption rate of two-year-old glycyrrhiza is tiny lower than one-year-old. Both one-year-old and two-year-old glycyrrhiza got the max absorption rate while the nitrogen concentration is0.4mmol·L-1. The study revealed that NH4+could boost the absorption of NO3-, while one-year-old glycyrrhiza increase12.2times and two-year-old glycyrrhiza increase71.1times.(3) In the supplying of five different concentration of nitrogen (0.5.1.2.4,8mmol·L-NH4NO3), the volume root respiration of both root class(0-class and1-class root) of one-year-old glycyrrhiza got significant seasonal dynamic change and present a single curve while July got the highest peak and October got the lowest peak. Generally speaking, the volume root respiration of both root class first ascend at the0.5mmol·L-1treatment and then descend and got the lowest peak at2mmol·L-1treatment, and then ascended again. During the whole observation period the volume root respiration of1-class root was always higher than0-class root.(4) While supplying five different concentration of nitrogen (0.5、1、2、4、8NH4NO3mmol·L-1) full nutrient solution, the biomass of0-class root and1-class root of one-year-old glycyrrhiza got highest peak at October and0-class root biomass was always higher than1-class root. The correlation between volume root respiration and biomass got negative correlation, under different nitrogen treatment, the correlations of0-class root respectively are-0.035、-0.525、-0.343、-0.424、-0.972**、-0.989**, and the correlations of1-class root respectively are-0.296、-0.904*、-0.422、-0.422、-0.113、-0.558. And nitrogen supply could enhance the correlation between volume root respiration and biomass and got best correlation at8mmol·L-1treatment, this result indicate that under8mmol-L-1treat could prohibit the rate of volume root respiration and enhance the root biomass best.(5) By supplying five different concentration of nitrogen full nutrient solution treatment, the five active chemical compounds percentage composition of0-class root of one-year-old glycyrrhiza got significant low content at July and significant high at October while1-class root got significant low content at June. At different nitrogen supplying the content of liquiritin and glycyrrhizic acid percentage composition of0-class root got significant difference under different nitrogen treatment, and got lowest content at2mmol·L-1treatment. In the other hand, glycyrrhizin, isoliquiritin and isoliquiritigenin got no significant difference. And the all five active chemical compounds content of1-class root got no significant difference under difference nitrogen treatment. During the whole observation period0-class root got higher active chemical compounds content and better correlation between active chemical compounds content and volume root respiration than1-class root, this result indicate that the amount of active chemical compounds of0-class root get more close relationship than1-class root. And liquiritin and glycyrrhizic got good correlation with volume root respiration, respectively are-0.404*、-0.589**, this result state that the synthetize and accumulation of liquiritin and glycyrrhizic got more impact by supplying nitrogen than other ative chemical compounds. Excepting isoliquiritin the other four compounds got better correlation with volume root respiration under nitrogen supplying and got the best at the1mmol·L-1treatment. |
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