施肥对喜马拉雅红豆杉生理指标及化学计量特征的影响.

【Objective】The present paper aimed to explore the effects of different fertilization rates on physiological indexes and nutrient content of Taxus himalayana seedlings, and to screen the best fertilization rate for the growth and development of T.himalayana.【Method】The effects of N, P2O5 and K2O (CK,F1,F2,F3 and F4) on the growth of T.himalayana were studied.The physiological indexes of leaves, stems and roots, and the contents of organic carbon (OC), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) were determined.【Result】 (i) With the increase of fertilizer application, Chla and chlb contents in leaves of T.himalayana increased gradually and reached the maximum value at F3.The carotenoid content was as follows: F1 > F2 > F3 > F4 > CK.The maximum contents of soluble sugar and soluble protein were 15.80 mmol/L and 1.22 mg/g in F3 treatment, which were significantly higher than those in CK and F1 treatment (P<0.05).Malondialdehyde content increased gradually with the increase of fertilizer application, and reached 1.38 μmol/L in F4 treatment. Therefore, in the scope of this study, F3 treatment was more conducive to the accumulation of nutrients in T.himalayana. (ii) The contents of OC, TN and TP in roots, stems and leaves increased with the increase of fertilizer application, while the contents of TK only increased in roots, and first increased and then decreased in stems and leaves; At the same fertilization level, the content of OC in stem was higher than that in leaf and root, and the content of TN, TP and TK in leaf was higher than that in stem and root. (iii) With the increase of fertilizer application, the C∶N ratio of root system increased, and F4 was 13.53% higher than CK; The C∶P ratio of root, stem and leaf were 166.01-323.68, 311.33-328.79 and 183.69-252.33, respectively, and the N∶P ratio were 2.50-5.39, 4.15-6.08 and 7.42-8.44, respectively. In view of this, the input of nitrogen fertilizer should be increased in the later fertilization experiment. 【Conclusion】 Fertilization could significantly increase the contents of N, P and K in root, stem and leaf of T.himalayana, but with the increase of fertilization, photosynthetic physiological indexes and nutrients of T.himalayana increased first and then decreased. In the range of fertilization ratio in this study, when N, P2O5 and K2O were 2.40 g, 1.80 g and 1.80 g respectively, Taxus grew better. [ABSTRACT FROM AUTHOR]