[Effects of humic acid water-soluble fertilizer on growth and physiological characteristics of Bupleurum chinense seedlings].

The effects of humic acid water-soluble fertilizer on the growth and physiological characteristics of Bupleurum chinense seedlings(Zhongchai No.1) were studied by using a single factor experiment design. When the seedling age was 60 days, the humic acid water-soluble fertilizer was diluted 1 200 times(T1), 1 500 times(T2), 1 800 times(T3), and 2 100 times(T4) for seedling treatment, respectively, and water was used as the control(CK). The effects of different treatments on growth indexes, biomass accumulation, root activity, antioxidant enzyme activity, membrane lipid peroxidation, and photosynthetic characteristics of B. chinense seedlings were analyzed after 30 days. The results showed that compared with CK, stem height, leaf number, root diameter, and root length of the B. chinense seedlings under T3 treatment were significantly increased by 36.82%, 37.03%, 42.78%, and 22.38%, respectively. Root fresh weight, leaf fresh weight, root dry weight, and leaf dry weight under T3 treatment were significantly increased by 90.36%, 98.68%, 123.84%, and 104.38%, respectively. In addition, humic acid water-soluble fertilizer also enhanced TTC reducing activity of the root of B. chinense seedlings, inhibited malonaldehyde(MDA) content, increased superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) enzyme activities, improved chlorophyll content, and enhanced P_n, G_s, T_r, and other photosynthetic parameters. In conclusion, the application of humic acid water-soluble fertilizer diluted 1 800 times can significantly promote the growth of B. chinense seedlings, enhance root vitality, improve seedling stress resistance, and enhance photosynthesis. The results of this study can provide a theoretical basis for fertilization of B. chinense seedlings.

[Comparative analysis on chemical constituents in Bupleurum chinense,B. marginatum,B. marginatum var. stenophyllum and B. smithii var. parvifolium].

UPLC-Q-TOF-MS was used to analyze the chemical differences in Bupleurum. chinense,B. marginatum,B. marginatum var. stenophyllum and B. smithii var. parvifolium. Chromatographic separation was carried out on an Acquity HSS T3 C_(18) column( 2. 1 mm ×100 mm,1. 8 µm,Waters) with the mobile phase composed of 0. 1% formic acid in water-acetonitrile in the gradient elution. A hybrid quadrupole time-of-flight tandem mass spectrometry( Q-TOF-MS~E) was used for mass spectrometric analysis. Finally,25 peaks were identified based on their exact mass data and fragmentation characteristics. B.chinense,B.marginatum,B. marginatum var. stenophyllum and B. smithii var. parvifolium were obviously clustered into 3 types through processing by principal component analysis( PCA). There was almost no difference between B. chinense and B. marginatum. However,the compounds existed in B. chinense were different from those in B. marginatum var. stenophyllum,and B. smithii var. parvifolium.

[Comparative analysis on seedling growth dynamics and physiological indices of Bupleurum smithii var. parvifolium and B. scorzonerifolium].

With Bupleurum smithii var. parvifolium and B. scorzonerifolium as test objects, in order to provide a theoretical basis for the introduction and domestication of B. smithii var. parvifolium, the growth and development dynamics of seedlings, biomass accumulation, the content of malonaldehyde(MDA), the activity of antioxidase such as SOD, POD, CAT and APX between them were comparatively analyzed by direct sowing culture in the open field. The results indicated that the morphological index and the biomass accumulation of B. smithii var. parvifolium such as root diameter, root length, plant height and leaf number were inferior to B. scorzonerifolium, the antioxidase SOD and POD activity of B. smithii var. parvifolium was significantly inferior to B. scorzonerifolium (P<0.05), the antioxidase CAT and APX activity of B. smithii var. parvifolium was inferior to B. scorzonerifolium but the difference wasn't significant, while MDA content was superior to B. scorzonerifolium(P<0.05). Thus, compared with cultivated B. scorzoneri folium, the plant growth velocity of wild B. smithii var. parvifolium was relatively slower and its resistance was relatively weaker after introduction and domestication.

[Reductive degradation of chlorophenols in aqueous solution by gamma irradiation].

Because chlorine is an electron withdrawing group, the highly chlorinated phenols may react quickly with hydrated electrons rather than with hydroxyl radicals. The process of reactions of four chlorophenols (4-CP, 2-CP, 2,4-DCP, 2,4,6-TCP) with e(aq)(-) was investigated in aqueous solutions by detecting the concentration of CPs, Cl- and intermediates. In the e(aq)(-) reductive system, the experimental results showed that the order of four kinds of chlorophenol degradation and dechlorination was 2,4,6-TCP > 2,4-DCP > 2-CP > 4-CP. The greater the chlorine content was the higher reactivity of hydrated electrons towards chlorophenols was. Furthermore, hydrated electrons may preferentially attack the ortho-position of chlorine atom rather than the para-position of chlorine atom. Phenol and Cl- were detected as the final product of the reductive reaction. Additionally, processes of degradation and dechlorination of CPs were observed as the pseudo-first-order kinetics. The reaction constant of degradation of 4-CP, 2-CP, 2,4-DCP and 2,4,6-TCP were 0.154, 0.253, 0.750 and 1.188 kGy(-1), respectively. Meanwhile, the dechlorination of 4-CP, 2-CP, 2,4-DCP and 2,4,6-TCP were 0.137, 0.219, 0.251 and 0.306 kGy(-1), respectively.