Field experiments on quantifying the contributions of Coreopsis canopies and roots to controlling runoff and erosion on steep loess slopes

Grass recovery is often implemented in the loess area of China to control erosion.However,the effect mechanisms of grass cover on runoff erosion dynamics on steep loess hillslopes is still not clear.Taking the typical forage species(Coreopsis)in semiarid areas as subject,this study quantified the effects of canopies and roots on controlling slope runoff and erosion.A series of field experiments were conducted in a loess hilly region of China.Field plots(5 m length,2 m width,25°slope gradient)constructed with three ground covers(bare soil;Coreopsis with intact grass;only roots of Coreopsis),were applied with simultaneous simulated rainfall(60mm h^(-1))and upslope inflow(10,30,50,70,90L min^(-1)).The results showed that compared with bare soil,intact grass significantly reduced runoff and soil loss rates by 16.6% and 62.4% on average,and decreased soil erodibility parameter by 66.3%.As inflow rate increased,the reductions in runoff and soil loss rates increased from 2.93 to 14.00 L min^(-1)and 35.11 to 121.96 g m^(-2)min^(-1),respectively.Canopies relatively contributed 66.7% to lowering flow velocity,turbulence,weakening erosive force and increasing hydraulic resistance.Roots played a predominant role in reducing soil loss and enhancing soil antierodibility,with relative contributions of 78.8% and 73.8%.Furthermore,the maximum erosion depth reduced by Coreopsis was at the upper slope section which was previously eroded the most.These results demonstrated the efficiency of Coreopsis cover in controlling runoff and erosion on steep loess slopes,especially under large inflow rates and at upper slope sections.We suggest protecting Coreopsis with intact grass at upper slope sections,while the aboveground grass biomass can be used for grazing or harvesting at middle and lower slope sections,with roots reserved.

Interactions Between Thrombin and Natural Proudcts of Coreopsis tinctoria Nuttt. and Cistanche deserticola Ma. in Capillary Zone Electrophoresis

Aim A capillary zone electrophoretic method （CZE） was used to determine the interactions between natural products and thrombin. Methods Samples containing natural products and thrombin at various ratios were incubated at 25 ℃ and then were separated by CZE with Tris-acetate buffer at pH 7.2. Each run could be accomplished within 5 min. Results In CZE, the peak width broadened due to the affinity interaction between natural products and thrombin. Compared with positive and negative control, the natural products （CB-1, CB-2） from Coreopsis tinctoria Nuttt. interacted with thrombin; CB-3 from Coreopsis tinctoria Nuttt. and HC-1, HC-2, HC-3 from Cistanche deserticola Ma. did not bind to thrombin. Both qualification and quantification characterizations of the binding were determined. Conclusion The established method is capable of sensitive and fast determination of natural products and thrombin interactions, it can be employed as an alternative method.

Antihypertensive Effects of Extract from Flower Buds of Coreopsis tinctoria on Spontaneously Hypertensive Rats

Objective To provide experimental evidence for the antihypertensive activity of the flavonoids in flower buds of Coreopsis tinctoria（CT-F）and to investigate the underlying mechanism.Methods The spontaneously hypertensive rats（SHRs）were divided into model,captopril（positive control）,and CT-F groups,and the Wistar-Kyoto rats were set as control group,eight in each group.The blood pressure of SHRs,the activity of angiotensin II（Ang-II）in plasma,nitric oxide（NO）,malondialdehyde（MDA）and thoracic aorta media thickness in SHRs were measured by tail-cuff method,radioimmunity method,nitrate reductase method,thibabituric acid（TBA）method,and the hematoxylin-eosin staining method.Q-PCR analysis was performed to determine the relative quantity of angiotensin-converting enzyme（ACE）,ACEII,angiotensin type 1receptor（AT1R）,and TGF-β1 mRNA in left ventricle.Results CT-F could lower the systolic blood pressure of SHRs dramatically（P〈0.01）.The levels of MDA in serum and Ang II in plasma of SHRs treated with CT-F decreased markedly（P〈0.05,0.01）,the level of NO in serum increased significantly（P〈0.01）.In addition,thoracic aorta media thickness in SHRs treated with CT-F was thinner than that of the model group（P〈0.05）.The mRNA expression of ACE,AT1R,and TGF-β1 in left ventricle was markedly decreased（P〈0.05）,while that of ACE II was increased（P〈0.05）.Conclusion CT-F is effective to lower the blood pressure of SHRs,and its antihypertensive effect is probably associated with lowering the oxidative stress by reducing MDA,ameliorating aorta remodeling,dilating vessel by increasing NO and decreasing Ang-II,and regulating the expression of rennin-angiotensin System-related various genes.

Identification and Determination of Fructooligosaccharides in Snow Chrysanthemum(Coreopsis tinctoria Nutt.)

Objective:Small molecules in snow chrysanthemum such as flavonoids,phenolic compounds and amino acids have been extensively investigated.No study to date has focused on water-soluble oligosaccharides.The objective of this study is identification and determination of water-soluble oligosaccharides in snow chrysanthemum.Methods:The oligosaccharides in snow chrysanthemum were identified by high performance thin layer chromatography(HPTLC),liquid chromatography-mass spectrometry(LC-MS)combined MS library and methylation analysis for the first time.Subsequently the oligosaccharides were determined by high performance liquid chromatography with a charged aerosol detector(HPLC-CAD).Results:The oligosaccharides in snow chrysanthemum were identified as inulin-type fructooligosaccharides(FOS).The yield of FOS(DP3~DP13)in the first extraction was over 97.6%.The RSDs of repeatability in three sample amount levels(0.08 g,0.1 g,0.12 g)are lower than 4.8%and the RSDs of stability are less than 3.5%.The recoveries of FOS(DP3~13)were ranging from 96.9%to 105.6%.The contents of FOS(DP3~DP13)in flowers of snow chrysanthemum from different regions of China were greatly variant.Conclusion:This is the first time to identify and quantify FOS in snow chrysanthemum which is helpful for its performance in the in the fields of biomedical,agriculture and functional food industry as well as development of the quality control methods.In addition,the identification approach developed in this work can also be used for screening potential natural sources containing FOS.

维药昆仑雪菊的研究进展

综述了维药昆仑雪菊(Coreopsis tinctoria Nuff.)的主要成分,重点介绍了昆仑雪菊主要药物成分的分离和纯化方法;阐述了目前昆仑雪菊在降血压、降血脂、抗衰老、抗肿瘤和抗炎症等药理方面的应用进展;旨在加深人们对昆仑雪菊药理作用的了解,从而促进其推广应用.