A simple multi-residue method for determination of plant growth retardants in Ophiopogon japonicus and soil using ultra-performance liquid chromatography-tandem mass spectrometry.

Plant growth retardants may play an important role in regulation of yield and quality of crops, fruits, and vegetables. Such compounds have begun to be used in the cultivation of traditional Chinese medicines (TCMs), especially for root medicines. Although the potential risks to human health of these compounds has attracted increasing attention, analytical methods for detection of plant growth retardants in TCMs remain poorly investigated. In this study, an effective and reliable method for simultaneous determination of 11 plant growth retardants in Ophiopogon japonicus and soil samples was developed by ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry (UPLC-QqQ-MS/MS). Extraction was conducted in acetonitrile containing 1.0% (v/v) acetic acid with ultrasonication. The octadecylsilyl (C18) and MgSO4 were used as the dispersive-solid phase extraction (d-SPE) sorbent and provided satisfactory recoveries for the analytes. The conditions of extraction and LC-MS/MS were optimized to achieve the highest recovery and sensitivity. Good linearity was achieved within a wide range with all correlation coefficients exceeding 0.9950. The recoveries of all analytes in O. japonicus and soil samples ranged from 57.37% (choline chloride) to 99.93% (trinexapac-ethyl) and from 54.37% (daminozide) to 94.82% (triadimenol), respectively. The limits of quantifications ranged from 0.03 to 3.54 µg/L. The proposed method was successfully applied to detect and quantify 11 plant growth retardants in empirical O. japonicus and soil samples. High frequency of paclobutrazol and choline chloride was found in O. japonicus samples. In addition, paclobutrazol showed a high residual concentration (>1100 µg/kg) in the soil of O. japonicus indigenous production.

The functional significance of black-pigmented leaves: photosynthesis, photoprotection and productivity in Ophiopogon planiscapus 'Nigrescens'.

Black pigmented leaves are common among horticultural cultivars, yet are extremely rare across natural plant populations. We hypothesised that black pigmentation would disadvantage a plant by reducing photosynthesis and therefore shoot productivity, but that this trait might also confer protective benefits by shielding chloroplasts against photo-oxidative stress. CO2 assimilation, chlorophyll a fluorescence, shoot biomass, and pigment concentrations were compared for near isogenic green- and black-leafed Ophiopogonplaniscapus 'Nigrescens'. The black leaves had lower maximum CO2 assimilation rates, higher light saturation points and higher quantum efficiencies of photosystem II (PSII) than green leaves. Under saturating light, PSII photochemistry was inactivated less and recovered more completely in the black leaves. In full sunlight, green plants branched more abundantly and accumulated shoot biomass quicker than the black plants; in the shade, productivities of the two morphs were comparable. The data indicate a light-screening, photoprotective role of foliar anthocyanins. However, limitations to photosynthetic carbon assimilation are relatively small, insufficient to explain the natural scarcity of black-leafed plants.

[Residuals of organochlorine pesticides and heavy metals in Radix Ophiopogonis and Ophiopogon japonicus growing soil].

OBJECTIVE: To determine the residues of organochlorine pesticides and heavy metals in Radix Ophiopogonis and Ophiopogon japonicus. METHOD: The residues of 4 isomers of benzene hexa chloride (BHC) and 4 isomers of dichloro dipheny trichloroethane (DDT) were determined by gas chromatography. The contents of Pb, Cd, Cu, Cr, Hg and As were determined by ICP. RESULT: The residues of organochlorine pesticides in Radix Ophiopogonis were lower than the permissible maximum limits of the Chinese national standard except hexachloride (BHC) in Radix Ophiopogonis from Cixi as well as Cu in soil of Luojiang. CONCLUSION: The enrichment capacity of Radix Ophiopogonis for (BHC) and Hg is higher. It is suggested that we should try to select herbs-growing soil for O. japonicus with a particular emphasis on the pesticides residues in soil.

[Comprehensive comparison between erective and creepy Ophiopogon japonicus of Sichuan].

OBJECTIVE: To compare the agronomic characters, HPLC fingerprints, the content of main component and amino acid between erective and creepy Ophiopogon japonicus of Sichuan. METHOD: Agronomic characters were measured by conventional methods; HPLC was applied on a C18 column with CH3OH-CH3CN-2% CH2COOH solution by gradient elution, quercetin was used as the internal standard reference, the contents of total saponins, flavone and polysaccharide were determined by UV spectrophotometry and amino acid was determined by automatic amino acid analyzer. RESULT: There were extremely significant differences in the most agronomic characters between erective and creepy O. japonicus of Sichuan. The yield per plant was closely relevant to the roots number and the fresh weight of aerial part. The differences were not significant both in 69 common peaks and 23 uncommon peaks in HLPC fingerprints and the content of main component between erective and creepy O. japonicus. CONCLUSION: There is no obvious difference in chemistry component between the two types of O. japonicus. The yield per plant was closely relevant to the roots number and the fresh weight of aerial part. In cultivation it is appropriate to choose the creepy O. japonicus.

[Study on biological characteristics and relative yield of Ophiopogon japonicus].

OBJECTIVE: To study the biological characteristics and the relative yield of Ophiopgon japonicus. METHOD: The observation of the selected plants nad determination of the selected samples. RESULT: The yield of O. japonicus was positively correlated to the height of plant, the weight of leaves, the length of nutritive roots, and the quantity of root tubers. It was also positively correlated to the weight of nutritive roots, but not significantly. CONCLUSION: According to the growing characteristics of O. japonicus, the yield of O. japonicus can be promoted by selecting porous soil, controlling the field water from planting to the middle 10 days of June and enhancing the management of fertilizer and water from July to November and from the end of February to early in March next year.

[Study on endophyte and the growth stages of Ophiopogon japonicus].

OBJECTIVE: To study on the relationship between the endophyte and the life cycle of Ophiopogon japonicus in Zhejiang. METHODS: Sample roots of Ophiopogon japonicus at different growth stages were thoroughly washed and cut into small fragments, then cleared (removing cytoplasmic contents from cells) using hot 10% KOH and stained with acid fuchsin (alternative stain). The hyphae, the arbuscular and the vesicular of endophyte were examined. RESULTS: The hyphae appeared and grew in the seedling stage, the hyphae grew into arbuscular in the root tuber generating stage and vesicular in the stage of root tuber expanding period. CONCLUSION: The endophytes in Ophiopogon japonicus appeared in forms of hyphae, arbuscular and vesicular at different growth stages to meet the needs of Ophiopogon japonicus developing.

[Study on N, P and K absorption and accumulation in Ophiopogon japonicus].

OBJECTIVE: To study the absorption and accumulation of N, P and K in Ophiopgon japonicus. METHOD: The contents of N, P, K and trace element were determined respectively by using the kjeldathl method digested with H2SO4 + H2O2, ammonium vanadstemolybdate chromoscopy, flame spectrometry and atomic absorption spectrophotometry. RESULT: The contents of N and K were the highest, and that of P was relatively lower O. japonicus. The changing pattern of N was low-high-low in the growth and development period. The accumulative speed of N had two relatively quicker and two relatively slower phases. The content of N is higher in nutritive organs; The changing pattern of P was similar to that of N, while the content of P is higher in leaves and nutritive roots at early stage of growth and development. It was high in root tuber during harvesting stage, and the accumulative quantity in the plant was increased gradually. The level of K was high in early stage and low in later stage of growth. The content of K was relatively higher in leaves and nutritive roots at early stage, and that in root tuber was slightly lower than the leaves but higher than that the nutritive roots from February to March. The accumulating quantity slightly increased in the plant. CONCLUSION: The application quantity of N should be increased gradually after transplant, stopped in autumn, and used again in early spring. Phosphate fertilizer is needed in autumn and winter, while large amount of potassium fertilizer shoule be used in winter tine.

[Study on tissue culture technique of Liriope spicata].

OBJECTIVE: To study the tissue culture technique of Liriope spicata. METHODS: The tender stem segments with roots as explants were cultured on various media with different kinds of hormones, a lot of bud clusters were induced and grew into seedlings. RESULTS: A great quantity of whole aseptic seedlings can be formed quickly by the tender stem segments on the media.

[Biological characteristics and damaging regularities of grubs endangering the growth of Ophiopogen japonicus (Thunb.) Ker-Gawl].

OBJECTIVE: To provide a scientific basis for prevention and control of the damage done to Ophiopogen japonicus by grubs. METHOD: Conducting laboratory observation along with field investigation. RESULT: The grubs endangering the growth of O. japonicus are mainly Hoplosternus incanus, Holotrichina paraullela and Anomala corpulenta, H. incanus takes two years to make a generation and overwinters in the form of second or third-instar larvae. H. parallela and A. corpulenta generate yearly and overwinter in the form of third-instar larvae. The extent of the damage done to O. japonicus by grubs is related to such factors as the number of sequential cropping years, the model of intercropping and the type of soil. CONCLUSION: Prevention and control of the pest grub should be based primarily on proper agricultural (cultivating) measures.