The Extraction Process Optimization of Phenolic Compounds from Okra Flower and Its Antioxidant Activities

[Objective] The aim of the study was to investigate extraction optimization and antioxidant activity of polyphenol in okra flower in order to enhance extraction efficiency and developing value of okra flower. [Method] Optimization of supersonic assisted extraction of phenolic compound in okra flower was investigated using uniform design methodology, and its antioxidant activity was analyzed including reducing power and the capacity of scavenging superoxide anion radicals（O-2·）. [Result]The optimal process parameters of supersonic assisted extraction were as follows：ratio of sample to solvent of 1：35, ethanol concentration of 55%, supersonic time of22 min, and in the extraction condition the experimental yield of phenolic compound was 4.28%. Moreover, phenolic compound in okra flower exhibited stronger antioxidant activities, reducing power of 0.2 mg/ml extraction fluid reached 0.672 and the rate of scavenging O-2· was 13.13%. [Conclusion] The optimization of extraction technology of phenolic compound in okra flower is simple and reliable, the result contributes to the development of phenolic compound in okra flower.

Effects of Fulvic Acid on Agronomic Traits and Yield of Autumn Potato

[Objective] This study was to investigate the effects of fulvic acid on agronomic traits and yield of autumn potato. [Method] The effects of fulvic acid on growth period, plant morphology, tuber, net photosynthetic rate, chlorophyll content, leaf area index （LAI） and yield of autumn potato were investigated. [Result] The application of fulvic acid prolonged the growth period and increased the plant height, stem diameter, leaf chlorophyll content, LAI, net photosynthetic rate, tuber number per plant, tuber weight per plant and marketable tuber rate of autumn potato, thus increasing the yield. Applying fulvic acid prolonged the growth period of autumn potato by 1-3 d and significantly increased the plant height, net photosynthetic rate, tuber weight per plant and yield of autumn potato （P〈0.05, P〈0.01）. When the application amount of compound fertilizer was reduced by half, applying fulvic acid almost showed the same seedling emergence stage, mature stage, growth period and net photosynthetic rate with applying full amount of compound fertilizer. In particular, no significant difference was found in the yield of autumn potato between fullamount and half-amount compound fertilizer treatment groups in the premise of solid- liquid fulvic acid combined application. [Conclusion] In the premise of unchanged yield, applying fulvic acid can reduce the application of chemical fertilizers and reduce the non-point source pollution of chemical fertilizers.

Distribution patterns of chlorophyll a in spring and autumn in association with hydrological features in the southern Yellow Sea and northern East China Sea

Two field studies were conducted to measure pigments in the Southern Yellow Sea (SYS) and the northern East China Sea (NECS) in April (spring) and September (autumn) to evaluate the distribution pattern of phytoplankton stock (Chl a concentration) and the impact of hydrological features such as water mass,mixing and tidal front on these patterns.The results indicated that the Chl a concentration was 2.43±2.64 (Mean ± SD) mg m-3 in April (range,0.35 to 17.02 mg m-3) and 1.75±3.10 mg m-3 in September (from 0.07 to 36.54 mg m-3) in 2003.Additionally,four areas with higher Chl a concentrations were observed in the surface water in April,while two were observed in September,and these areas were located within or near the point at which different water masses converged (temperature front area).The distribution pattern of Chl a was generally consistent between onshore and offshore stations at different depths in April and September.Specifically,higher Chl a concentrations were observed along the coastal line in September,which consisted of a mixing area and a tidal front area,although the distributional pattern of Chl a concentrations varied along transects in April.The maximum Chl a concentration at each station was observed in the surface and subsurface layer (0-10 m) for onshore stations and the thermocline layer (10-30 m) for offshore stations in September,while the greatest concentrations were generally observed in surface and subsurface water (0-10 m) in April.The formation of the Chl a distributional pattern in the SYS and NECS and its relationship with possible influencing factors is also discussed.Although physical forces had a close relationship with Chl a distribution,more data are required to clearly and comprehensively elucidate the spatial pattern dynamics of Chl a in the SYS and NECS.

THE N/P RATIO IN THE NORTHERN SOUTH YELLOW SEA IN AUTUMN

Study of horizontal and vertical distributions of the N/P (nitrogen versus phosphate) atom ratio in the northern South Yellow Sea showed that the ratio varied greatly in upper waters of the investigated area and was always much greater than the theoretical Redfield ratio of 16:1 found below the thermocline zone. It was in general higher near the coast and lower in the central part. With increasing depth, the ratio became smaller and smaller. This distribution pattern is attributed to: 1) the anthropogenic influence of the surface N and P which makes the N/P ratio differ from the normal value; 2) the easy adsorption of P on particles hinders P transport to the central part; 3) below the thermocline zone, the N and P mainly come from the remineralization of the sedimented phytoplankton residues which have almost the theoretical Redfield value and; 4) the existence of the Yellow Sea Bottom Cold Water which inhibits the vertical exchange of the water.

Stability Assessment of Some West African Okra （Abelmoschus caillel~ Genotypes in Nigerian Genebank

Stability among 50 accessions of West African okra （Abelmoschus caillei） was assessed under three diverse ecological environments at Abeokuta, Ibadan and Mokwa in Nigeria during 2005 and 2006 cropping season. The accessions were grown in a Randomized Complete Block Design with three replications; data were collected on 5-10 randomly selected plants from each plot. Only 20 accessions were subjected to stability analysis on the basis of yield across the three environments. The joint regression analysis, deviation means square were computed using Eberhart and Russell method and complemented with Francis and Kannenberg method. The regression coefficients of accessions mean yields on the environmental index resulted in regression coefficients ranging in values from 0.5549 to 1.6667. OAA/96/175-5328, NGAE-96-011 and NGAE-96-0060 were among the superior genotypes with high yield performance. The large variation in regression values indicated large differences in genotype response to different environments. It suggests that stability concept of Ebelhart and Russell could be modified to use any yield components that has strong correlation with yield for stability analysis. The two promising accessions ofA. caillei （NGAE-96-011 and NGAE-96-0060） needed to be further tested on farmers＇ field to obtain on-farm data, alter which it should be recommended for official registration and released by the National Committee on Naming, Registration and Release of Crop varieties in Nigeria.

Autotetraploidy induced in Nianmaohuangqin (Radix Scutellariae viscidulae) with colchicine in vitro

OBJECTIVE： To establish and optimize the propaga- tion of Nianmaohuangqin （Radix Scutellariae Viscid- ulae） and induce and characterize polyploidy of Nianmaohuangqin （Radix Scutellariae Viscidulae）. METHODS： Buds from germinating seed-derived explants were induced by tissue culture. With an or- thogonal test, different concentrations of 6-benzyl- aminopurine （BAP）, indole-3-acetic acid （IAA） and kinetin （KT） were used to determine the optimal concentrations for the propagation of Nianmaohuangqin （Radix Scutellariae Viscidulae）. The differ- ent concentrations of IAA and rooting powder （ABT） were used to induce rooting. A 0.3% w/v col- chicine solution was used to induce polyploidy and the induced buds was identified by root-tip chromosome determination and stomatal apparatus ob- servation. RESULTS： A large number of buds could be in- duced directly from epicotyl and hypocotyl ex- plants on Murashige and Skoog （MS） （Murashige and Skoog 1962） medium supplemented with 1.1-1.3 mg/L BAP and 0.2 mg/L IAA. Root induction and development could be observed within 20 days of inoculation on 1/2 MS medium supplemented with 0.2 mg/L IAA and 0.1 mg/L ABTo Furthermore, 27 lines of autotetraploid individuals were ob- tained with a plantlet chromosome number of 2n= 4x=36. CONCLUSION： Autotetraploid lines could be ob- tained through induction with colchicine in vitro, proving that this method might be used for plant selection and breeding.