Crypthecodinium cohnii(dinoflagellate) and Schizochytrium sp.(thraustochytrid) are the main sources for docosahexaenoic acid(DHA). The present study aimed to evaluate the antioxidant activity of petroleum ether, ethyl...Crypthecodinium cohnii(dinoflagellate) and Schizochytrium sp.(thraustochytrid) are the main sources for docosahexaenoic acid(DHA). The present study aimed to evaluate the antioxidant activity of petroleum ether, ethyl acetate, n-butanol, and water fractions of alcohol aqueous extracts of these two microalgae and to provide a theoretical basis for comprehensive utilization. The antioxidant activity was determined by total antioxidant capacity(TAC) determination, 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging assay, ferrous ion-chelating ability(FICA) assay, and reducing power(RP) assay. The total phenolic content(TPC) and total flavonoid content(TFC) were also measured by the Folin-Ciocalteu and spectrophotometry methods, respectively. The results indicated that the extracts from these two microalgae possessed good antioxidant capacity. Analysis showed that most antioxidant performance indicators(TAC, DPPH, and RP) were positively correlated with the TPC of the extracts, suggesting that the phenolics might be the major components in C. cohnii and Schizochytrium sp., contributing to their antioxidative function. Therefore, the polar fractions of C. cohnii and Schizochytrium sp. could be further examined and considered for application in health products or cosmetics.展开更多
In the present study, genetic differentiation of Bemisia tabaci （Gennadius） biotype Q was analyzed based on mitochondrial cytochrome oxidase I （mt CO1） gene sequence. The results showed that B. tabaci biotype Q co...In the present study, genetic differentiation of Bemisia tabaci （Gennadius） biotype Q was analyzed based on mitochondrial cytochrome oxidase I （mt CO1） gene sequence. The results showed that B. tabaci biotype Q could be separated into two subclades, which were labeled as subclades Q1 and Q2. Subclade Q1 was probably indigenous to the regions around the Mediterranean area and subclade Q2 to Israel or Cyprus. It was because B. tabaci was composed of several genetically distinct groups with a strong geographical association between more closely related biotypes. Not all of the B. tabaci biotype Q in the non-Mediterranean countries come from the same regions. Until now, all B. tabaci biotype Q in China were grouped into subclade Q 1. The B. tabaci biotype Q introduced into the US included both subclades Q 1 and Q2. The genetic structure analysis showed higher genetic variation of subclade Q 1 than that of subclade Q2.展开更多
基金supported by the Shandong Academy of Agriculture Sciences(No.2015YQN32)the Ministry of Science and Technology of China(No.2014DFA32120)the National Natural Science Foundation of China(No.81471000)
文摘Crypthecodinium cohnii(dinoflagellate) and Schizochytrium sp.(thraustochytrid) are the main sources for docosahexaenoic acid(DHA). The present study aimed to evaluate the antioxidant activity of petroleum ether, ethyl acetate, n-butanol, and water fractions of alcohol aqueous extracts of these two microalgae and to provide a theoretical basis for comprehensive utilization. The antioxidant activity was determined by total antioxidant capacity(TAC) determination, 2,2-diphenyl-1-picrylhydrazyl(DPPH) radical scavenging assay, ferrous ion-chelating ability(FICA) assay, and reducing power(RP) assay. The total phenolic content(TPC) and total flavonoid content(TFC) were also measured by the Folin-Ciocalteu and spectrophotometry methods, respectively. The results indicated that the extracts from these two microalgae possessed good antioxidant capacity. Analysis showed that most antioxidant performance indicators(TAC, DPPH, and RP) were positively correlated with the TPC of the extracts, suggesting that the phenolics might be the major components in C. cohnii and Schizochytrium sp., contributing to their antioxidative function. Therefore, the polar fractions of C. cohnii and Schizochytrium sp. could be further examined and considered for application in health products or cosmetics.
基金We would like to acknowledge Dr. Ian Denholm （Rothamsted Experimental Station） for providing whitefly samples for the experiments. We thank Prof. Dr. Imtiaz Ali Khan, Chairman, Department of Entomology, NWFP Agricultural University Peshawar, NWFP, Pakistan, for reviewing and editing the original manuscript. This work was funded by Key Project of Chinese National Programs for Fundamental Research and Development （2002CB 111400）, National Natural Science Foundation of China （Grant No. 30500331 No.30771410）, Innovation Foundation of Shandong Academy of Agricultural Sci- ences （No. 2007YCX030 No. Q2006B05）, and Key Projects in the National Science ＆ Technology Pillar Program in the Eleventh Five-year Plan Period （2006BAD08A18）.
文摘In the present study, genetic differentiation of Bemisia tabaci （Gennadius） biotype Q was analyzed based on mitochondrial cytochrome oxidase I （mt CO1） gene sequence. The results showed that B. tabaci biotype Q could be separated into two subclades, which were labeled as subclades Q1 and Q2. Subclade Q1 was probably indigenous to the regions around the Mediterranean area and subclade Q2 to Israel or Cyprus. It was because B. tabaci was composed of several genetically distinct groups with a strong geographical association between more closely related biotypes. Not all of the B. tabaci biotype Q in the non-Mediterranean countries come from the same regions. Until now, all B. tabaci biotype Q in China were grouped into subclade Q 1. The B. tabaci biotype Q introduced into the US included both subclades Q 1 and Q2. The genetic structure analysis showed higher genetic variation of subclade Q 1 than that of subclade Q2.
