[Objective] An HPLC method for the determination of caffeoylquinic acid compounds in sweet potato was developed in the present research. Quantitative analysis was performed on 11 sweet potato genotypes to provide a re...[Objective] An HPLC method for the determination of caffeoylquinic acid compounds in sweet potato was developed in the present research. Quantitative analysis was performed on 11 sweet potato genotypes to provide a reference for the development and utilization of sweet potato, especial y on the aboveground part. [Method] Caffeoylquinic acid compounds were extracted from sweet potato leaves by ultrasonic treatment for 20 min with 200 volumes of methanol. The mobile phase of HPLC was acetonitrile -0.2% aqueous phosphoric acid. Chlorogenic acid, 4, 5-O-coffeocylquinic acid, 3, 5-O-coffeeacylquinic acid and 3, 4-O-coffeeacylquinic acid were separated wel by gradient elution, with recovery rate of 94.74%, 102.63%, 100.01% and 101.05%, respectively. [Result] The contents of caffeoylquinic acids were significantly different between sweet potato genotypes and tissue parts. Among these compounds, the content of bi-caffeoylquinic acids was the highest in the aboveground part, and the content of chlorogenic acid was the highest in the root tubers. The content of caffeoylquinic acid in different parts of the plant was: 9.77-40.86 mg/g in stem apex, 2.68-13.97 mg/g in mature leaves, 0.56-7.90 mg/g in stems and 0.69-4.33 mg/g in root tubers, respectively. [Conclusion] Sweet potato stems and leaves can be used for the extraction of chlorogenic acid in development and utilization, in which the purple sweet potato series is superior to the non-purple sweet potato series. The performance of the two purple sweet potato materials of 11ZY series is particularly prominent.展开更多
The effect of different concentrations of 6-benzylaminopurine (BA) with or without 0.2 mg/L NAA on in vitro regeneration of sugarcane (Saccharum spp.) cultivars SP726180, B47419, M1176/77 and M2119/88 were evaluat...The effect of different concentrations of 6-benzylaminopurine (BA) with or without 0.2 mg/L NAA on in vitro regeneration of sugarcane (Saccharum spp.) cultivars SP726180, B47419, M1176/77 and M2119/88 were evaluated. Leaf base explants were cultured on Murashige and Skoog (MS) basal medium supplemented with 3.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) for 4 weeks. Thereafter, induction of somatic embryogenesis was observed following the transfer of resulting calli to 2,4-D-free medium for another 4 weeks. Regeneration was achieved by transfer of the embryogenic calli to regeneration media fortified with different concentrations of BA + tt-naphthylacetic acid (NAA). The number, length and vigor of shoots produced in all the genotypes were highest on media supplemented with 1.0 and 1.5 mg/L BA with and without 0.2 mg/L NAA. Among the genotypes tested, B47419 and M1176/77 recorded highest number of shoots, while maximum shoot length and crop vigor was obtained with M1176/77. Induction of callus with 3.0 mg/L 2,4-D and its subsequent incubation on 2,4-D-free media, followed by regeneration on media supplemented with 1.0 or 1.5 mg/L BA with 0.2 mg/L NAA was found to be efficient for in vitro regeneration of the sugarcane genotypes used in this study. This protocol could be applied for micropropagation of other elite genotypes.展开更多
Consumption of functional foods with health promoting benefits and/or disease prevention has been on the increase globally. The study aimed at evaluating the potential of utilizing Kenyan orange fleshed sweet potato ...Consumption of functional foods with health promoting benefits and/or disease prevention has been on the increase globally. The study aimed at evaluating the potential of utilizing Kenyan orange fleshed sweet potato (Ipomoea batatas Lam.) for functional food production with aesthetics benefits. Purees from three different varieties of orange fleshed sweet potato (OFSP) were analyzed for nutritional, physicochemical and microbial quality, The findings of the study show that the three purees were all microbiologically safe and of near neutral pH, but differed significantly (P 〈 0.05) in nutrient content (dry matter content, 12.76-28.23%; crude fiber, 1.37-2.90% fresh weight basis (FWB); 13-carotene, 0.94-9.27 mg/100g dry weight basis (DWB); starch, 10.20-18.30% FWB & total sugar 27.08-31.76% DWB). The purees had attractive appearance (ranging from yellow to dark orange), with varying significantly different spectrophotometer hunters color scale (P 〈 0.05), and flow ability. Conclusions from the findings show great potential of utilizing the varying properties of OFSP puree to produce enriched functional food products such as probiotic/prebiotic dairy, beverages, bakery and baby foods.展开更多
In Kenya almost all sugarcane grown is under rainfall conditions that are planted in different locations during both long and short rainy seasons. Effect of season, location, cultivar and spacing on yield and quality ...In Kenya almost all sugarcane grown is under rainfall conditions that are planted in different locations during both long and short rainy seasons. Effect of season, location, cultivar and spacing on yield and quality of sugarcane is not clearly understood. The research was conducted at Kibos and Mumias to determine if the yields and quality of three sugarcane cultivars were affected by season, location and row spacing. Cultivars CO 945, EAK 73-335 and KEN 83-737 were manually planted during June and September in 2011. The trial was laid out as split-split plot arranged in a randomized complete block design (RCBD) replicated three times. Data collected at harvest, 17 months after planting (MAP) including cane yields, cane yield components and cane quality. The results revealed that cane length differed significantly between June and September. Stalk population and cane yields were significantly more at Mumias compared to Kibos. Cultivar EAK 73-335 showed significantly more cane yield (t/ha) than KEN 83-737 and CO 945. Both row spacing 1.2 m and 1.5 m did not affect cane yields. Brix%, Sucrose% and Purity% differed significantly between cultivars. The relationship between cane yield and stalk population was positive and significant, which indicated stalk population is a strong determinant of cane yield. The results showed that cane yield was significantly affected by location and cane quality by cultivars. Therefore Mumias is a better zone for sugarcane cultivation for both June and September seasons compared to Kibos.展开更多
Initial errors and model errors are the source of prediction errors. In this study, the authors compute the conditional nonlinear optimal perturbation (CNOP)-type initial errors and nonlinear forcing singular vector...Initial errors and model errors are the source of prediction errors. In this study, the authors compute the conditional nonlinear optimal perturbation (CNOP)-type initial errors and nonlinear forcing singular vector (NFSV)- type tendency errors of the Zebiak-Cane model with respect to El Nifio events and analyze their combined effect on the prediction errors for E1 Nino events. The CNOP- type initial error (NFSV-type tendency error) represents the initial errors (model errors) that have the largest effect on prediction uncertainties for E1 Nifio events under the perfect model (perfect initial conditions) scenario. How- ever, when the CNOP-type initial errors and the NFSV- type tendency errors are simultaneously considered in the model, the prediction errors caused by them are not am- plified as the authors expected. Specifically, the predic- tion errors caused by the combined mode of CNOP-type initial errors and NFSV-type tendency errors are a little larger than those caused by the NFSV-type tendency er- rors. This fact emphasizes a need to investigate the opti- mal combined mode of initial errors and tendency errors that cause the largest prediction error for E1 Nifio events.展开更多
Maize is an important economic crop grown in Nigeria. Its production is dramatically affect by the pink stem borer--Sesamia caIamistis (Hampson, Noctuidae) and sugarcane borer--Eldana saccharina (Walker, Pyralidae...Maize is an important economic crop grown in Nigeria. Its production is dramatically affect by the pink stem borer--Sesamia caIamistis (Hampson, Noctuidae) and sugarcane borer--Eldana saccharina (Walker, Pyralidae) that are endemic in Southeastern Nigeria. In areas of stress, existing genotypes may marginally do well due to their inherent capabilities. Therefore, it is possible to find useful genes in such areas of stress, since such genes have been responsible for the survival of host crops over the years. Evaluation study was conducted for a range of agronomic characteristics and resistance attributes for 209 local maize collections from Southeastern Nigeria along with three improved check varieties. Field trials were conducted at three locations in a total of four environments in 2001. Highly significant genotypic variances as were noted in all the traits, are indicative of the magnitude of variation that exists among the genotypes, thus providing the opportunity of selection for desirable traits. Furthermore, four traits, namely, leaf feeding, ear damage, stalk lodging and yield were used from across the environments to construct a rank summation index (RSI), which was used to rank the entries for resistance to stem borers. This RSI led to the identification of 11 genotypes which represents the best 5% of the 212 genotypes in resistance ability. Genotype AMA TZBR-WC1 (from International Institute of Tropical Agriculture (IITA), Ibadan) had the best overall resistance levels, followed by genotypes SE NG-77 and SE NG-67 (from Umuahia North), SE NG-62 (from Ikwuano), SE NG-148 (from Ukwa West), SE NG-106 (from Bende), SE NG-119 (from Isiala Ngwa), SE NG-33 (from Ikwuano) and SE NG-65 (from Umuahia North).展开更多
Polydichlorophosphazene(PDCP)was synthesized from PCl5 and NH4Cl via a one-pot approach,and then further reacted with glycine ethyl ester and methylparaben via a two-step nucleophilic substitution approach to give pol...Polydichlorophosphazene(PDCP)was synthesized from PCl5 and NH4Cl via a one-pot approach,and then further reacted with glycine ethyl ester and methylparaben via a two-step nucleophilic substitution approach to give poly(methylparaben/glycine ethyl ester)phosphazene(PMGP),which was a kind of mix-substituted biodegradable polymer.NMR and FT-IR were used to characterize its structure.A series of experiments were conducted to study the effects of the ratio of methylparaben to glycine ethyl ester and the experimental conditions to the degradability of PMGP samples.The degradability of PMGP can be adjusted by altering the ratio of methylparaben to glycine ethyl ester easily.展开更多
The glycerol utilization (gyl) operon is involved in clavulanic acid (CA) production by Streptomyces clavuligerus, and possibly supplies the glyceraldehyde-3-phosphate (G3P) precursor for CA biosynthesis. The gyl oper...The glycerol utilization (gyl) operon is involved in clavulanic acid (CA) production by Streptomyces clavuligerus, and possibly supplies the glyceraldehyde-3-phosphate (G3P) precursor for CA biosynthesis. The gyl operon is regulated by GylR and is induced by glycerol. To enhance CA production in S. clavuligerus, an extra copy of ccaR expressed from Pgyl (the gyl promoter) was integrated into the chromosome of S. clavuligerus NRRL 3585. This construct coordinated the transcription of CA biosynthetic pathway genes with expression of the gyl operon. In the transformants carrying the Pgyl-controlled regulatory gene ccaR, CA production was enhanced 3.19-fold in glycerol-enriched batch cultures, relative to the control strain carrying an extra copy of ccaR controlled by its own promoter (PccaR). Consistent with enhanced CA production, the transcription levels of ccaR, ceas2 and claR were significantly up-regulated in the transformants containing Pgyl-controlled ccaR.展开更多
基金Supported by Postdoctoral Sustentation Fund of Hunan Province(2014RS4010)the Open Fund for Key Horticulture Discipline Research of Hunan Agricultural University(2013YYX021)~~
文摘[Objective] An HPLC method for the determination of caffeoylquinic acid compounds in sweet potato was developed in the present research. Quantitative analysis was performed on 11 sweet potato genotypes to provide a reference for the development and utilization of sweet potato, especial y on the aboveground part. [Method] Caffeoylquinic acid compounds were extracted from sweet potato leaves by ultrasonic treatment for 20 min with 200 volumes of methanol. The mobile phase of HPLC was acetonitrile -0.2% aqueous phosphoric acid. Chlorogenic acid, 4, 5-O-coffeocylquinic acid, 3, 5-O-coffeeacylquinic acid and 3, 4-O-coffeeacylquinic acid were separated wel by gradient elution, with recovery rate of 94.74%, 102.63%, 100.01% and 101.05%, respectively. [Result] The contents of caffeoylquinic acids were significantly different between sweet potato genotypes and tissue parts. Among these compounds, the content of bi-caffeoylquinic acids was the highest in the aboveground part, and the content of chlorogenic acid was the highest in the root tubers. The content of caffeoylquinic acid in different parts of the plant was: 9.77-40.86 mg/g in stem apex, 2.68-13.97 mg/g in mature leaves, 0.56-7.90 mg/g in stems and 0.69-4.33 mg/g in root tubers, respectively. [Conclusion] Sweet potato stems and leaves can be used for the extraction of chlorogenic acid in development and utilization, in which the purple sweet potato series is superior to the non-purple sweet potato series. The performance of the two purple sweet potato materials of 11ZY series is particularly prominent.
文摘The effect of different concentrations of 6-benzylaminopurine (BA) with or without 0.2 mg/L NAA on in vitro regeneration of sugarcane (Saccharum spp.) cultivars SP726180, B47419, M1176/77 and M2119/88 were evaluated. Leaf base explants were cultured on Murashige and Skoog (MS) basal medium supplemented with 3.0 mg/L 2,4-dichlorophenoxyacetic acid (2,4-D) for 4 weeks. Thereafter, induction of somatic embryogenesis was observed following the transfer of resulting calli to 2,4-D-free medium for another 4 weeks. Regeneration was achieved by transfer of the embryogenic calli to regeneration media fortified with different concentrations of BA + tt-naphthylacetic acid (NAA). The number, length and vigor of shoots produced in all the genotypes were highest on media supplemented with 1.0 and 1.5 mg/L BA with and without 0.2 mg/L NAA. Among the genotypes tested, B47419 and M1176/77 recorded highest number of shoots, while maximum shoot length and crop vigor was obtained with M1176/77. Induction of callus with 3.0 mg/L 2,4-D and its subsequent incubation on 2,4-D-free media, followed by regeneration on media supplemented with 1.0 or 1.5 mg/L BA with 0.2 mg/L NAA was found to be efficient for in vitro regeneration of the sugarcane genotypes used in this study. This protocol could be applied for micropropagation of other elite genotypes.
文摘Consumption of functional foods with health promoting benefits and/or disease prevention has been on the increase globally. The study aimed at evaluating the potential of utilizing Kenyan orange fleshed sweet potato (Ipomoea batatas Lam.) for functional food production with aesthetics benefits. Purees from three different varieties of orange fleshed sweet potato (OFSP) were analyzed for nutritional, physicochemical and microbial quality, The findings of the study show that the three purees were all microbiologically safe and of near neutral pH, but differed significantly (P 〈 0.05) in nutrient content (dry matter content, 12.76-28.23%; crude fiber, 1.37-2.90% fresh weight basis (FWB); 13-carotene, 0.94-9.27 mg/100g dry weight basis (DWB); starch, 10.20-18.30% FWB & total sugar 27.08-31.76% DWB). The purees had attractive appearance (ranging from yellow to dark orange), with varying significantly different spectrophotometer hunters color scale (P 〈 0.05), and flow ability. Conclusions from the findings show great potential of utilizing the varying properties of OFSP puree to produce enriched functional food products such as probiotic/prebiotic dairy, beverages, bakery and baby foods.
文摘In Kenya almost all sugarcane grown is under rainfall conditions that are planted in different locations during both long and short rainy seasons. Effect of season, location, cultivar and spacing on yield and quality of sugarcane is not clearly understood. The research was conducted at Kibos and Mumias to determine if the yields and quality of three sugarcane cultivars were affected by season, location and row spacing. Cultivars CO 945, EAK 73-335 and KEN 83-737 were manually planted during June and September in 2011. The trial was laid out as split-split plot arranged in a randomized complete block design (RCBD) replicated three times. Data collected at harvest, 17 months after planting (MAP) including cane yields, cane yield components and cane quality. The results revealed that cane length differed significantly between June and September. Stalk population and cane yields were significantly more at Mumias compared to Kibos. Cultivar EAK 73-335 showed significantly more cane yield (t/ha) than KEN 83-737 and CO 945. Both row spacing 1.2 m and 1.5 m did not affect cane yields. Brix%, Sucrose% and Purity% differed significantly between cultivars. The relationship between cane yield and stalk population was positive and significant, which indicated stalk population is a strong determinant of cane yield. The results showed that cane yield was significantly affected by location and cane quality by cultivars. Therefore Mumias is a better zone for sugarcane cultivation for both June and September seasons compared to Kibos.
基金sponsored by the National Basic Research Program of China (Grant No. 2012CB955202)the National Public Benefit (Meteorology) Research Foundation of China (Grant No. GYHY201306018)the National Natural Science Foundation of China (Grant Nos. 41176013 and 41230420)
文摘Initial errors and model errors are the source of prediction errors. In this study, the authors compute the conditional nonlinear optimal perturbation (CNOP)-type initial errors and nonlinear forcing singular vector (NFSV)- type tendency errors of the Zebiak-Cane model with respect to El Nifio events and analyze their combined effect on the prediction errors for E1 Nino events. The CNOP- type initial error (NFSV-type tendency error) represents the initial errors (model errors) that have the largest effect on prediction uncertainties for E1 Nifio events under the perfect model (perfect initial conditions) scenario. How- ever, when the CNOP-type initial errors and the NFSV- type tendency errors are simultaneously considered in the model, the prediction errors caused by them are not am- plified as the authors expected. Specifically, the predic- tion errors caused by the combined mode of CNOP-type initial errors and NFSV-type tendency errors are a little larger than those caused by the NFSV-type tendency er- rors. This fact emphasizes a need to investigate the opti- mal combined mode of initial errors and tendency errors that cause the largest prediction error for E1 Nifio events.
文摘Maize is an important economic crop grown in Nigeria. Its production is dramatically affect by the pink stem borer--Sesamia caIamistis (Hampson, Noctuidae) and sugarcane borer--Eldana saccharina (Walker, Pyralidae) that are endemic in Southeastern Nigeria. In areas of stress, existing genotypes may marginally do well due to their inherent capabilities. Therefore, it is possible to find useful genes in such areas of stress, since such genes have been responsible for the survival of host crops over the years. Evaluation study was conducted for a range of agronomic characteristics and resistance attributes for 209 local maize collections from Southeastern Nigeria along with three improved check varieties. Field trials were conducted at three locations in a total of four environments in 2001. Highly significant genotypic variances as were noted in all the traits, are indicative of the magnitude of variation that exists among the genotypes, thus providing the opportunity of selection for desirable traits. Furthermore, four traits, namely, leaf feeding, ear damage, stalk lodging and yield were used from across the environments to construct a rank summation index (RSI), which was used to rank the entries for resistance to stem borers. This RSI led to the identification of 11 genotypes which represents the best 5% of the 212 genotypes in resistance ability. Genotype AMA TZBR-WC1 (from International Institute of Tropical Agriculture (IITA), Ibadan) had the best overall resistance levels, followed by genotypes SE NG-77 and SE NG-67 (from Umuahia North), SE NG-62 (from Ikwuano), SE NG-148 (from Ukwa West), SE NG-106 (from Bende), SE NG-119 (from Isiala Ngwa), SE NG-33 (from Ikwuano) and SE NG-65 (from Umuahia North).
文摘Polydichlorophosphazene(PDCP)was synthesized from PCl5 and NH4Cl via a one-pot approach,and then further reacted with glycine ethyl ester and methylparaben via a two-step nucleophilic substitution approach to give poly(methylparaben/glycine ethyl ester)phosphazene(PMGP),which was a kind of mix-substituted biodegradable polymer.NMR and FT-IR were used to characterize its structure.A series of experiments were conducted to study the effects of the ratio of methylparaben to glycine ethyl ester and the experimental conditions to the degradability of PMGP samples.The degradability of PMGP can be adjusted by altering the ratio of methylparaben to glycine ethyl ester easily.
基金supported by grants from the Ministry of Science and Technology of China (2009CB118905)
文摘The glycerol utilization (gyl) operon is involved in clavulanic acid (CA) production by Streptomyces clavuligerus, and possibly supplies the glyceraldehyde-3-phosphate (G3P) precursor for CA biosynthesis. The gyl operon is regulated by GylR and is induced by glycerol. To enhance CA production in S. clavuligerus, an extra copy of ccaR expressed from Pgyl (the gyl promoter) was integrated into the chromosome of S. clavuligerus NRRL 3585. This construct coordinated the transcription of CA biosynthetic pathway genes with expression of the gyl operon. In the transformants carrying the Pgyl-controlled regulatory gene ccaR, CA production was enhanced 3.19-fold in glycerol-enriched batch cultures, relative to the control strain carrying an extra copy of ccaR controlled by its own promoter (PccaR). Consistent with enhanced CA production, the transcription levels of ccaR, ceas2 and claR were significantly up-regulated in the transformants containing Pgyl-controlled ccaR.