The whole cold-chain for exporting sweet potato(native variety“Abees”),to foreign market included immediate curing operation directly after harvest helped in healing skin texture,however,in order to reduce postharve...The whole cold-chain for exporting sweet potato(native variety“Abees”),to foreign market included immediate curing operation directly after harvest helped in healing skin texture,however,in order to reduce postharvest soft rot(Rhizopus stolonifer)incidence following trimming,and washing,ultraviolet light(UV-C)treatment was used as a main sanitizer for eliminating the soft rot.Exposure of the roots to UV-C(254 nm)was applied in a UV-C room on freshly harvested and cured sweet potato while rolling up on a movable line at 20 cm distance for 1,2,and 3 hr.As combining UV-C treatment with chlorine(200 ppm)on roots,marked and significant reduction of the total microbial load and Rhizopus potential was achieved on root surfaces respectively compared with chlorine alone.It also reduced soft rot percentage to almost 0%infection.After 3 months of cold-storage,quality assessment of sweet potato showed that root characteristics were markedly maintained.The ability of UV-C light to induce phenylalanine ammonia lyase(PAL)enzyme activity in root tissue and maintain the activities of peroxidase and polyphenol oxidase,however with slight increase,was detected.UV-C caused an increase of phenol content in sweet potato tissue that made an activation of defense reaction against the rot causal pathogen.As the exposure time to UV-C light increased,a higher content of phenols occurred.Moreover,UV-C application caused decrease in sugar content of root tissue that is flavored by soft rot-causal pathogen.展开更多
In Martinique (F.W.I.), biodiversity of vegetable varieties remain unexploited due to public unawareness or supply problems. To further enhance the sweet potato, physicochemical, sensory and nutritional characteristic...In Martinique (F.W.I.), biodiversity of vegetable varieties remain unexploited due to public unawareness or supply problems. To further enhance the sweet potato, physicochemical, sensory and nutritional characteristics of eight varieties of sweet potato were established. The eight sweet potatoes cultivars were noticeably diverse with phenotypic, sensory, physicochemical and nutritional characteristics which were very varied. The eight cultivars grown in Martinique were advantageously positioned in relation to the globally identified sweet potato, regarding fibre, starch, potassium, copper, vitamin B1, B3 and B9 contents. Compared to the ordinary potato, Martiniquan sweet potatoes have a much better nutritional potential. Energy value and vitamin C levels were twice as much as in normal potatoes. Martiniquan sweet potatoes cultivars were also richer in minerals and vitamins, with 2.7 times more vitamin B9 and 63 times more beta-carotene than the ordinary potato.展开更多
Allelopathic compounds have the potential to inhibit the growth and development of other organisms in a diverse manner ranging from shifting nutrients and enhancing their growth to inflicting diseases. In addition, th...Allelopathic compounds have the potential to inhibit the growth and development of other organisms in a diverse manner ranging from shifting nutrients and enhancing their growth to inflicting diseases. In addition, these compounds influence seedling growth and seed germination of various crops. The goal of this study was to identify and quantify different allelochemicals in various sweet potato cultivars through high-performance liquid chromatography techniques. Selected sweet potato slips (weight: 2.0 - 2.5 grams/slip) were propagated in separate glass tubes filled with 10.0 mL distilled water. Water extract from each glass tube was collected after 2, 4, and 6 weeks after transplanting (WAP) to identify and quantify allelochemical compounds by comparing their peaks with the retention time of standards. Results show that the concentration of allelochemicals in water extract was increased from 2 to 4 WAP but remained constant in the sixth week. Quantitative analysis revealed that the amount of chlorogenic acid was higher in all sweet potato cultivars compared to other allelochemicals. Some sweet potato cultivars, A5 and A39, exhibited higher allelopathy (18.28 - 19.37 ppm/slip) and reduced the height and biomass of Palmer amaranth the most due to the presence of increased concentration of combined allelochemicals, while other cultivars produced lesser allelochemicals (10.90 ppm/slip) and did not reduce the growth of the weed species. Allelopathic sweet potato cultivars high in chlorogenic acid production can effectively suppress Palmer amaranth with minimal dependence on chemicals to manage weeds and harmful pests under sustainable agricultural system.展开更多
Anthocyanin accumulation during storage root development in purple-fleshed sweet potato was analyzed by detection of anthocyanin concentration, accumulation rate and the expression pattern of anthocyanin biosynthetic ...Anthocyanin accumulation during storage root development in purple-fleshed sweet potato was analyzed by detection of anthocyanin concentration, accumulation rate and the expression pattern of anthocyanin biosynthetic genes by semi-quantitative RT-PCR. Anthocyanin concentration in sweet potato cvs Jishu 18 and Ayamurasaki increased steadily during storage root development stage. The accumulation rate in two genotypes peaked at 50 to 65 d after transplanting, and then declined rapidly. During storage root development of Ayamurasaki, the anthocyanin biosynthesis gene, IbCHS, was constitutively expressed, the genes IbF3H, IbDFR, IbANS were induced steadily, reaching a maximum at the later stage of root thickening, and IbPAL steadily decreased. Therefore, the mechanism of anthocyanin accumulation differed between the two cultivars, and anthocyanin biosynthesis was regulated through regulation of its synthetic enzymes.展开更多
用甘薯品种农林17号(中紫)的叶柄分离原生质体,对其在添加各种浓度的萘乙酸和激动素的改良细胞薄层培养基中进行悬浮培养。培养1～2 d 后,原生质体再生细胞壁,培养2～3 d 后,再生细胞发生第一次分裂,持续的细胞分裂形成小愈伤组织。悬...用甘薯品种农林17号(中紫)的叶柄分离原生质体,对其在添加各种浓度的萘乙酸和激动素的改良细胞薄层培养基中进行悬浮培养。培养1～2 d 后,原生质体再生细胞壁,培养2～3 d 后,再生细胞发生第一次分裂,持续的细胞分裂形成小愈伤组织。悬浮培养的结果表明萘乙酸和激动素的适宜浓度分别为2.0～5.0mg/L 和1.0～5.0mg/L。此后,将小愈伤组织转移到MS 固体培养基上培养,小愈伤组织迅速生长。本试验达到根的分化.展开更多
The effects of different drying methods （hot-air drying, microwave drying and vacuum-freeze drying） on the antioxidant activity and antioxidants in sweet potato （lpomoea batatas L. Lain.） tubers were investigated ...The effects of different drying methods （hot-air drying, microwave drying and vacuum-freeze drying） on the antioxidant activity and antioxidants in sweet potato （lpomoea batatas L. Lain.） tubers were investigated to determine the potential drying process. Sweet potato tubers were cut into 5 mm thick slices, steamed at 100℃ for 10 rain, then dried in either hotair, microwave, or vacuum-freeze. The dried sweet potatoes in microwave possessed the highest antioxidant activity, while the lowest activity was observed in hot-air dried samples. The phenolic contents were positively correlated with scavenging activity and reducing power of DPPH^＋. The microwave drying retains the highest antioxidant activity with the highest content of phenolic compounds in dried sweet potatoes. β-carotene and ascorbic acid showed minor contribution to the antioxidant activity in dried sweet potatoes.展开更多
文摘The whole cold-chain for exporting sweet potato(native variety“Abees”),to foreign market included immediate curing operation directly after harvest helped in healing skin texture,however,in order to reduce postharvest soft rot(Rhizopus stolonifer)incidence following trimming,and washing,ultraviolet light(UV-C)treatment was used as a main sanitizer for eliminating the soft rot.Exposure of the roots to UV-C(254 nm)was applied in a UV-C room on freshly harvested and cured sweet potato while rolling up on a movable line at 20 cm distance for 1,2,and 3 hr.As combining UV-C treatment with chlorine(200 ppm)on roots,marked and significant reduction of the total microbial load and Rhizopus potential was achieved on root surfaces respectively compared with chlorine alone.It also reduced soft rot percentage to almost 0%infection.After 3 months of cold-storage,quality assessment of sweet potato showed that root characteristics were markedly maintained.The ability of UV-C light to induce phenylalanine ammonia lyase(PAL)enzyme activity in root tissue and maintain the activities of peroxidase and polyphenol oxidase,however with slight increase,was detected.UV-C caused an increase of phenol content in sweet potato tissue that made an activation of defense reaction against the rot causal pathogen.As the exposure time to UV-C light increased,a higher content of phenols occurred.Moreover,UV-C application caused decrease in sugar content of root tissue that is flavored by soft rot-causal pathogen.
文摘In Martinique (F.W.I.), biodiversity of vegetable varieties remain unexploited due to public unawareness or supply problems. To further enhance the sweet potato, physicochemical, sensory and nutritional characteristics of eight varieties of sweet potato were established. The eight sweet potatoes cultivars were noticeably diverse with phenotypic, sensory, physicochemical and nutritional characteristics which were very varied. The eight cultivars grown in Martinique were advantageously positioned in relation to the globally identified sweet potato, regarding fibre, starch, potassium, copper, vitamin B1, B3 and B9 contents. Compared to the ordinary potato, Martiniquan sweet potatoes have a much better nutritional potential. Energy value and vitamin C levels were twice as much as in normal potatoes. Martiniquan sweet potatoes cultivars were also richer in minerals and vitamins, with 2.7 times more vitamin B9 and 63 times more beta-carotene than the ordinary potato.
文摘Allelopathic compounds have the potential to inhibit the growth and development of other organisms in a diverse manner ranging from shifting nutrients and enhancing their growth to inflicting diseases. In addition, these compounds influence seedling growth and seed germination of various crops. The goal of this study was to identify and quantify different allelochemicals in various sweet potato cultivars through high-performance liquid chromatography techniques. Selected sweet potato slips (weight: 2.0 - 2.5 grams/slip) were propagated in separate glass tubes filled with 10.0 mL distilled water. Water extract from each glass tube was collected after 2, 4, and 6 weeks after transplanting (WAP) to identify and quantify allelochemical compounds by comparing their peaks with the retention time of standards. Results show that the concentration of allelochemicals in water extract was increased from 2 to 4 WAP but remained constant in the sixth week. Quantitative analysis revealed that the amount of chlorogenic acid was higher in all sweet potato cultivars compared to other allelochemicals. Some sweet potato cultivars, A5 and A39, exhibited higher allelopathy (18.28 - 19.37 ppm/slip) and reduced the height and biomass of Palmer amaranth the most due to the presence of increased concentration of combined allelochemicals, while other cultivars produced lesser allelochemicals (10.90 ppm/slip) and did not reduce the growth of the weed species. Allelopathic sweet potato cultivars high in chlorogenic acid production can effectively suppress Palmer amaranth with minimal dependence on chemicals to manage weeds and harmful pests under sustainable agricultural system.
基金Support by the Youth Fund of Shandong Academy of Agricultural Science(2014QNM31)the China Agriculture Research System of Sweet Potato(CARS-11-B-06)
文摘Anthocyanin accumulation during storage root development in purple-fleshed sweet potato was analyzed by detection of anthocyanin concentration, accumulation rate and the expression pattern of anthocyanin biosynthetic genes by semi-quantitative RT-PCR. Anthocyanin concentration in sweet potato cvs Jishu 18 and Ayamurasaki increased steadily during storage root development stage. The accumulation rate in two genotypes peaked at 50 to 65 d after transplanting, and then declined rapidly. During storage root development of Ayamurasaki, the anthocyanin biosynthesis gene, IbCHS, was constitutively expressed, the genes IbF3H, IbDFR, IbANS were induced steadily, reaching a maximum at the later stage of root thickening, and IbPAL steadily decreased. Therefore, the mechanism of anthocyanin accumulation differed between the two cultivars, and anthocyanin biosynthesis was regulated through regulation of its synthetic enzymes.
文摘用甘薯品种农林17号(中紫)的叶柄分离原生质体,对其在添加各种浓度的萘乙酸和激动素的改良细胞薄层培养基中进行悬浮培养。培养1～2 d 后,原生质体再生细胞壁,培养2～3 d 后,再生细胞发生第一次分裂,持续的细胞分裂形成小愈伤组织。悬浮培养的结果表明萘乙酸和激动素的适宜浓度分别为2.0～5.0mg/L 和1.0～5.0mg/L。此后,将小愈伤组织转移到MS 固体培养基上培养,小愈伤组织迅速生长。本试验达到根的分化.
基金supported by the Science and Technology Project of Zhejiang Province,China(2009C12031)
文摘The effects of different drying methods （hot-air drying, microwave drying and vacuum-freeze drying） on the antioxidant activity and antioxidants in sweet potato （lpomoea batatas L. Lain.） tubers were investigated to determine the potential drying process. Sweet potato tubers were cut into 5 mm thick slices, steamed at 100℃ for 10 rain, then dried in either hotair, microwave, or vacuum-freeze. The dried sweet potatoes in microwave possessed the highest antioxidant activity, while the lowest activity was observed in hot-air dried samples. The phenolic contents were positively correlated with scavenging activity and reducing power of DPPH^＋. The microwave drying retains the highest antioxidant activity with the highest content of phenolic compounds in dried sweet potatoes. β-carotene and ascorbic acid showed minor contribution to the antioxidant activity in dried sweet potatoes.
