Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumb...Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumber species could be distinguished by their morphological and anatomical characteristics; however, their identification becomes difficult when they are processed. The aim of this study was to develop a new convenient method of identifying and distinguishing sea cucumber species. Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) analysis of mitochondrial cytochrome oxidase I gene(COI) was used to identifing five sea cucumber species(Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, Parastichopus californicus and Actinopyga lecanora). A 692 bp fragment of COI was searched for BamHI, KpnI, PstI, XbaI and Eco31 I restriction sites with DNAMAN 6.0, which were then used to PCR-RFLP analysis. These five sea cucumber species can be discriminated from mixed sea cucumbers. The developed PCR-RFLP assay will facilitate the identification of sea cucumbers, making their source tracing and quality controlling feasible.展开更多
Maize-rice cropping systems are expanding in Bangladesh. Hybrid maize has increasing demand and value, particularly for poultry feed, while rice remains the traditional dominant starch staple food. Bangladesh maize yi...Maize-rice cropping systems are expanding in Bangladesh. Hybrid maize has increasing demand and value, particularly for poultry feed, while rice remains the traditional dominant starch staple food. Bangladesh maize yields （with average farm yields around 5.7 t·ha^-1） are among the highest found in Asia. Cool winter （Rabi） season maize followed by T. Aman （monsoon） rice is the major cropping system; however it is now becoming diversified with many other crops including potato. Financially, hybrid maize is far more profitable than boro （irrigated） rice, wheat, or most other competing winter season Rabi crops. Although maize is relatively problem-free in Bangladesh, some constraints are intensifying with increased concern over input supply and soil-related environmental sustainability. An array of new technologies for sustainable intensive maize production systems is emerging in Bangladesh and some are being promoted and adopted. Continued sustainability of hybrid maize production in Bangladesh depends on optimization of planting time, quality seed of appropriate hybrids, balanced use of nutrient inputs along with soil fertility conservation and other management, for which further research would be high priority.展开更多
基金supported by National Natural Science Foundation of China (Nos. 31101281 and 31071525)National Marine Public Welfare Scientific Research Project of China (No. 201105029)
文摘Sea cucumbers are traditional marine food and Chinese medicine in Asia. The rapid expansion of sea cucumber market has resulted in various problems, such as commercial fraud and mislabeling. Conventionally, sea cucumber species could be distinguished by their morphological and anatomical characteristics; however, their identification becomes difficult when they are processed. The aim of this study was to develop a new convenient method of identifying and distinguishing sea cucumber species. Polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) analysis of mitochondrial cytochrome oxidase I gene(COI) was used to identifing five sea cucumber species(Apostichopus japonicus, Cucumaria frondosa, Thelenota ananas, Parastichopus californicus and Actinopyga lecanora). A 692 bp fragment of COI was searched for BamHI, KpnI, PstI, XbaI and Eco31 I restriction sites with DNAMAN 6.0, which were then used to PCR-RFLP analysis. These five sea cucumber species can be discriminated from mixed sea cucumbers. The developed PCR-RFLP assay will facilitate the identification of sea cucumbers, making their source tracing and quality controlling feasible.
文摘Maize-rice cropping systems are expanding in Bangladesh. Hybrid maize has increasing demand and value, particularly for poultry feed, while rice remains the traditional dominant starch staple food. Bangladesh maize yields （with average farm yields around 5.7 t·ha^-1） are among the highest found in Asia. Cool winter （Rabi） season maize followed by T. Aman （monsoon） rice is the major cropping system; however it is now becoming diversified with many other crops including potato. Financially, hybrid maize is far more profitable than boro （irrigated） rice, wheat, or most other competing winter season Rabi crops. Although maize is relatively problem-free in Bangladesh, some constraints are intensifying with increased concern over input supply and soil-related environmental sustainability. An array of new technologies for sustainable intensive maize production systems is emerging in Bangladesh and some are being promoted and adopted. Continued sustainability of hybrid maize production in Bangladesh depends on optimization of planting time, quality seed of appropriate hybrids, balanced use of nutrient inputs along with soil fertility conservation and other management, for which further research would be high priority.
