As a main component of efficiency in Rhodiola plants, salidroside is a promising environmental acclamation medicine and possesses specific medical properties against symptoms of fatigue, old age, microwave radiation, ...As a main component of efficiency in Rhodiola plants, salidroside is a promising environmental acclamation medicine and possesses specific medical properties against symptoms of fatigue, old age, microwave radiation, viral infections and tumors. Salidroside plays important roles, especially in military, aerospace, sport and healthcare medicine and has, therefore, recently, drawn more and closer attention. This article probes mainly into the probable biosynthetic pathway of salidroside following a brief introduction of the exploitation and utilization values of Rhodiola plants and the current condition of its natural resources. We have come to the conclusion that tyrosol, the aglycon of salidroside, is biosynthesized through the well-characterized shikimic acid pathway. A molecule of glucose is transferred by the UDP-glucosyltransferase （or possibly by the β-D-glucosidase too） to the tyrosol to form salidroside. On the other hand, salidroside may be degraded into tyrosol and glucose by β-D-glucosidase. Progress in research of these two key-enzymes, involved in the metabolism of salidroside, is finally elaborated.展开更多
Faidherbia albida is an ideal agroforestry tree commonly intercropped with annual crops like millet and groundnuts in the dry and densely populated areas of Africa. With its peculiar reverse phenology, it makes growth...Faidherbia albida is an ideal agroforestry tree commonly intercropped with annual crops like millet and groundnuts in the dry and densely populated areas of Africa. With its peculiar reverse phenology, it makes growth demands at a different time from that of crops. In addition, it deposits great amount of organic fertilizer on food crops. Leaves entering soils are comparable to fertilization of almost 50 t·ha^-1year^-1 of manure in dense stands of 50 large trees per ha. These nutrients help maximize agricultural production and reduce the need for a fallow period on poorer soils. Research has shown that millet grown under F. albida yielded 2.5 and 3.4 fold increases in grain and protein, respectively. Animals eat pods which contain mean amounts of crude protein of 20.63% and carbohydrate of 40.1% in seeds. Moreover, the continued existence ofF. albida in agroforestry parklands as in Ethiopia and Mali signifies the success of traditional conservation measures. Modem scientists have also developed much interest in the role of agroforestry in maintaining long-term biological balance between agriculture and livestock production systems. To ensure food security, which still remains a major challenge in sub-Saharan Africa, and concurrently minimize environmental degradation, promotion of agroforestry that specifically involves indigenous trees is crucial. We discuss the prospective role ofF. albida in alleviating poverty while simultaneously protecting the environment from factors associated with, for example, deforestation and loss of biodiversity. The overall aim is to promote wide-scale adoption ofF. albida as a valuable tree crop in farming systems, particularly in those areas where it remains unexploited.展开更多
In order to identify the relationship between diurnal changes in the net photosynthetic rate（Pn） of Pueraria lobata and environmental factors,diurnal changes in the Pn of leaves of two P.lobata cultivars were measur...In order to identify the relationship between diurnal changes in the net photosynthetic rate（Pn） of Pueraria lobata and environmental factors,diurnal changes in the Pn of leaves of two P.lobata cultivars were measured using a CIRAS-1 portable photosynthesis measurement system（PP-Systems,UK）.The results show that diurnal changes in Pn of both cultivars could be interpreted as double-peak curves,indicating the occurrence of an obvious midday depression.Further analyses indicate that the correlation between Pn and stomatal conductance was positive and extremely significant（p 〈 0.01）.The correlations of Pn with intercellular CO2 concentration and transpiration rate were positive and significant（p 〈 0.05）,while the correlations of Pn with air and leaf temperatures were negative and significant（p 〈 0.05）.The results indicate that among the factors affecting photosynthetic properties,some can be grouped as stomatal limitations while others are non-stomatal limitations.展开更多
文摘As a main component of efficiency in Rhodiola plants, salidroside is a promising environmental acclamation medicine and possesses specific medical properties against symptoms of fatigue, old age, microwave radiation, viral infections and tumors. Salidroside plays important roles, especially in military, aerospace, sport and healthcare medicine and has, therefore, recently, drawn more and closer attention. This article probes mainly into the probable biosynthetic pathway of salidroside following a brief introduction of the exploitation and utilization values of Rhodiola plants and the current condition of its natural resources. We have come to the conclusion that tyrosol, the aglycon of salidroside, is biosynthesized through the well-characterized shikimic acid pathway. A molecule of glucose is transferred by the UDP-glucosyltransferase （or possibly by the β-D-glucosidase too） to the tyrosol to form salidroside. On the other hand, salidroside may be degraded into tyrosol and glucose by β-D-glucosidase. Progress in research of these two key-enzymes, involved in the metabolism of salidroside, is finally elaborated.
文摘Faidherbia albida is an ideal agroforestry tree commonly intercropped with annual crops like millet and groundnuts in the dry and densely populated areas of Africa. With its peculiar reverse phenology, it makes growth demands at a different time from that of crops. In addition, it deposits great amount of organic fertilizer on food crops. Leaves entering soils are comparable to fertilization of almost 50 t·ha^-1year^-1 of manure in dense stands of 50 large trees per ha. These nutrients help maximize agricultural production and reduce the need for a fallow period on poorer soils. Research has shown that millet grown under F. albida yielded 2.5 and 3.4 fold increases in grain and protein, respectively. Animals eat pods which contain mean amounts of crude protein of 20.63% and carbohydrate of 40.1% in seeds. Moreover, the continued existence ofF. albida in agroforestry parklands as in Ethiopia and Mali signifies the success of traditional conservation measures. Modem scientists have also developed much interest in the role of agroforestry in maintaining long-term biological balance between agriculture and livestock production systems. To ensure food security, which still remains a major challenge in sub-Saharan Africa, and concurrently minimize environmental degradation, promotion of agroforestry that specifically involves indigenous trees is crucial. We discuss the prospective role ofF. albida in alleviating poverty while simultaneously protecting the environment from factors associated with, for example, deforestation and loss of biodiversity. The overall aim is to promote wide-scale adoption ofF. albida as a valuable tree crop in farming systems, particularly in those areas where it remains unexploited.
基金supported by the "Eleventh Five-year" National Science and Technology Support Program of China (Grant No. 2009BADA7B04 Grant No. 2008BAD95B03the National Science and Technology Major Project of China (Grant No. 2009ZX09308-002)
文摘In order to identify the relationship between diurnal changes in the net photosynthetic rate（Pn） of Pueraria lobata and environmental factors,diurnal changes in the Pn of leaves of two P.lobata cultivars were measured using a CIRAS-1 portable photosynthesis measurement system（PP-Systems,UK）.The results show that diurnal changes in Pn of both cultivars could be interpreted as double-peak curves,indicating the occurrence of an obvious midday depression.Further analyses indicate that the correlation between Pn and stomatal conductance was positive and extremely significant（p 〈 0.01）.The correlations of Pn with intercellular CO2 concentration and transpiration rate were positive and significant（p 〈 0.05）,while the correlations of Pn with air and leaf temperatures were negative and significant（p 〈 0.05）.The results indicate that among the factors affecting photosynthetic properties,some can be grouped as stomatal limitations while others are non-stomatal limitations.
