Acacia karroo(A.karroo) has been used as herbal medicine by the indigenous people of southern Africa for several centuries.The potential of.4.karroo as herbal medicine,its associated phytochemistry and biological acti...Acacia karroo(A.karroo) has been used as herbal medicine by the indigenous people of southern Africa for several centuries.The potential of.4.karroo as herbal medicine,its associated phytochemistry and biological activities are reviewed.The extensive literature survey revealed that A.karroo is traditionally used to treat or manage 32 and five human and animal diseases and ailmenls.respectively.The species is used as herbal medicine for diseases and ailments such as colds,diarrhoea,dysentery,flu.malaria,sexually transmitted infections(STis),wounds,and also as colic and ethnovetcrinary medicine.Multiple classes of phytochemicals such as flavonoids.phenols,phytosterols,proanthocyanidin.tannin,terpenes as well as several minerals have been identified from leaves and roots of A.karroo.Scientific studies on A.karroo indicate that it has a wide range of pharmacological activities which include antibacterial,antifungal,antigonococcal.antihelmintic,antilisterial,antimalarial,antimycobacterial,antioxidant.HIV-1 reverse transcriptase,anti-inflammatory and analgesic.Acacia karroo has a lot of potential as a possible source of pharmaceutical products for the treatment of a wide range of both human and animal diseases and ailments.Future research should focus on the mechanisms of action of the different plant parts used as herbal medicines.isolated compounds,their efficacy,toxicity and clinical relevance.展开更多
Fynbos plant communities developed under geographic and climatic conditions unique to South Africa. Acacia karroo is the most widespread tree species, well known for its drought tolerance. A. nilotica exudes a good qu...Fynbos plant communities developed under geographic and climatic conditions unique to South Africa. Acacia karroo is the most widespread tree species, well known for its drought tolerance. A. nilotica exudes a good quality gum which is edible and suitable for confectionery. The two species have been introduced to China but little is known about their adaptability under the new environmental conditions. For our present study, the growth potential and physiological and biochemical parameters of the two spe- cies in response to cold stress were investigated. The results, measured as seed qualities （purity, thousand seed weights, germination, etc.） show differences between A. karroo and A. nilotica. The seed germination rate was between 10% and 60%. Seedlings were es- tablished in fields, pots and plugs. Those in the field grew well during the growing season but completely died in the winter. Those in pots or plugs were moved to and managed in the greenhouse. The plants were green in winter. The electrical conductivity of cells, the contents of water soluble sugars, proteins, malondialdehyde （MDA） increased during eight hours of low temperature treatment at 4℃ The activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） decreased markedly during the eight hours of 4℃ treatment. We conclude that A. karroo and A. nilotica have little adaptability to the cold winter weather and cannot survive in the outdoors in the Beijing area, but could grow well indoors as ornamentals.展开更多
Acacia karroo is an indigenous, strong drought-tolerant and widely planted tree in South Africa. In order to match the plant with its adaptation to forest sites in China, it is important to know the drought-tolerance ...Acacia karroo is an indigenous, strong drought-tolerant and widely planted tree in South Africa. In order to match the plant with its adaptation to forest sites in China, it is important to know the drought-tolerance of this species under Chinese forest site con- ditions. Our study was carried out in cinnamon soils in Beijing and with Platycladus orientalis, the most drought-tolerant tree in Bei- j ing, as control. Physiological parameters of young plants of the trees were measured and divided into three groups in response to soil drying. The first group included root activity, ABA content in roots and peroxidase （POD） activity in leaves. Their values changed similarly to those of P. orientalis and dramatically increased to maximum values when the soil water content （SWC） decreased from its normal level of 20% to 7.6% where the three indices decreased dramatically when SWC was reduced further from 7.6%. The sec- ond group of parameters included the contents of proline, soluble protein and malondialdehyde （MDA）. Their values showed greater variation than those ofP. orientalis and significantly increased when SWC decreased from 20% in response to soil drying. However, the proline and soluble protein contents fluctuated in A. karroo at a lower level than those in P. orientalis. In contrast, the content of MDA in A. karroo was much higher than that in P. orientalis which almost did not increase in the drying soil. The third group of parameters consisted of soluble sugar, superoxide dismutase （SOD） and catalase （CAT）. These parameters showed greater diversity and fluctuations among the three varieties ofA. karroo compared with the control in response to soil drying. These results suggest that A. karroo is characterized as a strong, drought tolerant species in most of physiological parameters but weaker than P orientalis in membrane lipid antioxidation.展开更多
Acacia karroo Hayne is an arbor species widely distributed in South Africa with the characteristics of fast growth and drought resistance. The species was introduced to China recently. In vitro culture is an effective...Acacia karroo Hayne is an arbor species widely distributed in South Africa with the characteristics of fast growth and drought resistance. The species was introduced to China recently. In vitro culture is an effective method to rapidly produce plants and a strategy to minimize somaclonal variation among regenerated plants. Browning, however, is a problem in establishing the in vitro culture system. The present study diminished the problem by selecting explants, using different browning inhibitors and chilling treatment. Results showed that the use of embryos as explants reduced the browning ratio to 46.7%, whilst stem segment explants were browned up to 56.7%. The adventitious buds were successfully induced in the modified tissue culture medium supplemented with 5.0 mg·L^-1 6-BA and 0.1 mg·L^-1 NAA. The proliferation coefficient of adventitious buds is 2.8.展开更多
The 15th International Geological Congress was held in South Africa in 1929.Many interesting issues were tackled,thanks to the development of geophysical techniques,ideas about magmatic differentiation,and the origin ...The 15th International Geological Congress was held in South Africa in 1929.Many interesting issues were tackled,thanks to the development of geophysical techniques,ideas about magmatic differentiation,and the origin of the Karroo System,among others.The importance of the Congress from the point of view of the history of geology lies in the fact that an‘inflection point’occurred as regards thinking about the continental drift theory that had been proposed by Wegener a few years earlier.It can be said that the contributions of Du Toit allowed a deepening in the theoretical bases of this scientific hypothesis,which celebrated its first hundred years in 2012.展开更多
基金the National Research Foundation(NRF)Govan Mbeki Research and Development Centre(GMRDC),University of Fort Hare for financial support to conduct this research
文摘Acacia karroo(A.karroo) has been used as herbal medicine by the indigenous people of southern Africa for several centuries.The potential of.4.karroo as herbal medicine,its associated phytochemistry and biological activities are reviewed.The extensive literature survey revealed that A.karroo is traditionally used to treat or manage 32 and five human and animal diseases and ailmenls.respectively.The species is used as herbal medicine for diseases and ailments such as colds,diarrhoea,dysentery,flu.malaria,sexually transmitted infections(STis),wounds,and also as colic and ethnovetcrinary medicine.Multiple classes of phytochemicals such as flavonoids.phenols,phytosterols,proanthocyanidin.tannin,terpenes as well as several minerals have been identified from leaves and roots of A.karroo.Scientific studies on A.karroo indicate that it has a wide range of pharmacological activities which include antibacterial,antifungal,antigonococcal.antihelmintic,antilisterial,antimalarial,antimycobacterial,antioxidant.HIV-1 reverse transcriptase,anti-inflammatory and analgesic.Acacia karroo has a lot of potential as a possible source of pharmaceutical products for the treatment of a wide range of both human and animal diseases and ailments.Future research should focus on the mechanisms of action of the different plant parts used as herbal medicines.isolated compounds,their efficacy,toxicity and clinical relevance.
文摘Fynbos plant communities developed under geographic and climatic conditions unique to South Africa. Acacia karroo is the most widespread tree species, well known for its drought tolerance. A. nilotica exudes a good quality gum which is edible and suitable for confectionery. The two species have been introduced to China but little is known about their adaptability under the new environmental conditions. For our present study, the growth potential and physiological and biochemical parameters of the two spe- cies in response to cold stress were investigated. The results, measured as seed qualities （purity, thousand seed weights, germination, etc.） show differences between A. karroo and A. nilotica. The seed germination rate was between 10% and 60%. Seedlings were es- tablished in fields, pots and plugs. Those in the field grew well during the growing season but completely died in the winter. Those in pots or plugs were moved to and managed in the greenhouse. The plants were green in winter. The electrical conductivity of cells, the contents of water soluble sugars, proteins, malondialdehyde （MDA） increased during eight hours of low temperature treatment at 4℃ The activities of superoxide dismutase （SOD）, peroxidase （POD） and catalase （CAT） decreased markedly during the eight hours of 4℃ treatment. We conclude that A. karroo and A. nilotica have little adaptability to the cold winter weather and cannot survive in the outdoors in the Beijing area, but could grow well indoors as ornamentals.
文摘Acacia karroo is an indigenous, strong drought-tolerant and widely planted tree in South Africa. In order to match the plant with its adaptation to forest sites in China, it is important to know the drought-tolerance of this species under Chinese forest site con- ditions. Our study was carried out in cinnamon soils in Beijing and with Platycladus orientalis, the most drought-tolerant tree in Bei- j ing, as control. Physiological parameters of young plants of the trees were measured and divided into three groups in response to soil drying. The first group included root activity, ABA content in roots and peroxidase （POD） activity in leaves. Their values changed similarly to those of P. orientalis and dramatically increased to maximum values when the soil water content （SWC） decreased from its normal level of 20% to 7.6% where the three indices decreased dramatically when SWC was reduced further from 7.6%. The sec- ond group of parameters included the contents of proline, soluble protein and malondialdehyde （MDA）. Their values showed greater variation than those ofP. orientalis and significantly increased when SWC decreased from 20% in response to soil drying. However, the proline and soluble protein contents fluctuated in A. karroo at a lower level than those in P. orientalis. In contrast, the content of MDA in A. karroo was much higher than that in P. orientalis which almost did not increase in the drying soil. The third group of parameters consisted of soluble sugar, superoxide dismutase （SOD） and catalase （CAT）. These parameters showed greater diversity and fluctuations among the three varieties ofA. karroo compared with the control in response to soil drying. These results suggest that A. karroo is characterized as a strong, drought tolerant species in most of physiological parameters but weaker than P orientalis in membrane lipid antioxidation.
文摘Acacia karroo Hayne is an arbor species widely distributed in South Africa with the characteristics of fast growth and drought resistance. The species was introduced to China recently. In vitro culture is an effective method to rapidly produce plants and a strategy to minimize somaclonal variation among regenerated plants. Browning, however, is a problem in establishing the in vitro culture system. The present study diminished the problem by selecting explants, using different browning inhibitors and chilling treatment. Results showed that the use of embryos as explants reduced the browning ratio to 46.7%, whilst stem segment explants were browned up to 56.7%. The adventitious buds were successfully induced in the modified tissue culture medium supplemented with 5.0 mg·L^-1 6-BA and 0.1 mg·L^-1 NAA. The proliferation coefficient of adventitious buds is 2.8.
文摘The 15th International Geological Congress was held in South Africa in 1929.Many interesting issues were tackled,thanks to the development of geophysical techniques,ideas about magmatic differentiation,and the origin of the Karroo System,among others.The importance of the Congress from the point of view of the history of geology lies in the fact that an‘inflection point’occurred as regards thinking about the continental drift theory that had been proposed by Wegener a few years earlier.It can be said that the contributions of Du Toit allowed a deepening in the theoretical bases of this scientific hypothesis,which celebrated its first hundred years in 2012.
