Arsenic （As） in the soils of South-Eastern Bangladesh is not rely a threat for the health of millions of people but also a problem for plant growth due to its higher concentration in soil. Gmelina arborea Linn. is a...Arsenic （As） in the soils of South-Eastern Bangladesh is not rely a threat for the health of millions of people but also a problem for plant growth due to its higher concentration in soil. Gmelina arborea Linn. is a promising fast growing tree species in Bangladesh which has dso a potential to be planted in arsenic contaminated areas. This study tssessed the role of arbuscular mycorrhizal （AM） fungi on the growth of 7. arborea in arsenic amended soils at nursery stage. Before sowing ;eeds, soils were treated with four different concentrations （10 mg.kg^-1, 25 mg.kg^-1, 50 mg.kg^-1, and 100 mg.kg^-1） of Arsenic. Growth parameters length of shoot and root, collar diameter, fresh and dry weight of shoot and root） of the plant, and mycorrhizal root colonization and spore population in the rhizosphere soil of G. arborea were recorded. Mycorrhizal seedlings showed better growth than non-mycorrhizal eedlings. Myeorrhizal seedlings planted in soil with 10-mg.kg^-1 arsenic howed best performance in terms of growth, biomass and mycorrhizal ：olonization, compared to other treatments with higher concentration of Lrsenie. With increasing arsenic concentration, growth of seedlings, nycorrhizal infection rate and spore population, all decreased ignificantly （p〈0.05）. The mycorrhizal seedlings had as much as 40% higher increment in total growth and 2.4 times higher increment in biomass compared to non-mycorrhizal seedlings. The study clearly indicated that mycorrhizal inoculation could reduce the harmful effects of arsenic on the initial growth of G. arborea Linn. in degraded soil at nursery stage.展开更多
In order to investigate the differences of macropores vertical distribution under different surface plants, and to assess the influences of root systems, organic matter and texture on macropore flow paths, two dye tra...In order to investigate the differences of macropores vertical distribution under different surface plants, and to assess the influences of root systems, organic matter and texture on macropore flow paths, two dye tracer infiltration experiments were performed in slopes under two different plants(Campylotropis polyantha(Franch.) Schindl vs. Cynodon dactylon(Linn.) Pers). Dye tracer infiltration experiments with field observations and measurements of soil properties were combined. Results show that the discrepancy in macropores distribution between two slopes under different plants is significant. Root systems have significant effects on macropore flow paths distribution and the effect become more pronounced as the diameter of roots become larger. Organic matter and stone are important factors to affect macropores distribution. Root-soil interface, inter-aggregate macropore and stone-soil interface are important macropore flow paths in well vegetated slopes.展开更多
SC （Saussurea costus） （Asteraceae） is a traditionally known and potent plant which is well considered for its medicinal uses in different indigenous Indian systems of medicine. This study was undertaken to investi...SC （Saussurea costus） （Asteraceae） is a traditionally known and potent plant which is well considered for its medicinal uses in different indigenous Indian systems of medicine. This study was undertaken to investigate the hepatoprotective effect of SC against liver injury induced by CC14 intoxication. Animals were divided into five groups. Group I, served as normal control. Group II received 2 mL CC14/kg b.w. diluted with olive oil, at 1：1 ratio on day 11. Groups III and IV were pre-treated orally respectively with 100 and 200 mg/kg b.w. aqueous roots extract of SC for 10 days followed by subcutaneous injection of CC14 （2 mL/kg b.w.）, once on day 11. Group V were orally given Liv-52 （100 mg/kg b.w.） once daily for 10 days followed by subcutaneous injection of CC14 （2 mL/kg b.w.）, once on day 11. Our results show that, the activity of serum hepatic enzymes （ALT, AST, and ALP） were significantly elevated in guinea pigs treated with CC14, while both the SC root extract and Liv-52 reduced significantly these enzymes activity. Also, the levels of glucose, urea and cholesterol were decreased when compared with intoxicated control. Histopathological examination of intoxicated animals showed dilation, hemorrhage, vacuolization, inflammation and necrosis indicating liver damage, while the animals received SC or Liv-52 that showed less pathological effects or normal liver when compared to animals treated with CC14 alone. Biochemical and histological results confirm the hepatoprotective effect of aqueous extract of SC.展开更多
Aims Competition,temperature and nutrient are the most important determinants of tree growth in the cold climate on the eastern Tibetan Plateau.Although many studies have reported their individual effects on tree grow...Aims Competition,temperature and nutrient are the most important determinants of tree growth in the cold climate on the eastern Tibetan Plateau.Although many studies have reported their individual effects on tree growth,little is known about how the interactions of competition with fertilization and temperature affect root growth.We aim to test whether climate warming and fertilization promote competition and to explore the functional strategies of Picea asperata in response to the interactions of these factors.Methods We conducted a paired experiment including competition and non-competition treatments under elevated temperature(ET)and fertilization.We measured root traits,including the root tip number over the root surface(RTRS),the root branching events over the root surface(RBRS),the specific root length(SRL),the specific root area(SRA),the total fine root length and area(RL and RA),the root tips(RTs)and root branching(RB)events.These root traits are considered to be indicators of plant resource uptake capacity and root growth.The root biomass and the nutrient concentrations in the roots were also determined.Important Findings The results indicated that ET,fertilization and competition individually enhanced the nitrogen(N)and potassium(K)concentrations in fine roots,but they did not affect fine root biomass or root traits,including RL,RT,RA and RB.However,both temperature and fertilizationz as well as their interaction,interacting with competition increased RL,RA,RT,RB and nutrient uptake.In addition,the SRL,SRA,RTRS and RBRS decreased un der fertilization,the interaction between temperature and competition decreased SRL and SRA,while the other parameters were not affected by temperature or competition.These results indicate that P.asperata maintains a conservative nutrient strategy in response to competition,climate warming,fertilization and their interactions.Our results improve our understanding of the physiological and ecological adaptability of trees to global change.展开更多
文摘Arsenic （As） in the soils of South-Eastern Bangladesh is not rely a threat for the health of millions of people but also a problem for plant growth due to its higher concentration in soil. Gmelina arborea Linn. is a promising fast growing tree species in Bangladesh which has dso a potential to be planted in arsenic contaminated areas. This study tssessed the role of arbuscular mycorrhizal （AM） fungi on the growth of 7. arborea in arsenic amended soils at nursery stage. Before sowing ;eeds, soils were treated with four different concentrations （10 mg.kg^-1, 25 mg.kg^-1, 50 mg.kg^-1, and 100 mg.kg^-1） of Arsenic. Growth parameters length of shoot and root, collar diameter, fresh and dry weight of shoot and root） of the plant, and mycorrhizal root colonization and spore population in the rhizosphere soil of G. arborea were recorded. Mycorrhizal seedlings showed better growth than non-mycorrhizal eedlings. Myeorrhizal seedlings planted in soil with 10-mg.kg^-1 arsenic howed best performance in terms of growth, biomass and mycorrhizal ：olonization, compared to other treatments with higher concentration of Lrsenie. With increasing arsenic concentration, growth of seedlings, nycorrhizal infection rate and spore population, all decreased ignificantly （p〈0.05）. The mycorrhizal seedlings had as much as 40% higher increment in total growth and 2.4 times higher increment in biomass compared to non-mycorrhizal seedlings. The study clearly indicated that mycorrhizal inoculation could reduce the harmful effects of arsenic on the initial growth of G. arborea Linn. in degraded soil at nursery stage.
基金Project(U1502232)supported by the National Natural Science Foundation of China-Yunan Joint FundProject(KKSY201406009)supported by the Natural Science Foundation of Kunming University of Science and Technology,ChinaProject(2014FD007)supported by the Natural Science Foundation of Yunnan Province,China
文摘In order to investigate the differences of macropores vertical distribution under different surface plants, and to assess the influences of root systems, organic matter and texture on macropore flow paths, two dye tracer infiltration experiments were performed in slopes under two different plants(Campylotropis polyantha(Franch.) Schindl vs. Cynodon dactylon(Linn.) Pers). Dye tracer infiltration experiments with field observations and measurements of soil properties were combined. Results show that the discrepancy in macropores distribution between two slopes under different plants is significant. Root systems have significant effects on macropore flow paths distribution and the effect become more pronounced as the diameter of roots become larger. Organic matter and stone are important factors to affect macropores distribution. Root-soil interface, inter-aggregate macropore and stone-soil interface are important macropore flow paths in well vegetated slopes.
文摘SC （Saussurea costus） （Asteraceae） is a traditionally known and potent plant which is well considered for its medicinal uses in different indigenous Indian systems of medicine. This study was undertaken to investigate the hepatoprotective effect of SC against liver injury induced by CC14 intoxication. Animals were divided into five groups. Group I, served as normal control. Group II received 2 mL CC14/kg b.w. diluted with olive oil, at 1：1 ratio on day 11. Groups III and IV were pre-treated orally respectively with 100 and 200 mg/kg b.w. aqueous roots extract of SC for 10 days followed by subcutaneous injection of CC14 （2 mL/kg b.w.）, once on day 11. Group V were orally given Liv-52 （100 mg/kg b.w.） once daily for 10 days followed by subcutaneous injection of CC14 （2 mL/kg b.w.）, once on day 11. Our results show that, the activity of serum hepatic enzymes （ALT, AST, and ALP） were significantly elevated in guinea pigs treated with CC14, while both the SC root extract and Liv-52 reduced significantly these enzymes activity. Also, the levels of glucose, urea and cholesterol were decreased when compared with intoxicated control. Histopathological examination of intoxicated animals showed dilation, hemorrhage, vacuolization, inflammation and necrosis indicating liver damage, while the animals received SC or Liv-52 that showed less pathological effects or normal liver when compared to animals treated with CC14 alone. Biochemical and histological results confirm the hepatoprotective effect of aqueous extract of SC.
基金supported by National Key Research and Development Project of China(2017YFC0505002)National Natural Science Foundation of China(31400424,31570477).
文摘Aims Competition,temperature and nutrient are the most important determinants of tree growth in the cold climate on the eastern Tibetan Plateau.Although many studies have reported their individual effects on tree growth,little is known about how the interactions of competition with fertilization and temperature affect root growth.We aim to test whether climate warming and fertilization promote competition and to explore the functional strategies of Picea asperata in response to the interactions of these factors.Methods We conducted a paired experiment including competition and non-competition treatments under elevated temperature(ET)and fertilization.We measured root traits,including the root tip number over the root surface(RTRS),the root branching events over the root surface(RBRS),the specific root length(SRL),the specific root area(SRA),the total fine root length and area(RL and RA),the root tips(RTs)and root branching(RB)events.These root traits are considered to be indicators of plant resource uptake capacity and root growth.The root biomass and the nutrient concentrations in the roots were also determined.Important Findings The results indicated that ET,fertilization and competition individually enhanced the nitrogen(N)and potassium(K)concentrations in fine roots,but they did not affect fine root biomass or root traits,including RL,RT,RA and RB.However,both temperature and fertilizationz as well as their interaction,interacting with competition increased RL,RA,RT,RB and nutrient uptake.In addition,the SRL,SRA,RTRS and RBRS decreased un der fertilization,the interaction between temperature and competition decreased SRL and SRA,while the other parameters were not affected by temperature or competition.These results indicate that P.asperata maintains a conservative nutrient strategy in response to competition,climate warming,fertilization and their interactions.Our results improve our understanding of the physiological and ecological adaptability of trees to global change.
