The scalar of Japanese yew （Taxus cuspidata） population and the relationship between individual distribution and site factors were analyzed according to investigating data in 74 sample belts with a total sampled are...The scalar of Japanese yew （Taxus cuspidata） population and the relationship between individual distribution and site factors were analyzed according to investigating data in 74 sample belts with a total sampled area of 436.872 hm2 in Muling Nature Reserve. The result showed that the distribution rules of Japanese yew population were correlated to elevation, slope position, slope aspect and slope gradient. The optimal distribution range in elevation for the natural Japanese yew population is at the attitudes of 700-800 m. The amounts of Japanese yew individuals on shady slope were more than those on sunny slope. On top slope and mid-slope, the individual amounts of Japanese yew are more than those on toe slope. Most of Japanese yew individuals occurred on slope gradient of less than 15. The scalar of the population was decreased with the slope gradient increasing.展开更多
The Himalayan Yew (Taxus baccata subsp. wallichiana) is an endangered native high value medicinal plant of the Himalayan Region. The several medicinal properties of the bark and leaves of this species have increased i...The Himalayan Yew (Taxus baccata subsp. wallichiana) is an endangered native high value medicinal plant of the Himalayan Region. The several medicinal properties of the bark and leaves of this species have increased its risk of extinction due to pressures for utilization. It is also subjected to harvest for fuelwood. The species does not regenerate well from seed and that is another risk factor. The objective of this research was to investigate the population ecology of the species as a foundation for its conservation. Six forest communities in the Khokhan Wildlife Sanctuary where the species is present were sampled. The abundance of the species, impacts of harvesting and its current regeneration patterns indicate that it may soon be extirpated from the Sanctuary. A plan for conserving the remaining sub-populations is presented. It could provide a template for conservation in other locations where the species is at risk.展开更多
The extracts of yew tree have showed unique anti-tumor and anti-leakematic activities. Taxol extracted from it is effective against a variety of cancers, such as ovarian cancer and breast cancer. However the hypoglyce...The extracts of yew tree have showed unique anti-tumor and anti-leakematic activities. Taxol extracted from it is effective against a variety of cancers, such as ovarian cancer and breast cancer. However the hypoglycemic efficacy of the extract has not been reported yet, so the effects of oral administration of yew tree extracts on streptozotocin-induced diabetic rats were examined. Administration of shah tang ping （STP）, a fraction from the column separation of extract （450 mg/kg body weight）, for 14 days reduced the serum glucose concentrations of fasted diabetic rats by 52.4%. In addition, it also decreased the concentrations of triglyceride （TG）, total cholesterol （TC）, and low density lipoprotein cholesterol （LDL-C）. An oral glucose tolerance test （OGTT） was performed, a significant improvement in glucose tolerance was observed in rats treated with STP. These results suggest that STP has hypoglycemic properties and hypolipidemic action on streptozotocin-induced diabetic rats.展开更多
How can a man perform the role of a winner?He may be a scholar topping the study of a sub-ject,an engineer proficient in certain skills,an entrepreneur capable of creat-ing boundless wealth,a social worker working for...How can a man perform the role of a winner?He may be a scholar topping the study of a sub-ject,an engineer proficient in certain skills,an entrepreneur capable of creat-ing boundless wealth,a social worker working for the betterment of the so-展开更多
Paclitaxel in southern yew tree was quantitatively determined by high performance liquid chromatography (HPLC) with ODS-C18 column. A mixture of CH3OH-H2O-CH3COOH(volume ratio: 55 :44 :1) is used as mobile phase and U...Paclitaxel in southern yew tree was quantitatively determined by high performance liquid chromatography (HPLC) with ODS-C18 column. A mixture of CH3OH-H2O-CH3COOH(volume ratio: 55 :44 :1) is used as mobile phase and UV detection is carried out at 227 nm, and the column temperature is 20℃. The results show that there is a good linear felationship between the area of paclitaxel and the concentration of the sample in the range 50-500 mg/L for paclitaxel. The corresponding regression equation is Y= 13 021. 7 + 1. 01 × 106X, r=0. 9990. The average recovery is 95. 3% and the relative standard deviation is 2. 08%.展开更多
The Chinese yew Taxus chinensis is catalogued as an endangered species in China because of the small size andsenescent status of most populations. Its lack of natural regeneration is the most important reason for its ...The Chinese yew Taxus chinensis is catalogued as an endangered species in China because of the small size andsenescent status of most populations. Its lack of natural regeneration is the most important reason for its endangeredstatus. We investigated the regeneration of an ex-situ conservation population, which was introduced intothe Nanjing Botanical Garden Memorial Sun Yat-Sen in the 1950s, and evaluated the role of frugivorous birds on theestablishment of this regenerating population. Two hundred and thirteen individual yew seedlings and saplingswere found on the hillside in 2006, and the nearest seedling was found more than 10 m away from mother trees. Thespatial pattern of all seedlings and saplings occurred as a clumped distribution, which is typical for vertebratedispersedplants. Six bird species were seen ingesting whole “fruits” at yew trees in the present study and 745 visitsby avian frugivores were recorded. Red-billed blue magpie (Urocissa erythrorhyncha), Chinese bulbul (Pycnonotussinensis) and azure-winged magpie (Cyanopica cyana) were the most frequent visitors over the two years of thestudy. Comparing the flights of departure and perching habitats of the three main bird species, we inferred that U.erythrorhyncha would be the most important disperser. This regeneration population has had good developmentover the past 20 or more years;frugivorous birds have removed seeds to the hillside every year until now, and seedgermination and seedling growth continue to develop well under natural conditions. We suggest that the conservationsystem of the Chinese yew should be composed of yews, avian dispersers and habitats for seed germinationand seedling growth.展开更多
In this research, some of site and silvicultural characteristics of Yew stand in northern forests of Iran was studied. For this purpose, compartment number 16 of district 4 Shir-ghalaye was selected. According to rese...In this research, some of site and silvicultural characteristics of Yew stand in northern forests of Iran was studied. For this purpose, compartment number 16 of district 4 Shir-ghalaye was selected. According to research purposes, stands with an area of 20 ha were chosen in center of the compartment and was separated from map. Due to restricted area of region and according to few number of Yew trees in the stand, the full-callipering method was conducted for measuring quantitative and qualitative characteristics. In the stand diameter at breast height （D.B.H.）, height and canopy diameter of all Yew trees were measured. The results showed that the diameter distribution curve and height distribution curve of Yew trees were similar to even-age forests curve. But according to average annual increment, mixture type of Yew trees in stand, diameter distribution of other species and low rate regeneration of Yew, it can be concluded that the studied Yew stand, is an uneven-age stand and because of low rate regeneration in previous years the number of young Yew trees were reduced and even-age forest curve was formed subsequently. The maximum height and diameter of Yew trees were recorded 26.8 m and 112 cm, respectively. Also, the number of trees per hectare and basal area per hectare of Yew trees were calculated 14.55 and 3.23 m2 respectively.展开更多
Population connectivity through seed and pollen dispersal determines the genetic diversity,adaptive potential,and demography of plant metapopulations.In wind-pollinated trees,population connectivity is typically maint...Population connectivity through seed and pollen dispersal determines the genetic diversity,adaptive potential,and demography of plant metapopulations.In wind-pollinated trees,population connectivity is typically maintained by long-distance pollen flow,counteracting the genetic differentiation generated by drift and restricted seed dispersal.Although strong population fragmentation is theoretically expected to disrupt connectivity in forest trees,empirical evidence remains scarce and inconclusive.We investigated contemporary connectivity within a network of small remnant populations of a declining conifer(Taxus baccata L.),which have been hypothesized to be largely isolated from each other.We tested this hypothesis using molecular data for adult trees and naturally recruited seedlings from all known remnants across a fragmented landscape spanning a length of 20 km,and a specifically designed statistical approach to quantify contemporary pollen and seed migration rates between populations.We additionally assessed dispersal potential using a spatially explicit parentage analysis to estimate seed and pollen dispersal kernels within one of the remnants.Estimated pairwise migration rates between populations were barely detectable for seeds,while they were larger(up to 1.1%)and significant for pollen.Both seed and pollen migration rates decreased with geographic distance between populations,more steeply in the case of pollen migration.According to parentage-based dispersal kernels,51.8% of seeds and 11.4% of pollen travel less than 25 m,whereas 0.2% of seeds and 36.1%of pollen travel more than 250 m from a source tree.In addition,1.2% of pollen can travel more than 2.5 km.We showed that strong present-day population fragmentation,with separation distances over a few kilometers between small fragments,can substantially limit the connectivity of a wind-pollinated declining tree,leading to low pollen-mediated contemporary gene flow and null or virtually null demographic connectivity via seed dispersal.展开更多
目的:研究东北红豆杉心材的化学成分。方法:采用硅胶柱色谱、制备薄层色谱和制备型高效液相色谱等手段对化学成分进行分离和纯化,用现代核磁技术对化合物进行结构鉴定。结果:从东北红豆杉心材分离得到10个化合物,分别鉴定为taxin ine(1)...目的:研究东北红豆杉心材的化学成分。方法:采用硅胶柱色谱、制备薄层色谱和制备型高效液相色谱等手段对化学成分进行分离和纯化,用现代核磁技术对化合物进行结构鉴定。结果:从东北红豆杉心材分离得到10个化合物,分别鉴定为taxin ine(1),taxusin(2),-βsitosterol(3),1-βhydroxybaccatin I(4),2,α5,α10β-triace-toxy-14β-(2-′m ethyl)butanoyloxy-4(20),11-taxad iene(5),2,α5,α10-βtriacetoxy-14-β(2-′m ethyl-3-′hydroxy-butanoy-loxy)-4(20),11-taxad iene(yunnanxane)(6),9,α10,β13α-triacetoxy-5-αc innamoyltaxa-4(20),11-d iene(7),2-deace-toxytaxin ine J(8),taxezop id ine G(9),2,α7,β9,α10,β13-αpentaacetoxyl-taxa-4(20),11-d ien-5-ol(5-dec innamoyltaxi-n ine J)(10)。结论:化合物4,6,10是首次从该植物中分离得到。展开更多
基金This work was supported by Northeast Forestry University fund Program from Science and Technology Department of Heilongjiang Province (LC05C14)
文摘The scalar of Japanese yew （Taxus cuspidata） population and the relationship between individual distribution and site factors were analyzed according to investigating data in 74 sample belts with a total sampled area of 436.872 hm2 in Muling Nature Reserve. The result showed that the distribution rules of Japanese yew population were correlated to elevation, slope position, slope aspect and slope gradient. The optimal distribution range in elevation for the natural Japanese yew population is at the attitudes of 700-800 m. The amounts of Japanese yew individuals on shady slope were more than those on sunny slope. On top slope and mid-slope, the individual amounts of Japanese yew are more than those on toe slope. Most of Japanese yew individuals occurred on slope gradient of less than 15. The scalar of the population was decreased with the slope gradient increasing.
文摘The Himalayan Yew (Taxus baccata subsp. wallichiana) is an endangered native high value medicinal plant of the Himalayan Region. The several medicinal properties of the bark and leaves of this species have increased its risk of extinction due to pressures for utilization. It is also subjected to harvest for fuelwood. The species does not regenerate well from seed and that is another risk factor. The objective of this research was to investigate the population ecology of the species as a foundation for its conservation. Six forest communities in the Khokhan Wildlife Sanctuary where the species is present were sampled. The abundance of the species, impacts of harvesting and its current regeneration patterns indicate that it may soon be extirpated from the Sanctuary. A plan for conserving the remaining sub-populations is presented. It could provide a template for conservation in other locations where the species is at risk.
文摘The extracts of yew tree have showed unique anti-tumor and anti-leakematic activities. Taxol extracted from it is effective against a variety of cancers, such as ovarian cancer and breast cancer. However the hypoglycemic efficacy of the extract has not been reported yet, so the effects of oral administration of yew tree extracts on streptozotocin-induced diabetic rats were examined. Administration of shah tang ping （STP）, a fraction from the column separation of extract （450 mg/kg body weight）, for 14 days reduced the serum glucose concentrations of fasted diabetic rats by 52.4%. In addition, it also decreased the concentrations of triglyceride （TG）, total cholesterol （TC）, and low density lipoprotein cholesterol （LDL-C）. An oral glucose tolerance test （OGTT） was performed, a significant improvement in glucose tolerance was observed in rats treated with STP. These results suggest that STP has hypoglycemic properties and hypolipidemic action on streptozotocin-induced diabetic rats.
文摘How can a man perform the role of a winner?He may be a scholar topping the study of a sub-ject,an engineer proficient in certain skills,an entrepreneur capable of creat-ing boundless wealth,a social worker working for the betterment of the so-
基金Project (00KNY1010 ) supported by the Key Program of Science and Technology Office of Hunan Province
文摘Paclitaxel in southern yew tree was quantitatively determined by high performance liquid chromatography (HPLC) with ODS-C18 column. A mixture of CH3OH-H2O-CH3COOH(volume ratio: 55 :44 :1) is used as mobile phase and UV detection is carried out at 227 nm, and the column temperature is 20℃. The results show that there is a good linear felationship between the area of paclitaxel and the concentration of the sample in the range 50-500 mg/L for paclitaxel. The corresponding regression equation is Y= 13 021. 7 + 1. 01 × 106X, r=0. 9990. The average recovery is 95. 3% and the relative standard deviation is 2. 08%.
基金the National Natural Science Foundation of China(No.30170165).
文摘The Chinese yew Taxus chinensis is catalogued as an endangered species in China because of the small size andsenescent status of most populations. Its lack of natural regeneration is the most important reason for its endangeredstatus. We investigated the regeneration of an ex-situ conservation population, which was introduced intothe Nanjing Botanical Garden Memorial Sun Yat-Sen in the 1950s, and evaluated the role of frugivorous birds on theestablishment of this regenerating population. Two hundred and thirteen individual yew seedlings and saplingswere found on the hillside in 2006, and the nearest seedling was found more than 10 m away from mother trees. Thespatial pattern of all seedlings and saplings occurred as a clumped distribution, which is typical for vertebratedispersedplants. Six bird species were seen ingesting whole “fruits” at yew trees in the present study and 745 visitsby avian frugivores were recorded. Red-billed blue magpie (Urocissa erythrorhyncha), Chinese bulbul (Pycnonotussinensis) and azure-winged magpie (Cyanopica cyana) were the most frequent visitors over the two years of thestudy. Comparing the flights of departure and perching habitats of the three main bird species, we inferred that U.erythrorhyncha would be the most important disperser. This regeneration population has had good developmentover the past 20 or more years;frugivorous birds have removed seeds to the hillside every year until now, and seedgermination and seedling growth continue to develop well under natural conditions. We suggest that the conservationsystem of the Chinese yew should be composed of yews, avian dispersers and habitats for seed germinationand seedling growth.
文摘In this research, some of site and silvicultural characteristics of Yew stand in northern forests of Iran was studied. For this purpose, compartment number 16 of district 4 Shir-ghalaye was selected. According to research purposes, stands with an area of 20 ha were chosen in center of the compartment and was separated from map. Due to restricted area of region and according to few number of Yew trees in the stand, the full-callipering method was conducted for measuring quantitative and qualitative characteristics. In the stand diameter at breast height （D.B.H.）, height and canopy diameter of all Yew trees were measured. The results showed that the diameter distribution curve and height distribution curve of Yew trees were similar to even-age forests curve. But according to average annual increment, mixture type of Yew trees in stand, diameter distribution of other species and low rate regeneration of Yew, it can be concluded that the studied Yew stand, is an uneven-age stand and because of low rate regeneration in previous years the number of young Yew trees were reduced and even-age forest curve was formed subsequently. The maximum height and diameter of Yew trees were recorded 26.8 m and 112 cm, respectively. Also, the number of trees per hectare and basal area per hectare of Yew trees were calculated 14.55 and 3.23 m2 respectively.
基金supported by the National Science Centre,Poland(the grant UMO-2018/31/B/NZ8/01808 to IJC).
文摘Population connectivity through seed and pollen dispersal determines the genetic diversity,adaptive potential,and demography of plant metapopulations.In wind-pollinated trees,population connectivity is typically maintained by long-distance pollen flow,counteracting the genetic differentiation generated by drift and restricted seed dispersal.Although strong population fragmentation is theoretically expected to disrupt connectivity in forest trees,empirical evidence remains scarce and inconclusive.We investigated contemporary connectivity within a network of small remnant populations of a declining conifer(Taxus baccata L.),which have been hypothesized to be largely isolated from each other.We tested this hypothesis using molecular data for adult trees and naturally recruited seedlings from all known remnants across a fragmented landscape spanning a length of 20 km,and a specifically designed statistical approach to quantify contemporary pollen and seed migration rates between populations.We additionally assessed dispersal potential using a spatially explicit parentage analysis to estimate seed and pollen dispersal kernels within one of the remnants.Estimated pairwise migration rates between populations were barely detectable for seeds,while they were larger(up to 1.1%)and significant for pollen.Both seed and pollen migration rates decreased with geographic distance between populations,more steeply in the case of pollen migration.According to parentage-based dispersal kernels,51.8% of seeds and 11.4% of pollen travel less than 25 m,whereas 0.2% of seeds and 36.1%of pollen travel more than 250 m from a source tree.In addition,1.2% of pollen can travel more than 2.5 km.We showed that strong present-day population fragmentation,with separation distances over a few kilometers between small fragments,can substantially limit the connectivity of a wind-pollinated declining tree,leading to low pollen-mediated contemporary gene flow and null or virtually null demographic connectivity via seed dispersal.
文摘目的:研究东北红豆杉心材的化学成分。方法:采用硅胶柱色谱、制备薄层色谱和制备型高效液相色谱等手段对化学成分进行分离和纯化,用现代核磁技术对化合物进行结构鉴定。结果:从东北红豆杉心材分离得到10个化合物,分别鉴定为taxin ine(1),taxusin(2),-βsitosterol(3),1-βhydroxybaccatin I(4),2,α5,α10β-triace-toxy-14β-(2-′m ethyl)butanoyloxy-4(20),11-taxad iene(5),2,α5,α10-βtriacetoxy-14-β(2-′m ethyl-3-′hydroxy-butanoy-loxy)-4(20),11-taxad iene(yunnanxane)(6),9,α10,β13α-triacetoxy-5-αc innamoyltaxa-4(20),11-d iene(7),2-deace-toxytaxin ine J(8),taxezop id ine G(9),2,α7,β9,α10,β13-αpentaacetoxyl-taxa-4(20),11-d ien-5-ol(5-dec innamoyltaxi-n ine J)(10)。结论:化合物4,6,10是首次从该植物中分离得到。
