The effect of first thinning and pruning on height, diameter at breast height （DBH）, and volume growth was studied in individual trees of Pinus patula Schiede and Deppe in Chongoni Plantation, using four plots for t...The effect of first thinning and pruning on height, diameter at breast height （DBH）, and volume growth was studied in individual trees of Pinus patula Schiede and Deppe in Chongoni Plantation, using four plots for thinning trials. Each of the plots was 0.5 ha and subjected to one of the fol- lowing silvicultural treatments： first thinning and pruning, first thinning and no pruning, pruning and no thinning, and control （no pruning and no thinning）. The silvicultural treatments were randomized in four replicates. Fourteen years after planting, the following parameters were measured including total height, DBH, and volume. The highest DBH and volume growth was observed in thinning and pruning, while the highest growth in height was observed where there was pruning and no thinning. Clearly, both thinning and pruning are an important manage- ment option in pine species plantations in Malawi to maximize the increase in volume productivity.展开更多
Objective:To investigate the inflammatory and antioxidant activities of ethanolie extract of aerial part of Vernonia patula(Dryand.)Merr(EAV).Methods:The anti-inflammatory activity of EAV was studied using carrageenan...Objective:To investigate the inflammatory and antioxidant activities of ethanolie extract of aerial part of Vernonia patula(Dryand.)Merr(EAV).Methods:The anti-inflammatory activity of EAV was studied using carrageenan and histamine-induced rat paw edema test at different doses(100.200 and 400 mg/kg body weight).DPPH free radical scavenging,nitric oxide scavenging,reducing power and Fe^(2+)ion chelating ability were used for determining antioxidant activities.Results:The EAV,at the dose of 400 mg/kg,showed a significant anti-inflammatory activity(P<0.01)both in the carrageenan and histamine-induced oedema test models in rats,showing62.86%and 64.42%reduction in the paw volume comparable to that produced by the standard drug indomethacin(67.26%and 66.01%)at 5 h respectively.In DPPH free radical scavenging test,IC_(50)value for EAV was found fairly significant 36.59μg/mL when compared to the IC_(50)value of the reference standards ascorbic acid 8.97μg/mL.The IC_(50)values of the extract and ascorbic acid were 47.72 and 12.39μg/mL,respectively in nitric oxide scavenging assay.The IC_(50)value of the EAV(33.59μg/mL)as percentage of Fe^(2+)ion chelating ability was also found significant compared to that of EDTA(9.16μg/mL).The maximum absorbance for reducing power assay was found to be1.928 at 100μg/mL when compared to 2.449 for standard ascorbic acid.The total phenolic content was 198.81 mg/g of gallic acid equivalent.Acute toxicity test showed that the plant might be safe for pharmacological uses up to a dose level of 3200 mg/kg of body weight in rats.Conclusions:Therefore,the obtained results suggest the acute anti-inflammatory and antioxidant activities of the EAV and thus provide the scientific basis for the traditional uses of this plant part as a remedy for inflammations.展开更多
Pinus patula is a species commonly used for reforestation in Mexico.However,efficient methods for the mass production seedlings are required.Micropropagation particularly by somatic embryogenesis provides an option fo...Pinus patula is a species commonly used for reforestation in Mexico.However,efficient methods for the mass production seedlings are required.Micropropagation particularly by somatic embryogenesis provides an option for the rapid multiplication of high-quality,genetically improved material.This study induces somatic embryogenesis in this species using the thin cell layer(TCL)technique.Two sources of explants(complete immature embryos;lTCL segments from immature embryos)were evaluated.The efficiency of TCL from longitudinal sections[lTCL]and transverse[tTCL]was evaluated.The results show using thin cell layers from immature embryos cultivated in 16 light/8 dark hours achieves induction of somatic embryos.A higher percentage of embryogenic callus was obtained when tTCL segments were used as an explant source.These results produced somatic embryos from tTCL segments of an immature embryo without germinating the seed,making the process more time efficient.In addition,this technique can be used to generate somatic embryogenesis in forest species that have low germination rates.展开更多
Hydrogel amendments have been used to improve seedling survival and establishment particularly in dry environments. However, their effect on survival and growth of newly transplanted seedlings under varying water stre...Hydrogel amendments have been used to improve seedling survival and establishment particularly in dry environments. However, their effect on survival and growth of newly transplanted seedlings under varying water stress conditions is poorly known. In this regard, we examined the effects of Aqua Matrix Forestry~？, a potassium-based water-absorbent polymer, on the survival and early growth of Pinus patula seedlings planted in early-,mid-and late-dry season in the eastern highlands of Zimbabwe. The late-dry season was hotter and received more rainfall than the early-and mid-dry season. Hydrogel increased seedling survival by 34 and 22% in the mid-and late-dry season, respectively. Also, hydrogel-treated seedlings were significantly taller than untreated seedlings（P ／ 0.001）. The height to root collar diameter ratio of hydrogel-treated seedlings was greater than that of untreated seedlings only in the mid-dry season. In conclusion, increase in survival and early growth of hydrogel-treated seedlings suggests that hydrogels can be used to extend planting beyond the rainy season to include the dry months, a feat previously unattainable due to high seedling mortality. Further, these findings reflect similar findings with other hydrogels, suggesting that improved seedling survival and plant performance may be a general consequence of hydrogel amendments.展开更多
Pinus patula is one of the major exotic species grown in Malawi mainly for saw-timber production. It is native to Mexico. Little has been reported about the mechanical properties of the wood. The objective of this stu...Pinus patula is one of the major exotic species grown in Malawi mainly for saw-timber production. It is native to Mexico. Little has been reported about the mechanical properties of the wood. The objective of this study was to investigate the mechanical properties of Pinus patula in more detail, in order to provide a basis for utilizing this resource. The mechanical properties of small clear wood specimens of Pinus patula were evaluated using 40 cm logs from 1, 3, 5, 7 and 9 m above the ground. Small clear wood specimens were selected and subjected to a bending test in accordance with Japan Industrial Standards (JIS) air-dry conditions. The growth rate did not affect the mechanical properties measured. There were significant correlations at 1% level between air-dry density and Modulus Of Elasticity (MOE) (R = 0.85) and between air-dry density and Modulus Of Rupture (MOR) (R = 0.83). There was also a significant correlation between MOE and MOR at 1% level (R = 0.90). At about 12% moisture content, the tested five Pinus patula families have average MOR and MOE of 105.17 MPa and 10.93 GPa, respectively.展开更多
文摘The effect of first thinning and pruning on height, diameter at breast height （DBH）, and volume growth was studied in individual trees of Pinus patula Schiede and Deppe in Chongoni Plantation, using four plots for thinning trials. Each of the plots was 0.5 ha and subjected to one of the fol- lowing silvicultural treatments： first thinning and pruning, first thinning and no pruning, pruning and no thinning, and control （no pruning and no thinning）. The silvicultural treatments were randomized in four replicates. Fourteen years after planting, the following parameters were measured including total height, DBH, and volume. The highest DBH and volume growth was observed in thinning and pruning, while the highest growth in height was observed where there was pruning and no thinning. Clearly, both thinning and pruning are an important manage- ment option in pine species plantations in Malawi to maximize the increase in volume productivity.
基金Supported by the Ministry of Science and Information&Communication Technology(Grant No.MOSICT/Sha-9/PRC-24/2009-2010/(Part-1)/BS72/192.date-03/12/2009),Government of Bangladesh
文摘Objective:To investigate the inflammatory and antioxidant activities of ethanolie extract of aerial part of Vernonia patula(Dryand.)Merr(EAV).Methods:The anti-inflammatory activity of EAV was studied using carrageenan and histamine-induced rat paw edema test at different doses(100.200 and 400 mg/kg body weight).DPPH free radical scavenging,nitric oxide scavenging,reducing power and Fe^(2+)ion chelating ability were used for determining antioxidant activities.Results:The EAV,at the dose of 400 mg/kg,showed a significant anti-inflammatory activity(P<0.01)both in the carrageenan and histamine-induced oedema test models in rats,showing62.86%and 64.42%reduction in the paw volume comparable to that produced by the standard drug indomethacin(67.26%and 66.01%)at 5 h respectively.In DPPH free radical scavenging test,IC_(50)value for EAV was found fairly significant 36.59μg/mL when compared to the IC_(50)value of the reference standards ascorbic acid 8.97μg/mL.The IC_(50)values of the extract and ascorbic acid were 47.72 and 12.39μg/mL,respectively in nitric oxide scavenging assay.The IC_(50)value of the EAV(33.59μg/mL)as percentage of Fe^(2+)ion chelating ability was also found significant compared to that of EDTA(9.16μg/mL).The maximum absorbance for reducing power assay was found to be1.928 at 100μg/mL when compared to 2.449 for standard ascorbic acid.The total phenolic content was 198.81 mg/g of gallic acid equivalent.Acute toxicity test showed that the plant might be safe for pharmacological uses up to a dose level of 3200 mg/kg of body weight in rats.Conclusions:Therefore,the obtained results suggest the acute anti-inflammatory and antioxidant activities of the EAV and thus provide the scientific basis for the traditional uses of this plant part as a remedy for inflammations.
基金supported by grant from the Mexican Forest Service(CONAFOR)(No.11385232709—“Promotion and Operation of the Forest Genetic Resources Subsystem,within CNRGINIFAP’’)
文摘Pinus patula is a species commonly used for reforestation in Mexico.However,efficient methods for the mass production seedlings are required.Micropropagation particularly by somatic embryogenesis provides an option for the rapid multiplication of high-quality,genetically improved material.This study induces somatic embryogenesis in this species using the thin cell layer(TCL)technique.Two sources of explants(complete immature embryos;lTCL segments from immature embryos)were evaluated.The efficiency of TCL from longitudinal sections[lTCL]and transverse[tTCL]was evaluated.The results show using thin cell layers from immature embryos cultivated in 16 light/8 dark hours achieves induction of somatic embryos.A higher percentage of embryogenic callus was obtained when tTCL segments were used as an explant source.These results produced somatic embryos from tTCL segments of an immature embryo without germinating the seed,making the process more time efficient.In addition,this technique can be used to generate somatic embryogenesis in forest species that have low germination rates.
文摘Hydrogel amendments have been used to improve seedling survival and establishment particularly in dry environments. However, their effect on survival and growth of newly transplanted seedlings under varying water stress conditions is poorly known. In this regard, we examined the effects of Aqua Matrix Forestry~？, a potassium-based water-absorbent polymer, on the survival and early growth of Pinus patula seedlings planted in early-,mid-and late-dry season in the eastern highlands of Zimbabwe. The late-dry season was hotter and received more rainfall than the early-and mid-dry season. Hydrogel increased seedling survival by 34 and 22% in the mid-and late-dry season, respectively. Also, hydrogel-treated seedlings were significantly taller than untreated seedlings（P ／ 0.001）. The height to root collar diameter ratio of hydrogel-treated seedlings was greater than that of untreated seedlings only in the mid-dry season. In conclusion, increase in survival and early growth of hydrogel-treated seedlings suggests that hydrogels can be used to extend planting beyond the rainy season to include the dry months, a feat previously unattainable due to high seedling mortality. Further, these findings reflect similar findings with other hydrogels, suggesting that improved seedling survival and plant performance may be a general consequence of hydrogel amendments.
文摘Pinus patula is one of the major exotic species grown in Malawi mainly for saw-timber production. It is native to Mexico. Little has been reported about the mechanical properties of the wood. The objective of this study was to investigate the mechanical properties of Pinus patula in more detail, in order to provide a basis for utilizing this resource. The mechanical properties of small clear wood specimens of Pinus patula were evaluated using 40 cm logs from 1, 3, 5, 7 and 9 m above the ground. Small clear wood specimens were selected and subjected to a bending test in accordance with Japan Industrial Standards (JIS) air-dry conditions. The growth rate did not affect the mechanical properties measured. There were significant correlations at 1% level between air-dry density and Modulus Of Elasticity (MOE) (R = 0.85) and between air-dry density and Modulus Of Rupture (MOR) (R = 0.83). There was also a significant correlation between MOE and MOR at 1% level (R = 0.90). At about 12% moisture content, the tested five Pinus patula families have average MOR and MOE of 105.17 MPa and 10.93 GPa, respectively.
