[Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass （Lolium perenne） - white clover （ Trifolium repens） artificial grassland in Maiping Townsh...[Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass （Lolium perenne） - white clover （ Trifolium repens） artificial grassland in Maiping Township, Guizhou Province as the research object, the grassland vegetation of 40 quadrate from different areas （area around the sheep shed, hilltop, hillside, flatland at the foot of the hill） were analyzed by comparing the dominance and richness index. [ Result] Degradation of different degrees appeared in various areas of this artificial grassland. To be specific, the degradation of grassland around the sheep shed was not serious for less consumption by the sheep; however, the areas on the hilltop and hillside degenerated to the grassland types of dallis grass （ Paspalum dilatatum Poir. ） -Indian lovegrass （ Eragrostis pilosa） and dallis grass - cogongrass [ Imperata cylindrica （ Linn. ） Beauv. ], respectively, and the area at the foot of the hill degenerated to the grassland type dominated by garland chrysanthetnum （ Chrysanthemum coronarium L. ） and knotgrass （ Paspalum distichum L. ）. [ Conclusion ] This study provided a basis for grassland improvement as well as the efficient and sustainable utilization of grazing-type artificial grassland in South China.展开更多
Phytoremediation has been used as an emerging technology for remediation of soil contamination with polycyclic aromatic hydrocarbons(PAHs),ubiquitous persistent environmental pollutants derived from natural and anthro...Phytoremediation has been used as an emerging technology for remediation of soil contamination with polycyclic aromatic hydrocarbons(PAHs),ubiquitous persistent environmental pollutants derived from natural and anthropogenic processes,in the last decade.In this study,a pot experiment was conducted to investigate the potential of phytoremediation of pyrene from spiked soils planted with white clover(Trifolium repens)in the greenhouse with a series of pyrene concentrations ranging from 4.22 to 365.38 mg kg-1.The results showed that growth of white clover on pyrenecontaminated soils was not affected.The removal of pyrene from the spiked soils planted with white clover was obviously higher than that from the unplanted soils.At the end of the experiment(60 d),the average removal ratio of pyrene in the spiked soils with white clover was 77%,which was 31%and 57%higher than those of the controls with or without micobes, respectively.Both roots and shoots of white clover took up pyrene from the spiked soils and pyrene uptake increased with the soil pyrene concentration.However,the plant-enhanced dissipation of soil pyrene may be the result of plant-promoted microbial degradation and direct uptake and accumulation of pyrene by white clover were only a small part of the pyrene dissipation.Bioconcentration factors of pyrene(BCFs,ratio of pyrene,on a dry weight basis,in the plant to that in the soil)tended to decrease with increase in the residual soil pyrene concentration.Therefore,removal of pyrene in the contaminated soils was feasible using white clove.展开更多
Although white clover has been widely studied and applied,less is known about its physiological responses to chilling stress in northern China.The effects of acclimation time of chilling stress in the two white clover...Although white clover has been widely studied and applied,less is known about its physiological responses to chilling stress in northern China.The effects of acclimation time of chilling stress in the two white clover cultivars,Rivendel and Haifa,after exposure to 4℃for 0,4,8,12,24 and 48 h were investigated.Seven physiological indexes were measured in shoots of the two cultivars.It was found that Rivendel had a strong ability to maintain the stability of cells,cope with oxidative damage and accumulate osmotic adjustment substances compared with Haifa.In addition,a comprehensive evaluation on the chilling tolerance of the two cultivars based on subordinate function value analysis showed a stronger chilling tolerance of Rivendel than Haifa.展开更多
Resource sharing in the different parts of the clonal white clover plant (Trifolium repens L.) was investigated in this study. The results showed that the integration of water and nitrogen metabolism occured among par...Resource sharing in the different parts of the clonal white clover plant (Trifolium repens L.) was investigated in this study. The results showed that the integration of water and nitrogen metabolism occured among parental, young and old branches of a plant when water passed through its stolons. Under the sufficient supply of light, water and nutrients from soil the newly developed branches showed similar capacity in taking in sufficient water and nitrogen to that of old branches. The development of the new branches did not affect the growth of the old and parental branches attached. The results also indicated that energy values in roots was significantly related with plant age, however, the energy values were various in the different parts of a plant.展开更多
Agroforestry systems have the potential to provide year-long income opportunities via the integrated forage or crop, timber, and livestock. Legumes are an attractive alternative option during the growing season when m...Agroforestry systems have the potential to provide year-long income opportunities via the integrated forage or crop, timber, and livestock. Legumes are an attractive alternative option during the growing season when more traditional forages may not be as productive. The objective of this study was to test the establishment of arrowleaf and white clover grown under varying pine tree alley widths. In 2011, existing forage was removed in 15-yr old loblolly pine tree row alleys of different widths (3.7, 4.9, 7.3, and 9.8 m), including an open area. Arrowleaf, as an annual, was replanted in 2012. Seedlings were counted twice/year, while dry matter was measured three times/year. Photosynthetically active radiation (PAR) was measured in all alley widths to compare light penetration through the canopy. Hot and dry conditions occurred throughout 2012, affecting results. In 2012 and 2013, the greatest PAR for most treatments was observed in June. Seedling counts for all treatments were greatest immediately after establishment, and gradually declined throughout the course of the study. Dry matter yields increased throughout the growing season, and were greatest in arrowleaf clover in the open area on all measurement dates;however, increased weed pressure and repeated flooding affected yields. This study demonstrated that clover establishment in shady wooded areas is possible, but only under suitable environmental conditions.展开更多
In the present study,genetic diversity and genetic relationship of 11materials including red clover ( Trifolium pretense L.),white clover ( T.repen L.) and alsike clover ( T.hybridum L.) and leaf-type variants of whit...In the present study,genetic diversity and genetic relationship of 11materials including red clover ( Trifolium pretense L.),white clover ( T.repen L.) and alsike clover ( T.hybridum L.) and leaf-type variants of white clover were investigated by SRAP (sequence related amplified polymorphism).Forty SRAP primers were screened,and 792 reliable bands were amplified,among which 426 (53.8%) were polymorphic.The number of polymorphic bands per pair of primers ranged from 3 to 38 with an average of 10.6.SRAP cluster analysis showed that the similarity coefficients between white clover materials were from 0.465 to 0.997 with an average of 0.812,indicating that there was certain genetic diversity among white clover.Specific bands appeared in white clover variants,indicating that there were certain differences in DNA sequence between normal while clover plants and their leaf-type variants.The similarity coefficients between red clover materials were from 0.457 to 0.827 with an average of 0.597,indicating that the different red clover germplasms had genetic diversity at the DNA molecular level.The results also showed that the genetic relationship of the alsike clover with the red clover was closer than that with the white clover.This study shows that SRAP technique can be effectively used for the analysis on interspecific and intraspecific relationship,germplasm resource identification and genetic diversity of clover.展开更多
以白三叶为材料,在盆栽条件下研究丛枝菌根真菌粘屑多样孢囊霉（Diversispora spurca）、地表球囊霉（Glomus versiforme）和隐类球囊霉（Paraglom us occultum）对其叶绿素含量、根系构型及组织蔗糖和葡萄糖含量的影响.结果表明,接种8...以白三叶为材料,在盆栽条件下研究丛枝菌根真菌粘屑多样孢囊霉（Diversispora spurca）、地表球囊霉（Glomus versiforme）和隐类球囊霉（Paraglom us occultum）对其叶绿素含量、根系构型及组织蔗糖和葡萄糖含量的影响.结果表明,接种85 d后白三叶根系菌根侵染率为66.80％～82.51％.3种丛枝菌根真菌都增加地上部、地下部和植株总干物质量,其中地表球囊霉的效果最显著.接种丛枝菌根真菌处理也显著地改善根系构型参数,如长度、投影面积、表面积、体积、根尖数、分支数和交叉数,但因真菌种类而异,其中地表球囊霉的效果最明显.丛枝菌根真菌接种同时显著提高叶绿素含量,达36％～58％,也显著增加叶片和根系的蔗糖和葡萄糖含量,除地表球囊霉侵染的根系蔗糖含量下降外.菌根侵染率与叶片葡萄糖（r=0.852,P＜0.01）、叶片蔗糖（r=0.722,P＜0.01）和根系葡萄糖（r=0.884,P＜0.01）均呈极显著正相关关系.文章讨论了丛枝菌根-糖-根系构型三者的关联.展开更多
基金Supported by National Key Technology R & D Program(2006BAD16B07) Fund of Science and Technology in Guizhou Province ([2008]2074)~~
文摘[Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass （Lolium perenne） - white clover （ Trifolium repens） artificial grassland in Maiping Township, Guizhou Province as the research object, the grassland vegetation of 40 quadrate from different areas （area around the sheep shed, hilltop, hillside, flatland at the foot of the hill） were analyzed by comparing the dominance and richness index. [ Result] Degradation of different degrees appeared in various areas of this artificial grassland. To be specific, the degradation of grassland around the sheep shed was not serious for less consumption by the sheep; however, the areas on the hilltop and hillside degenerated to the grassland types of dallis grass （ Paspalum dilatatum Poir. ） -Indian lovegrass （ Eragrostis pilosa） and dallis grass - cogongrass [ Imperata cylindrica （ Linn. ） Beauv. ], respectively, and the area at the foot of the hill degenerated to the grassland type dominated by garland chrysanthetnum （ Chrysanthemum coronarium L. ） and knotgrass （ Paspalum distichum L. ）. [ Conclusion ] This study provided a basis for grassland improvement as well as the efficient and sustainable utilization of grazing-type artificial grassland in South China.
基金Project supported by the National Natural Science Foundation of China(Nos.40432004 and 20677015)the Postdoctoral Science Foundation of China(No.20070420094)+2 种基金the Postdoctoral Science Foundation of Shanghai Municipality,China(No.08R214116)the Science and Technology Commission of Shanghai Municipality,China(No.0752nm025)theNational High-Tech Research and Development Program(No.2007AA06Z331)
文摘Phytoremediation has been used as an emerging technology for remediation of soil contamination with polycyclic aromatic hydrocarbons(PAHs),ubiquitous persistent environmental pollutants derived from natural and anthropogenic processes,in the last decade.In this study,a pot experiment was conducted to investigate the potential of phytoremediation of pyrene from spiked soils planted with white clover(Trifolium repens)in the greenhouse with a series of pyrene concentrations ranging from 4.22 to 365.38 mg kg-1.The results showed that growth of white clover on pyrenecontaminated soils was not affected.The removal of pyrene from the spiked soils planted with white clover was obviously higher than that from the unplanted soils.At the end of the experiment(60 d),the average removal ratio of pyrene in the spiked soils with white clover was 77%,which was 31%and 57%higher than those of the controls with or without micobes, respectively.Both roots and shoots of white clover took up pyrene from the spiked soils and pyrene uptake increased with the soil pyrene concentration.However,the plant-enhanced dissipation of soil pyrene may be the result of plant-promoted microbial degradation and direct uptake and accumulation of pyrene by white clover were only a small part of the pyrene dissipation.Bioconcentration factors of pyrene(BCFs,ratio of pyrene,on a dry weight basis,in the plant to that in the soil)tended to decrease with increase in the residual soil pyrene concentration.Therefore,removal of pyrene in the contaminated soils was feasible using white clove.
基金Supported by the National Natural Science Foundation of China(31802120)the Natural Science Foundation of Heilongjiang Province of China(LH2021C040)Academic Backbone Fund Project of Northeast Agricultural University。
文摘Although white clover has been widely studied and applied,less is known about its physiological responses to chilling stress in northern China.The effects of acclimation time of chilling stress in the two white clover cultivars,Rivendel and Haifa,after exposure to 4℃for 0,4,8,12,24 and 48 h were investigated.Seven physiological indexes were measured in shoots of the two cultivars.It was found that Rivendel had a strong ability to maintain the stability of cells,cope with oxidative damage and accumulate osmotic adjustment substances compared with Haifa.In addition,a comprehensive evaluation on the chilling tolerance of the two cultivars based on subordinate function value analysis showed a stronger chilling tolerance of Rivendel than Haifa.
文摘Resource sharing in the different parts of the clonal white clover plant (Trifolium repens L.) was investigated in this study. The results showed that the integration of water and nitrogen metabolism occured among parental, young and old branches of a plant when water passed through its stolons. Under the sufficient supply of light, water and nutrients from soil the newly developed branches showed similar capacity in taking in sufficient water and nitrogen to that of old branches. The development of the new branches did not affect the growth of the old and parental branches attached. The results also indicated that energy values in roots was significantly related with plant age, however, the energy values were various in the different parts of a plant.
文摘Agroforestry systems have the potential to provide year-long income opportunities via the integrated forage or crop, timber, and livestock. Legumes are an attractive alternative option during the growing season when more traditional forages may not be as productive. The objective of this study was to test the establishment of arrowleaf and white clover grown under varying pine tree alley widths. In 2011, existing forage was removed in 15-yr old loblolly pine tree row alleys of different widths (3.7, 4.9, 7.3, and 9.8 m), including an open area. Arrowleaf, as an annual, was replanted in 2012. Seedlings were counted twice/year, while dry matter was measured three times/year. Photosynthetically active radiation (PAR) was measured in all alley widths to compare light penetration through the canopy. Hot and dry conditions occurred throughout 2012, affecting results. In 2012 and 2013, the greatest PAR for most treatments was observed in June. Seedling counts for all treatments were greatest immediately after establishment, and gradually declined throughout the course of the study. Dry matter yields increased throughout the growing season, and were greatest in arrowleaf clover in the open area on all measurement dates;however, increased weed pressure and repeated flooding affected yields. This study demonstrated that clover establishment in shady wooded areas is possible, but only under suitable environmental conditions.
基金Supported by Innovation Project of Shandong Academy of Agricultural Sciences(CXGC2016A02-1)China Agriculture Research System-Green Manure(CARS-22)Young Talents Training Program of Shandong Academy of Agricultural Sciences(2018-2020)
文摘In the present study,genetic diversity and genetic relationship of 11materials including red clover ( Trifolium pretense L.),white clover ( T.repen L.) and alsike clover ( T.hybridum L.) and leaf-type variants of white clover were investigated by SRAP (sequence related amplified polymorphism).Forty SRAP primers were screened,and 792 reliable bands were amplified,among which 426 (53.8%) were polymorphic.The number of polymorphic bands per pair of primers ranged from 3 to 38 with an average of 10.6.SRAP cluster analysis showed that the similarity coefficients between white clover materials were from 0.465 to 0.997 with an average of 0.812,indicating that there was certain genetic diversity among white clover.Specific bands appeared in white clover variants,indicating that there were certain differences in DNA sequence between normal while clover plants and their leaf-type variants.The similarity coefficients between red clover materials were from 0.457 to 0.827 with an average of 0.597,indicating that the different red clover germplasms had genetic diversity at the DNA molecular level.The results also showed that the genetic relationship of the alsike clover with the red clover was closer than that with the white clover.This study shows that SRAP technique can be effectively used for the analysis on interspecific and intraspecific relationship,germplasm resource identification and genetic diversity of clover.
