澜沧梨藤竹(Melocalamus arrectus)是滇西南及滇南地区常见竹种之一,具有重要的生态价值。本研究采用简化基因组测序(double digest RAD sequencing,ddRAD-seq)技术对澜沧梨藤竹的3个种群27个个体进行了遗传多样性研究。通过质量控制分...澜沧梨藤竹(Melocalamus arrectus)是滇西南及滇南地区常见竹种之一,具有重要的生态价值。本研究采用简化基因组测序(double digest RAD sequencing,ddRAD-seq)技术对澜沧梨藤竹的3个种群27个个体进行了遗传多样性研究。通过质量控制分析和过滤,共获得6136569个SNP,杂合率均值为29.53%,纯合率均值为70.47%,转换与颠换比值(Ts/Tv)平均值为2.45,说明SNP变异以转换为主。遗传多样性分析显示3个种群有较低的遗传多样性(π=0.174,He=0.162,Ho=0.160,F_(IS)=0.045,PIC=0.394,等位基因频率均值为0.885)。两两种群间分化指数均值为0.0347,基因流(N_(m))均值为6.95,表明种群间的遗传分化很小,基因流动广泛;3个种群遗传距离均值为0.0161,反映澜沧梨藤竹种群间遗传差异小,亲缘关系较近。系统发育分析将澜沧梨藤竹分为3个支系,主成分判别分析(DAPC)将澜沧梨藤竹分为2个支系,个体间遗传多样性差异较小;群体结构分析显示澜沧梨藤竹被分为2组,2组个体间存在不同程度的基因交流。本研究为澜沧梨藤竹遗传多样性提供数据支撑,有助于发现近亲繁殖、遗传多样性丧失的迹象,对其遗传资源保护、管理和遗传改良提供参考。展开更多
Mangosteen peel （Garcinia mangostana L.） is well known as an excellent source of antioxidative compounds. The objective of this study was to determine the most suitable processing condition for ethanolic extraction ...Mangosteen peel （Garcinia mangostana L.） is well known as an excellent source of antioxidative compounds. The objective of this study was to determine the most suitable processing condition for ethanolic extraction of mangosteen peel. The experimental factors included raw material prepared as fresh and dried forms, material-to-solvent ratio varying at 1：3, 1：4, 1：5, 1：6, 1：9 and 1：12, and contacting time at 1, 3, 6, 9, 12 and 16 hours. Antioxidative capacity of all extracts were evaluated and compared according to DPPH radical scarvenging assay, trolox equivalent antioxidant capacity （TEAC assay） and total phenolic compounds. It was found that the extract from dried mangosteen peel had significantly stronger antioxidative capacity than that from fresh mangosteen peel （P 〈 0.05）. The suitable ethanolic extraction was found at the material-to-solvent ratio of 1：6 and 12 hours of contacting time. Mangosteen peel extracts prepared from fresh peel, dried peel, boiled and dried peel were also tested for oxidative rancidity reduction in lard at accelerated temperature of 60 ~C. The antioxidative rancidity was measured by acid value, totox value and thiobarbituric acid test. Commercial rosemary extract and BHT were compared at the equivalent concentration of 1,000 mg/kg. The results showed that the extract from dried mangosteen peel provided antioxidative capacity slightly stronger than fresh mangosteen peel extract, similar to rosemary extract but still poorer than BHT.展开更多
Mikania micrantha(Asteraceae)is an invasive vine found in tropical and southern subtropical Asian and the Pacifc Islands.The current methods used to control this vine are inadequate,which warrants the development of e...Mikania micrantha(Asteraceae)is an invasive vine found in tropical and southern subtropical Asian and the Pacifc Islands.The current methods used to control this vine are inadequate,which warrants the development of ecologically sustainable methods.Therefore,we investigated the ability of four grass species to prevent the invasion of M.micrantha,with an ultimate goal of developing ecologically sustainable control methods for widespread application.The clumps of native grass species from China(Panicum incomtum,Pennisetum purpureum,Saccharum arundinaceum and Microstegium vagans)were established.We sowed M.micrantha seeds and transplanted the seedlings into the grass clumps to examine whether the clumps could eliminate the new M.micrantha plants.In addition,we transplanted M.micrantha into existing grass clumps to examine whether the grass clumps could prevent the re-invasion of M.micrantha.Furthermore,we grew M.micrantha with P.incomtum and P.purpureum in the feld to examine whether the grasses could outcompete M.micrantha.Mikania micrantha seeds germinated hardly in the grass clumps,and all seedlings died within 3 months.It was diffcult for the vine to survive in the grass clumps.Our feld experiments showed that the coverage of M.micrantha was signifcantly lower than that of the grass species in the frst year,and that the vine was outcompeted after 2 years.To the best of our knowledge,this study is the frst to reveal that tall grasses,particularly P.incomtum and P.purpureum,have potential to serve as bio-control agents for M.micrantha.展开更多
文摘澜沧梨藤竹(Melocalamus arrectus)是滇西南及滇南地区常见竹种之一,具有重要的生态价值。本研究采用简化基因组测序(double digest RAD sequencing,ddRAD-seq)技术对澜沧梨藤竹的3个种群27个个体进行了遗传多样性研究。通过质量控制分析和过滤,共获得6136569个SNP,杂合率均值为29.53%,纯合率均值为70.47%,转换与颠换比值(Ts/Tv)平均值为2.45,说明SNP变异以转换为主。遗传多样性分析显示3个种群有较低的遗传多样性(π=0.174,He=0.162,Ho=0.160,F_(IS)=0.045,PIC=0.394,等位基因频率均值为0.885)。两两种群间分化指数均值为0.0347,基因流(N_(m))均值为6.95,表明种群间的遗传分化很小,基因流动广泛;3个种群遗传距离均值为0.0161,反映澜沧梨藤竹种群间遗传差异小,亲缘关系较近。系统发育分析将澜沧梨藤竹分为3个支系,主成分判别分析(DAPC)将澜沧梨藤竹分为2个支系,个体间遗传多样性差异较小;群体结构分析显示澜沧梨藤竹被分为2组,2组个体间存在不同程度的基因交流。本研究为澜沧梨藤竹遗传多样性提供数据支撑,有助于发现近亲繁殖、遗传多样性丧失的迹象,对其遗传资源保护、管理和遗传改良提供参考。
文摘Mangosteen peel （Garcinia mangostana L.） is well known as an excellent source of antioxidative compounds. The objective of this study was to determine the most suitable processing condition for ethanolic extraction of mangosteen peel. The experimental factors included raw material prepared as fresh and dried forms, material-to-solvent ratio varying at 1：3, 1：4, 1：5, 1：6, 1：9 and 1：12, and contacting time at 1, 3, 6, 9, 12 and 16 hours. Antioxidative capacity of all extracts were evaluated and compared according to DPPH radical scarvenging assay, trolox equivalent antioxidant capacity （TEAC assay） and total phenolic compounds. It was found that the extract from dried mangosteen peel had significantly stronger antioxidative capacity than that from fresh mangosteen peel （P 〈 0.05）. The suitable ethanolic extraction was found at the material-to-solvent ratio of 1：6 and 12 hours of contacting time. Mangosteen peel extracts prepared from fresh peel, dried peel, boiled and dried peel were also tested for oxidative rancidity reduction in lard at accelerated temperature of 60 ~C. The antioxidative rancidity was measured by acid value, totox value and thiobarbituric acid test. Commercial rosemary extract and BHT were compared at the equivalent concentration of 1,000 mg/kg. The results showed that the extract from dried mangosteen peel provided antioxidative capacity slightly stronger than fresh mangosteen peel extract, similar to rosemary extract but still poorer than BHT.
基金funded by the National Natural Science Foundation of China(Project 30570330 and 30370243)Hongda Zhang Scientifc Research Fund,Sun Yat-Sen University,and Shenzhen Greening Committee:Non-Environmental Disruptive Control of Mikania micrantha(2010-13)Ecological Forestry Special Fund,Forestry Administration of Guangdong Province(KH2101501).
文摘Mikania micrantha(Asteraceae)is an invasive vine found in tropical and southern subtropical Asian and the Pacifc Islands.The current methods used to control this vine are inadequate,which warrants the development of ecologically sustainable methods.Therefore,we investigated the ability of four grass species to prevent the invasion of M.micrantha,with an ultimate goal of developing ecologically sustainable control methods for widespread application.The clumps of native grass species from China(Panicum incomtum,Pennisetum purpureum,Saccharum arundinaceum and Microstegium vagans)were established.We sowed M.micrantha seeds and transplanted the seedlings into the grass clumps to examine whether the clumps could eliminate the new M.micrantha plants.In addition,we transplanted M.micrantha into existing grass clumps to examine whether the grass clumps could prevent the re-invasion of M.micrantha.Furthermore,we grew M.micrantha with P.incomtum and P.purpureum in the feld to examine whether the grasses could outcompete M.micrantha.Mikania micrantha seeds germinated hardly in the grass clumps,and all seedlings died within 3 months.It was diffcult for the vine to survive in the grass clumps.Our feld experiments showed that the coverage of M.micrantha was signifcantly lower than that of the grass species in the frst year,and that the vine was outcompeted after 2 years.To the best of our knowledge,this study is the frst to reveal that tall grasses,particularly P.incomtum and P.purpureum,have potential to serve as bio-control agents for M.micrantha.
