在植物生活史中,种子扩散和种子休眠是物种为提高种子萌发率而进化出的生存策略,在时间和空间上规避从种子萌发到幼苗建成所遇到的风险,种子扩散与休眠之间的关系对于理解物种响应不同环境胁迫的进化选择具有重要理论意义。本研究从Web ...在植物生活史中,种子扩散和种子休眠是物种为提高种子萌发率而进化出的生存策略,在时间和空间上规避从种子萌发到幼苗建成所遇到的风险,种子扩散与休眠之间的关系对于理解物种响应不同环境胁迫的进化选择具有重要理论意义。本研究从Web of Science核心合集中检索到1017篇1999—2022年期间发表的关于种子扩散与休眠等生活史策略的文献,运用文献计量学工具CiteSpace 6.2.R1和R软件的“bib-liometrix”程序包提取样本文献数据,利用可视化手段展示了该领域年度发文量、发文国家、发文作者、关键词趋势等信息。根据对样本文献的统计分析发现:1)种子扩散与种子休眠之间显著负相关,显著性程度随环境和组织层次的变化表现出差异;2)某些荒漠植物为适应极端环境,进化出两种或两种以上形态的种子,不同形态的种子分别对应不同的扩散能力和休眠水平的组合,以提高种子扩散后的成活率,扩大种群范围;3)休眠使种子在扩散过程中保持活性,所以最佳扩散距离与休眠水平的权衡是物种繁殖策略领域探究的重要问题之一;4)种子的休眠和扩散特性及其他生活史策略具有协同进化特征,种子扩散与休眠之间的关系还受到环境温度、降雨量、种子数量和大小等因子的影响。种子休眠和扩散策略的进化目标均在于帮助物种应对生存环境的不可预测性,提高适合度,保持物种的更新繁衍能力。理解植物种子休眠与扩散的关系有赖于对植物生活史对策的联合探究。展开更多
Seeds of Fenugreek （Trigonellafoenum-graecum L.）, an international spice commodity, are much consumed in Sudan as a food, for flavoring and as a folk-remedy for several ailments, together with local beliefs in nutra...Seeds of Fenugreek （Trigonellafoenum-graecum L.）, an international spice commodity, are much consumed in Sudan as a food, for flavoring and as a folk-remedy for several ailments, together with local beliefs in nutraceutical benefits. The authors have noted an immense variability in colour and other morphological characters of Fenugreek seeds offered in local Sudanese markets and wondered whether this variability is extended to their chemical composition. Steroidal sapogenins are important chemical constituents of Fenugreek seeds in view of their potential as precursors for the commercial synthesis of steroid drugs and their continually revealed beneficial biological activities. In this study, thirty Sudanese Fenugreek seed accessions collected from different geographical regions in Sudan were analyzed for their 25α-, 25β- and total sapogenin content using a simple and specific infra-red spectroscopic method. The seed accessions exhibited much morphological variability particularly in outer seed coat color and size. Preparative TLC followed by gravimetric analysis showed that steroidal sapogenins, mostly diosgenin and yamogenin, represented more than 70% of the steroids of Fenugreek seeds. Infra-red spectroscopic analysis showed that total 25α-sapogenins （calculated as diosgenin） varied from 0.65% to 1.68%. Total 25β-sapogenin （calculated as yamogenin） varied from 0.38% to 2.03%. The content of total sapogenins （α ＋ β epimeric forms） varied between 1.24% and 3.0% of the oven-dry weight of seeds. β-sapogenins （mostly yamogenin） were dominant over α-sapogenins （diosgenin） in most Sudanese Fenugreek seed accessions.展开更多
文摘在植物生活史中,种子扩散和种子休眠是物种为提高种子萌发率而进化出的生存策略,在时间和空间上规避从种子萌发到幼苗建成所遇到的风险,种子扩散与休眠之间的关系对于理解物种响应不同环境胁迫的进化选择具有重要理论意义。本研究从Web of Science核心合集中检索到1017篇1999—2022年期间发表的关于种子扩散与休眠等生活史策略的文献,运用文献计量学工具CiteSpace 6.2.R1和R软件的“bib-liometrix”程序包提取样本文献数据,利用可视化手段展示了该领域年度发文量、发文国家、发文作者、关键词趋势等信息。根据对样本文献的统计分析发现:1)种子扩散与种子休眠之间显著负相关,显著性程度随环境和组织层次的变化表现出差异;2)某些荒漠植物为适应极端环境,进化出两种或两种以上形态的种子,不同形态的种子分别对应不同的扩散能力和休眠水平的组合,以提高种子扩散后的成活率,扩大种群范围;3)休眠使种子在扩散过程中保持活性,所以最佳扩散距离与休眠水平的权衡是物种繁殖策略领域探究的重要问题之一;4)种子的休眠和扩散特性及其他生活史策略具有协同进化特征,种子扩散与休眠之间的关系还受到环境温度、降雨量、种子数量和大小等因子的影响。种子休眠和扩散策略的进化目标均在于帮助物种应对生存环境的不可预测性,提高适合度,保持物种的更新繁衍能力。理解植物种子休眠与扩散的关系有赖于对植物生活史对策的联合探究。
文摘Seeds of Fenugreek （Trigonellafoenum-graecum L.）, an international spice commodity, are much consumed in Sudan as a food, for flavoring and as a folk-remedy for several ailments, together with local beliefs in nutraceutical benefits. The authors have noted an immense variability in colour and other morphological characters of Fenugreek seeds offered in local Sudanese markets and wondered whether this variability is extended to their chemical composition. Steroidal sapogenins are important chemical constituents of Fenugreek seeds in view of their potential as precursors for the commercial synthesis of steroid drugs and their continually revealed beneficial biological activities. In this study, thirty Sudanese Fenugreek seed accessions collected from different geographical regions in Sudan were analyzed for their 25α-, 25β- and total sapogenin content using a simple and specific infra-red spectroscopic method. The seed accessions exhibited much morphological variability particularly in outer seed coat color and size. Preparative TLC followed by gravimetric analysis showed that steroidal sapogenins, mostly diosgenin and yamogenin, represented more than 70% of the steroids of Fenugreek seeds. Infra-red spectroscopic analysis showed that total 25α-sapogenins （calculated as diosgenin） varied from 0.65% to 1.68%. Total 25β-sapogenin （calculated as yamogenin） varied from 0.38% to 2.03%. The content of total sapogenins （α ＋ β epimeric forms） varied between 1.24% and 3.0% of the oven-dry weight of seeds. β-sapogenins （mostly yamogenin） were dominant over α-sapogenins （diosgenin） in most Sudanese Fenugreek seed accessions.
