China is a hotspot of relict plant species that were once widespread throughout the Northern Hemi-sphere.Recent research has demonstrated that the occurrence of long-term stable refugia in the mountainous regions of central and south-western China allowed their persistence through the late Neogene climate fluctuations.One of these relict lineages is Dipteronia,an oligotypic tree genus with a fossil record extending to the Paleocene.Here,we investigated the genetic variability,demographic dynamics and diversification patterns of the two currently recognized Dipteronia species(Dipteronia sinensis and D.dyeriana).Molecular data were obtained from 45 populations of Dipteronia by genotyping three cpDNA regions,two single copy nuclear genes and 15 simple sequence repeat loci.The genetic study was combined with niche comparison analyses on the environmental space,ecological niche modeling,and landscape connectivity analysis.We found that the two Dipteronia species have highly diverged both in genetic and ecological terms.Despite the incipient speciation processes that can be observed in D.sinensis,the occurrence of long-term stable refugia and,particularly,a dispersal corridor along Daba Shan-west Qinling,likely ensured its genetic and ecological integrity to date.Our study will not only help us to understand how populations of Dipteronia species responded to the tectonic and climatic changes of the Cenozoic,but also provide insight into how Arcto-Tertiary relict plants in East Asia survived,evolved,and diversified.

随着工农业的迅速发展,土壤重金属和多环芳烃等无机、有机物污染问题日益突出,对作物安全和人体健康造成威胁.相对其他技术,生物修复具有经济成本低和环境友好等优点而颇具潜力.但土壤是无机黏土矿物、有机质及有机-无机胶体等组成的复合体系,对进入其中的污染物质具有较强的吸附作用,因而限制了污染物的生物有效性,不利于生物修复的开展.向污染土壤施加表面活性剂可以改变土壤的表面电荷、吸收位能及污染物的赋存形态或溶解度,对提高生物修复效率具有积极作用,因此,围绕表面活性剂强化生物修复的相关研究成为当前热点.本文综述了土壤中重金属和多环芳烃的污染现状、表面活性剂类型以及不同因素对表面活性剂强化生物修复效果的影响,最后对该技术存在的问题进行了总结和展望,以期为表面活性剂筛选及其强化生物修复污染土壤提供理论基础.

明确设施大棚土壤微量元素累积特点及污染风险是进行设施农业土壤风险管控的重要前提.本研究通过测定山东典型设施土壤中铁(Fe)、锰(Mn)、锌(Zn)、铜(Cu)、镉(Cd)、铅(Pb)、铬(Cr)总量和各形态含量,采用地积累指数法(Igeo)、风险编码法(RAC)和潜在生态危害指数法(PERI)评价土壤微量元素的污染特征,结合正定矩阵因子分解(PMF)模型和健康风险评估模型鉴定微量元素的潜在来源并计算其风险水平.结果表明:研究区域土壤Fe、Mn、Zn、Cu、Cd、Cr全量均呈累积趋势,Cd含量最大值超出土壤污染风险管制值.随种植年限增加,Mn、Zn、Cd和Cr元素有效态含量均呈增加趋势;PMF模型确定研究区域土壤主要受农业源、工业源的影响,贡献率分别为31.49％和24.07％;Igeo、RAC和PERI评价结果显示,土壤Cd、Pb、Cu、Zn全量均有超标,Pb和Zn有效态含量超标,Cd元素单项生态危害指数(Ei)高,综合潜在生态危害指数(RI)均无风险.研究区土壤中微量元素对成人构成非致癌风险和致癌风险的概率分别为36.78％和0.03％,Cr元素是非致癌和致癌风险优先控制元素.

目的:建立高效液相色谱-电感耦合等离子体质谱（HPLC-ICP-MS）法检测尿液中亚砷酸盐、砷酸盐、一甲基砷、二甲基砷、砷胆碱和砷甜菜碱6种砷形态化合物的方法，为职业性砷中毒患者的健康评估提供依据。方法:采用Hamilton PRP-X100阴离子分析柱，以磷酸铵溶液为流动相，梯度洗脱分离，进行HPLC-ICP-MS分析。结果:本方法6种砷形态化合物线性关系良好，相关系数均大于0.999，方法检出限为0.46~0.57 μg/L，方法定量下限为1.52~1.91 μg/L，加标回收率为96.5%~106.4%，批内相对标准偏差为2.9%~6.2%，批间相对标准偏差为3.8%~8.7%。结论:所建立方法灵敏度和准确度高，检测速度快，可用于职业接触人群尿液中砷形态的测定。

电感耦合等离子体质谱（ICP-MS）技术具有灵敏度高、线性范围宽、稳定性好、操作简单等优势，在多元素定量分析、同位素分析、形态分析等领域发挥着重要作用。通过ICP-MS技术可以准确、同步测定人体不同类型样本中的微量元素及有毒元素，这对于临床相关疾病的诊断治疗具有重要意义，其与激光烧蚀、色谱等进样和分离技术的联用使其应用范围更为广泛。

Orchidaceae are one of the largest families of angiosperms in terms of species richness.In the last decade,numerous studies have delved into reconstructing the phylogenetic framework of Orchidaceae,leveraging data from plastid,mitochondrial and nuclear sources.These studies have provided new in-sights into the systematics,diversification and biogeography of Orchidaceae,establishing a robust foundation for future research.Nevertheless,pronounced controversies persist regarding the precise placement of certain lineages within these phylogenetic frameworks.To address these discrepancies and deepen our understanding of the phylogenetic structure of Orchidaceae,we provide a comprehensive overview and analysis of phylogenetic studies focusing on contentious groups within Orchidaceae since 2015,delving into discussions on the underlying reasons for observed topological conflicts.We also provide a novel phylogenetic framework at the subtribal level.Furthermore,we examine the tempo and mode underlying orchid species diversity from the perspective of historical biogeography,highlighting factors contributing to extensive speciation.Ultimately,we delineate avenues for future research aimed at enhancing our understanding of Orchidaceae phylogeny and diversity.

Polyploidy is a major factor in the evolution of plants,yet we know little about the origin and evolution of polyploidy in intertidal species.This study aimed to identify the evolutionary transitions in three true-mangrove species of the genus Acanthus distributed in the Indo-West Pacific region.For this purpose,we took an integrative approach that combined data on morphology,cytology,climatic niche,phylogeny,and biogeography of 493 samples from 42 geographic sites.Our results show that the Acanthus ilicifolius lineage distributed east of the Thai-Malay Peninsula possesses a tetraploid karyotype,which is morphologically distinct from that of the lineage on the west side.The haplotype networks and phylogenetic trees for the chloroplast genome and eight nuclear genes reveal that the tetraploid species has two sub-genomes,one each from A.ilicifolius and A.ebracteatus,the paternal and maternal parents,respectively.Population structure analysis also supports the hybrid speciation history of the new tetraploid species.The two sub-genomes of the tetraploid species diverged from their diploid progenitors during the Pleistocene.Environmental niche models revealed that the tetraploid species not only occupied the near-entire niche space of the diploids,but also expanded into novel environments.Our findings suggest that A.ilicifolius species distributed on the east side of the Thai-Malay Peninsula should be regarded as a new species,A.tetraploideus,which originated from hybridization between A.ilicifolius and A.ebracteatus,followed by chromosome doubling.This is the first report of a true-mangrove allo-polyploid species that can reproduce sexually and clonally reproduction,which explains the long-term adaptive potential of the species.

Heterosis,also known as hybrid vigor,is commonly observed in rice crosses.The hybridization of rice species or subspecies exhibits robust hybrid vigor,however,the direct harnessing of this vigor is hindered by reproductive isolation.Here,we review recent advances in the understanding of the molecular mech-anisms governing reproductive isolation in inter-subspecific and inter-specific hybrids.This review en-compasses the genetic model of reproductive isolation within and among Oryza sativa species,emphasizing the essential role of mitochondria in this process.Additionally,we delve into the molecular intricacies governing the interaction between mitochondria and autophagosomes,elucidating their signif-icant contribution to reproductive isolation.Furthermore,our exploration extends to comprehending the evolutionary dynamics of reproductive isolation and speciation in rice.Building on these advances,we offer a forward-looking perspective on how to overcome the challenges of reproductive isolation and facilitate the utilization of heterosis in future hybrid rice breeding endeavors.

Eremurus was described at the beginning of the 19th century.However,due to limited sampling and the small number of gene markers to date,its phylogeny and evolution are largely unknown.In this study,we analyzed plastomes from 27 species belonging to 2 subgenera and 3 sections of Eremurus,which are found in Central Asia(its center of diversity)and China.We also analyzed nuclear DNA ITS of 33 species,encompassing all subgenera and sections of the genus in Central Asia,southwest Asia and China.Our findings revealed that the genus was monophyletic,although both subgenera Eremurus and Henningia were found to be paraphyletic.Both plastome and nrDNA-based phylogenetic trees had three clades that did not reflect the current taxonomy of the genus.Our biogeographical and time-calibrated trees suggest that Eremurus originated in the ancient Tethyan area in the second half of the Eocene.Diversification of Eremurus occurred from the early Oligocene to the late Miocene.Paratethys Sea retreat and several orogenetic events,such as the progressive uplift of the Qinghai-Tibet Plateau and surrounding mountain belts(Altai,Pamir,Tian Shan),caused serious topographic and climate(aridification)changes in Central Asia that may have triggered a split of clades and speciation.In this transformed Central Asia,speciation proceeded rapidly driven mainly by vicariance caused by numerous mountain chains and specialization to a variety of climatic,topographic and soil conditions that exist in this region.

生存与繁殖对生物体维持和延续种群数量稳定至关重要.表皮碳氢化合物具有维持昆虫水分平衡和信息通讯的双重功能,目前对于昆虫在不同气候条件下如何权衡防脱水与保持化学信号可靠性的潜在冲突尚不清楚.本文以寄生于鸡嗉子榕(Ficus semicordata)雄花期果内的传粉榕小蜂窝榕小蜂(Ceratosolen gravelyi)为研究对象,利用气相色谱-质谱联用仪(GC-MS)解析雨季、雾凉季和干热季中雌、雄成虫表皮碳氢化合物的种类及含量,运用非度量多维尺度排序、相似性分析、置换多元方差分析和随机森林等方法分析了窝榕小蜂表皮碳氢化合物对不同季节变化的响应机制.结果表明:(1)窝榕小蜂表皮碳氢化合物由34种C7-C44的化合物组成,包括正链烷烃、甲基烷烃、烯烃和甲基烯烃;其中角鲨烯(squalene)、2-甲基二十八烷(2-Me-C28)、正三十四烷(n-C34)、正三十六烷(n-C36)和正四十四烷(n-C44)为主要成分(＞5％).(2)不同性别窝榕小蜂表皮碳氢化合物的组成及含量存在显著差异,正四十二烷(n-C42)、17-三十五烯(17-C35∶1)、1-二十九烯(C29∶1)、2-Me-C28和角鲨烯是造成两性差异的重要贡献量化合物.(3)雌、雄成虫表皮碳氢化合物均具有明显的季节变化:在干热季中,雌蜂正链烷烃(n-C34、n-C36和n-C44)的比例及碳氢化合物的总绝对含量增加,2-Me-C28和角鲨烯的比例降低;雄蜂甲基烯烃的比例增加,正链烷烃和甲基烷烃的比例降低,碳氢化合物总绝对含量无明显变化.本研究发现窝榕小蜂表皮碳氢化合物具有明显的性二型和强烈的季节可塑性,2-Me-C28和角鲨烯可作为雄蜂配偶识别时的候选性信息素;雌、雄成虫在适应高温和/或干燥的气候条件时存在差异化响应,表明窝榕小蜂两性表皮碳氢化合物在不同季节变化中采取不同的适应性策略.本研究揭示了榕小蜂应对不同气候环境的化学适应机制,为研究昆虫双重性状和理解生态适应与物种形成之间的功能联系奠定了化学基础.