重金属污染已成为影响作物品质的重要因素之一。通过土壤镉（Cd）胁迫下施加0.75、1.50、3.00 g/kg三种浓度硫酸钾，研究硫酸钾对岗梅根际土壤理化性质和岗梅植株中镉积累的影响。结果表明，施用高浓度硫酸钾肥会使土壤pH下降，降低幅度最高达8.09%。镉胁迫会使土壤有机质含量降低，施用中（1.50 g/kg）、高（3.00 g/kg）浓度硫酸钾肥可以提高土壤有机质含量、全钾含量和速效钾含量。施用硫酸钾普遍提高了土壤中生物有效态镉含量，只有施用低浓度硫酸钾（0.75 g/kg）第30天，土壤中的生物有效态镉含量相比Cd处理组降低1.94%。在镉胁迫下，施加硫酸钾可以提高岗梅叶的SOD活性，进而提升对镉胁迫的耐受性。低浓度硫酸钾（0.75 g/kg）可以抑制岗梅植株内的镉从根和茎向叶片转运，且可以有效地减少镉在岗梅根和茎中的积累。因此，施用高浓度钾肥会使土壤pH下降；施用中（1.50 g/kg）、高（3.00 g/kg）浓度硫酸钾肥可以提高土壤有机质含量、全钾含量和速效钾含量，从而提高土壤肥力；低浓度硫酸钾可以降低土壤中生物有效态镉含量，可以较好抑制岗梅植株内的镉从根、茎向叶片转运，且可以较好地减少镉在岗梅根和茎中的积累。

为提高中药材岗梅的种子质量,开展岗梅种子不同清选方法的对比试验。对岗梅种子进行水选、色选及风选试验,而后测定种子千粒重、净度和生活力,对比3种清选方法的优劣。结果表明,风选的岗梅种子不仅能实现清选目的,同时还能达到分级效果,进一步提高岗梅种子质量。岗梅主要通过种子直播育苗繁殖,播种前对岗梅种子进行风选处理,能够得到质量较优的岗梅种子,提高种子萌发率。

目的 应用ITS2序列对93份岗梅药材及其近缘物种进行鉴定研究。方法 对药材、基原植物样本进行基因组DNA提取,PCR扩增ITS2序列,用MEGA5.0进行序列分析,采用相似性搜索法、最近距离法、构建NJ树对序列鉴定能力进行评估。结果 岗梅药材ITS2序列长度为241 bp,平均GC含量为63.4%,种内K2P遗传距离为0～0.030,岗梅药材及其近缘种的种间最小K2P距离为0.043。岗梅药材和基原物种在NJ树单独聚为一支,能有效地与其他物种分开,相似性搜索法结果表明ITS2序列能够准确鉴定岗梅药材及其近缘种。结论 ITS2序列能够准确鉴定岗梅药材及其近缘物种,可为保障岗梅药材临床用药安全提供新的技术手段。

Ilex (Aquifoliaceae) are of great horticultural importance throughout the world for their foliage and decorative berries, yet a dearth of genetic information has hampered our understanding of phylogenetic relationships and evolutionary history. Here, we compare chloroplast genomes from across Ilex and estimate phylogenetic relationships.

Ferns have generally been neglected in studies of chloroplast genomics. Before this study, only one polypod and two basal ferns had their complete chloroplast (cp) genome reported. Tree ferns represent an ancient fern lineage that first occurred in the Late Triassic. In recent phylogenetic analyses, tree ferns were shown to be the sister group of polypods, the most diverse group of living ferns. Availability of cp genome sequence from a tree fern will facilitate interpretation of the evolutionary changes of fern cp genomes. Here we have sequenced the complete cp genome of a scaly tree fern Alsophila spinulosa (Cyatheaceae).

Rutaceae family comprises economically important plants due to their extensive applications in spices, food, oil, medicine, etc. The Rutaceae plants is able to better utilization through biotechnology. Modern biotechnological approaches primarily rely on the heterologous expression of functional proteins in different vectors. However, several proteins are difficult to express outside their native environment. The expression potential of functional genes in heterologous systems can be maximized by replacing the rare synonymous codons in the vector with preferred optimal codons of functional genes. Codon usage bias plays a critical role in biogenetic engineering-based research and development. In the current study, 727 coding sequences (CDSs) obtained from the chloroplast genomes of ten Rutaceae plant family members were analyzed for codon usage bias. The nucleotide composition analysis of codons showed that these codons were rich in A/T(U) bases and preferred A/T(U) endings. Analyses of neutrality plots, effective number of codons (ENC) plots, and correlations between ENC and codon adaptation index (CAI) were conducted, which revealed that natural selection is a major driving force for the Rutaceae plant family's codon usage bias, followed by base mutation. In the ENC vs. CAI plot, codon usage bias in the Rutaceae family had a negligible relationship with gene expression level. For each sample, we screened 12 codons as preferred and high-frequency codons simultaneously, of which GCU encoding Ala, UUA encoding Leu, and AGA encoding Arg were the most preferred codons. Taken together, our study unraveled the synonymous codon usage pattern in the Rutaceae family, providing valuable information for the genetic engineering of Rutaceae plant species in the future.© 2024. The Author(s).

Theaceae species are dicotyledonous angiosperms with extremely high ornamental and economic value. The chloroplast genome is traditionally used to study species evolution, expression of chloroplast genes and chloroplast transformation. Codon usage bias (CUB) analysis is beneficial for investigations of evolutionary relationships and can be used to improve gene expression efficiency in genetic transformation research. However, there are relatively few systematic studies of the CUB in the chloroplast genomes of Theaceae species. In this study, CUB and nucleotide compositions parameters were determined by the scripts written in the Perl language, CodonW 1.4.2, CU.Win2000, RStudio and SPSS 23.0. The chloroplast genome data of 40 Theaceae species were obtained to analyse the codon usage (CU) characteristics of the coding regions and the influence of the source of variation on CUB. To explore the relationship between the CUB and gene expression levels in these 40 Theaceae plastomes, the synonymous codon usage order (SCUO) and measure independent of length and composition (MILC) values were determined. Finally, phylogenetic analysis revealed the genetic evolutionary relationships among these Theaceae species. Our results showed that based on the chloroplast genomes of these 40 Theaceae species, the CUB was for codons containing A/T bases and those that ended with A/T bases. Moreover, there was great commonality in the CUB of the Theaceae species according to comparative analysis of relative synonymous codon usage (RSCU) and relative frequency of synonymous codon (RFSC): these species had 29 identical codons with bias (RSCU > 1), and there were 19 identical high-frequency codons. The CUB of Theaceae species is mainly affected by natural selection. The SCUO value of the 40 Theaceae species was 0.23 or 0.24, and the chloroplast gene expression level was moderate, according to MILC values. Additionally, we observed a positive correlation between the SCUO and MILC values, which indicated that CUB might affect gene expression. Furthermore, the phylogenetic analysis showed that the evolutionary relationships in these 40 Theaceae species were relatively conserved. A systematic study on the CUB and expression of Theaceae species provides further evidence for their evolution and phylogeny.