Background: Limited access to genetic information has greatly hindered our understanding of the molecular evolution, phylogeny, and differentiation time of subg.Amygdalus. This study reported complete chloroplast (cp) genome sequences of subg.Amygdalus, which further enriched the available valuable resources of complete cp genomes of higher plants and deepened our understanding of the divergence time and phylogenetic relationships of subg.Amygdalus.Results: The results showed that subg.Amygdalusspecies exhibited a tetrad structure with sizes ranging from 157,736 bp (P. kansuensis) to 158,971 bp (P. davidiana), a pair of inverted repeat regions (IRa/IRb) that ranged from 26,137–26,467 bp, a large single-copy region that ranged from 85,757–86,608 bp, and a small single-copy region that ranged from 19,020–19,133 bp. The average GC content of the complete cp genomes in the 12 species was 36.80%. We found that the structure of the subg.Amygdaluscomplete cp genomes was highly conserved, and the 12 subg.Amygdalusspecies had anrps19 pseudogene. There was not rearrangement of the complete cp genome in the 12 subg.Amygdalusspecies. All 12 subg.Amygdalusspecies clustered into one clade based on both Bayesian inference and maximum likelihood. The divergence time analyses based on the complete cp genome sequences showed that subg.Amygdalusspecies diverged approximately 15.65 Mya.Conclusion: Our results provide data on the genomic structure of subg.Amygdalusand elucidates their phylogenetic relationships and divergence time.

The genus of Nitraria L. are Tertiary-relict desert sand-fixing plants, which are an important forage and agricultural product, as well as an important source of medicinal and woody vegetable oil. In order to provide a theoretical basis for better protection and utilization of species in the Nitraria L., this study collected global distribution information within the Nitraria L., along with data on 29 environmental and climatic factors. The Maximum Entropy (MaxEnt) model was used to simulate the globally suitable distribution areas for Nitraria L. The results showed that the mean AUC value was 0.897, the TSS average value was 0.913, and the model prediction results were excellent. UV-B seasonality (UVB-2), UV-B of the lowest month (UVB-4), precipitation of the warmest quarter (bio18), the DEM (Digital Elevation Model), and annual precipitation (bio12) were the key variables affecting the distribution area of Nitraria L, with contributions of 54.4%, 11.1%, 8.3%, 7.4%, and 4.1%, respectively. The Nitraria L. plants are currently found mainly in Central Asia, North Africa, the neighboring Middle East, and parts of southern Australia and Siberia. In future scenarios, except for a small expansion of the 2030s scenario model Nitraria L., the potential suitable distribution areas showed a decreasing trend. The contraction area is mainly concentrated in South Asia, such as Afghanistan and Pakistan, North Africa, Libya, as well as in areas of low suitability in northern Australia, where there was also significant shrinkage. The areas of expansion are mainly concentrated in the Qinghai–Tibet Plateau to the Iranian plateau, and the Sahara Desert is also partly expanded. With rising Greenhouse gas concentrations, habitat fragmentation is becoming more severe. Center-of-mass migration results also suggest that the potential suitable area of Nitraria L. will shift northwestward in the future. This study can provide a theoretical basis for determining the scope of Nitraria L. habitat protection, population restoration, resource management and industrial development in local areas.

Atractylodes chinensis has a high medicinal value and is widely cultivated. However, root rot disease seriously affects the yield and quality of A. chinensis. To develop green and safe pesticides, the inhibitory effect of essential oils (EOs) of three Labiatae plants on the pathogenic fungi that causes root rot disease in Atractylodes chinensis was investigated. The results showed that the Origanum vulgare EO and Thymus mongolicus EO exhibited strong inhibitory effects on Fusarium oxysporum, Fusarium solani, and Fusarium redolens, with 100% inhibition rate. The low MIC values of EOs and their main components against the three pathogenic fungi indicated that all of them showed strong fungicidal effects. The MIC values of O. vulgare EO against F. oxysporum, F. solani, and F. redolens were 2.60 mg/mL, 3.13 mg/mL, and 1.56 mg/mL, respectively. Analyses using scanning electron microscopy (SEM) and transmission electron microscopy (TEM) showed that the O. vulgare EO severely damaged the cell wall and cell membrane of mycelial cells. The O. vulgare EO increased cell permeability, leading to a large leakage of cell contents (DNA and proteins). In addition, O. vulgare EO inhibited F. oxysporum by inducing ROS production and reducing the amount of intracellular GSH, leading to a large accumulation of ROS. This study showed that plant EOs have excellent fungicidal activity and can be used as novel natural and environmentally friendly pesticides for the control of root rot in A. chinensis.

Tribulus terrestris is an important traditional medicine in China, which is widely distributed in north China. Here, the chloroplast genome sequences were detected. The chloroplast genome of T. terrestris is circular-mapping molecule of 158,184 bp in size, which consisted of a pair of inverted repeat regions of 25,842 bp each, a large single copy region of 88,878 bp, and a small single copy region of 17,622 bp. A total of 129 genes were annotated, including 37 tRNA, 8 rRNA, and 84 protein-coding genes. Phylogenetic analysis showed T. terrestris clustered with Krameria lanceolate and Krameria bicolor.