This study aimed to establish the minimum area required for surveys of species diversity in forest communities in Langqi Island, Fuzhou, to improve research accuracy and reduce survey costs. Nest sampling of 20 m × 20 m quadrats was employed to investigate species-area curves of forest communities on the island. Three models (logarithmic function, power function, and logistic function) were selected to fit three types of forest communities, namely Acacia confusa Merr., Eucalyptus citriodora Hook. f., and Celtis sinensis Pers., as well as the species-area relationships of the shrub and herb layers. The optimal fitting model was selected using the Akaike Information Criterion (AIC) to calculate the minimum sampling area for the three species in the three communities. Results showed that: (1) Power function fit models were the best fitting models for the species-area relationships of the three target species in the three forest communities. (2) The minimum sampling areas for the A. confusa community, shrub layer, and herb layer were 113.5, 68.9, and 24.4 m², respectively, when sampling precision was set to 50%–90%. The minimum sampling areas for the E. citriodora community, shrub layer, and herb layer were 153.1, 69.6, and 41.4 m², respectively. The minimum sampling areas for the C. sinensis community, shrub layer, and herb layer were 65.5, 38.0, and 15.2 m², respectively. (3) The minimum sampling areas for the forest community, shrub layer, and herb layer in Langqi Island were 10 m × 15 m, 10 m × 10 m, and 6 m × 6 m, respectively. (4) A positive correlation was found between the minimum sampling area and number of species in the community, which was also influenced by community differences, sampling area, human disturbance, occasional species, and other factors.

Taking the Castanopsis carlesii community in Wuyi Mountain as the research object, the dominant C. carlesii community species in the arbor layer were analyzed using niche determination and interspecific association methods. Results showed that C. carlesii, Dendropanax dentiger (Harms.) Merr., Rhododendron henryi Hance., and Engelhardtia fenzlii Merr. had higher niche breadths than other species. Niche similarity and niche overlap among populations were 0.36 and 0.42, respectively. Low niche overlap between dominant populations accounted for 71% of all species pairs, while high niche overlap only accounted for 9.67%, indicating that competition for common resources was not strong. The overall interspecific association in the tree layer was not significantly positive among dominant species. Pearson and Spearman rank correlation tests showed that the significantly correlated populations accounted for a relatively low proportion, with the majority found to be not significant. Negatively associated species pairs were greater than positively associated pairs. Based on principal component analysis ordination and interspecific association results, 25 dominant species were divided into four ecological species groups. In general, the C. carlesii community was in a relatively stable stage, and most species pairs showed no significant correlation or no correlation, with relatively strong independence.

To explore the dominant factors determining thermal insulation in Androsace tapete Maxim., as well as its adaptability to survive extreme temperature changes, the internal temperatures of living and dead individuals were measured. The diurnal changes in surface and internal temperatures of A. tapete and nearby air and soil temperatures were also recorded in summer, winter, and under simulated hail conditions. The temperature data revealed no significant differences between the internal temperatures of living and dead individuals of A. tapete. For diurnal temperature changes, the variation amplitude of the surface temperature of A. tapete was much larger than that of the air, while the variation amplitude of the internal temperature was similar to that of the soil, which was much lower than that of the air. Although the surface temperature dropped to 0℃ after the low-temperature simulated hail treatment, the internal temperature was maintained above 10℃. These results showed that the heat preservation effect of A. tapete was mainly due to its structural characteristics and was less affected by altitude differences, metabolic activities, and cold acclimation. Its heat preservation capacity was slightly weaker than the 5-cm soil layer, which may significantly buffer the high plateau from severe diurnal temperature differences and reduce the stress of extreme environmental temperatures. This study compared diurnal variation in the internal temperature of A. tapete in summer and winter, as well as the internal temperature of surviving and dead individuals, which should inform research on the structural characteristics of cushion plants adapted to extreme environments.

In this study, four dominant sand-binding shrub populations in the semi-fixed dunes of the Gurbantünggüt Desert were used as research objects at the stand-scale. Isotropic and anisotropic spatial variation characteristics of plant height and crown width (east-west and north-south) were analyzed using variation function. Results showed that: (1) The plant height and crown width size of the four sand-fixing shrub populations followed the order Haloxylon persicum Bunge ex Boiss. et Buhse > Calligonum leucocladum (Schrenk) Bge. > Artemisia ordosica Krasch. > Ephedra distachya L.. Significant differences in plant height and crown width were observed among the four populations, except for between E. distachya and A. ordosica. (2) The variation function values of plant height and crown width of the four populations exhibited the same trend with increasing spacing distance, with a certain fluctuation within the local range. (3) Plant height and crown width of most populations showed strong spatial autocorrelation patterns. Spatial variation in crown width of the C. leucocladum population and plant height of the E. distachya population were co-determined by random and structural factors. The spatial variation patterns of plant height and crown width of the other populations were mainly due to structural factors. (4) The spatial patterns of plant height and crown width of the four populations were relatively simple, with spatial heterogeneity shown in different directions.

In this study, we sequenced the chloroplast genome of Quercus austroglauca Y. T. Chang and analyzed the structural characteristics of the chloroplast genome and factors influencing codon preference using various software. Results showed that the chloroplast genome of Q. austroglauca was 160 913 bp in length, encoding 133 genes. Analysis of 52 screened protein-coding sequences revealed an average GC content of the third base of 29.14%, signifying a pronounced preference for A or U as the terminal codon. These results were confirmed by relative synonymous codon usage analysis. Number of effective codons (ENC) was greater than 35, indicating weak codon preference. Neutral mapping, ENC-plot, and PR2-plot analyses showed that natural selection was the dominant factor affecting codon preference in the Q. austroglauca chloroplast genome. In total, 13 optimal codons were identified by screening. Multiple analysis showed that variation mostly occurred in the non-coding regions, although the ycf1 gene exhibited a large degree of variation in the coding region. Inverted repeat (IR) boundary analysis identified a ycf1 pseudogene in Q. austroglauca Phylogenetic analysis showed that Q. austroglauca was closely related to Q. hypargyrea (Seemen) C. C. Huang et Y. T. Chang.

The conserved rps2 gene cluster (rps2-atpI-atpH-atpF-atpA) is broken in the chloroplast genome of Campanulaceae. To explore whether the evolutionary rates of the related genes changed after the cluster was broken, we selected the chloroplast genome sequences of 50 Campanulaceae and two Menyanthaceae species to construct their phylogenetic relationships, and further analyzed the evolutionary rate, selection pressure, and adaptive evolutionary process of the rps2 gene cluster-related genes. Results showed that all species with a broken rps2 gene cluster in Campanulaceae were from Campanuloideae and formed monophyletic branches on the phylogenetic tree. Compared with the unbroken species, the mean evolutionary rate of the related genes decreased in the broken species. There were significant differences in the nonsynonymous substitution rate between genes. In adaptive evolutionary analysis, the site model detected positive-selection sites in the atpI and rps2 genes. Our findings suggest that the fragmentation of the gene cluster holds phylogenetic implications, leading to alterations in evolutionary rates and diverse evolutionary trajectories among individual genes.

Male sterility plays an important role in the hybrid breeding of water dropwort (Oenanthe javanica (Blume) DC.). In the current study, a male-sterile water dropwort (OJBY001) with a degenerated stamen was described. OJBY001 was characterized by many lateral branches, dark green leaf blades and petioles, atrophic filaments and anthers, elongated stigma, and the ability to secrete nectar and receive exotic pollen from other water dropwort belonging to O. javanica. Compared to fertile water dropwort (OJKY002), OJBY001 exhibited significantly higher stem and petiole dry matter and and significantly or extremely significantly higher contents of vitamin C, soluble sugar, and flavonoids in the stolon.

The aim of this study was to reveal nitrogen (N) preference and optimal ammonium-nitrate ratio for growth of sugarcane (Saccharum officinarum L.). A hydroponic experiment was conducted with cultivar ‘Yunzhe05-51’ grown under a total N supply of 10 mmol/L, with seven ammonium-nitrate ratios, i.e., 0∶100, 20∶80, 40∶60, 50∶50, 60∶40, 80∶20, and 100∶0. Plant growth and physiological responses in relation to N assimilation were characterized. Results showed that the plant biomass of ‘Yunzhe05-51’ peaked at an ammonium-nitrate ratio of 20∶80. Under this treatment, plants showed the best root morphology, highest N assimilation-related enzyme activity, and relatively higher N uptake and utilization efficiency. Root growth began to display depression when the ammonium-nitrate ratio reached 40∶60, while shoot growth was significantly limited when the ammonium-nitrate ratio increased to 80∶20. Plants under single ammonium supply had the highest levels of N concentration, N uptake per unit root length, free amino acid content, and soluble protein content, but showed lower N assimilation-related enzyme activity and the lowest N utilization efficiency, as well as the most stunted plant growth and root morphology. In conclusion, exploring the combined effects of ammonium and nitrate on plant growth, N assimilation and utilization were better than single administration of either ammonium or nitrate, and the optimal ammonium-nitrate ratio for ‘Yunzhe05-51’ was 20∶80.

Dalbergia odorifera T. Chen and Hevea brasiliensis Muell. Arg were used to explore the effects of drought and nitrogen application on the growth, chlorophyll fluorescence characteristics, and interaction effects of the seedlings. Results showed that under the same nitrogen level, drought stress significantly increased the fluorescence parameters F_o and NPQ of the seedlings, but decreased plant height, basal diameter, leaf length, total chlorophyll, F_v/F_o, F_v/F_m, and ETR. Under the same water level, plants in the nitrogen application group exhibited better growth performance, and the promotion effects on D. odorifera were stronger than that on H. brasiliensis. Combined drought treatment and nitrogen application significantly affected the number of branches in D. odorifera and plant height increment, petiole length, chlorophyll a content, total chlorophyll content, and carotenoid content in H. brasiliensis. Mixed planting promoted the growth and development of D. odorifera and H. brasiliensis under humid conditions, while D. odorifera significantly inhibited the growth and photosynthetic performance of H. brasiliensis under drought conditions. These results showed that nitrogen application could alleviate the adverse effects of drought stress on the two species, and plant growth and photosynthetic pigment accumulation showed the best performance under nitrogen application in well-water. In addition, variations in soil moisture could change the interaction effects between D. odorifera and H. brasiliensis.

Vitex agnus-castus L. is a highly ornamental and important summer and autumn flowering plant used to enrich urban landscapes. However, there is a serious shortage of seedlings in the market and seed propagation is difficult. In this paper, we used paraffin sectioning to observe the fruit and seed structure of V. agnus-castus and applied various germination techniques to determine the most effective method for seed germination. Results showed that V. agnus-castus possesses a hard endocarp and exhibits a high seed abortion rate. Among the various germination methods, treating the fruit with concentrated sulphuric acid for 20 min followed by soaking in 600 mg/L GA3 for 24 h proved to be the most efficient, leading to a substantial increase in germination potential, germination rate, and germination index to 10%, 14.44%, and 1.09, respectively.

The cosmopolitan submerged plant, Potamogeton crispus L., was used as a model species to study the effects of climate warming on reproduction. Turions from four different geographic temperate regions in China were used for the mesocosm experiment. A glasshouse experiment was used to mimic climate warming of 2.0 ℃–5.8 ℃. Number and biomass of turions and fruits were selected as proxies for asexual and sexual reproduction, respectively. Based on the potential correlation between scale leaf number of the turions and fitness of asexual propagules, the turions were classified into two categories: oligophyllous (scale leaf number ≤ 4) and pleiophyllous turions (scale leaf number > 4). Geographic sources and warming conditions significantly affected asexual and sexual reproduction in P. crispus. Although simulated warming had different effects on turion number in different clonal populations, total turion biomass did not decrease. Simulated warming led to a decrease in the percentage of oligophyllous turions and an increase in the percentage of pleiophyllous turions. Moreover, simulated warming led to total loss of sexual reproduction in three clonal populations. As P. crispus is mainly hydrophilous, we speculate that warming destroyed pollen viability, resulting in the total loss of sexual reproduction. The scale leaves were capable of nutrient storage and photosynthesis. Additionally, a positive correlation was found between scale leaf number and axillary bud number. We speculate that P. crispus maintains fitness via the production of larger-size asexual propagules under warming conditions as a reproductive life-history strategy to cope with climate warming.

Lotus (Nelumbo), as a basal eudicotyledon, is of great significance for studying the evolution and phylogeny of plants. It is also an economically important aquatic horticultural plant with ornamental, edible, and medicinal value. With the completion of genome sequencing, assembly, and annotation in the last decade, molecular level studies have greatly driven and expanded our understanding of all biological aspects of this species. In this review, we systematically discuss the latest advances in molecular biology studies of the lotus, with a focus on: (1) Recent progress in genomic research; (2) Genetic and multiomics studies of different horticultural traits and physiological processes; and (3) Characterization of key genes controlling important horticultural traits and their functions. Based on these, we also discuss current research challenges and future prospects.

Lotus (Nelumbo) is an economically important aquatic crop and contains abundant bioactive compounds, such as flavonoids, alkaloids, and polysaccharides. More than 100 flavonoids have been identified in lotus, including rutin, quercetin, and chrysin, which exhibit various antibacterial, anti-obesity, and antioxidant medicinal properties. In this review, we introduce the types of flavonoids in lotus and various effective extraction and identification methods, including microporous resin chromatography (MPRC) and high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Moreover, the functional activities of flavonoids in lotus and their latest applications, including disease treatment and functional product development, are further summarized. This review provides a reference for future research and the comprehensive utilization of lotus flavonoids.

The trehalose-6-phosphate metabolic pathway is an important component of the plant physiological regulation network in response to abiotic stress. Trehalose-6-phosphate synthase (TPS) is a key gene for trehalose synthesis in plants. To better understand the role of the TPS gene in plant response to abiotic stress and regulation of flowering time, this study presents an overview of current information on the phylogenetics and sequence structure of plant TPS gene family members, as well as the regulatory function and molecular mechanism of TPS in plant responses to drought, salt damage, high temperature, and low temperature stress, and research progress regarding its effects on plant flowering regulation. This study presents a comprehensive summary of research progress on the TPS gene in response to abiotic stress and flowering regulation, while also providing future research directions and potential applications of TPS homologs.