During examination of Corydalis specimens collected from the alpine subnival zone of the Tibet Autonomous Region in 2018, two new species records for China, C. filicina Prain and C. crassifolia Royle, were identified. This study presents the first detailed Chinese morphological descriptions and color photographs of these species based on the specimens. While C. filicina resembles C. cornuta Royle, it can be distinguished based on its slender stems; apex of outer petals keel with or without purplish brown speckles; upper petal broad, nearly 3-lobed, with narrow crest; cylindric spur straight, as long as limb; subrhombic lower petal suddenly constricted into cuspidate apex; and square and flat stigma with 10 papillae. While C. crassifolia is morphologically similar to C. retingensis Ludlow, it can be distinguished based on different leaf shapes, raceme structures, and non-thickening fruit stalks. This discovery enriches the species diversity of Corydalis in Tibet and provides new data for floristic research and resource development of the genus.

This paper reports 18 new records of diatoms from the genus Gomphonema in the Hengduan Mountains of China, including G. intricatum var. capitata Hustedt, G. angustius Reichardt, G. afrhombicum Reichardt, G. pseudointermedium Reichardt, G. auguriforme Levkov, G. californicum Stancheva & Kociolek, G. sublaticollum Reichardt, G. sphenovertex Lange-Bertalot & Reichardt, G. wiltschkorum Lange-Bertalot, G. vardarense Reichardt, G. parvuliforme Lange-Bertalot, G. parvuloides Cholnoky, G. lacus-victoriensis Reichardt, G. yucatanense Metzeltin & Lange-Bertalot, G. angusticephalum Reichardt & Lange-Bertalot, G. lange-bertalotii Reichardt, G. intermedium Hustedt, and G. medioasiae Metzeltin, Lange-Bertalot & Nergui. Detailed descriptions of the morphological characteristics, geographical distribution, habitat preferences, and physicochemical indices for each species are provided. Furthermore, comparative analyses of the morphological characteristics of the newly recorded species and their closely related counterparts are discussed.

Field investigations and artificial pollination experiments were conducted to explore the flowering characteristics and breeding system of the remnant Myricaria laxiflora (Franch.) P. Y. Zhang et Y. J. Zhang population in Dianjun Yanzhiba in Yichang, downstream of the Three Gorges Dam. Results showed that: (1) The flowering period of the M. laxiflora remnant population extended from September to April, with a peak blooming period from October to November and a single flower lifespan of two to seven days. The temporal and spatial overlap of the female and stamen structures within a single flower facilitated self-pollination. (2) The out-crossing index (OCI) was 2 and the pollen-ovule (P/O) ratio was 329, suggesting that M. laxiflora operates under a facultative autogamy (xenogamy) system. (3) Artificial pollination experiments demonstrated that while M. laxiflora exhibited partial self-compatibility, the rate of seed setting from cross-pollination significantly exceeded that of self-pollination. The study suggested that a high rate of self-crossing within the remnant population. Thus, conservation measures should be implemented to reduce human disturbance and protect the habitat and genetic diversity of the remnant populations should be subjected to ongoing surveillance.

Temporal and spatial variations of sexual reproduction in a remnant population of the endangered species Myricaria laxiflora (Franch.) P. Y. Zhang et Y. J. Zhang were investigated based on changes in flowering and fruiting traits with elevation on Guanzhou Island, Zhijiang, China. The impact of cascade water conservancy and hydropower construction projects on the sexual reproduction of remnant populations was analyzed based on the characteristics of water-level fluctuations in the habitat of M. laxiflora. Results showed significant differences in the sexual reproduction of the remnant population at different elevations. Flower branch number per plant, flower number per branch, and flower number per plant of plants at the upper part of the fluctuation zone were 66.09%, 50.14%, and 98.63% higher than those at the middle part, and 79.50%, 283.33%, and 461.05% higher than those at the lower part, respectively. Fruit branch number per plant, fruit number per branch, fruit number per plant, seed number per fruit, and seed germination percentage of plants at the upper part of the fluctuation zone were 60.17%, 25.26%, 88.05%, 6.96%, and 30.69% higher than those at the middle part, and 97.39%, 82.45%, 208.31%, 19.12%, and 45.91% higher than those at the lower part. Correlation analysis showed significant correlations between the flowering and fruiting characteristics and elevation, plant exposure period, soil water content, and temperature. The influence of environmental factors on sexual reproduction was in the order of exposure time, elevation, daily average temperature, and soil moisture content.

In this study, we investigated the diversity of bumblebees and their floral resources during the late flowering season across 19 meadows near Shangri-La city in Northwest Yunnan, a renowned global biodiversity hotspot. We calculated the diversity index for bumblebees and measured several variables related to landscape structure and configuration for each meadow. Generalized linear models revealed that bumblebee abundance and species richness were primarily influenced by local floral resources, whereas the Shannon diversity index was largely determined by landscape variables, especially the percentage of woodland coverage. We further analyzed bumblebees with varying body size and tongue length, as these traits may influence responses to local and landscape variables. Notably, large-bodied bumblebees showed greater sensitivity to surrounding landscape variables in relation to flight capabilities, while small- and medium-bodied bumblebees were more dependent on local floral resources and habitat connectivity. Regarding tongue length, short-tongued bumblebees predominantly utilized local floral resources, whereas medium- and long-tongued bumblebees leveraged resources more extensively at the landscape scale, reflecting their different foraging strategies. This study illustrated the significant impact of flower availability and landscape characteristics on bumblebee diversity, highlighting how flight ability and foraging strategy profoundly influence the environmental dependence patterns of different bumblebees.

Soil nematodes play an important role in indicating the structure and function of alpine meadow ecosystems, yet the impact of plant functional group loss on soil nematode communities remains unclear. In this study, five treatments involving the removal of above-ground plant functional groups were established in an alpine meadow ecosystem of the eastern Qinghai-Tibet Plateau, including a control (CK), graminoids, legumes, forbs, and remove all. The aim was to explore the impact of plant functional group loss on soil nematode communities. Results showed that: (1) Above-ground removal of plant functional groups had no significant effect on plant root biomass and soil nematode total density. (2) Above-ground removal of plant functional groups had a significant effect on the relative abundance of nematode trophic taxa. Under legume treatment, the relative abundance of bacterial feeder nematodes was the highest, while that of plant parasite nematodes was the lowest; under forbs treatment, the relative abundance of plant parasite nematodes was the highest, while that of bacterial feeder nematodes was the lowest. (3) Nonmetric multidimensional-scaling analysis (NMDS) showed that the removal of different plant functional groups led to differences in soil nematode taxa, with significant impact on soil nematode community structure.

TM8 genes, belonging to the ancient subfamily of type Ⅱ MADS-box genes, have been lost in various angiosperm lineages but have undergone a dramatic expansion in gymnosperms. While TM8 genes are known to participate in female flower development in angiosperms, their roles in gymnosperms remain poorly understood. In this study, three TM8-like genes, including one gene with two transcripts, were characterized in Gnetum montanum Markgr. using fluorescence in situ hybridization (FISH) and transgenic experiments. Results indicated that all three genes were involved in the development of female ovules, sterile ovules, and antherophores, but their expression levels, and presumably their roles, differed substantially among these organs. The morphology of transgenic Arabidopsis thaliana (L.) Heynh. flowers suggested that the TM8-like genes had a substantial effect on the emergence and development of short stamens. In addition, the expression patterns of the two transcripts were different and associated with different phenotypes in A. thaliana flowers, suggesting divergent functions in reproductive organ development in G. montanum.

This study explored the genetic diversity and structure of 261 wild Rosa roxburghii Tratt. samples from 29 populations across eight provinces in China, utilizing 10 pairs of polymorphic EST-SSR primers and capillary electrophoresis, providing a clear genetic background for the collection and breeding of R. roxburghii germplasm resources. Results identified 95 alleles among the 261 germplasm materials. The average polymorphism information content of the loci was 0.568. At the population level, the average number of alleles and effective number of alleles were 3.131 and 2.331, respectively, with observed heterozygosity and expected heterozygosity averaging 0.508 and 0.488. The average Shannon’s information index was 0.858, indicating substantial genetic diversity, likely due to the extensive range of sampling sites. Analysis of population genetic differentiation revealed an average genetic differentiation coefficient of 0.067 and gene flow of 4.511, suggesting considerable inter-population gene flow. Analysis of molecular variance (AMOVA) indicated that most genetic variation in R. roxburghii came from within populations (r=0.467, P<0.000 1). Nei’s standard genetic distance among populations ranged from 0.054 to 1.269, with an average of 0.657, and was significantly related to geographical distance. Clustering analysis grouped the 29 populations into three main clusters, which was related to geographical location. These results highlight southwestern China as a core distribution area for wild R. roxburghii resources, providing theoretical guidance for the formulation of R. roxburghii conservation strategies.

Nuclear DNA C value and genome size are important characteristics of biodiversity. In this study, young leaves of 18 cultivars of ornamental crabapple (Malus spp.) were used as test material, and Zea mays L. cv. ‘B73’ was used as an internal reference sample. The genome size of ornamental crabapple was measured by flow cytometry. It provides a theoretical basis for germplasm resource identification, genomics research and new variety breeding of ornamental crabapple. The results showed that the C value of 18 samples of ornamental crabapple ranged from 0.74 to 1.50 pg, and the average size was 0.96 pg. Among them, ‘Mary Potter’ had the highest C value (1.50 pg), while ‘Red Jewel’ had the lowest C value (0.74 pg). ANOVA showed that there were significant differences in the C value between ornamental begonia cultivars. The research results indicate significant diversity in DNA C values and genome sizes among different ornamental crabapple cultivars.

The water composition in chestnut fruit plays an important role in physiological metabolism and quality changes. In this study, Chinese chestnuts (Castanea mollissima Blu.) from Wangmo County in Southwest Guizhou Province, China, were used as test material. Low-field nuclear magnetic resonance (NMR) technology was used to test the transverse relaxation decay signal of hydrogen nuclei in chestnut fruit with different moisture contents (48%, 38%, 28%, 18%). The SIRT model was used to obtain inversion data of the transverse relaxation time (T2). Nuclear magnetic resonance images (MRI) were obtained by spin echo (SE) imaging, while texture analysis and colorimetry were employed to assess textural and color attributes of the pulp, respectively. Results showed that natural water loss changed the binding state of water in chestnut fruit, leading to significant water migration and gradual weakening of free and immobile water signal amplitudes with increasing water loss. The total inversion peak area of chestnuts with different moisture content differed. With increasing water content, the NMR signal and peak area both increased, showing significant correlation. NMR imaging enabled direct visualization of water content in different stages based on light and dark imaging features. The chestnut flesh underwent calcification during natural storage, with hardened fruit texture, increased resistance to extrusion and chewing, and decreased cohesiveness and springiness (in the later stage). Adhesiveness exhibited an initial decrease, with no significant variation in the later stage. In the early stage of water loss, fruit pulp underwent oxidization, causing a gradual change to a dark red color. In the late stage of water loss, the chestnut fruit underwent severe calcification, and the pulp turned white with increased brightness. These results provide a reference for understanding the mechanism underlying moisture migration and product quality control in the processing of fresh C. mollissima fruit.

Plant growth in coastal estuarine riparian zones is vulnerable to combined waterlogging and salt stresses. Previous studies have shown that Syzygium nervosum A. Cunn. ex DC. and Syzygium cumini (L.) Skeels possess strong waterlogging tolerance. However, their tolerance to combined salinity and waterlogging stress is still unclear. In this study, three treatments, including waterlogging, salinity treatment (350 mmol/ L), and combined salinity-waterlogging treatment (175 mmol/L), were used to compare the effects of different stresses on plant growth, physiological and biochemical traits, and ion accumulation in both species. After 24 d of treatment, the three stress treatments resulted in a decrease in the biomass of both species, as well as an increase in reduced glutathione (GSH) content and activities of ascorbate peroxidase (APX) and glutathione reductase (GR). Compared to the control, waterlogging treatment decreased the contents of superoxide anion (O₂⁻) and hydrogen peroxide (H₂O₂) in the leaves of both species, while increasing the potassium ion (K⁺) content and decreasing the K⁺/Na⁺ ratio in the roots. Compared to the control, salinity treatment decreased the O₂⁻ content in the S. cumini seedlings but increased content in the S. nervosum seedlings. In addition, salinity treatment increased the contents of proline, H₂O₂, sodium ion (Na⁺), and chloride ion (Cl⁻) in both species but decreased the K⁺/Na⁺ ratio. Compared to the control, combined salinity-waterlogging treatment increased the contents of O₂⁻, Na⁺, and Cl⁻ in both species but decreased the K⁺/Na⁺ ratio. In addition, compared to the waterlogging treatment, combined salinity-waterlogging treatment decreased biomass accumulation in both species, while increasing the contents of O₂⁻, Na⁺, and Cl⁻. Compared to the S. nervosum seedlings, the S. cumini seedlings exhibited higher biomass accumulation, proline content, GR activity, and K⁺/Na⁺ ratio, and lower levels in H₂O₂, Na⁺, and Cl⁻ under salinity treatment and combined salinity-waterlogging treatment, suggesting that S. cumini seedlings possess stronger tolerance to salinity and combined salinity-waterlogging than S. nervosum. These findings provide theoretic guidance for vegetation restoration and reconstruction in coastal estuarine wetland systems.

The utilization of male sterile lines for seed production represents an effective strategy for exploiting heterosis in self-pollinating crops such as wheat and rice. ABCG transporters, a large subfamily of ABC transporters, play integral roles in various biological processes, including the regulation of male fertility. This review examines the structural characteristics of ABC transporters, emphasizes the critical role of ABCG transporters in regulating the development of the pollen wall and anther cuticle, and discusses the current state of research on ABCG transporters, along with future research prospects. The aim of this review is to enhance our understanding of the involvement of ABCG transporters in the regulation of plant male sterility, thereby providing a theoretical basis for the cross-breeding of self-pollinated crops.

Graphene oxide (GO), characterized by its unique ²-sp³ hybrid structure, exhibits many excellent properties that have facilitated its widespread application across many fields, including nanoelectronics, biomedicine, and energy storage. GO has attracted considerable attention in recent years due to its capacity to enhance plant growth and development. This paper provides a systematic summary of the effects of GO on the growth and development of different plants, elucidates the mechanisms underlying these effects, and identifies potential limitations in its application. The insights presented here aim to serve as a reference for the application of GO in the agricultural and forestry fields, thereby broadening its comprehensive utilization and promoting the sustainable development of food production and environmental protection.

Nitrogen is an important element necessary for plant growth and development. The role of nitrogen in host-pathogen interactions is complex and regulated by multiple factors. In this paper, the relationship between nitrogen and plant disease development is reviewed, and the molecular mechanisms are described from the perspectives of host defense and pathogen infection. The effects of different nitrogen forms on plant disease are also compared.