Subjects: Biology >> Botany >> Applied botany submitted time 2024-05-15 Cooperative journals: 《广西植物》
Abstract： Rock outcrop is a typical feature of karst ecosystem, on which there are complex microhabitats and various colonized plants, but the relationship between these plants and microhabitats is not clear. Taking a tropical seasonal humid forest in Xishuangbanna as the research object in this study, we measured the morphological characteristics and external environmental factors of 586 microhabitats on rock outcrops surface. All colonized vascular species on these microhabitats were identified and counted. Then, Pearson correlation analysis and redundancy analysis (RDA) were used to reveal the relationship between microhabitats (including morphological characteristics and environmental factors) and vascular plants richness. The results were as follows: (1) In tropical karst forest, the microhabitat characteristic such as soil depth [(4.92±4.00)] cm and area [(532.28±1 575.10) cm2] have great variability. (2) A total of 1 518 individuals of 90 species belonging to 82 genera and 44 families were recorded in all microhabitats, and karst preferent species that dominants on limestone accounted for 35.6%. (3) The area size and soil depth of microhabitat can explain more than 70% of species composition and colonized plants richness in RDA model. (4) The species-area relationship between the richness of the colonized plants and the area of rock outcrops microhabitats shows an obvious exponential decay. In conclusion, microhabitats on rock outcrops in the tropical karst forest is highly heterogeneous, the area size and soil depth are the key factors affecting plant colonization, and the species-area relationship dominates the species richness pattern on rock outcrops microhabitats.
Subjects: Biology >> Botany >> Applied botany submitted time 2024-05-15 Cooperative journals: 《广西植物》
Abstract： The updated List of National Key Protected Wild Plants (LNKPWP) was released by 1National Forestry and Grassland Administration and Ministry of Agriculture and Rural Affairs of China in September 2021. By integrating literature search, herbarium record, field investigation and expert consultation, we compiled the updated list, investigated the geographic map, research progresses, threatened status, and protection status of National Key Protected Wild Plants (NKPWP) in Hubei Province. The results were as follows: (1) There are 155 species on the LNKPWP in Hubei Province, of which 11 species belong to Category I and the remaining 144 species belong to Category II. (2) Geographic distribution of NKPWP in Hubei Province is uneven and concentrated in west and southwest areas, with Shennongjia and Lichuan have the greatest numbers of NKPWP. (3) The most studied species are the species with economic value, flagship species and regional representative species. In addition, more than a third of the species (55 species) were almost unstudied. The research of NKPWP in Hubei Province focused on genetic diversity, genetic structure, future distribution prediction under global change conditions, and phylogeography. (4) According to the “China Red List of Biodiversity-Higher Plants Volume”, the NKPWP in Hubei Province contain 9 critically endangered species, 30 endangered species, 41 vulnerable species and 19 near-threatened species. The main threatened factors are direct mining or logging, habitat degradation or loss, and species intrinsic factors. (5) Until now, 137 species(88%) of NKPWP in Hubei Province are wholly or partially located in protected areas, and the remaining 18 species (12%) are completely located outside protected areas. At present, 93 species of NKPWP have been introduced and cultivated in Hubei Province, while the other 62 species have not been recorded under ex situ conservation. In addition, very few species have been reintroduced into the wild. (6) At present, although the distribution ranges of seven wild plants in Hubei Province (five of which are endemic to Hubei) are limited and they are negatively affected by internal causes and human interference, they have not been included in the LNKPWP. In addition, this study points out the knowledge gaps in the research and protection of NKPWP in Hubei Province, and puts forward specific research suggestions and protection strategies.
Subjects: Biology >> Botany >> Applied botany submitted time 2024-05-15 Cooperative journals: 《广西植物》
Abstract： Based on the 25 ha karst forest big plot in Gulinqing, Yunnan, through sample-plot investigation, specimen collection and identification, floristic analysis, Jaccard similarity coefficient and PCA, we explored its floristic characteristics and the status of the Gulinqing big plot in Yunnnan and the geographical relationships among Gulinqing in Yunnan, Bubeng in Yunnan, and Nonggang in Guangxi, China. The results were as follows: (1) There were about 78 families, 238 genera, and 406 species（including infraspecies taxa and excluding woody vines）of woody plants with DBH≥ 1cm. (2) In the plot, the families with two–five species and with one species were dominant and accounted for 37.18% and 34.62% of the total number of families, respectively, while the genera with two–four species and with one species were also dominant and accounted for 30.25% and 65.13% of the total number of genera, respectively. (3) Through analysis of the areal-types of families and genera, it was found that it had been divided into 9 areal-types and 7 variations at the family level, and the proportion of families was the highest at Pantropic, accounting for 50.77%, and the ratio of tropical flora to temperate flora (R/T) was 4.42; there were 11 areal-types at the genera level, mainly composed of Tropical Asian, Pantropic, Old World Tropics, 33.47%, 18.22%, and 13.98% respectively, and with R/T of the genera was 10.25. (4) The composition of Gulinqing, Bubeng and Nonggang big plots showed that Gulinqing and Bubeng had the highest similarity in family and genera level at Jaccard similarity coefficient (0.674 and 0.395, respectively), and Bubeng and Nonggang with the smallest Jaccard similarity coefficient (0.575 and 0.297, respectively). (5) PCA principal component analysis of the floristic spectrum had similar result of the Jaccard similarity coefficient above in the level of genera, but different one at the level of families, e.g. a higher geographical connection between Gulinqing and Nonggang. In summary, this plot has a high diversity of families and genera, significant tropical characteristics, ancient floristic characteristics, obvious transitional status and extensive flora connections. However, there is an inconsistent geographical connection among Gulinqing, Bubeng and Nonggang from the composition and floristic spectrum.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-12-24 Cooperative journals: 《广西植物》
Abstract： The seeds are invariably exposed to high temperature conditions since global warming frequently causes abnormally high temperatures. This study used intermediate Citrus maxima ‘Mansailong’ seeds as the research material, heated the seeds at different developmental stages, and simultaneously detected changes in seed morphology, contents of soluble and heat-stable proteins, and cellular ultrastructure in order to investigate the physiological basis of high-temperature tolerance in seeds. The results were as follows: (1) The seed moisture content dramatically dropped between 23 and 49 WAF (weeks after flowering), whereas the percentage of DW/FW and fresh weight increased significantly. All of these indicators began to change quickly from 31 WAF and stabilized around 41 WAF. (2) At 29 WAF, the seeds acquired full seedling formation ability and a preliminary tolerance to high temperatures; from there, the high-temperature tolerance gradually grew and improved quickly between 37 and 49 WAF. The improvement in high-temperature tolerance was accompanied by a steady increase in the contents of soluble and heat-stable protein in seeds, from 23 to 49 WAF. The results of the correlation analysis showed a substantial positive correlation between the accumulation of heat-stable and soluble proteins and the ability of seeds to tolerate high temperatures. (3) Ultrastructural observation showed that the number of mitochondria progressively dropped as the seed developed, the volume of the embryonic axis cells gradually decreased, and the number of lipid bodies in the cells gradually rose and their arrangement became more and more regular. In addition, the vacuoles enlarge at the same time, and at a later stage, they were packed with black floccules. In conclusion, the Citrus maxima ‘Mansailong’ seeds reached physiological maturity at 41 WAF without any noticeable maturation drying; the ability to withstand high temperatures was acquired during seed development and was further enhanced until a later stage; changes in cellural ultrastructure and an increase in soluble and heat-stable protein contents of the seeds were essential in helping the seeds develop their high-temperature tolerance.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-12-24 Cooperative journals: 《广西植物》
LUO Yahuang
MA Liangliang
GAO Lianming
WANG Xinjie
ZHAO Wei
YANG Xingliang
MA Shaobin
SHI Xiaochun
LIU Jie
Abstract： A better understanding of the spatiotemporal dynamics of species composition and biodiversity provides significant insights into the distribution patterns of biodiversity and the prediction of biodiversity fate in a global change context. However, how species and phylogenetic diversity change along elevational gradient with temporal scale in mountain ecosystems is largely unknown. In this study, we used census data (2004, 2008 and 2013) of an elevational transect (elevational range 960-2 878 m) covering eastern and western slopes of Gaoligong Mountains, SW China, to investigate the spatiotemporal dynamics of forest arbor layer (DBH≥5 cm) species diversity and phylogenetic diversity. The results were as follows: (1) Species diversity was humpshaped along the elevational gradient, while the phylogenetic diversity increased with increasing elevation. Clustering phylogenetic structure was observed at low elevations, and overdispersed or random structure was detected at high elevations. (2) Overall, temporal species and phylogenetic beta diversity analysis showed no significant difference among these three investigation time points. However, we found a higher clustering of phylogenetic structure along the temporal scale. (3) Spatial beta diversity showed that there was a significant loss of species at low elevations (960-1 381 m) on the eastern slope, where the vegetation has been disturbed or completely converted into farmland. The main lost species including Terminalia chebula, Quercus acutissima,Pistacia weinmanniifolia, Hovenia acerba and Ilex wattii. In contrast, the change in the western slope is mild at low elevations, only observing species abundance increasing, which include Cyclobalanopsis oxyodon, Symplocos chinensis, and Taiwania cryptomerioides. Therefore, we speculate that the change in species and phylogenetic diversity of the arbor layer of subtropical evergreen broadleaf forest may be related to succession process and climatic change in middle and high elevations, while the communities at low elevations were seriously impacted by human activities in the Gaoligong Mountains. The results will deepen the understanding of the mechanisms of plant community dynamics in the Gaoligong Mountains and provide new insights to guide precise conservation strategies in the region.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-08-04 Cooperative journals: 《广西植物》
Abstract： The decline in seedling growth of Malania oleifera as the age increases is often observed in the absence of host plants. A better knowledge of nutrient dynamics in terms of concentration and distribution patterns in different parts of the declining seedlings can provide valuable information for evaluating seedling growth vigor and offer scientific guidance for rational fertilization in M. oleifera nurseries. In this study, the concentrations of N, P, and K were comparatively analyzed in various organs of unattached M. oleifera seedlings grown for half a year, two years, and three years. Additionally, the starch content and distribution patterns in the roots and stems of seedlings with different vigor levels were qualitatively assessed by staining cross-sections. The results were as follows: (1) As the growth vigor of M. oleifera seedlings declined, the concentrations of N, P, and K in most organs decreased, except for a significant increase in K concentration in lateral roots. The leaf N/P ratios of the declining seedlings became increasingly imbalanced, indicating different nutrient deficiency types among the seedlings with varying decline degrees. Unattached M. oleifera seedlings grown for half a year were primarily limited by insufficient N supply (with an average N/P ratio of 11.33) and subsequently by P limitation after two years (average N/P ratio 17.81). The leaf N/P ratio of unattached M. oleifera seedlings grown for three years was remarkably imbalanced (with an average value of 52.46). As the growth vigor of unattached three-year seedlings is considerably low, they are deemed unsuitable for afforestation. (2) A decrease in starch content was observed in declining seedlings, as evidenced by the reduced staining intensity of cross-sections. After three years, the starch content of unattached M. oleifera seedlings was found to have decreased to an extremely low level. Significant differences in starch content were observed at various locations, including the connecting point of the stems and roots, the basal swelling top of the root, the main root, and lateral roots, among seedlings with different degrees of decline. These findings suggest that starch content levels can serve as crucial criteria for evaluating the growth vigor of seedlings. Specifically, lateral roots were identified as optimal sampling materials for assessing seedling growth vigor through a minimally invasive method.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-13 Cooperative journals: 《广西植物》
Abstract： Paphiopedilum parishii is a rare and endangered species with few localities and fragmented populations found in China, Myanmar, Thailand and Lao. Environmental changes and over-harvesting have led to a decrease in its wild populations. It is important to protect endangered species' genetic diversity since it provides the species with the ability to adapt and survive. However, little is known about the genetic information of this species. This study aims to detect intraspecific variation and develop polymorphic genetic markers of P. parishii. The complete chloroplast genome of four individuals of wild P. parishii was obtained by sequencing, assembling and annotating, then compared with the existing genomic data of two individuals available from GenBank to detect the intraspecific variation. Further, simple sequence repeats (SSRs), single nucleotide polymorphisms (SNPs), and insertions and deletions (InDels) were identified. The results were as follows: (1) The four new sequencing chloroplast genomes were quadripartite, with a length between 154 403 bp and 154 809 bp, with 129 genes (78 protein coding genes, 39 tRNAs, 8rRNAs and 4 pseudogenes). (2) As a result of comparison of six individuals, 103-107 SSR loci were identified in the chloroplast genome of six individuals of P. parishii, and 21SSRs were polymorphic. And 60 long repeats were found, including 17-21 forward repeats, 18-29 reverse repeats, 9-16 palindromic repeats, and 4-9 complement repeats. (3) In addition, a total of 10 SNPs and 60 InDels were uncovered across the plastome. Three of the non-synonymous mutations caused amino acid changes in functional domains. 19 InDels might be selected for possible chloroplast DNA markers to determine intraspecific variation. (4) The value of nucleotide diversity (Pi) was calculated ranging from 0-0.006 32 suggesting sequences with low variation. Hyper-polymorphic regions, e.g. intergenic spacers rps3-rpl22, trnL-UAC-rpl32, rpoB-trnC-GCA and ycf4 gene were identified as potential barcoding regions. (5) The phylogenetic analyses based on the complete chloroplast genome supported three lineages in Paphiopedilum, and 6 individuals of P. parishii form a monophyletic group. SSRs, long repeats, InDels, SNPs and nucleotide sequences showed sufficient intraspecific genetic variation in P. parishii. The molecular markers developed here will contribute to further evolutionary studies and conservation of P. parishii.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-07-05 Cooperative journals: 《广西植物》
Abstract： The restoration and reconstruction of mangrove wetland ecosystems is one of the key research fields in ecological restoration in the coastal zones of South China. How to optimize the assembly of mangrove species is the priority to be concerned in the restoration and transformation of mangrove forest community. In order to reveal the physiological and ecological strategies to light conditions of mangrove plant species and provide theoretical guidance for optimal assembly of mangrove community structure, the characteristics of leaf total soluble protein content and activities of five antioxidant enzymes in seedlings of eight mangrove plant species (Sonneratia apetala, Kandelia candel, Bruguiera gymnorrhiza, Aegiceras corniculatum, Acanthus ilicifolius, Acrostichum aureum, Heritiera littoralis and Hibiscus tiliaceus) under different light intensities (100%, 45%, 30%, and 10% of natural sunlight) were studied using shading control experiment. The results were as follows: (1) Low light intensities had little impact on the leaf total soluble protein content of Bruguiera gymnorrhiza, Acanthus ilicifolius and Acrostichum aureum, whereas the other five species showed a decreasing trend in the leaf soluble protein content with the decline in light intensity. (2) The activities of superoxide dismutase (SOD) and ascorbate peroxidase (APX) in the leaves of Bruguiera gymnorrhiza, Acanthus ilicifolius and Acrostichum aureum in 10% of natural light intensity were not significantly from control, while the other five mangrove species showed a decreasing trend in activities of all the five antioxidant enzymes. In conclusion, our results indicate that Bruguiera gymnorrhiza, Acanthus ilicifolius and Acrostichum aureum are suitable for planting under the forest with high canopy density, while Sonneratia apetala, Kandelia candel, Aegiceras corniculatum, Heritiera littoralis, Hibiscus tiliaceus are suitable to be planted under forest with lower canopy density or planted as upper layer tree species in mangrove.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-07-05 Cooperative journals: 《广西植物》
Abstract： The circadian clock is a conservative endogenous regulatory mechanism that stimulates and maintains the rhythmic expression of plant physiological characteristics. The PRR proteins are critical components of the circadian clock central oscillator and regulate a variety of life processes such as seed germination and flowering. Anthocyanins are plant secondary metabolites, which play an important role in plant growth, reproduction and stress responses. In this study, we took Arabidopsis thaliana as the research object and explored the function and mechanism of circadian clock PRR proteins in the control of anthocyanin biosynthesis. The results were as follows: (1) The accumulation of anthocyanins and the expression of some anthocyanin synthesis-related genes were significantly reduced in PRR genes single mutant and multiple mutant seedlings. (2) In the seedlings with overexpression of PRR5, the accumulation of anthocyanin and the expression of some anthocyanin synthesis-related genes were significantly increased. (3) The results of the protein-protein interaction experiment showed that PRR5 protein can interact with MYB75, MYB90, MYB113 and TT8 to form protein complexes. (4) Results of genetic analysis showed that PRR5 promoted anthocyanin synthesis in A. thaliana seedlings was the MYB family anthocyanin regulatory proteins dependent. In conclusion, the circadian clock PRR protein may promote the synthesis and accumulation of anthocyanins in A. thaliana seedlings through the interaction of PRR5 protein with MYB75, TT8.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-03-18 Cooperative journals: 《广西植物》
Abstract： As a traditional Dai medicine, “Dai-Bai-Jie” is a kind of antidote, and its source plant was firstly recorded as Dregea sinensis. Currently, the source plant has been corrected as Marsdenia tenacissima. In order to further clarify the source plants of “Dai-Bai-Jie”, we carried out an integrated analysis of the source plants of “Dai-Bai-Jie” and its related species in this study. Our key results were as follows: (1) Phylogenetic relationship of Marsdenia and other species of Marsdenieae using three DNA fragments (psbD-trnT, trnL-trnF, ITS) showed that all “Dai-Bai-Jie” samples were supported as monophyletic with the sample of M. tenacissima, and were sister to M. cavaleriei; (2) Comparative analyses of morphological characters with type specimen proved that morphological characters of the “Dai-Bai-Jie” samples were consistent with those of the type specimen of M. tenacissima and obviously different from those of M. cavaleriei. In this study, the source plant of “Dai-Bai-Jie” was identified as the species M. tenacissima. Meanwhile, it is easy to discriminate from M. cavaleriei in the leaf and floral characters. According to both morphological and molecular evidence, it has been confirmed that the source plant of “Dai-Bai-Jie” was M. tenacissima that can be used for rapid and accurate authentication of medicinal herbs in the market, and also benefit for the development and utilization of the “Dai-bai-jie” medicine in future.
Subjects: Biology >> Botany >> Applied botany submitted time 2019-10-17 Cooperative journals: 《广西植物》
Abstract：脱落酸（Abscisic acid，ABA）激素是一类重要的生长调节物质，参与调控植物的多种生理过程。花青素（Anthocyanins）是植物次生代谢产生的类黄酮化合物，对植物的生长发育和逆境胁迫响应有着重要的作用。最近几年，关于花青素生物合成的转录因子及合成酶基因已有较多研究，然而控制其合成的信号物质及作用机制仍有待深入探究。本文以拟南芥（Arabidopsis thaliana）为对象探讨了ABA信号对花青素生物合成的调控功能和作用机制。实验结果表明外源施加ABA显著提高野生型幼苗茎尖中花青素的积累。相一致的，ABA能诱导某些与花青素合成相关的转录因子及合成酶基因的表达。此外，遗传学分析发现ABA诱导花青素合成部分依赖于MBW复合体中的核心转录因子，如TTG1、TT8及MYB75等。初步机制研究揭示ABA信号途径中的bZIP类转录因子ABI5能与TTG1、TT8及MYB75等相互作用形成蛋白复合物。综上所述，该研究认为ABA信号诱导拟南芥幼苗中花青素的积累，并可能通过ABI5与MBW复合体协同作用调控花青素的合成。
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