Subjects: Biology >> Botany >> Applied botany submitted time 2024-04-17 Cooperative journals: 《广西植物》
Abstract： Vatica guangxiensis is a national first-class protected wild plant and extremely small populations wild plant. This paper provides a comparative analysis of the photosynthetic physiological characteristics and structural features of Vatica guangxiensis seedlings and adult trees. The Li-6400 portable photosynthesis measurement system analyzer and vacuum electron scanning microscope were utilized to investigate the differences between the photosynthetic capacity and leaf structure of leaves at different stages of growth and development. The results were as follows: (1) The right-angled hyperbolic modified model was the best model to fit the light response of Vatica guangxiensis seedlings and adult plants. (2) The maximum net photosynthetic rate(Pnmax), light saturation point (LSP) and dark respiration rate (Rd) of adult leaves were significantly higher than those of seedlings, the light compensation point (LCP) of adult plants was lower than that of seedlings(P<0.05). (3) Chlorophyll a, chlorophyll b, chlorophyll (a+b) and carotenoids in seedlings were significantly lower than in adult plants(P<0.05). (4) The stomatal long axis, stomatal organ area and stomatal density of adult plants were significantly higher than those of seedlings; the leaf area and specific leaf weight (SLW) of adult plants were significantly larger than seedling (P<0.05), and the specific leaf area (SLA) was smaller than seedling. In summary, Vatica guangxiensis exhibits photosynthetic characteristics of a shade-loving seedling and a sun-loving adult tree. The seedlings have weak light adaptation ability and light energy utilization, and are unable to photosynthesize sufficiently to meet their growth needs due to excessive shading by adult trees. This is a significant reason why seedlings are unable to grow into large trees. Therefore, for insitu conservation of Vatica guangxiensis, human interference can be used to artificially create ‘windows’ in the tree layer to provide sufficient light sources. This is conducive to the growth of Vatica guangxiensis seedlings into large trees and the renewal of the population. On the other hand, for the introductory cultivation of Vatica guangxiensis, the seedlings need to be appropriately shaded and transplanted to a certain degree of shade. During the initial cultivation process, it is important to provide appropriate shading for seedlings and transplant them to an environment with a suitable level of shade.
Subjects: Biology >> Botany >> Applied botany submitted time 2023-12-24 Cooperative journals: 《广西植物》
Abstract： Exploring the stoichiometric characteristics of understory plants’ leaves and soil in different forest types in Maoershan can reveal the adaptation strategies of understory plants in Maoershan, and provide data support for forest management. In this paper, coniferous and broad-leaved mixed forest (ZK), evergreen broad-leaved secondary forest (CLC) and evergreen broad-leaved forest (CL) in Maoershan were selected as three forest types, the leaf stoichiometry of main plants in herb layer and shrub layer, and the soil stoichiometry under three forest types were measured and analyzed. The results were as follows: (1) There was no significant difference in leaf C and N contents between herb layer and shrub layer, but P and K contents in herb layer were extremely significantly higher than that in shrub layer, and N∶P was significantly lower than that in shrub layer. Plants in herb layer was more likely to be restricted by N, plants in shrub layer was more likely to be restricted by P and the utilization efficiency of N and P were higher. There was no significant difference in leaf stoichiometry of plants in shrub layer among different forest types, but there were significant differences in leaf N content, C∶N, C∶P of plants in herb layer among different forest types. Plants in herb layer of coniferous and broad-leaved mixed forest had higher nutrient use efficiency. (2) The soil C and N contents of the three forest types showed that CL > CLC > ZK, and there were extremely significant differences among the three forest types. The soil P content of coniferous and broad-leaved mixed forest was the highest, while that of C∶P and N ∶ P was the lowest. (3) Soil in coniferous and broad-leaved mixed forest significantly affected some leaf stoichiometry of plants in herb layer and shrub layer, while the other two forest types had no significant effect on underforest plants. To sum up, there are significant or extremely significant differences in soil stoichiometry among different forest types in Maoershan. The nutrient requirements and environmental adaptation strategies of plants in herb layer and shrub layer are different. The soil of coniferous and broad-leaved mixed forest has a strong influence on the leaf stoichiometry of understory plants, and the soil with low decomposition efficiency of organic matter in this forest type, and the soil is limited by N due to the low decomposition efficiency of organic matter, so the management of N in the mixed forest should be strengthened.
Subjects: Biology >> Botany submitted time 2022-12-29 Cooperative journals: 《广西植物》
Abstract：
In order to clarify the nutritional value characteristics and development direction of different parts of Malania oleifera, essential nutrients, amino acids and minerals in the kernel, peel, leaf, branch bark and bark of M. oleifera were determined by using the analysis method of conventional food nutrients and the nutritional value of each portion of the amino acids was evaluated. The results were as follow: (1) In terms of essential nutrients, except for carbohydrates, there were extremely significant differences in the contents of the remaining seven basic nutrients among five parts (P<0.01). The ash content of peel was highest than other parts, which was 5.7 g/100 g. The contents of crude fat and protein in kernel were highest than other parts, which were 36.0 and 14.0 g/100 g respectively. The content of Vitamin C in leaf was highest than other parts, which was 33.9 mg/100 g. The content of crude fiber in branch bark was highest than other parts, which was 40.5 g/100 g. The content of carbohydrate in bark was highest than other parts, which was 78.6 g/100 g. Volatile oil was detected only in kernel and leaf, with the content of 0.26 and 0.15 mL/100 g respectively. (2) A total of 16 amino acids were detected in the five parts of M. oleifera, including 7 essential amino acids. The total amount of amino acids and essential amino acids of kernel were much higher than those of other parts. In terms of amino acid nutritional value, the nutritional value of kernel and peel were higher than other parts, followed by leaf, bark and bark. And the essential amino acid ratio coefficient score ( SRC ) was 62.98, 59.40, 57.31, 52.25, 48.17, respectively. (3) The highest content of major elements in kernel, peel and leaf was K, the highest content of major elements in branch bark and bark was Ca, and the content of Na in five parts of M. oleifera was lowest. Among the macro-minerals, the contents of P and Mg in kernel were significantly higher than those in other parts (P<0.05). The contents of K and Na in peel were significantly higher than those in other parts (P<0.05). And the results also showed high levels of K/Na ratios at all parts. In terms of trace elements, the content of Mn and Fe in five parts of M. oleifera were higher than others. The content of Mn in kernel was the highest, and the content of Fe in branch bark was the highest. The total contents of Mn and Fe in kernel and leaf were higher than other parts. Comprehensive results show that the kernel has the highest nutritional value and each part has its own characteristics and advantages. Different parts can be effectively and accurately developed and utilized according to different value characteristics.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-07-05 Cooperative journals: 《广西植物》
Abstract： The investigation of the calcium speciation characteristics in leaf under different habitats can help to understand deeply the adaptation mechanisms of golden Camellia species to soil calcium and provide a reference for the development of their conservation measures. In this study, 10 species of golden Camellia from calcareous soil habitats and 4 from acidic soil habitats were employed. The calcium content (Soil-Ca) and pH (Soil-pH) of habitat soil, and the content of calcium nitrate and calcium hloride (AIC-Ca), water soluble calcium (H2O-Ca), calcium pectate (NaCl-Ca), calcium phosphate and calcium carbonate (HAC-Ca), calcium oxalate (HCl-Ca), sili-cate calcium (Res-Ca), and total calcium (Tot-Ca) of leaves were measured. The results were as follows: (1) the Soil-Ca and Soil-pH of calcareous soils were extremely significantly (P<0.01) higher than those of acidic soils. (2) The leaf calcium speciation of golden Camellia species from calcareous soil habitats was primarily HCl-Ca (41.17%), while species from acidic soil habitats was primarily NaCl-Ca (43.10%), and all calcium speciation and total calcium content in leaves of species from calcareous soil were extremely significantly (P<0.01) higher than that from acidic soil except for AIC-Ca and NaCl-Ca. (3) Correlation analysis showed that most of the content of calcium speciation in leaves was extremely significantly (P<0.01) and positively correlated with Soil-Ca and Soil-pH, indicating that soil environment had an important influence on the leaf calcium speciation characteristics of golden Camellia species. (4) According to ANOVA, the content of each leaf calcium speciation was extremely significant (P<0.01) difference among the species in golden Camellia revealing that the calcium speciation char-acteristics have a considerable variation during the species differentiation. (5) Cluster analysis based on calcium speciation characteristics showed that the 14 species of golden Camellia could be grouped into three categories. In summary, the differences in leaf calcium speciation of plants of golden Camellia species in different habitats may be the consequence of a combination of soil environmental and genetic factors.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-05-21 Cooperative journals: 《广西植物》
Abstract： In order to study the chemical constituents in the leaves of Champereia manillana var. longistaminea, the chemical composition was analyzed by the silica gel column chromatography (CC), thin-layer chromatography (TLC), dextran gel column chromatography (Sephadex LH-20), reversed-phase silica (RP-18) gel column chromatography and high performance liquid chromatography (HPLC). The ethyl acetate extraction part of the ethanol extraction was separated and 6 monomer compounds were obtained. The structures of these compounds were identified using nuclear magnetic resonance spectroscopy (NMR), high resolution mass spectrometry (HR-ESI-MS) and the data of the literature. Six compounds were elucidated as Taraxerol (1), 1H-indole-3-carboxylic acid (2), (24R)-cycloartane-3β,24,25-triol (3), (24R,S)-3β-24,31-Epoxy-24-methylcycloartane(4),1-O-linolenoyl-3-O-β-D-galactospyranosyl-snglycerol (5), and Hyloglyceride (6). All compounds 1-6 were isolated from this plant for the first time.
Subjects: Biology >> Botany >> Applied botany submitted time 2022-03-30 Cooperative journals: 《广西植物》
Abstract： Keteleeria calcarea is a precious tree species in the mid-subtropical karst area, this species has a narrow distribution range and very few seedlings in wild populations, which severely limits the natural renewal of the population. In order to explore the causes for the endangerment of this species and provide reference for its protection and utilization, the cones and seeds morphological characteris-tics of K. calcarea were measured, and the effects of temperatures, light conditions, soil water con-tents, substrates, storage temperatures and time, and different geographical provenances on seed ger-mination were studied. The results were as follows: (1) The average seed setting rate of K. calcarea cone was 7.45%±6.54%, the seed wing length was 2.27±0.32 cm, the average seed length was 1.55±0.15 cm (excluding seed wing), the average width was 0.62±0.05 cm, the average thickness was 0.46±0.04 cm, and the average 1 000-seed weight was 214.81±14.76 g, the average water content of dried seeds was 15.28%±1.66%. (2) The optimum temperature for seed germination was 25 ℃, and the germination rate decreased significantly at 20 ℃ and 30 ℃ (P<0.05); Seed germination did not need light, but the germination rate under periodic light was significantly higher than that under con-tinuous light and continuous darkness (P<0.05); The seeds could germinate under the conditions of 10%-30% soil water contents, and could withstand a certain degree of drought; Peat soil and perlite with loose texture and good air permeability were suitable for germination; The seeds were not re-sistant to storage and should be sown in time after collection; The seed germination rate of Sanjiang population in Gongcheng County was the highest among the three geographical provenances. The seed setting rate of K. calcarea cone was low, the seed germination was strict with temperature, and the seed was easy to lose vigor, which may be an important reason for its endangerment.
Subjects: Biology >> Botany >> Applied botany submitted time 2021-07-20 Cooperative journals: 《广西植物》
Abstract： Plant species can adapt to heterogeneous habitats through variations in functional traits. For the plants with different growth forms, how to adjust their phenotypes to adapt to the environment has been one of the core topics in ecology. To clarify the response mechanisms of plant species with different growth forms to heterogeneous habitats in south subtropical forests, we measured a total of 8 functional traits involving 4 structural traits (leaf thickness, leaf length/width ratio, leaf dry matter content and leaf specific leaf area) and 4 stoichiometric traits (leaf N concentration, leaf P concentration, 13C and 15N) of 5 dominant trees (2 canopy species and 3 understory species) and their diameter at breast height, in 27 quadrats (20 m × 20 m) at different elevations and convexity along three mountain ridges within the 20-hm2 lower subtropical evergreen broad-leaved forest plot at Dinghu Mountain in Guangdong Province. We analyzed and compared the differences in responses of the canopy and understory species to different elevations and convexity in terms of functional traits. The results were as follows: (1) There existed some leaf functional traits in each tree species that were significantly correlated with altitude, but for convexity, only the leaf area of Cryptocarya chinensis was positively correlated with convexity and the leaf nitrogen content of Blastus cochinchinensis was negatively correlated with convexity. (2) Specific leaf area, leaf thickness and 15N were generally more responsive to elevation, while leaf length/width ratio and leaf dry matter content were less responsive. (3) There were significant differences in specific leaf area, leaf dry matter content and leaf N concentration between canopy and understory tree species in heterogeneous habitats. Compared with canopy tree species, understory tree species had lower leaf thickness, leaf dry matter content and 13C. Moreover, canopy and understory species responded to elevation and convexity to different extents, with understory species having more functional traits with significant differences in different types of habitats. The results indicate that the degree of response to the environment varied greatly between plants with different growth forms, i.e., the dominant understory tree species had greater plasticity in the heterogeneous habitats than the dominant canopy species in the forest plot. In addition, specific leaf area, leaf thickness and 15N are important and effective traits indicating plant adaptation and responses to the environment in the lower subtropical evergreen broad-leaved forest.
Subjects: Biology >> Botany >> Applied botany submitted time 2019-03-14 Cooperative journals: 《广西植物》
Abstract：试验以向日葵幼苗为试材，采用营养液培养法探索重金属镍胁迫对其生理生化指标的影响，揭示向日葵对镍胁迫的响应机制和幼苗生长发育的影响研究，为镍污染环境修复提供一定的科学依据。结果显示：低浓度的镍胁迫（≤10 mg•L-1）有利于幼苗的生长，高浓度的镍胁迫（≥50 mg•L-1）对幼苗具有明显的抑制作用。随着镍胁迫浓度逐渐增加，向日葵幼苗各项生理生化指标的变化较大，其中叶绿素、可溶性糖（SS）、可溶性蛋白（SP）、过氧化物酶（POD）活性、游离脯氨酸（Pro）的含量均在1~10 mg•L-1呈先上升趋势，50~100 mg•L-1呈下降的趋势；丙二醛（MDA）含量则呈现持续上升趋势。研究表明：向日葵幼苗对低浓度（1~10 mg•L-1）镍胁迫能通过自身调节，增加POD、Pro和MDA等物质的含量来提高对生态环境的抗逆能力，说明向日葵幼苗对重金属镍具有一定抗性，而高浓度（50~100 mg•L-1）镍胁迫会破坏其自身防御系统，影响幼苗的生长发育。
Subjects: Biology >> Botany >> Applied botany submitted time 2018-12-19 Cooperative journals: 《广西植物》
Abstract：锥栗C Castanea henryi Rehd. & Wils)是我国南方重要的木本粮食树种和特色果树资源，具有很高的食用及药用价值。为了探明最适宜锥栗种子萌发的条件，为锥栗种苗繁育提供理论基础，该试验以当年采收的锥栗种子为材料，研究了温度、光照、基质、基质含水量以及破壳处理等对锥栗种子萌发的影响。结果表明，锥栗种子萌发的最适温度是25℃，其最终萌发率为(92.672.67，在其它温度条件下，锥栗种子的萌发率有所下降，但与25 0C条件下的萌发率无显著差异;黑暗条件可缩短锥栗种子发芽时间，明显提高种子的萌发率和发芽势，但黑暗条件下的种子胚根长度显著小于周期性光照条件下的胚根长度;锥栗种子在泥炭土中的萌发率和发芽势均高于在河沙中的萌发率和发芽势，且泥炭土中种子胚根长度显著长于河沙中的种子胚根长度;基质含水量对锥栗种子萌发率和发芽势无显著性影响;种皮的机械阻碍是限制锥栗种子萌发的因素之一，破壳处理后，锥栗种子的萌发率明显提高，其发芽势和胚根长度与未破壳相比差异显著，实际生产中剪破种壳能加快种子的萌发进程。
Subjects: Biology >> Botany submitted time 2018-06-12 Cooperative journals: 《广西植物》
Abstract： 测定不同脱水程度金丝李（Garcinia paucinervis）种子的萌发情况及其复水后的吸水率、脱水过程中抗性生理指标的变化以及不同贮藏方式下种子的萌发情况，研究金丝李种子的脱水敏感性和储藏特性。结果显示：（1）金丝李种子初始含水量为45.29%，室温下放置35d失水率即达45%。（2）种子失水率低于18%时，萌发率和复水后的吸水率变化不显著；失水率超过18%时，萌发率和复水后吸水率均显著下降，失水率为42%时萌发率为0。其种子的临界含水量为27.29%，半致死含水量为12.72%。（3）随着种子脱水程度的加深，相对电导率、可溶性糖及脯氨酸含量逐步上升；丙二醛含量在失水率低于24%时变化不大，高于24%时显著提高；SOD和POD的活性均呈波动性变化，失水率为18%时活性均最高。（4）室温干藏1个月和-1℃、-20℃下湿藏1个月的种子均不能萌发；水浸贮藏1个月的种子萌发率显著降低；4℃湿藏1、3和6个月均显著延缓种子萌发，但对萌发率无显著影响。表明金丝李种子在失水率低于18%时，种子可通过抗性调节维持细胞的正常代谢，能忍受一定程度的脱水和低温，属于低度的顽拗性种子；当失水率超过18%时，种子代谢失衡发生劣变直至死亡。4℃湿沙藏（含水量7.5%）是短期贮藏其种子的较好方法。该研究为保育和利用珍稀濒危树种金丝李提供理论依据。
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