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 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 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 2018-10-26 Cooperative journals: 《广西植物》
Abstract：本研究以 6 个金槐品种和 2 个米槐品种的花粉为材料，采用美国卡尔蔡司 EVO18 扫描电镜对其极面、赤道面、外壁纹饰等形态特征进行了观察，并对金槐、米槐品种间的亲缘关系进行了分析。结果表明：金槐和米槐花粉的共有特征包括：极面观为三裂圆形，极面光滑；具 3 孔沟，沟较窄且达两极；沟缘中部外凸，具颗粒状突起；沟在极面上没有交会，形成宽大的沟界极区；金槐的花粉粒为长球形，金槐 J6 的极轴最长，金槐 J2 的极轴最短，极轴长/赤道轴长表现的规律与极轴长相一致；网眼直径最大的是金槐 J2，最小的是金槐 J5；网眼密度最大的是金槐 J6，最小的是金槐 J2；米槐的花粉粒为近圆球形，极轴长和极轴长/赤道轴长明显小于金槐，但其赤道轴长大于金槐；双季米槐的赤道轴长、极轴长、极轴长/赤道轴长、网眼密度都小于单季米槐；8 个品种可分为 3 组，其中金槐 J4、金槐 J1 和金槐 J6 3 个品种亲缘关系较近，金槐J5、金槐 J3 和金槐 J2 3 个品种亲缘关系较近，单季米槐和双季米槐 2 个品种亲缘关系较近；花粉形态是鉴别金槐和米槐两大类品种的重要根据，并可为进一步的品种划分提供重要依据。
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