Subjects: Biology >> Botany >> Applied botany submitted time 2022-05-21 Cooperative journals: 《广西植物》
Abstract： To comprehensively understand the effects of selenium (Se) supplementation on Codonopsis pilosula, effects of sodium selenite levels on Se accumulation, growth, physiology and quality were explored by using hydroponic experiments. The results were as follows: (1)Treatment with 0.2 mg∙L-1 Se promoted leaf size, plant height and biomass of C. pilosula, while treatment with 10 mg∙L-1 Se suppressed them. (2)Both increasing Se level and exposure time to C. pilosula seedlings could raise its Se content in roots and leaves, and Se was distributed in organs with an order of root>leaf>stem. (3)Treatment with 0.2 mg∙L-1 Se increased photosynthetic pigment contents and root activity, and reduced malondialdehyde, proline and hydrogen peroxide content, while treatment with 10 mg∙L-1 Se had opposite effects. (4)Treatment with 0.2 mg∙L-1 Se had positive effects on accumulations of lobetyolin, polysaccharides, and soluble protein, while treatment with 10 mg∙L-1 Se had negative effects on the accumulations of polysaccharides and soluble protein. Collectively, sodium selenite had dual effects on C. pilosula; Application of appropriate Se was beneficial to its growth, plant physiology and quality, and 0.2 mg·L-1 Se level was the optimum. This work may improve our understanding the effect of selenite level on the biology effect of C. pilosula, which would be useful for the basic research and cultivation of Se-enriched C. pilosula.
Subjects: Biology >> Botany >> Applied botany submitted time 2020-10-20 Cooperative journals: 《广西植物》
Abstract：喀斯特地区群落结构动态研究，是生态重建和石漠化治理中需解决的关键问题。基于黔中普定县6 块永久监测样地在2013 年、2015 年和2019 年的监测资料，分析7 年间喀斯特次生林重要值、物种消长结构、物种多样性、径级结构和垂直结构的动态特征。结果表明：(1)刺楸（Kalopanax septemlobus）、朴树（Celtis sinensis）等乔木种的优势度增大，更新率较高，竹叶椒（Zanthoxylum armatum）、杭子梢（Campylotropis macrocarpa）和火棘（Pyracantha fortuneana）等先锋种的重要值减少，且死亡率较高。(2)物种多样性指数各年间无显著差异，物种丰富度和Margalef 丰富度指数呈先增加后减少的趋势，Shannon-Wiener 多样性指数基本稳定，均匀度指数呈先减少后增加趋势，其在2013 年和2019 年之间差异显著。(3)径级和树高结构呈“倒J 型”和“左偏正态”分布，各年间差异不显著，乔木层大径级（DBH≥10 cm）个体数增加，但高大乔木（H≥9 m）个体数和种数减少，灌木层中火棘、杭子梢和小冻绿树（Rhamnus rosthornii）等灌木种在0 m≤H＜3 m 和0 cm≤DBH＜2.5 cm 的个体数减少，而刺楸、朴树等乔木种个体数增加。喀斯特次生林的自然演替过程较缓慢且复杂多样，层次结构不明显，群落总体处于演替进展的中前期，群落更新良好，将进一步以乔木占优势的方向发展。
Subjects: Biology >> Botany >> Applied botany submitted time 2020-10-20 Cooperative journals: 《广西植物》
Abstract：本研究旨在探索硒酸钠浓度对茶树的生长和生理的影响，为富硒茶栽培的基础研究提供参考。以一年生扦插苗为材料，采用水培试验，研究不同浓度的硒酸钠(0、0.15、0.3、1.5、.3、5、8 mg‧L-1)对茶苗的硒积累、植株生长、生理指标和根尖显微结构等参数的影响。结果表明：茶苗的根和新梢中的硒含量与营养液中的硒浓度正相关；随着硒浓度升高，茶苗的鲜重、侧根数量、根系生物量、光合色素含量、根系活力等生长指标，茶多酚、可溶性糖等茶叶质量指标均呈现先升后降趋势，而丙二醛、过氧化氢、脯氨酸含量等抗逆生理指标则呈现先降后升趋势。显微结构分析显示在不同硒浓度处理条件下根尖的显微构造存在差异。低硒浓度(0.15、0.3、1.5 mg‧L-1)处理的茶苗根尖的皮层薄壁细胞饱满、完好，表皮细胞较小；高硒浓度(Se≥3 mg‧L-1)处理的茶苗根尖的皮层薄壁细胞变形或受损，表皮细胞增厚，表现出胁迫反应。上述结果说明硒对茶树具有双重效应：合适浓度(0.3 mg‧L-1)硒对茶树生长和茶叶品质有益，表现为光合作用和根系活力增强，过氧化物和脯氨酸含量降低，生物量增加，茶叶茶多酚含量增加；硒浓度过高(≥3 mg‧L-1)对茶苗的生长和茶叶品质有害，表现为茶苗出现胁迫反应，茶多酚降低。本工作为进一步研究茶硒对茶树的双重作用机制和富硒茶的栽培提供有益参考。
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