Search

To comprehensively understand the effect 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 contents in root and leaf, 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 content and root activity, and reduced malondialdehyde, proline and hydrogen peroxide contents, 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, polysaccharide, and soluble protein, while treatment with 10 mg·L-1 Se had negative effects on the accumulations of polysaccharide and soluble protein. In summary, sodium selenite has double effect on C. pilosula; application of appropriate Se is beneficial to its growth, plant physiology and quality, and 0.2 mg·L-1 Se level is the optimum. This study may improve us to understand the effect of selenite level on the biology effect of C. pilosula, which will be useful for the basic research and cultivation of Se-enriched C. pilosula. [ABSTRACT FROM AUTHOR]

The restoration and reconstruction of mangrove wetland ecosystem is one of the key research fields in ecological restoration in the coastal zone of South China. In order to reveal the physiological and ecological strategies to light conditions of mangrove species, the characteristics of leaf soluble protein contents and activities of antioxidant enzymes in seedlings of eight mangrove species(Sonneratia apetala, Kandelia obovata, Bruguiera gymnorhiza, Aegiceras corniculatum, Acanthus ilicifolius, Acrostichum aureum, Heritiera littoralis and Hibiscus tiliaceus)under different light intensity treatments(100%, 45%, 30%, and 10% of natural light intensity)were studied using shading control experiment. The results were as follows:(1)Low light intensities had little effect on the leaf soluble protein contents of Bruguiera gymnorhiza, Acanthus ilicifolius and Acrostichum aureum, whereas the other five species showed a decreasing trend of leaf soluble protein contents with the decline in light intensity.(2)The activities of superoxide dismutase(SOD)and ascorbate peroxidase(APX)in the leaves of Bruguiera gymnorhiza, Acanthus ilicifolius and Acrostichum aureum under 10% of natural light intensity treatment had no significant differences compared with the control, while the other five mangrove species showed a decreasing trend of all the five antioxidant enzyme activities. In conclusion, the results indicate that Bruguiera gymnorhiza, Acanthus ilicifolius and Acrostichum aureum are suitable to be planted under the forest with high canopy density, while Sonneratia apetala, Kandelia obovata, Aegiceras corniculatum, Heritiera littoralis, Hibiscus tiliaceus are suitable to be planted under the forest with lower canopy density or planted as middle and upper layer tree species in mangrove. The results of this study provide theoretical guidance for the optimal allocation of artificial mangrove communities. [ABSTRACT FROM AUTHOR]

Copyright of Guihaia is the property of Guihaia Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The dynamic study of community structure in karst area is a key problem to be solved in ecological reconstruction and rocky desertification control. Based on the monitoring data of six permanent monitoring sample plots in Puding County of Central Guizhou Province in 2013, 2015 and 2019, the dynamic characteristics of important value, species fluctuation structure, species diversity, diameter class structure and vertical structure of karst secondary forest in seven years were analyzed. The results were as follows:(1)The dominant degree and regeneration rate of Kalopanax septemlobus and Celtis sinensis increased, while the important values of Zanthoxylum armatum, Campylotropis macrocarpa and Pyracantha fortuneana decreased, and the mortality rate was higher.(2)There was no significant differences in species diversity indexes between different years. Species richness and Margalef richness index increased first and then decreased. Shannon-Wiener diversity index was basically stable, and uniformity index decreased first and then increased, the differences were significant between 2013 and 2019.(3)The distribution of diameter class and tree height showed “inverted J” and “left partial normal” distribution, and there was no significant differences in different years. The number of individuals of large diameter class(DBH≥10 cm)increased, but the number of tall trees(H≥9 m)decreased. In the shrub layer, the number of individuals of Pyracantha fortuneana, Campylotropis macrocarpa and Rhamnus rosthornii at 0≤H<3 m and 0≤DBH<2.5 cm, decreased, while the number of individual tree species such as Kalopanax septemlobus and Celtis sinensis increased. The natural succession process of karst secondary forest is slow and complex, and the hierarchical structure is not obvious. The community is in the middle and early stage of succession, and the community regeneration is good, which will further develop in the direction of arbor dominance [ABSTRACT FROM AUTHOR]

Copyright of Guihaia is the property of Guihaia Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Guihaia is the property of Guihaia Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Guihaia is the property of Guihaia Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Mangrove associates are a category of plants that can grow and reproduce on both intertidal coastal zones and land. As subtropical coastal zones are characterized by high sun light and temperature, how mangrove associates adapt to such an environment is an important issue. Some researches show that mangrove associates are similar to land plant as well as thalassophyte in certain morphological structures and biochemical characteristics. However, there are few studies focusing on plant physiological characteristics of mangrove associates, especially in leaf gas exchange characteristics. Hibiscus tiliaceus(Malvaceae)is a pantropical mangrove associate that usually occurs in coastal zones. It is widely used for the conservation of sea banks, architecture and medicine. In order to disentangle the photosynthetic physiological mechanims underlying its habitat adaptation to high light and temperature under south subtropical climate, leaf gas exchange characteristics of H. tiliaceus were measured using LI-6400 portable photosynthesis system(Li-Cor Inc, USA)at Mangrove Natural Reserve of Qi'ao Island of Zhuhai City, Guangdong Province during July and August of 2013. The nature reserve(22°23'40'' N, 113°36'40'' E)is characterized by a typical south subtropical monsoon climate. The diurnal changes in photosynthetic rate(Pn), stomatal conductance(Gs), intercellular CO2 concentration(Ci)and transpiration rate(E)in H. tiliaceus all exhibited a mono-peak modal, and the peak value of Pn occurring at noon was around 26.8 μmol CO2 · m-2 · s-1 without obvious photoinhibition during the daytime. The high photosynthetic rate in H. tiliaceus was associated with high stomatal conductance, which was probably related to anatomical features of leaves, such as high stomatal density and dense trichomes in the lower leaf epidermis. Analysis of light response curves revealed that its light saturation point was 800 μmol photons·m-2 ·s-1 and its light compensation point was 26 μmol photons·m-2 ·s-1. The net photosynthesis at saturating irradiances was high at 27.8 μmol CO2 · m-2 · s-1. These photosynthesis parameters, along with high daily mean photosynthetic rate(19.6 μmol CO2 · m-2 · s-1)in H. tiliaceus suggested that this mangrove associate was characterized as a typical sun plant species. The results showed that the fast growth of H. tiliaceus might be attributed to its high and stable photosynthetic capacity, thus providing basic data for further revealing the eco-physiological mechanism underlying habitat adaptation of H. tiliaceus and other mangrove associates to coastal environment with high temperature and high light in summer. These results can also provide theoretical supports for its planting and reforestation practices. [ABSTRACT FROM AUTHOR]

Copyright of Guihaia is the property of Guihaia Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)