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, Available online doi: 10.11833/j.issn.2095-0756.20240399
Abstract:
Objective Quantitatively evaluate the eco-hydrological effects of litter layer of typical plantations in central Yunnan, is aimed to provide theoretical basis for plantation water storage capacity and realizing forest ecosystem sustainable management. Method With 3 typical plantations (over-matured Eucalyptus benthamil, over-matured Pinus armandii, medium-aged E. benthamil) selected as the research objects, field investigation, indoor immersion experiment, water loss experiment and laboratory rainfall simulation experimental analysis was conducted of the eco-hydrological effects in plantation. Result (1) The total litter stocks range of typical plantations in central Yunnan is 13.07−16.84 t·hm−2, and over-matured P. armandii＞medium-aged E. benthamil＞over-matured E. benthamil. The total thickness of over-matured Eucalyptus benthamil in the 3 kinds of plantation forests was significantly greater than that of medium-aged E. benthamil. (2) The natural moisture content of litter in three types of plantations ranged from 42.28%−78.51%. Both indoor soaking experiments and artificial rainfall simulation tests demonstrated that the water-holding capacity of the litter, and over-matured P. armandii＞medium-aged E. benthamil＞over-matured E. benthamil. The impact of rainfall intensity on the litter's water-holding performance was not significant. (3) The cumulative water uptake (loss) of litter in each forest type was a logarithmic function with time, and the rate of water uptake (loss) was a power function with time. (4) The 3 typical stands water loss process of litter was a change process from rapid water loss to slow water loss and then to gradual non-water loss, which better reflected the water holding capacity of litter. Conclusion The results of laboratory rainfall simulation and litter indoor immersion experiments were consistent, the natural water content and water-holding (interception) performance of the over-matured E. benthamil are the minimum. Based on the water holding capacity and evaporation of litter of 3 typical plantations in central Yunnan, it is suggested that the area of over-matured Eucalyptus spp. forest should be appropriately reduced and the planting proportion of P. armandii should be increased from the aspect of water conservation. [Ch, 5 fig. 3 tab. 29 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240378
Abstract:
Objective The objective is to analyze the ecological niche and interspecific relationship of Machilus and Phoebe forest in Jiande Forest Park, home to the largest existing natural Machilus and Phoebe forest in Asia, so as to provide theoretical basis for its protection, population restoration and near-nature management. Method Based on the survey data of 1 hm2 sample plot in July 2023, the ecological niche and interspecific association of 19 dominant tree species with important values≥1% were examined, including M. pauhoi, M. leptophylla, M. thunbergii, and P. sheareri, through species composition, niche breadth, niche overlap index, χ2 test, variance ratio method, interspecific association coefficient, and co-occurrence percentage. Result (1) M. pauhoi had the highest important value (23.44%), and was the constructive species of the community. The important values of M. leptophylla, M. thunbergii, and P. sheareri were 1.20%−1.80%, ranking after the 12th place. (2) In the sample plots, there was a high niche overlap between M. pauhoi and other dominant tree species, among which the ecological niche overlap value with M. leptophylla was as high as 0.87. The niche overlap values between M. leptophylla, M. thunbergii, P. sheareri, and other tree species were relatively small, ranging from 0.10 to 0.50. (3) There was a significant positive correlation (P＜0.05) among the dominant trees in Machilus and Phoebe forest in Jiande. The χ2 test, interspecific association coefficient, and percentage of co-occurrence revealed that there was a strong correlation between M. pauhoi and 18 dominant tree species, while the correlation between M. leptophylla, M. thunbergii, and P. sheareri and the dominant tree species was weak. (4) Regression analysis showed that interspecific association coefficient, and percentage of co-occurrence of the main dominant tree species were significantly positively correlated with the ecological niche overlap value (P＜0.01). Conclusion The species of Machilus and Phoebe forest in Jiande are relatively independently distributed and in the middle stage of succession, with loose interspecific relationship. Appropriate measures such as selective logging and understory replanting can be taken to achieve long-term stable growth of Machilus and Phoebe trees. [Ch, 4 fig. 2 tab. 33 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240426
Abstract:
Objective This study aims to screen a high-yielding indoleacetic acid strain from earthworm compost, and optimize its fermentation parameters to increase indoleacetic acid yield, so as to provide reference for enriching indoleacetic acid producing resource pool and preparing high-quality bacterial fertilizers. Method Salkowski colorimetric method combined with high-performance liquid chromatography was used to screen high-yielding strains of indoleacetic acid, and the target strains were identified through 16S rRNA sequence analysis. The metabolites of the target strains were analyzed by liquid chromatography-mass spectrometry, and the synthesis pathway of indoleacetic acid was explored based on metabolomics analysis. Single factor experiments were performed to optimize the fermentation parameters of the target strains for producing indoleacetic acid. The effect of the target strains on promoting seed germination was evaluated through seed germination experiments. Result A new strain with high indoleacetic acid yield of 39.99 mg·L−1was isolated from earthworm compost. It was identified as Bacillus sp. by 16S rRNA sequencing analysis and named GA2022. The optimum fermentation parameters for producing indoleacetic acid from strain GA2022 were incubation time 36 h, inoculum amount 2% (v/v), NaCl concentration 20 g·L−1, initial pH 8, L-tryptophan concentration 3.0 g·L−1, and incubation temperature 40 ℃. Under these optimal conditions, the indoleacetic acid yield of strain GA2022 could reach 204.25 mg·L−1, which was 410.75% higher than that before optimization. The results of mass spectrometry showed that this strain might possess 3 indoleacetic acid synthesis pathways, namely indole-3-acetamide pathway, indole-3-pyruvate pathway, and indole-3-ethanol pathway. The strain could promote the seed germination of Brassica rapa var. chinensis. Conclusion A high-yielding indoleacetic acid strain GA2022 is obtained from earthworm compost. The simultaneous coexistence of 3 indoleacetic acid synthesis pathways endows it with high indoleacetic acid production capacity and saline-alkali tolerance. [Ch, 7 fig. 1 tab. 31 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240219
Abstract:
Objective Bag controlled release fertilizer has the characteristics of wrapping the fertilizer and controlling the nutrient release through biodegradable materials. The study of bag controlled release fertilizer for Lei bamboo (Phyllostachys violascens) forests was carried out in order to reduce the loss of fertilizers and improve the nutrient utilization rate, which in turn increased the yield of Lei bamboo shoots. Method Twelve experimental plots of Lei bamboo forest were randomly selected, and four treatments were set up, namely, bag controlled release fertilizer, spreading compound fertilizer, hole-applied compound fertilizer, and no fertilizer (the control) with each treatment replicated for three times. The differences in nutrient loss, fertilizer utilization, and bamboo shoot yield among different treatments were analyzed by determining the indexes such as ammonia volatilization, the changes of N, P, and K contents of runoff and seepage liquid, and the changes in the appearance and quality of bagged controlled-release fertilizer under different treatments. Result Bag controlled-release fertilizer significantly reduced soil ammonia volatilization as well as nutrients lost by runoff leakage, in which the cumulative ammonia volatilization of bag controlled release fertilizer treatments was reduced by 35.5% and 40.5% compared to sprinkled compound fertilizer and hole-applied compound fertilizer, respectively. The amount of total nitrogen, total phosphorus and total potassium in the soil leachate of bagged controlled-release fertilizers was reduced by 33.9%−40.3%, 41.3%−45.1% and 36.7%−39.7%, respectively, compared with that of sprinkler-applied fertilizers and hole-applied fertilizers. Bagged controlled-release fertilizers reduced the amount of total nitrogen and phosphorus in soil runoff liquid by 22.8% to 29.2% and 36.4% to 44.3%, respectively, compared to spreading fertilizers and hole-applied compound fertilizers. And the fertilizer efficacy period of bagged controlled-release fertilizer in Lei bamboo forest was about 5.0 months, and the time of complete release of fertilizer was 6.5 months. The release rate of bagged controlled-release fertilizer was slower in the early stage of application, and the rate of release reached the maximum in the 2nd−3rd month after the application of fertilizer. The apparent utilization rate of nitrogen, phosphorus and potassium in the bag controlled-release fertilizer treatment was greater than that in the spreading compound fertilizer treatment, in which the apparent utilization rate of nitrogen was increased by 27.74%, which was 2.89 times higher than that in the spreading compound fertilizer treatment. The shoot yield of bag controlled-release fertilizer treatment reached 14.7 t·hm−2, which was 62.1% and 25.8% higher than that of the control and spreading compound fertilizer treatment, respectively. Conclusion Bag-controlled release fertilizer effectively enhance the shoot yield of Lei bamboo and the efficiency of fertilizer utilization, while concurrently mitigating nutrient loss and environmental pollution. [Ch, 6 fig. 3 tab. 34 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240397
Abstract:
Leaf color variation in plants is a common and easily recognized phenomenon in nature, which affects the photosynthetic efficiency of plants and leads to poor growth, so it was once considered to be an undesirable variation and gradually eliminated. But in recent years, social advancements and increased demand for ornamental landscaping have brought renewed attention to leaf color mutants. Leaf color mutants are generally regulated at the molecular level, resulting in abnormal chloroplast structure, inhibited photosynthesis, and abnormal pigment synthesis and metabolic pathways. Therefore, they serve as ideal materials for studying pigment metabolism, chloroplast development and differentiation, photosynthesis, and related pathways, and can also provide important information for variety improvement. This paper reviews the research progress of leaf color mutants in recent years, and clarifies that leaf color mutants in higher plants mainly come from natural mutation and artificial mutation. Leaf color mutants can be divided into several types based on color, such as yellowing, yellow green, green yellow, green white, albino, light green, white emerald, stripe and so on. According to the way of leaf color change, leaf color mutants can be divided into monochromatic mutation, variegated mutation and stage chlorosis. Its inheritance mode is generally divided into nuclear inheritance, cytoplasmic inheritance and nucleocytoplasmic interaction inheritance. Compared with normal green leaf plants, the net photosynthetic rate, stomatal conductance, transpiration rate of most leaf color mutants decrease, so does the utilization rate of carbon dioxide. Mutations in genes related to synthesis and metabolism of chlorophyll, carotenoids, and flavonoids (particularly anthocyanins), as well as genes involved in chloroplast differentiation and development, can explain the molecular mechanism underlying leaf color mutants. Leaf color mutants can be applied in landscaping and widely used in basic research and breeding as excellent experimental materials. The findings of this review can provide theoretical reference for further research on leaf color variation. [Ch, 112 ref.]
Leaf color variation in plants is a common and easily recognized phenomenon in nature, which affects the photosynthetic efficiency of plants and leads to poor growth, so it was once considered to be an undesirable variation and gradually eliminated. But in recent years, social advancements and increased demand for ornamental landscaping have brought renewed attention to leaf color mutants. Leaf color mutants are generally regulated at the molecular level, resulting in abnormal chloroplast structure, inhibited photosynthesis, and abnormal pigment synthesis and metabolic pathways. Therefore, they serve as ideal materials for studying pigment metabolism, chloroplast development and differentiation, photosynthesis, and related pathways, and can also provide important information for variety improvement. This paper reviews the research progress of leaf color mutants in recent years, and clarifies that leaf color mutants in higher plants mainly come from natural mutation and artificial mutation. Leaf color mutants can be divided into several types based on color, such as yellowing, yellow green, green yellow, green white, albino, light green, white emerald, stripe and so on. According to the way of leaf color change, leaf color mutants can be divided into monochromatic mutation, variegated mutation and stage chlorosis. Its inheritance mode is generally divided into nuclear inheritance, cytoplasmic inheritance and nucleocytoplasmic interaction inheritance. Compared with normal green leaf plants, the net photosynthetic rate, stomatal conductance, transpiration rate of most leaf color mutants decrease, so does the utilization rate of carbon dioxide. Mutations in genes related to synthesis and metabolism of chlorophyll, carotenoids, and flavonoids (particularly anthocyanins), as well as genes involved in chloroplast differentiation and development, can explain the molecular mechanism underlying leaf color mutants. Leaf color mutants can be applied in landscaping and widely used in basic research and breeding as excellent experimental materials. The findings of this review can provide theoretical reference for further research on leaf color variation. [Ch, 112 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240564
Abstract:
Soil carbon (C), nitrogen (N) and phosphorus (P) stoichiometric characteristics are indicators to characterize the composition of soil organic matter and nutrient availability, which play a key role in understanding the carbon, nitrogen and phosphorus cycle in soil and the balance of ecosystem. However, the current research on the specific effects of each driving factor on soil stoichiometric characteristics needs to be further strengthened. By analyzing the annual publications and research hotspots in the field of soil ecological stoichiometry home and abroad in the past 15 years, we discussed the changes of soil ecological stoichiometric characteristics in 4 parts: biological factors (plant, soil microorganism and soil animal), natural environmental factors (geological hazard, topography and soil parent material), global climate change factors (climate warming, extreme weather, nitrogen deposition, acid rain) and human activity (land use pattern). The driving factors of the change of soil ecological stoichiometric ratios were discussed, and the law and internal mechanism of the change of soil carbon, nitrogen and phosphorus stoichiometric ratios were expounded. The results showed that plant, soil microorganism, soil animal and their interactions jointly drive soil carbon, nitrogen and phosphorus cycle. Soil animals affect microbial community structure through feeding and thus influence soil carbon turnover. The complexity of microbial community regulates soil C-N-P coupling. Geological disasters disturb the balance of soil stoichiometry through nutrient loss and decreased microbial activity. Topography, climate warming and extreme climate indirectly affect soil stoichiometry by changing water and heat conditions, whereas the mineral composition and structure of parent material directly regulate soil C∶N∶P. Nitrogen deposition and acid rain affect plant growth and soil microbial activity through soil acidification and nutrient loss and thus change soil C-N-P stoichiometry. Land use patterns directly or indirectly affect soil stoichiometry through agricultural management and vegetation cover. Environmental factors affect soil C-N-P stoichiometry through biotic factors, directly or indirectly, but with uncertain direction and degree. Further study should pay attention to the synergistic effect of multiple factors and multi-path regulation mechanism so as to provide a reference for soil nutrient management and ecosystem stability in the context of global change. [Ch, 3 fig. 70 ref.]
Soil carbon (C), nitrogen (N) and phosphorus (P) stoichiometric characteristics are indicators to characterize the composition of soil organic matter and nutrient availability, which play a key role in understanding the carbon, nitrogen and phosphorus cycle in soil and the balance of ecosystem. However, the current research on the specific effects of each driving factor on soil stoichiometric characteristics needs to be further strengthened. By analyzing the annual publications and research hotspots in the field of soil ecological stoichiometry home and abroad in the past 15 years, we discussed the changes of soil ecological stoichiometric characteristics in 4 parts: biological factors (plant, soil microorganism and soil animal), natural environmental factors (geological hazard, topography and soil parent material), global climate change factors (climate warming, extreme weather, nitrogen deposition, acid rain) and human activity (land use pattern). The driving factors of the change of soil ecological stoichiometric ratios were discussed, and the law and internal mechanism of the change of soil carbon, nitrogen and phosphorus stoichiometric ratios were expounded. The results showed that plant, soil microorganism, soil animal and their interactions jointly drive soil carbon, nitrogen and phosphorus cycle. Soil animals affect microbial community structure through feeding and thus influence soil carbon turnover. The complexity of microbial community regulates soil C-N-P coupling. Geological disasters disturb the balance of soil stoichiometry through nutrient loss and decreased microbial activity. Topography, climate warming and extreme climate indirectly affect soil stoichiometry by changing water and heat conditions, whereas the mineral composition and structure of parent material directly regulate soil C∶N∶P. Nitrogen deposition and acid rain affect plant growth and soil microbial activity through soil acidification and nutrient loss and thus change soil C-N-P stoichiometry. Land use patterns directly or indirectly affect soil stoichiometry through agricultural management and vegetation cover. Environmental factors affect soil C-N-P stoichiometry through biotic factors, directly or indirectly, but with uncertain direction and degree. Further study should pay attention to the synergistic effect of multiple factors and multi-path regulation mechanism so as to provide a reference for soil nutrient management and ecosystem stability in the context of global change. [Ch, 3 fig. 70 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240375
Abstract:
Nitrous oxide (N2O) is the third most important greenhouse gas next to carbon dioxide and methane. Forest restoration may mediate the changes in plant-soil biological-physicochemical environment, and thereby significantly affect the dynamics of soil N2O emissions. It is of great scientific significance to explore the biotic and abiotic mechanisms of the impact of forest restoration on soil N2O emissions. In this study, four microbial pathways (autotrophic nitrification, heterotrophic nitrification, biological denitrification and nitrifying bacterial denitrification) of N2O produced from forest soil were reviewed. The regulation mechanisms of biotic factors (litter, root biomass, root exudates, soil microorganisms and animal communities) and abiotic factors (climate type, temperature, moisture, pH, carbon pool, as well as nitrogen, phosphorus and potassium pools) affecting soil N2O emissions during forest restoration were discussed. At present, research about the effect of forest restoration on soil N2O emissions mainly focuses on the analysis of single-factor mechanism, while there is a relative lack of research on the mechanism of multi-factor coupling in regulating the direction, intensity and dynamics of forest soil N2O emissions. Future research on the regulatory mechanism of greenhouse gas emissions from forest soil should focus on the synergistic direct or indirect effects of multiple factors of “plant-microbial-soil fauna-physicochemical environment” under the background of global climate change intensification, so as to provide key theoretical support for accurately predicting the impact of forest restoration on global climate change. [Ch, 91 ref.]
Nitrous oxide (N2O) is the third most important greenhouse gas next to carbon dioxide and methane. Forest restoration may mediate the changes in plant-soil biological-physicochemical environment, and thereby significantly affect the dynamics of soil N2O emissions. It is of great scientific significance to explore the biotic and abiotic mechanisms of the impact of forest restoration on soil N2O emissions. In this study, four microbial pathways (autotrophic nitrification, heterotrophic nitrification, biological denitrification and nitrifying bacterial denitrification) of N2O produced from forest soil were reviewed. The regulation mechanisms of biotic factors (litter, root biomass, root exudates, soil microorganisms and animal communities) and abiotic factors (climate type, temperature, moisture, pH, carbon pool, as well as nitrogen, phosphorus and potassium pools) affecting soil N2O emissions during forest restoration were discussed. At present, research about the effect of forest restoration on soil N2O emissions mainly focuses on the analysis of single-factor mechanism, while there is a relative lack of research on the mechanism of multi-factor coupling in regulating the direction, intensity and dynamics of forest soil N2O emissions. Future research on the regulatory mechanism of greenhouse gas emissions from forest soil should focus on the synergistic direct or indirect effects of multiple factors of “plant-microbial-soil fauna-physicochemical environment” under the background of global climate change intensification, so as to provide key theoretical support for accurately predicting the impact of forest restoration on global climate change. [Ch, 91 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240347
Abstract:
Objective The study of physiological characteristics of Lagerstroemia indica flowers during the opening process provides reference for further floral regulation. Method This study took the petals of L. indica in different periods of flower opening as experimental materials, and investigated the physiological and biochemical changes, including cell morphology change, cell relative water content, carbohydrate content and endogenous hormone content. The correlations between the indicators were analyzed by Pearson detection method. Result According to the phenological observation, the single flower opening process can be divided into 4 periods: tight bud stage (S1), flower bud expansion stage (S2), early blooming stage (S3) and full blooming stage (S4). Scanning electron microscope observation showed that the upper and lower epidermal cells of the petals gradually expanded during flower opening, and there were undulating, striped and radial patterns on the cell surface with the progress of flower opening, and the area of the lower epidermal cells was larger than the area of the upper epidermis in each stage. The relative water content of petals, sepals and the whole bract/whole flower showed an overall increasing trend, the total soluble sugar content also showed an overall increasing trend, and the starch content showed an increasing and then decreasing trend. Abscisic acid (ABA) content was relatively low and changed steadily, the content of auxin (IAA) and gibberellin (GA3) was low and the overall expression trend was different, the content of zeatin riboside (ZR) was higher and the change was larger, and the ratio of ZR/ABA was larger and the change was large. Correlation analysis showed highly significant positive correlation (P＜0.01) between the 9 indicators, significant negative correlation (P＜0.05) between starch content and sucrose content, and non-significant correlation between starch content and other indicators. Conclusion During the opening process of L. indica, accompanied by significant changes in the morphology of the upper and lower epidermal cells of the petals, increase in relative water content of floral cells, rise in carbohydrate content and dynamic adjustment of endogenous hormone content, these changes jointly promoted the normal opening of L. indica flowers. [Ch, 6 fig. 1 tab. 33 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240505
Abstract:
Objective The objective is to analyze the variation characteristics and driving factors of functional traits of Salix matsudana, a common species distributed along the precipitation gradient, and reveal the adaptation mechanism and potential of S. matsudana under climate change. Method From July to September 2021, taking the transect from southeast to northwest of China as its research platform, 10 sampling points were selected along the precipitation gradient in Xuancheng, Xinyang, Sanmenxia, Tongchuan, Qingyang, Wuzhong, Jinchang, Zhangye, Jiuquan, and Hami. The common species of S. matsudana was used as the target plant and 16 functional traits including leaf mass per area (ALM), Huber value (Hv), and maximum net photosynthetic rate per unit mass (Amass) were measured. One-way ANOVA and plant trait network were used to explore the variation characteristics and adaptation strategies of S. matsudana in the precipitation gradient. The main climatic factors driving trait variation were further revealed by hierarchical partitioning method. Result (1) There were regional differences in functional traits of S. matsudana. Amass, Hv and ALM all reached extreme values under moderate rainfall. Amass and Hv in semi-humid and semi-arid regions were significantly higher than those in humid and arid regions (P＜0.05), while ALM was the opposite, significantly lower in semi-humid and semi-arid regions than in humid and arid regions (P＜0.05). (2) S. matsudana exhibited higher resource utilization efficiency in semi-humid and semi-arid regions with more favorable conditions, where the average path length was shorter, and the average clustering coefficient and edge density were higher. The average path length in descending order was as follows: arid region (2.124), humid region (2.013), semi-humid region (1.838), and semi-arid region (1.681). The average clustering coefficient from high to low was semi-arid region (0.750), semi-humid region (0.700), arid region (0.576), and humid region (0.505). The semi-humid region had the highest edge density, which was 0.400, followed by the semi-arid region at 0.325. (3) The contribution rate of climatic factors to the variation of the overall functional traits of S. matsudana along precipitation gradient from high to low was as follows: mean annual precipitation (21.57%), photosynthetically active radiation during the growing season (19.73%), and mean temperature during the growing season (11.94%), totalling 53.24%. Conclusion Precipitation change is the main climatic factor driving the regional differentiation of functional traits of S. matsudana. [Ch, 4 fig. 3 tab. 40 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240486
Abstract:
Objective This study aims to explore the spatial distribution pattern and correlation of the major tree species in deciduous broad-leaved forests in the transition zone from northern margin of subtropical zone to warm temperate zone in China. Method Taking the deciduous broad-leaved forest of Tianma National Nature Reserve as research object, the adjacent grid method was used to divide the forest into nine 24 m × 24 m sample plots. The names and spatial coordinates of tree species with diameter at breast height (DBH) ≥ 2.5 cm in the sample plots were recorded. The major tree species were determined based on their important values. The spatial distribution pattern and correlation of major tree species were analyzed by using spatial point pattern O-ring function, complete spatial stochastic zero model, and heterogeneous Poisson zero model. Result There were 27 species belonging to 20 genera and 17 families in Mazongling area of Tianma National Nature Reserve, with Quercus serrata and Castanea seguinii as dominant species, and Platycarya strobilacea as subdominant species. The diameter structure of trees showed an inverted “J”-type distribution. The spatial pattern results showed that the dominant tree species were initially clustered in 0−30 m scale, and gradually tended to be irregular and random with the increase of the scale. The spatial correlation analysis revealed that there was no significant correlation among the three dominant tree species (i.e., Q. glandulifera var. brevipetiolata, C. seguinii, and P. strobilacea). However, there was some correlation among the three dominant species and their companion tree species at a certain scale. Conclusion The community type is typical heterogeneous forests of Quercus spp. and P. strobilacea deciduous broad-leaved forests. Q. serrata forest regeneration was better and had an increasing trend, while the regeneration of C. seguinii and P. strobilacea forests was poor and the growth trend was not obvious. With the succession of the community, the light-loving and slightly shade-tolerant species will gradually replace the light-loving species. [Ch, 4 fig. 2 tab. 35 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240361
Abstract:
Objective The objective is to achieve a green method for the preparation of bamboo carbon quantum dots and to improve the utilization efficiency and added value of waste biomass materials. Method Fluorescent carbon quantum dots were prepared by a one-step hydrothermal method using bamboo waste materials (bamboo septa) as the initial carbon source and water as the solvent. The micro-morphology, chemical structure and optical properties of the carbon quantum dots of bamboo septa were characterized and analyzed by means of transmission electron microscopy, X-ray diffraction, infrared spectrometry, X-ray photoelectron spectroscopy, UV-visible photometry and fluorescence spectroscopy. Result The shape of the prepared carbon quantum dots had a near-circular shape, with a size distribution of 0−1.6 nm. The absolute fluorescence quantum yield was 6.85%, and they had excellent fluorescence properties, with a blue fluorescence under a 365 nm ultraviolet lamp. Conclusion The prepared carbon quantum dots aqueous solution is environmentally friendly and has good performance, which can be further optimized for application in the field of fluorescence anti-counterfeiting of wood materials such as furniture wood products and artificial boards. [Ch. 7 fig. 35 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240461
Abstract:
Objective This study, with an investigation into the response of yield and active component accumulation of medicinal plants to the regulation of forest canopy density and litter treatment, is aimed to provide theoretical basis for the regulation of light intensity and nutrient content of medicinal plants in simulated cultivation. Method Corydalis yanhusuo, a medicinal plant under Chinese fir (Cunninghamia lanceolata) forest plantation, was first selected as the research object before two-factorial split plot design was employed to explore the impact of three canopy density treatments (high, medium and low) and two litter treatments (i.e., removal and mulching) on the yield and active accumulation component of Corydalis yanhusuo. Result The yield of tuber and tetrahydropalmatine content of Corydalis yanhusuo were significantly affected by canopy density, litter and their interaction with the yield decreasing when the litter was removed and the tetrahydropalmatine content increasing with the increase of canopy density. The yield and tetrahydropalmatine content of the three treatments did not show a consistent pattern with the increase of canopy density when litter was covered. According to the radar map, the best planting scheme was to remove litter at low canopy density. Plant biomass, soil organic carbon and soluble nitrogen contents were the important factors affecting tuber yield, while net photosynthetic rate, soil available phosphorus and organic carbon contents were the important factors affecting tetrahydropalmatine content. Conclusion The litter removal treatment with low canopy density can significantly increase the tuber yield of Corydalis yanhusuo and maintain the tetrahydropalmatine content. [Ch, 3 fig. 4 tab. 35 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240371
Abstract:
Objective The objective is to analyze the chloroplast genome characteristics of four published plants in the genus Pennisetum, and to develop corresponding molecular markers. This will provide new insights into the evolutionary and phylogenetic relationships of Pennisetum. Method Bioinformatics methods were used to analyze the complete chloroplast genome sequences of four species of Pennisetum published in the NCBI database. The analysis included repeat sequences, codon preferences, polymorphisms, collinearity, and development of simple sequence repeat (SSR) molecular markers. Result The chloroplast genome length and GC content of the 4 species of Pennisetum are relatively similar, with a low degree of codon shift. Boundary expansion analysis indicates no significant contraction between different regions. Collinearity analysis shows strong inter-species collinearity among the 4 species of Pennisetum. Phylogenetic analysis based on chloroplast genome sequences reveals that P. flaccidum has the closest phylogenetic relationship with P. glaucum, P. purpureum, and P. alopecuroides. 5 pairs of SSR molecular markers have high practicality in plant species within the genus Pennisetum. Specifically, primer SSR2 is expressed in both P. flaccidium and P. alopecuroides; while primer SSR5 is specifically expressed in P. flaccidum. Additionally, SSR1, SSR3, and SSR4 show high conservatism among all four species in this genus. Conclusion This study concludes that the chloroplast genomes of these 4 species are relatively conserved; furthermore, it confirms that genetic relationship between P. flaccidium is closest to those found in P. flaccidum, P. purpureum as well as P. alopecuroides. SSR2 molecular markers are specifically expressed in both P. flaccidium and P. alopecuroides, while SSR5 molecular markers are specifically expressed in P. flaccidum. [Ch,7 fig. 2 teb. 28 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240423
Abstract:
Objective This study, with an exploration of the structure and species composition of the plant community of Dachen Island and its relationships with soil factors, is aimed to provide a scientific basis for its maintenance and management. Method Based on the investigation of 15 plots (20 m × 20 m) on Dachen Island and combining with the method of Redundancy Analysis (RDA), a study was conducted of its species composition, diameter structure, community similarity and environmental factors. Result The Dachen Island community boasts a record of 34 species of woody plants, which belong to 26 families and 32 genera. The size-class distribution of species individuals was generally inverse J-shaped. The communities dominated by Casuarina equisetifolia had higher value of diversity indexes, while those dominated by Eurya japonica and Ficus erecta had lower value diversity indexes. The communities dominated by E. japonica and Dalbergia odorifera and those dominated by E. japonica and Clerodendrum trichotomum had the highest similarity coefficient, while the community dominated by F. erecta and those dominated by Clerodendrum trichotomum and Celtis sinensis had the lowest similarity coefficient. Furthermore, there was a negative correlation between soil total phosphorus content and community similarity coefficient whereas soil nitrate nitrogen, ammonium nitrogen, and available phosphorus showed a positive correlation with species diversity of communities. Conclusion The communities in Dachen Island are primarily dominated by Casuarina equisetifolia, E. japonica and F. erecta, and the soil total phosphorus had a close link with species composition. [Ch, 4 fig. 2 tab. 30 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240429
Abstract:
Objective This study aims to clarify the metabolite differences in the fruit stalks of Hovenia acerba and H. trichocarpavar var. robusta, and lay a foundation for the development and utilization of Hovenia plants. Method Through a comprehensive targeted metabolomics approach of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS), the differences in metabolites and metabolic pathways in the fruit stalks of H. acerba and H. trichocarpa var. robusta were analyzed. Result A total of 1810 metabolites were detected in the fruit stalks of the two Hovenia species, of which 782 metabolites showed significant differences (P＜0.05). Compared with the fruit stalks of H. acerba, there were 378 up-regulated differential metabolites and 404 down-regulated differential metabolites in the fruit stalks of H. trichocarpa var. robusta, and the relative contents of tannin and quinone metabolites were significantly down-regulated. The differential metabolites in the fruit stalks of the two Hovenia species were primarily enriched in the biosynthetic pathways of phenylalanine compounds, flavonoids, and isoquinoline alkaloids. Among them, the extremely significant differential metabolites included alkaloid substances such as ligustroside, N-methylligustroside and methylcoclaurine, as well as flavonoids like naringin, naringin chalcone, and 2’,3,4,4’,6’-pentahydroxy chalcone. Conclusion There are significant differences in the metabolic profiles of the fruit stalks of the two Hovenia species under the same ecological conditions, especially the relative content of alkaloids and flavonoids with medicinal value and high sweetness. [Ch, 7 fig. 1 tab. 41 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240471
Abstract:
Objective The objective is to investigate the effect of temperature on enzyme activity in Heterolocha jinyinhuaphaga. Method The experimental insects were collected from Sanjie Town, Chuzhou City in Anhui Province and reared in a laboratory. The photoperiod was 14 h of daylight and 10 h of darkness, and the relative humidity was 70%. The activity of lactate dehydrogenase (LDH), peroxidase (POD), carboxylesterase (CarE) and acid phosphate (ACP) was measured in larvae, pupae, female and male moths of H. jinyinhuaphaga at different temperatures (16, 19, 22, 25, 28, 31, and 34 ℃). Result There were differences in the activity of four enzymes in larvae, pupae, female and male moths of H. jinyinhuaphaga at different temperatures. At 16−34 ℃, the activity of the four enzymes increased first, and then decreased with increasing temperature. LDH activity in larvae, pupae, female, and male moths was the highest at 22 ℃ (17.93×16.67, 15.25×16.67, 19.63×16.67 , and 18.81×16.67 μkat·g−1, respectively), POD activity was the highest at 25 ℃ (34.63×16.67, 31.83×16.67, 37.19×16.67, and 36.87×16.67 μkat·g−1, respectively), CarE activity was the highest at 28 ℃ (26.78×16.67, 23.36×16.67, 29.44×16.67, and 28.32×16.67 μkat·g−1, respectively), ACP activity was the highest at 25 ℃ (13.82×16.67, 11.37×16.67, 15.43×16.67, and 14.38×16.67 μkat·g−1, respectively). According to the established regression model, the optimal temperatures for the highest LDH activity in larvae, pupae, female, and male moths were found to be 21.45, 21.44, 22.32 and 21.56 ℃, respectively, the optimal temperatures for the highest POD activity were 26.16, 25.94, 25.67and 25.54 ℃, respectively, the optimal temperatures for the highest CarE activity were 29.20, 29.65, 28.93 and 28.92 ℃, respectively, the optimal temperatures for the highest ACP activity were 25.05, 26.39, 24.86 and 25.24 ℃, respectively. Two-way ANOVA showed that the interaction between temperature and insect stage had no significant effect on the activity of four enzymes. Conclusion Temperature can affect the activity of LDH, POD, CarE and ACP in larvae, pupae, female and male moths of H. jinyinhuaphaga. [Ch, 4 fig. 26 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240473
Abstract:
Objective This study aims to investigate the variations of soil nutrients during leaching processes under different vegetation restoration modes in degraded red soil regions and to enrich the understanding of water-soil-nutrient loss patterns and their influencing mechanism. Method 4 different vegetation restoration modes, named Pinus massoniana pure forest (PM), P. elliottii pure forest (PE), mixed P. massoniana and Schima superba forest (RMS), and mixed P. elliottii and S. superba forest (RES), were taken as the objects of the study. The characteristics of the soil runoff, sediment production, sediment particle changes and nutrient loss during the process of leaching were investigated in four leaching intensities, namely, 60, 90, 120, and 150 mm·h−1 in the red soil vegetation restoration area of Taihe County, Jiangxi Province. Result (1) With the increase of leaching intensity, the flow rate and sediment yield of red soil also increased, and the composition and stability characteristics of sediment particles changed significantly. Mean weight diameter (DMW) and ＞0.250 mm sediment particles (R0.25) increased significantly (P＜0.05). PM with low understory vegetation cover had low agglomerate stability under leaching erosion, and soil aggregates in RMS with high vegetation cover had high stability. (2) At a leaching intensity of 150 mm·h−1, the nutrient loss in red soil was significantly higher than that in 60 mm·h−1, but there was no significant difference in nutrient loss in 90 and 120 mm·h−1. Sediment was the main medium for nutrient migration and loss in this study. (3) Nutrient loss in red soil was positively correlated with leaching intensity, runoff yield rate, sediment yield, and R0.25, while negatively correlated with sediment ≤0.053 mm particles. (4) Random forest analysis showed that leaching intensity and runoff rate were the main factors affecting nutrient loss, with contribution rates of 16.33% and 20.91%, respectively. Conclusion With the increase of leaching intensity, the runoff and sediment yield significantly increase, and the composition and stability of sediment particles change. Moreover, leaching intensity and runoff rate are the main factors affecting nutrient loss. In the ecological construction of the subtropical degraded red soil zone in China, emphasis should be placed on enhancing the richness of understory vegetation in the vegetation restoration area in order to improve the structure of the forest stand and consolidate the results of management. [Ch, 7 fig. 2 tab. 44 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240345
Abstract:
Objective This study aims to prepare wooden decorative laminates-sheets made from polyethylene film (WDL) based on the laminated composite structure of high-pressure decorative laminates made from thermosetting resins impregnated sheets (HPL), which provides a theoretical basis for the preparation of aldehyde-free composite decorative panels with excellent performance. Method Polyethylene film and reconstituted decorative veneer were used as raw materials, and the five-layer structural WDL were prepared by hot pressing in the way of smooth-grain grouping. Box-Behnken Response Surface Analysis was used to study the impact of hot-pressing factors on the impregnation peeling performance and tensile strength of the smooth grain and to optimize the process parameters for the preparation of decorative panels. Result The impregnation peeling performance of WDL was affected greatly by hot-pressing temperature and hot-pressing time, while hot-pressing pressure had no significant effect on the impregnation peeling performance. The peeling length gradually decreased with the increase of hot-pressing temperature and hot-pressing time. Hot-pressing temperature and time, hot-pressing time and pressure also had significant interaction effects on the impregnation peeling performance of WDL. The tensile strength along the grain of WDL was mainly determined by the strength and thickness of the reconstituted decorative veneer, and the hot-pressing temperature also affected the tensile strength of WDL. Low temperature could result in inadequate cementation of the reconstituted decorative veneer and PE, and high temperature could lead to degradation of the hemicellulose in the veneer, all of which adversely affect the tensile strength along the grain of WDL. When the hot-pressing temperature was 160 ℃, the hot-pressing time was 109 s, and the hot-pressing pressure was 1 MPa, the impregnation peeling length of the decorative boards under these conditions reached 0 mm, and the tensile strength of the smooth grain reached 38.2 MPa, which was close to the prediction results of the optimization model. Conclusion A new type of veneer-PE laminated decorative panels is prepared, which has no formaldehyde release, and its water resistance meets the requirements of the Type Ⅱ immersion peel test according to GB/T 17657−2022. It can meet the needs of general interior decoration field, and there is no need to add adhesive again in the post-finishing process, which is an upgraded product of HPL. [Ch, 8 fig. 3 tab. 27 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240394
Abstract:
Objective In order to establish a suitable evaluation methods for eggplant resources, the agronomic characters and quality indexes of different eggplant cultivars are analyzed, which will provide a theoretical reference for rapid screening of germplasm resources and eggplant breeding. Method 10 eggplant varieties ‘Zilong No.5’ ‘Zilong No.7’ ‘Liangzi No.7’ ‘Zheqie No.10’ ‘Hangqie No.716’ ‘Hangqie No.718’ ‘Z1’ ‘Z2’ ‘Z3’ ‘Hangqie No.2020’ were used to determine 16 indicators relevant with plant growth and fruit characteristics. The principal component analysis method was used for comprehensive evaluation. Result There were differences among different eggplant cultivars. Plant of ‘Z2’ was the highest. The highest plant breadth and stem diameter was found in ‘Zilong No. 7’ and ‘Hangqie No. 716’, respectively. For fruit length, ‘Z1’ was the longest, while ‘Zilong No. 7’ was the shortest. The highest and lowest chroma value was found in fruit of ‘Z1’ and ‘Z3’, respectively. The hardness of fruit peel and pulp for ‘Hangqie No. 716’ was significantly higher than those of the other 9 cultivars (P＜0.05). The pericarp toughness of ‘Liangzi No. 7’ was significantly higher than others (P＜0.05). Soluble sugar and protein contents of ‘Z2’ were the highest. Fruits of ‘Liangzi No. 7’ and ‘Zilong No. 5’ showed the highest levels of amino acid. Principal component analysis extracted a total of 5 principal components with a cumulative contribution rate of 87.126%. Conclusion A comprehensive evaluation model of eggplant was constructed by taking the eigenvalues corresponding to the five principal components and the ratio of single principal component to the extracted principal components. The best comprehensive score was found from ‘Liangzi No. 7’, while the worst was found from ‘Zilong No. 7’. [Ch, 1 fig. 6 tab. 29 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240358
Abstract:
Objective This study is to analyze the habitat quality and its influencing factors in Haikou, so as to provide data support and scientific reference for ecological environment protection and urban construction. Method Based on the land use data of 2000, 2010 and 2020, InVEST model and the methods of land use transfer, habitat quality change rate and spatial statistical analysis were used to analyze the spatial-temporal dynamic changes in habitat degradation and habitat quality in Haikou, and summarize the influencing factors. Result ① From 2000 to 2020, forestland was the main type of land use in Haikou, accounting for 47.22%, 55.03%, and 48.75% of the total area in each period, followed by cropland. During the research period, the increase of built land area was the largest, with an increase of 230.37 km2, mainly transformed from forestland, cropland, and grassland. ②The change rate of habitat degradation degree was −1.77% from 2000 to 2010, and 12.20% from 2010 to 2020. The level of habitat degradation showed a spatial distribution pattern centered around the urban area and decreasing in circles. ③The overall habitat quality in Haikou was good. The proportion of areas with excellent habitat quality grades was around 50.00% in all stages, while the proportion of areas with poor grades increased from 5.33% in 2000 to 16.83% in 2020. The habitat quality level changed significantly and frequently in areas such as the urban-rural fringe in the central urban area of Haikou. During the research period, the habitat quality index of Haikou firstly increased and then decreased, and showed an overall decrease from 0.6880 to 0.6588. Conclusion From 2000 to 2020, the overall habitat quality in Haikou firstly increased and then decreased, which is closely related to the intensity of urban construction. Haikou should maintain the ecological priority and pay attention to ecological restoration of the main urban area, ecological infrastructure construction, and strengthen the protection and comprehensive management of the ecological system of the peripheral natural environment of the main urban area. [Ch, 5 fig. 7 tab. 25 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240458
Abstract:
Objective The study is to explore the niche and interspecific association of dominant species of woody plants in the evergreen broad-leaved forest in Bailushan scenic area, Zhejiang Province and understand their relationship and succession characteristics, so as to provide reference for ecological restoration and biodiversity conservation of subtropical evergreen broad-leaved forests. Method Taking the dominant species of woody plants in the evergreen broad-leaved forest in the study area as the research object, a long-term fixed plot with an area of 1 hm² was established. Ecological niche analysis, variance ratio method (RV), χ2 test, Pearson correlation coefficient, and Spearman rank correlation coefficient were used to analyze the niche and interspecific relationship of dominant woody plant species with importance values greater than 1.00%. Result (1) Schima superba, Lithocarpus glaber, Quercu sphillyreoides, and Pinus massoniana were the constructive species of the community. Among them, S. superba had the highest importance value (VI=27.37%), Levins niche width (BL=20.95), and Shannon niche width (BS=3.11), while the other three species had importance values greater than 10%. The average BL and BS were 16.63 and 2.87, respectively. (2) The mean niche overlap index of dominant species was 0.39. Most species were relatively independent in resource utilization and interspecific competition was weak. S. superba, L. glaber, Q. sphillyreoides, and P. massoniana had high niche overlap (mean Oik=0.73), indicating a high degree of similarity in resource utilization. The niche overlap index of Castanopsis sclerophylla with these four species was relatively low (mean Oik=0.17), indicating the weakest competition. (3) The overall association of dominant species in the community showed a significant positive correlation (P＜0.05). According to χ2 test, among the 153 pairs out of 18 dominant woody plant species, only 12 pairs showed significant associations (P＜0.05), while 91.00% pairs were not significantly correlated. Similar results were observed in Pearson correlation and Spearman rank correlation tests, and 71.25% and 71.90% of species pairs were not significantly correlated. The positive and negative association ratio was greater than 1, indicating that species tended to distribute independently. Conclusion The community is in the middle to late stage of succession and has a relatively stable ecological state. In the management of evergreen broad-leaved forests in the early or middle stage of succession in central Zhejiang, it is recommended to moderately retain P. massoniana when regulating high-density stands and appropriately plant Q. sphillyreoides in forest gaps and edges to promote positive succession and enhance the stability of forest ecosystems. [Ch, 4 fig. 2 tab. 36 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240401
Abstract:
Objective The objective of this study is to interpret the carbon accumulation characteristics during the growth process of typical Pinus massoniana forests, and investigate the mechanism and potential of carbon sequestration in P. massoniana forests. Method Four different afforestation years (8, 12, 22, 38 years) of P. massoniana plantations with similar slopes and altitudes were selected in Laoshan Forest Farm, Qiandaohu Town, Chun’an County, Zhejiang Province. Multiple statistical methods combined with redundancy analysis and structural equation modeling were employed to analyze the carbon density characteristics of P. massoniana forests with different afforestation years and the main factors affecting their carbon density. Result The total biomass reached its maximum value at 38 years (mature forest), which was significantly higher than that of young and middle-aged forests (P＜0.05). The biomass of the herb layer and litter layer reached their maximum values at 22 years of afforestation, with values of 13.74 and 5.24 t·hm−2, respectively. Carbon density of the tree layer increased with the increase of afforestation years, reaching a maximum value of 176.36 t·hm−2 at 38 years (mature forest). There were significant differences in soil carbon density among different ages of P. massoniana forests (P＜0.05). The carbon density in the soil layers of 0−10 and 10−30 cm reached their maximum values at 38 years (mature forest), which were 38.60 and 57.13 t·hm−2, respectively. Redundancy analysis revealed that total potassium, available potassium, and slope direction were the main contributing factors to carbon density of P. massoniana forests, accounting for approximately 28.70%, 27.00%, and 9.90% of the carbon density of each component, respectively, and were crucial to overall carbon sequestration of soil and vegetation. The structural equation model demonstrated that bulk density, vegetation density, and total potassium content had significant effects on carbon density in P. massoniana forests. Conclusion The carbon density of P. massoniana forests is closely related to the years of afforestation, with mature P. massoniana forests exhibiting the highest capacity for carbon sequestration. Environmental factors and soil nutrient status are crucial for enhancing the carbon sequestration potential of P. massoniana forests. [Ch, 4 fig. 5 tab. 44 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240381
Abstract:
Objective Analyze the effects of different microorganisms on the weathering and elemental release of basalt, to explore the role of microorganisms in the weathering process of basalt, and to provide a theoretical basis for microorganisms promoting basalt weathering. Method Different microbial strains (Bacillus mucilaginosus and Trichoderma asperellum) were selected to carry out simulation experiments on biological weathering of basalt. By means of elemental geochemical methods (elemental dissolution amount and rate) and mineral analytical methods (material composition), the effects of microorganisms on the release amount, release rate, and release capacity of Si, Ca, Al, Fe, and Mg elements from basalt were investigated, and preliminarily explored the release mechanisms. Result Microorganisms contributed to the weathering of basalt and the dissolution of elements, compared to the control group, the pH of the fungal and bacterial system solutions decreased by 1.46 and 0.88 units, respectively. Compared to the control group, the release amounts of Si, Ca, Al, Fe and Mg elements in basalt was significantly increased by 10.2, 2.6, 8.2, 92.9 and 9.9 times under the action of fungi, and it was significantly increased by 2.7, 1.2, 1.7, 19.7 and 3.2 times under bacterial action. The order of element release from basalt under the action of fungi and bacteria was same: Ca＞Mg＞Fe＞Si＞Al. Microorganisms create an acidic environment mainly by secreting organic acids or by complexing to promote the weathering of basalt and increase the rate of elemental dissolution. Conclusion Microorganisms can effectively increase the release and rate of elements during the weathering process of basalt, there are also differences among different strains. The release and rate of elements during the weathering process of basalt under the treatment of T. asperellum are higher than those under the treatment of B. mucilaginosus, indicating that fungi have a more significant role in accelerating the weathering process of basalt. [Ch, 6 fig. 41 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240415
Abstract:
Objective The objective is to investigate the effects of leaf microstructure of garden plants on particle retention capacity, and provide theoretical basis for the selection of urbangarden tree species. Method 13 evergreen shrubs, including Pyracantha fortuneana, Fatsia japonica and Nerium oleander were studied in Zhengzhou City, Henan Province. The retention of particles of different sizes [total suspended particulate matter (TSP), large particulate matter (PM>10), inhalable particulate matter (PM10) and fine particulate matter (PM2.5)] per unit leaf area was measured by graded membrane filtration method. The microstructure of leaf surface was observed by scanning electron microscopy and ultra depth microscope, and the relationship between particle retention capacity and leaf surface microstructure features was analyzed. Result (1) There were significant differences in the retention capacity of 13 evergreen shrubs with different particle sizes (P＜0.05), and the strongest comprehensive dust-retention ability was found in P. fortuneana, F. japonica, and N. oleander, with a dust retention capacity per unit area of 2.59, 2.23 and 1.97 g·m−2, respectively, 3.58−4.70 times that of Mahonia fortunei and Nandina domestica, which had a weak dust retention capacity. (2) Particles tended to be distributed near the midrib and leaf tip. Observation of leaf surface microstructure revealed that there were various structures such as grooves, fuzz, and protrusions on the upper surface. Most of the stomata were located on the lower surface of the leaf. These structures synergistically affected the retention of particles in plants, and concurrently enhanced the roughness of leaf surfaces. The surface roughness in N. oleander leaves was the highest (4.53 μm), with regular semi-circular protrusions on the upper surface and large concave stomata on the lower surface, surrounded by hairy tissue to attach dust particles. (3) Correlation analysis indicated that leaf area, roughness, stomatal length were significantly positively correlated with the content of TSP, PM10 and PM2.5 retention per unit leaf area (P＜0.05, P＜0.01), and stomatal width and stomatal area were significantly positively correlated with PM10 and PM2.5 retention (P＜0.05). Conclusion P. fortuneana, F. japonica, and N. oleander are recommended as excellent garden dust-retaining species in controlling air pollution in Zhengzhou City. [Ch, 5 fig. 3 tab. 35 ref.]
, Available online doi: 10.11833/j.issn.2095-0756.20240327
Abstract:
Objective The objective is to study the gibberellin oxidase JrGA3ox gene, which is of great significance for improvement, growth and development, and drought resistance of Juglans regia varieties. Method J. regia wild-type (WT), JrGA3ox overexpression (OE) and interference (RNAi) plants were used as experimental materials. Drought treatment with 5% PEG 8000 volume fraction was simulated to investigate the plant phenotype, physiological and biochemical indexes and expression level of drought resistance gene under drought stress, and clarify the drought resistance mechanism of JrGA3ox gene. Result (1) Real-time fluorescent quantitative PCR verification showed that the expression level of JrGA3ox gene in OE plants and RNAi plants were 120 and 0.3 times that of WT plants, respectively. (2) Plant growth phenotype analysis showed that plant height and internode length of OE plants were significantly higher than those of WT plants, while those of RNAi plants were significantly lower than those of WT plants (P＜0.05). (3) Compared with WT plants, under drought stress for 0−28 days, RNAi plants showed better growth, while OE plants showed weaker growth. (4) Stomatal opening and chlorophyll mass fraction decreased gradually with the extension of drought stress time. Stomatal opening of RNAi plants were significantly lower than that of WT plants (P＜0.05), while stomatal opening of OE plants were significantly higher than that of WT plants. The chlorophyll mass fraction of RNAi plants were always significantly higher than that of OE plants and WT plants (P＜0.05). (5) After drought stress, the mass molar concentration of reactive oxygen species and malondialdehyde in OE plants were significantly higher than that in WT plants, while that in RNAi plants were significantly lower than that in WT plants (P＜0.05). (6) The activity of antioxidant enzymes and expression level of related resistance genes firstly increased and then decreased during the stress process, reaching their maximum value at 14 days of drought stress, and those in RNAi plants were significantly higher than those in WT plants, while those in OE plants were significantly lower than those in WT plants (P＜0.05). Conclusion JrGA3ox gene in J. regia can positively regulate plant height and internode length, and negatively regulate stomatal opening, photosynthesis, antioxidant enzyme activity of plants, thus improving plant drought resistance. [Ch.10 fig. 1 tab. 28 ref.]
