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Genetic Analysis and Family Selection of Growth, Heartwood and Wood Traits for Toona ciliata var. pubescens
Wei Yi, Fan Yan-ru, Qiu Yong-bin, Shen Han, Zheng Chen-zhong, Lin Jie, Fu Ai-ping, Jiang Jing-min, Liu Jun
, Available online  , doi: 10.12403/j.1001-1498.20230376
Abstract:
Objective By studying the genetic variation of the growth, heartwood and wood character of 15 year old T. ciliata var. pubescens families for selecting the fast growing and high quality families of T. ciliata var. pubescens. Methods Based on A 15-year old family test forest of T. ciliata var. pubescens in Kaihua forest farm, Zhejiang Province, the tree height, DBH, volume, heartwood percentage, heartwood volume and wood basic density were measured, and the variance, correlation and principal component analysis were performed. Results There were significant differences in tree height, DBH, wood volume, heartwood percentage, heartwood volume and wood basic density among families, and heartwood and wood properties had high genetic stability, but there were no significant differences in crown width and height at crown base among families. Phenotypic and genetic correlation analysis showed that there was a significant positive correlation between DBH and heartwood volume and volume, and DBH could indirectly realize the selection of volume and volume of heartwood. The results of principal component analysis showed that volume (V), heartwood volume (Vh), diameter at breast height (D), tree height (H) and heartwood ratio (Rh) represented the quality and economic traits of T. ciliata var. pubescens, and contributed significantly to the first two principal components, PC1 and PC2. By constructing a comprehensive index selection equation for four characters: volume, heartwood percentage, heartwood volume, and wood basic density, two excellent families meeting the improvement conditions were selected. The average genetic gains of volume, heartwood percentage, heartwood volume and wood basic density were: 52.84%, 0.49%, 66.23% and 2.13%. Conclusion The breeding objectives of T. ciliata var. pubescens should focus on growth and heartwood traits, but heritability of crown width and height at crown base are small and the differences between families are not significant, which indicates that crown width and height at crown base are not suitable targets for genetic improvement.
Analysis of transcription factor ZF-HD gene family and expression pattern of Eucalyptus grandis
ZHANG Shuang, WANG Xue-jun, ZENG Bing-shan, Xu Zhi-ru, FAN Chun-jie
, Available online  , doi: 10.12403/j.1001-1498.20230399
Abstract:
Objective In order to analyze the role of the transcription factor ZF-HD in the growth and development in Eucalyptus and to further understand its function, ZF-HD gene family in eucalyptus. Method In this study, bioinformatics was used to identify members of the E. grandis ZF-HD gene family, and their chromosomal location, physical and chemical properties, gene structure, protein conserved domains and expression patterns were analyzed. Result A total of 10 ZF-HD gene members were identified in E. grandis, which encoded 78-343 amino acids. Meanwhile, almost all genes were basic proteins which mainly located in the nucleus. Moreover, motif1 is very conserved in the ZF-HD family, and their cis-acting promoter elements mainly included hormone response, growth and development, and stress response elements. Furthermore, the expression analysis of ZF-HD gene in various tissues, adventitious roots and buds inducing process was analyzed. The results showed that most of the family members were differentially expressed in various tissues, which mainly acted in the downward direction of stem apex, Meanwhile, the expression levels of ZF-HD family members altered significantly during adventitious root and bud induction. EgrZHD2 expressed in higher level at the stem apex and decreased significantly with gradually increased secondary growth. And the further subcellular localization analysis showed EgrZHD2 localized in cell nucleus, which was consistent with predicted results. Conclusion The ZF-HD gene family members of Eucalyptus grandis play an important regulatory role in the development of adventitious roots and adventitious buds. EgrZHD2 acts as an important transcription factor in the biological processes of primary growth and adventitious root induction in Eucalyptus.
Cloning and Functional Verification of Geraniol Synthase Gene PsGES in Tree Peony ‘High Noon’
WANG Pei-yun, LI Ziang, BAI Yang, YANG Ping, YIN Cheng-peng, SONG Xiu-hua
, Available online  , doi: 10.12403/j.1001-1498.20230404
Abstract:
[ Objective ] To explore the mechanism of synthesis and metabolism of terpenoids released by plants, and to provide theoretical basis for further elucidating the biological functions of the terpenoid synthase gene family in tree peony. [ Method ] Based on the aromatic peony variety ‘High Noon’, the PsGES gene was cloned based on transcriptome sequencing of the obtained fragments. Simultaneously, the PsGES gene overexpression vector was injected into tobacco leaves and ‘Fengdan’ petals using transient expression methods to verify gene function. [ Result ] The complete CDS sequence of this structural gene was 897 bp long, encoding 298 amino acids. Amino acid sequence analysis showed that the protein has high conservation, with a conserved domain Terpene_ Cyclase_ Plant_ C1. The expression level of PsGES gene was highest in the blooming petals and significantly higher than other organs. Subcellular localization analysis showed that PsGES was mainly localized in chloroplasts. The release of geraniol in tobacco leaves and ‘Fengdan’ petals could be detected by GC-MS method, while the PsGES gene is highly expressed in tobacco leaves and ‘Fengdan’ petals. [ Conclusion ] This study indicates that the PsGES gene regulates the synthesis of geraniol in plants.
Effects of Substrate pH on Flowering Quality of Primula vulgaris
CHEN Hua-le, WEN Jing-yi, TANG Tian-qi, YANG Jia-wei, GAO Xing, ZHAO Ting-ting, SU Qi-zhen, SHI Qian-qian
, Available online  , doi: 10.12403/j.1001-1498.20230301
Abstract:
Objective To explore the effects of different gradients of substrate pH (4.5, 5.5, 6.5, 7.5) on the flowering quality of Primula vulgaris, and to provide a certain theoretical basis for the refined cultivation of Primula vulgaris. Methods Based on four different-colored P. vulgaris varieties ('Beautiful Scenery,' 'Hot Lover,' 'Blue Onstar,' 'Huangli'), sulfuric acid ferrous and sodium hydroxide solutions were used to adjust the pH of potted substrate to different gradients. Morphological indicators such as plant height and flower leaf growth were observed, and data such as cell protective enzyme activity, pigment content, and membrane permeability were measured to study the effects of substrate pH on the flowering quality of P. vulgaris. Results P. vulgaris had better flower morphology at substrate pH5.5 and pH6.5, and growth was inhibited at all other pH conditions. The L* value of the petals decreased under acid-alkaline stress, while the content of anthocyanins and flavonoids exhibited a decreasing trend with an increase in substrate pH. The petal cell sap pH of 'Hot Lover' showed a slight increase compared with control treatment (CK). Compare with CK, the CAT activities of the four varieties increased significantly under pH 4.5 treatment. Correlation analysis between morphological and physiological indicators indicated that POD had the highest correlation with carotenoid content and the lowest correlation with anthocyanin content. The results of principal component analysis and a comprehensive evaluation based on membership functions suggested that petal cell sap pH, blade relative water content, flowering count, CAT activity, soluble sugar content, and plant height could be used as the primary indicators for evaluating the flowering quality of P. vulgaris under different substrate pH conditions. Regardless of the substrate pH conditions, 'Blue Onstar' consistently exhibited the highest flowering quality. Conclusion The optimal substrate pH for the best flowering quality of P. vulgaris falls within the range of 5.5 to 6.5. Under different substrate pH stresses, the flowering quality of 'Blue Onstar' was the highest, followed by 'Beautiful Scenery,' 'Hot Lover,' and 'Huangli.'
Fine Root Respiration and its Relationship with Morphological and Chemical Traits of Cunninghamia lanceolata Provenances
SHOU Ye, WANG Bin, NIU Xiang, SONG Xi-qiang, XU Ting-yu, WANG Yi-hui
, Available online  , doi: 10.12403/j.1001-1498.20240068
Abstract:
Objective : To analyze the difference of fine root respiration and its morphological and chemical characters among different provenances of Cunninghamia lanceolata for understanding the relationship between root respiration and other root characteristics. Methods : Based on the 10 provenances of Chinese fir[Cunninghamia lanceolata (Lamb.) Hook.] provenances homogenous garden in Dagangshan, Jiangxi Province, the variation between provenances of fine root respiration, morphology and chemical traits of Chinese fir and the correlation among different traits were studied. Results : The coefficient of variation of fine root respiration, fine root morphological traits and chemical traits among provenances of Chinese fir were 40.42%, 18.82-22.88% and 7.844-19.73%, respectively. There were significant differences in fine root respiration among provenances (P<0.05). The fine root respiration rate was the highest in Kaihua Zhejiang provenances (7.97 ± 1.08 nmol·g−1·s−1) and the lowest in Yongchuan provenances (1.63 ± 0.40 nmol·g−1·s−1 nmol·g−1·s−1). The morphological and chemical characters of fine roots of Chinese fir from different provenances were also significantly different (P<0.05). The provenances of Jian 'ou Fujian had the largest specific root length (579.17 ± 17.11 cm·g−1), root specific surface area (139.97 ± 10.18 cm2·g−1). The root C content (458.12 ± 5.40 g·kg−1) and N content (10.58 ± 0.02 g·kg−1) were the largest in Kaihua Zhejiang provenance; The local provenances of Fenyi Jiangxi Province had the largest root tissue density (0.62 ± 0.12 g·cm−3), and the lowest root N content (6.38 ± 0.11 g·kg−1), C:P (481.39 ± 8.94), N:P (10.64 ± 0.41). The trade-off analysis of fine root respiration, morphological and chemical traits of Chinese firprovenances showed that there was a significant correlation between fine root respiration and root nitrogen content (P<0.05), but insignificant correlation with specific root length and root tissue density. Conclusion : The adaptation strategies of fine roots of Chinese fir provenances to environmental changes are different. The correlation between fine root respiration and root morphological traits is little, and it is mainly related to root N content.
Molecular Simulation of Lymantria dispar Methuselah-like and Targeting Small Molecular Inhibitors
WU Yuan-wang, XIE Jia-ming, CONG Pei-juan, CAO Chuan-wang, SUN Li-li
, Available online  , doi: 10.12403/j.1001-1498.20230413
Abstract:
Objective The aim is to screen potential small molecule inhibitors of methuselah-like (Ldmthl1) protein through virtual screening technology and explore the inhibitory ability of potential compounds on Ldmthl1 protein through molecular dynamics simulation, MM-PBSA, and bioassays. It lays a theoretical foundation for developing new insecticides targeting Lymantria dispar Ldmthl1. Method The homology model of Ldmthl1 receptor was constructed in Lymantria dispar for virtual screening the small molecule inhibitors of the Ldmthl1 receptor. The binding strength of 6 potential small molecule inhibitors to Ldmthl1 receptor was analyzed by using molecular dynamics and MM-PBSA; The toxicity of 6 potential small molecule inhibitors was analyzed by bioassay, and the synergistic effect of the six potential compounds was explored by combining them with deltamethrin. Result Ldmthl1 contained 7 transmembrane structures, which was consistent with the structural characteristics of G protein-coupled receptors, and met the evaluation criteria of protein models; 20 candidate compounds were obtained by molecular docking, and 6 small molecule compounds were identified as potential inhibitors based on the binding models and binding energies; Molecular dynamics simulations showed that 6 potential small molecule inhibitors were stably bound to Ldmthl1 receptors through hydrogen bonding and hydrophobic forces; The MM-PBSA calculation of binding free energy revealed that 6 potential small molecule inhibitors were tightly bound to the Ldmthl1 receptor; The lethal concentration of LC30 deltamethrin and 6 inhibitors were combined to feed the 3rd instars of Lymantria dispar larvae at the ratio of 1 : 1, 1 : 2 and 2 : 1. The combination of 6 inhibitors with deltamethrin showed synergistic effect, and the synergistic effect was most significant when the mixing ratio was 1 : 2. However, no synergistic effect was found when the concentration of deltamethrin was too high. Conclusion Six potential small molecule inhibitors with insecticidal activity that can stably bind to the Ldmthl1 receptor were obtained through virtual screening. They showed synergistic effects when combined with cypermethrin. This study can lay a theoretical foundation for the development of new insecticides targeting Ldmthl1.
Dynamic Characteristics of Soil Bacterial Community Under Camellia oleifera Plantation with Different Ages in Karst Area of Northern Guangdong Province
ZHENG Quan-sheng, WU Bin, BAILA Qu-zhen, YE Fei, WANG Yu, FENG Han-hua
, Available online  , doi: 10.12403/j.1001-1498.20230320
Abstract:
: Objective The large-scale plantation of Camellia oleifera forestry is a special mode for the comprehensive management of rocky desertification in northern Guangdong with good economic benefits. However, the effects of planting years of Camellia oleifera forestry on soil microbial communities in karst areas are still unclear. Method Based on soils with planting years of 2, 3, and 7 of Camellia oleifera plantation from Fushushan planting base in Lechang City of Guangdong Province , high-throughput sequencing and molecular ecological network analysis methods were used to analyze the soil bacterial community dynamic. Result The increase in planting years of Camellia oleifera could promote the accumulation of soil ammonium and total nitrogen contents. Although the community diversity of soil bacteria did not change significantly with the increase of planting years, significant variation was observed on bacterial community composition. Moreover, soil moisture content was the key environmental factor affecting soil bacterial community under Camellia oleifera forestry with 2 and 3 years, while soil bacterial community under Camellia oleifera forestry with plantation of 7 year was mainly affected by pH. In addition, compared with Camellia oleifera forest planted for 2 and 3 years, the soil bacterial taxa in the camellia oleifera forest planted for 7 years were more closely connected, but at the same time, there was a lack of modularity of the bacterial network and the evolution of key species. Conclusion This study reveals the dynamic characteristics of soil bacterial community with different planting years of Camellia oleifera in rocky desertification area of northern Guangdong, which provides a theoretical basis for the practical management in maintaining the soil ecosystem function of Camellia oleifera forestry.
Prediction of Potential Habitat Areas for the Invasive Pest Sphaerolecanium Prunastri Based on Biomod2 Combined Model
GUO Fa-cheng, MA Gui-long, GAO Gui-zhen
, Available online  , doi: 10.12403/j.1001-1498.20230368
Abstract:
Purpose Sphaerolecanium prunastri Boyer de Fonscolombe, as a polyphagous pest in wild fruit forests in Xinjiang Uygur Autonomous Region, China, exhibits notable characteristics such as fast reproduction, high reproductive rates, and rapid dissemination. These features highlight its substantial ecological adaptability and competitive edge in the ecosystem. Notably, it poses a severe threat not only to Prunus armeniaca L., commonly known as wild apricot, but also to the ecological environment and biodiversity of the wild fruit forests and local orchards. To obtain a more precise habitat distribution for S. prunastri, species distribution models were established and compared under various types of influencing factors. Methods This study, integrating the R programming language with the Biomod2 package, species distribution models (SDMs) were established to predict the distribution patterns of S. prunastri: one only including climatic variables and the other incorporating climatic variables and host factors. Results The ecological niche results, incorporating biological variables, were consistent with actual distribution patterns. This approach eliminated the overestimation issue observed when using only climatic variables, leading to higher predictive accuracy. Therefore, the predictions based on the inclusion of host factors were selected for analysis. With the addition of host factors, the current total suitable habitat area was 15.06 × 105 km2, mainly distributed near the border with Kazakhstan, the northern foothills of the Tian Shan Mountains, and the lli River Valley. Under the SSP5-85 scenario in 2090, the total suitable habitat area reached a maximum of 45.31 × 105 km2. Under different future climate scenarios, the total suitable habitat area for S. prunastri showed varying degrees of expansion, with significantly improved suitability observed in areas such as the lli Kazakh Autonomous Prefecture, Bortala Mongolian Autonomous Prefecture, Changji Hui Autonomous Prefecture, and Altay Region. Conclusion The ensemble model comprising seven individual models constructed in this study had an average AUC value of 0.97 and an average TSS value of 0.88, indicating high predictive accuracy. After introducing the host factors to the distribution model, the suitable habitat was more consistent with the actual situation, and the result was more reliable than only considering the climate factor.. These predictions offer a scientific basis for the early warning, monitoring, and management of S. prunastri in Xinjiang.
Analysis of Antifungal Activity of Volatile Gas from Biocontrol Strain Trichoderma songyi M75
Zhang Ming, Zhu Fan, Zhang Hui, Cheng Yuan, Xie Xian, Zhang Xing-yao, Liang Jun
, Available online  , doi: 10.12403/j.1001-1498.20230481
Abstract:
Objecive To analyze the composition of volatile organic compounds produced by the biocontrol strain Trichoderma songyi M75. Method Using headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPMEGC-MS), volatile organic components of T. songyi M75 were analyzed and the antibacterial activity of some of the substance components was tested. Result There were 18 volatile components successfully identified from M75 strain, including aldehydes, terpenes, ketones, alkanes, aromatics and esters. The content of 6-amyl-2H-pyran-one was the highest, with a relative content of 18.56%, but linalool had the best inhibitory effect against S. sapinea, with a relative content of 5.86%. Linalool had a wide antibacterial spectrum and also had good inhibitory effects on a variety of plant pathogens such as Cytospora chrysosperma, Cryphonectria parastica and Alternria sp, with an inhibition rate of more than 70.00%. Conclusion Trichoderma spp generally have the ability to produce volatile organic compounds. This study successfully analyzed the volatile organic compounds produced by Trichoderma songyi M75 strain, providing scientific basis for the antibacterial mechanism of Trichoderma spp and the metabolism of antibacterial substances, and laying the foundation for the development of biocontrol agents using Trichoderma spp.
Adaptability Analysis of Walnut Anthracnose based on MaxEnt Model
BO Shu-wen, YU Hong-chou, HAN Chang-zhi
, Available online  , doi: 10.12403/j.1001-1498.20230317
Abstract:
Objective As an important ecological and economic tree species, walnut tree belongs to Juglandaceae deciduous and has been widely cultivated in the world. Anthracnose caused by Colletotrichum species including C. gloeosporioides, C. siamense etc., is one of the main diseases of walnut. According to the known distribution of walnut anthracnose, the range of its suitable growing areas was predicted and analyzed in China and Yunnan province, and the potential distribution range of walnut anthracnose in China was identified, which would help to take scientific and efficient monitoring and prevention measures in production and reduce potential ecological and economic losses. Methods The species distribution model MaxEnt was used to develop the model by selecting bioclimate variables and optimizing model parameters, and then applied the model to predict the suitable habitat of walnut anthracnose in China and Yunnan province. ArcGIS software was used to visualize the prediction results and deal with area statistics, and the results of the model were used to analyze the main environmental factors affecting walnut anthracnose. Results The results showed that the main environmental factors affecting the adaptability of walnut anthracnose were annual rainfall, rainfall in the driest month, temperature seasonality, average temperature in the coldest quarter, annual average temperature, isotherm, average daily range, and average rainfall in the warmest quarter. The total area of walnut anthracnose in China's ecological suitable areas was about 3.1712 million square kilometers, accounting for 33.03% of the total land area. It was mainly distributed in all areas of central, eastern and southern China, as well as most areas in the southwest and a few areas of the northwest, north and northeast in China. The suitable growth area of walnut anthracnose was mainly concentrated in western Yunnan, about 226400 square kilometers, accounting for 57.44% of the total area of the province. Conclusion Walnut anthracnose has a relatively wide range of suitable growth areas in China, especially in Yunnan province, where anthracnose has the largest number of occurrence points and the widest distribution of highly suitable areas. The predicted suitable growth areas are consistent with the obtained distribution points of walnut anthracnose. In the future, the prediction and control of walnut anthracnose should be further strengthened in combination with the biological characteristics and field distribution of the local walnut anthracnose pathogen.
Effects of Bacillus Subtilis and Silicon Fertilizer on the Shoots Output and Quality of Phyllostachys violascens Under Mulching
ZHANG Xu, WANG An-ke, WEN Zuo-rong, BI Yu-fang, WANG Zi-jie, NING Yi-lin, HE Qi-jiang, HU Jun-jing, DU Xu-hua
, Available online  , doi: 10.12403/j.1001-1498.20230401
Abstract:
Objective In order to provide some theoretical basis about fertilization for the cultivation management of high-quality Phyllostachys violascens shoots. We study on the effects of Bacillus subtilis and silicon fertilizer on the yield and quality of bamboo shoots in Phyllostachys violascens under mulching treatment. Methods In the Phyllostachys violascens forests, before mulching in winter, three fertilization treatments were set up: BS (compound fertilizer 750 kg·hm−2 + Bacillus subtilis 37.5 L·hm−2), SI (compound fertilizer 750 kg·hm−2 + silicon fertilizer 675 kg·hm−2) and CK (compound fertilizer 750 kg·hm−2). The changes in yield, appearance, nutrition and palatability of bamboo shoots under each treatment were analyzed. Results The application of Bacillus subtilis or silicon fertilizer had different effects on the quality of bamboo shoots. Comparing with the traditional fertilization, the characteristics of bamboo shoots with treatments were listed as follows: (1) The bamboo shoots thickness, single plant quality and output increased. Among them, the application of Bacillus subtilis made the bamboo shoots sprout in advance by 9 days, and extended the shoot emergence period by 12 days. The bamboo shoot yield increased significantly, with an increase of 85.60%. (2) Bamboo shoots showed the high protein and low carbon water, with reduced roughness, in which the protein content increased significantly, with an increase of 21.81% and 17.46%. The contents of essential amino acids and total amino acids in bamboo shoots increased significantly. The proportion of bitter and aromatic amino acids increased significantly, while the proportion of sweet amino acids decreased significantly, and that of delicious amino acids did not change significantly. In addition, the contents of starch, lignin and cellulose decreased significantly, but the change in fat content did not change significantly. (3) The soluble sugar content and sugar-acid ratio of bamboo shoots increased, and the content of oxalic acid and total acid did not change significantly. However the content of tannin decreased significantly after the addition of silicon fertilizer, with a decrease of 41.76%. Conclusion Applying Bacillus subtilis or silicon fertilizer before mulching, Phyllostachys violascens forest can improve the yield, nutritional quality and palatability of bamboo shoots, and achieve the effect of improving quality and increasing production.
Understory Plant Diversity and its Relationship with Soil Physicochemical Properties in Different Plantations in Mu Us Sandy Land
HU Er-cha, WANG Zheng, LI Zi-hao, LI Zhuo-fan, DONG Da-wei, BAO Hu, GAO Run-hong
, Available online  , doi: 10.12403/j.1001-1498.20230410
Abstract:
Objective The diversity characteristics of understory plants in different plantations and their relationship with soil physical and chemical properties were studied to provide theoretical basis for exploring scientific and reasonable ecological restoration mode of sandy land and near-natural vegetation reconstruction. Methods In this study, based on four kinds of plantations (I: Pinus sylvestris plantation ; II: Poplar plantation ; III: Salix psammophila plantation ; IV : Caragana microphylla plantation ), the species diversity of understory herb communities and the physical and chemical properties of surface soil in different plantations were analyzed, and also their relationships were explored. Results The results showed that the species of understory herbaceous plants in Caragana microphylla plantation were the highest, followed by Pinus sylvestris plantation, Populus plantation, and Salix psammophila plantation. There were many species of Asteraceae, Gramineae and Leguminosae, accounting for 65.39% of the total plant species. There were no significant differences in Shannon-Wiener diversity index, Margalef richness index, Pielou evenness index and Simpson dominance index among the four plantations. However, there were significant differences in soil pH value, organic matter, available phosphorus, hydrolyzable nitrogen and particle composition among different plantations. The soil pH value of Pinus sylvestris plantation was significantly lower than that of the other three plantations. The contents of organic matter and hydrolyzable nitrogen in arbor forest were higher than those in shrub forest, while the content of available phosphorus was higher in shrub forest. There was no significant difference in soil available potassium content among different plantations. There were significant differences in soil pH value, organic matter, available phosphorus, hydrolyzable nitrogen and particle composition among different plantations. The soil pH value of Pinus sylvestris plantation was significantly lower than that of the other three plantations, and the organic matter and water of arbor forest were significantly lower than those of the other three plantations. Conclusion The composition of understory plants and soil physical and chemical properties of different plantations in the Mu Us Sandy Land are different. Different plantations have no significant effect on the diversity of understory plants. Organic matter, available phosphorus, pH and hydrolytic nitrogen are the main soil factors affecting the diversity of understory plants in plantations.
Effects of Foliar Spray of Selenite on Metabolome in Leaves of Torreya grandis Seedlings
CHEN Zhen-sheng, LI Ai-hua, DU Shi-ping, HUANG Pei-geng, XU Xiu-huan, NING Bo-lin, LI Wen
, Available online  , doi: 10.12403/j.1001-1498.20240012
Abstract:
Objective To investigate the effects of foliar spray of selenite on metabolome in the leaves of Torrey grandis seedlings and changes in levels of secondary metabolites in the leaves. Method Sodium selenite of 100 μg·L−1 was sprayed to the leaves of 2-year-old seedlings of T. grandis at an interval of 15 days. 15 days after the second spraying, one-year-old leaves were harvested for metabolome analysis. Result The results showed that there were 909 differential metabolites between treatment group and control under positive ionization mode, with 69 metabolites of significant changes (27 metabolites up-regulated and 42 metabolites down-regulated). Under negative ionization mode, 433 differential metabolite occurred between treatment group and control, with 43 differential metabolites of significant changes (11 metabolites up-regulated and 32 metabolites down-regulated). Some metabolites beneficial to human health increased significantly in the treated leaves of T. grandis seedlings, such as plantagoside (increasing 2.827 times as control), ligustilide (increasing 2.524 times) , 6-sialyllactose (increasing 2.021 times), and azilsartan (increasing 1.931 times). Conclusion The results indicate that selenite foliar application on the leaves of T. grandis can increase biosynthesis of beneficial metabolites and accumulation in their leaves.
Effects of Different Thinning Retention Densities on Branch Growth of Chinese Fir Plantations
WANG Jia-qi, MA Dong-xu, LAN Wei-li, CHEN Kuai-ming, LIN Kai-min
, Available online  , doi: 10.12403/j.1001-1498.20230334
Abstract:
Objective To study the effects of different thinning retention densities on the branch growth of Chinese fir plantations, and to provide scientific theoretical basis and technical support for directed cultivation of Chinese fir knotless-wood. Method Based on the 9-year-old Chinese fir plantations in Guanzhuang state-owned forest farm, Shaxian County, Fujian province, three kinds of thinning retention densities (1200 trees·hm−2(thinning intensity: 67% , L) , 1800 trees·hm−2(thinning intensity: 51% , M) and 2250 trees·hm−2(thinning intensity: 27% , H) were set up. In the fifth year after thinning, standard trees were selected in different plots to study the effect of thinning treatments on the branch growth of Chinese fir. Result 1)The total number of branches, the number of branches below 8 m, the number of branches above 8 m, the number of dead branches, the number of living branches all under L treatment were the largest, followed by treatment M and H, and the percentage of dead branches under treatment H were the largest, followed by treatment M and L. 2)The basal diameter increased with the decrease of thinning intensity which showed L > m > H, and there was significant difference between L and H (P < 0.05) , which indicated that the lower retention density was more conducive to the branch growth. 3)There was a significant linear correlation between the basal diameter and the length of the living branch, while correlation between the basal diameter and the length of the dead branch was small. 4)The basal diameter, branch length, the number of dead branches and the number of living branches increased with the increase of vertical height, while the basal diameter and the length of living branches and the branching angle of H and M decreased with the increase of vertical height of the trunk. 5)The basal diameter, branch length and branching angle of dead and living branches were larger in the southern region (90~225 °) than in the northern region, but the number of branches was larger in the eastern region (0~180 °) than in the western region. Conclusion The thinning intensity should be adjusted according to different cultivation purposes. The lower retention density can inhibit the growth of basal diameter and number of branches, thus reducing the size and number of knots and improving the wood quality. In this study, the retention density1800 trees/ha is more suitable to cultivate knotless large-diameter timber.
Effects of Different Exogenous Substances on Rooting, Basal Physiology and Biochemistry of Quercus mongolica Cuttings
ZHONG Ming-xia, AI Wan-feng, YUAN Xin, HUANG Yi-he, WEI Jun, WANG Yu-tao, LU Xiu-jun
, Available online  , doi: 10.12403/j.1001-1498.20230362
Abstract:
Objective Cutting propagation is an important way to propagate excellent seedlings, and the application of suitable exogenous substances can promote rooting of cuttings. The rooting of Quercus mongolica cuttings is difficult. Exploring the effects of different concentrations of exogenous substances and their combine applications on the rooting of Quercus mongolica softwood cuttings can provide technical support for large-scale propagation by cutting propagation. Method Using rapid dipping or soaking methods, different concentrations of indole butyrate potassium (IBA-K), rooting powder (ABT1), K599 Agrobacterium rhizogenes, propiconazole (PCZ), and their combination were used to treat cuttings. The rooting rate, callus rate, rooting number, root length, nutrient content, enzyme activity, and changes in endogenous hormone content of cuttings were measured. Result When different exogenous substances were used separately, the rooting rate of K599 Agrobacterium rhizogenes (OD600 = 0.8) was the highest after soaking for 30 minutes, reaching 24.71%. After soaking in 50 μM PCZ for 2 hours, the root callus rate of cuttings was the highest, reaching 43.62%. For other exogenous substances alone, the rooting effect of cuttings was poor. When different combinations of exogenous substances were used, 50 μmol·L−1 PCZ soaking for 2 hours combined with K599 Agrobacterium rhizogenes (OD600 = 0.8) soaking for 30 minutes significantly improved the rooting rate of Quercus mongolica cuttings, reaching 36.37% for rooting and 51.14% for callus. The average number of roots and root length were 2.25 and 5.72 cm, respectively. In addition, the results indicated that the use of PCZ can accelerate the consumption of soluble sugars and proteins during the rooting process of cuttings, promote the activities of peroxidase (POD) and polyphenol oxidase (PPO), increase the content of IAA during the induction period of adventitious roots, and increase the IAA/ABA and IAA/ZR ratios. Conclusion The combined application of PCZ and Agrobacterium rhizogenes K599 can significantly improve the rooting rate of Quercus mongolica softwood cuttings. Slow consumption of nutrients (soluble sugars, proteins), weak activity of antioxidant enzymes (PPO, POD), and low content of IAA may be the reasons of the difficulty in rooting of Quercus mongolica cuttings. PCZ has an important inhibitory effect on this, and can play an important role in difficult rooting species such as Quercus mongolica cuttings.
Functional Characteristics of Rhizosphere Soil Microbial Communities of Relict Plant Glyptostrobus pensilis in Different Seasons
ZHANG Chen, ZHOU Liu-ting, WANG Yan-yan, LIN Rui-yu, WU Ze-yan
, Available online  , doi: 10.12403/j.1001-1498.20230221
Abstract:
Objective To explore the structure and function of rhizosphere microbial community of Glyptostrobus pensilis and its seasonal variation. Methods PCR-DGGE and Biolog-ECO microplate methods were used to determine the soil physicochemical properties, structure and function of rhizosphere microbial community of G. pensilis in different seasons, and the intrinsic patterns of rhizosphere microecological factors were analyzed by principal component analysis and redundancy analysis. Result The dominant bacterial in the rhizosphere microbial community of G. pensilis were Alphaproteobacteria, Acidobacteria and Deltaproteobacteria, and the dominant fungi was Sordariomycetes. Rhizosphere microbial biomass content and microbial diversity in the soil of G. pensilis are the highest in summer. Carbon metabolism of rhizosphere microorganisms in the summer was the largest, followed by autumn, spring, and winter. Available nitrogen may be the main factor driving changes in the functional diversity of carbon metabolism in rhizosphere microbial communities. Conclusion The diversity and carbon metabolism ability of rhizosphere microbial community of G. pensilis are the best in summer and the worst in winter. Seasonal factors significantly affect the structure and function of rhizosphere microbial community, and the fluctuation caused by seasonal factors should be fully considered in the future related research.
Root Exudates Improving Soil Phosphorus Availability: A Review
HUANG Yu-xuan, You Xin, ZHANG Lin-ping, WU Fei, ZHANG Yang, HUANG Shao-hua
, Available online  , doi: 10.12403/j.1001-1498.20230477
Abstract:
Phosphorus is an essential mineral nutrient element that plays an important role in plant growth and development. Although most soils have sufficient total phosphorus reserves, most of the organic and inorganic phosphorus in the soil exhibit low solubility and low available, leading to the extremely low soil available phosphorus content. Plant root exudates are important mediators linking energy, matter and information transfer at the interface between the plant root system and the soil. They can directly regulate the activation of soil ineffective phosphorus, and also can indirectly improve the bioavailability of soil phosphorus by recruiting inter-root microorganisms. In this paper, the potential mechanisms of different root exudates to improve soil phosphorus effectiveness are elucidated, and how root exudates can recruit inter-root microorganisms to promote soil phosphorus activation is discussed in the light of the existing studies at home and abroad. Meanwhile, the future research direction is also prospected. It will provide a theoretical basis for analyzing the mechanism of efficient plant phosphorus utilization and cultivating phosphorus efficient varieties.
Sugar Accumulation and the Relevant Enzymes Activities of Camellia gauchowensis
LIU Zhen, CHEN Rui-fan, SHEN Chun-hui, XI Ru-chun, DENG Xiao-mei
, Available online  , doi: 10.12403/j.1001-1498.20230398
Abstract:
: Objective To study the characteristics of sugar accumulation in various source-sink organs during the growth and development of Camellia gauchowensis and its relationship with the enzymatic activities related to sugar metabolism for providing a basis for further improving the theory of sugar accumulation in characteristic oil tea camellia varieties in the South China region. Method We employed the 13C isotope pulse labeling method to determine the 13C content in various source-sink organs at different developmental stages of C. gauchowensis. We also measured changes in non-structural carbohydrate (NSC) content, sugar component characteristics, and related enzyme activities in the respective organs during the corresponding periods. Result 1) After the stabilization of the transport of 13C-labeled photosynthates, during the early developmental stages, these products were primarily accumulated in the eaves, while in the later stages, the seed kernels gradually became the central location for assimilate distribution and accumulation. 2) The soluble sugar content in various organs was mainly observed in the order of peels > seeds > leaves, while starch content showed the order of leaves > seeds > peels. 3) The activities of SPS and SS-II were positively correlated with the soluble sugar content in leaves, peels, and seeds. B-AI primarily played a role during the later stages of development, with peak activities in seed kernels occurring in August and October. In leaves, NI served as the primary sugar-converting enzyme, with activity ranging between 50 and 60 U·g−1. In seed kernels, the activities of S-AI and NI were roughly similar, with S-AI primarily acting during the early developmental stages, while NI was more active during the later stages of development. Conclusion In C. gauchowensis, during the early stages of development, photosynthates primarily accumulate leaves of the source organ,. As fruit grows, the seed kernels gradually becomes the central location for assimilate distribution. Regarding sugar accumulation, during the early developmental stages, seed kernels primarily accumulates fructose and glucose, while in the later stages of development, they mainly accumulate sucrose. In the later stages of development, the sucrose transported to the peels will be decomposed into fructose and glucose, and the peels continues to thicken and extend, and continue to complete lignification. At this stage, there is intense competition for nutrients between the peels and seeds, resulting in the phenomenon of thick peels and large fruit size. The functions of SPS and SS-II complement each other and simultaneously influence sugar accumulation in C. gauchowensis, with SS-II being the key enzyme for sugar accumulation. This may be the primary reason for differences in sugar content among various source-sink organs. Sugar accumulation in C. gauchowensis is regulated comprehensively by sugar metabolism-related enzymes. NI serves as the primary conversion enzyme in the leaves, while S-AI and NI play roles in seed kernels during the early and late developmental stages, respectively. In peels, sucrose conversion primarily depends on S-AI. B-AI primarily functions in the later stages of development but with relatively low activity and limited conversion capacity.
Identification and Expression Analysis of PtoS1-bZIP Subfamily in Populus tomentosa
WU Jiang-ting, JIA Chen-lin, LUO Zhi-bin, DENG Shu-rong
, Available online  , doi: 10.12403/j.1001-1498.20230333
Abstract:
Objective To identify S1-bZIP subfamily members in Populus tomentosa and analyze the expression profiles of PtoS1-bZIP genes in different tissues in response to abiotic stress. Method Members of PtoS1-bZIP subfamily were systematically analyzed using bioinformatic approaches. Real-time PCR was performed to explore the expression patterns of PtoS1-bZIP genes in different tissues, as well as under different hormonal or abiotic stress treatment. Result A total of ten intron-lacking PtoS1-bZIP genes were identified in the genome of Populus tomentosa, which were distributed to eight distinct chromosomes. According to phylogenetic analysis, PtoS1-bZIP subfamily members were divided into three sub-clades, designated as Clades I to III. 12 pairs of fragment replicates were identified in the genome of Populus tomentosa. Cis-acting element prediction showed that the promoter regions of PtoS1-bZIP genes were rich of various regulatory elements involving light, hormone or abiotic stress response. qRT-PCR analysis revealed that the members of PtoS1-bZIP subfamily were specifically expressed across different tissues. The majority of PtoS1-bZIP genes in the first and second clades were upregulated under ABA and drought treatments, while expression levels were downregulated under salt treatment. In contrast, all of the PtoS1-bZIP members in the third clades were upregulated under ABA, drought, and salt treatments. Conclusion In the genome of Populus tomentosa, ten PtoS1-bZIP genes are identified and divided into three clades. The expression of major PtoS1-bZIP genes in the first and second clades were induced by drought stress and inhibited by salt stress. The expression of members in the third clades were induced by both drought and salt stress. It indicates that different clades of PtoS1-bZIP genes may have functional differentiation, which play different roles in response to abiotic stresses. Our results lay a foundation for further investigation of the biological functions of PtoS1-bZIP genes and their molecular mechanisms involved in regulating stress resistance of poplars.
The Physiological Response of Populus alba to Drought Stress
XU Hui, XUE Yuan
, Available online  , doi: 10.12403/j.1001-1498.20230472
Abstract:
Objective In this study, Populus alba was used to detect the effect of drought stress on growth and development, which provided reference for the molecular mechanism of the response to drought stress in woody. Method The seedlings of Populus alba about five weeks were treated with drought stress, the growth state and drought stress-related physiological indicators and genes were record and detected to reveal the resistance of Populus alba to drought stress. Result The results showed that the water content of leaves decreased significantly and stomatal aperture became smaller after 8 days of drought treatment; meanwhile ROS increased significantly, ABA accumulated in the body, and the growth-related hormone IAA content decreased, drought stress-related genes were upregulated. Conclusion By detecting the tolerance of Populus alba to drought stress from multiple perspective, the growth of their seedlings is significantly inhibited after drought treatment for 8 days, which indicates that watering timely is necessary.
Investigation and Analysis on Host Species and Their Resistance Substances to Bacterial Bark Canker of Populus × euramericana
LI Yong, CHANG Ju-pu, GUO Li-min, SUN Shang, YANG Xu-qi, PIAO Chun-gen
, Available online  
Abstract:
Objective To investigate and analyze the host species of bacterial canker of Populus × euramericana, the disease-resistant varieties and the possible disease-resistant substances they contain. Method The host of the pathogen and the resistant varieties were determined by field investigation and inoculation tests. The content of active substances in the bark of disease-resistant and susceptible varieties was analyzed by HPLC. Result The hosts of bacterial pathogen of P. × euramericana canker are P. deltoides, P. × euramericana and Salix matsudana. P. × euramericana cl. 'Zhonglin 46', P. deltoides cl. '2025', P. × euramericana cv. '2001', P. deltoides cl '313', P. deltoides 'Zhonghe-1' and P. deltoides '16-09' were highly susceptible to the bark canker disease; P. × euramericana 'Yukang 1' and P. deltoides '16-10' were highly resistant varieties, P. deltoides '131', P. deltoides '03-59', P. deltoides '02-212' and P. deltoides '03-34' were resistant varieties. Hybrid willows and Salix babylonica are resistant to the pathogen, and Salix × aureo-pendula can be affected, but do not cause serious disease. The HPLC analysis showed that the contents of catechol, benzoic acid and chlorogenic acid in the bark of resistant and highly susceptible poplar varieties were significantly different. The catechol and catechin increased when the hosts were infected by Lonsdalea populi. Conclusion In this study, the host species of bacterial canker of P. × euramericana are determined, and resistant and highly susceptible poplar varieties are screened. It is showed the catechol and catechin are important compound for host to defense the pathogen infection. The results will be helpful to the control of the bacterial disease of poplar.
Effects of Castanopsis kawakamii Forest Litter on Seed Germination of Pinus massoniana
JIA Mei-hua, WANG Zhe, LIU Jin-fu, JIN Meng-ran, HE Zhong-sheng, XING Cong, SHI You-wen, SHEN Cai-xia
, Available online  
Abstract:
Objective To understand the effect of litter of Castanopsis kawakamii natural forest on the competitive intensity of regeneration of Pinus massoniana. Method The allelopathic effects of litter extract of natural forest with different concentration and decomposition degree on seed germination and radicle growth of P. massoniana were studied. Result (1) The main factor affecting the germination of P. massoniana seeds was the degree of litter decomposition. Compared with the blank control, the litter of undecomposed layer and fully decomposed layer had no significant effect on the germination of P. massoniana seeds; the semi-decomposed layer inhibited the germination rate and germination index and promoted the germination potential. (2) The main factors affecting the growth of radicle were the concentration and action time of litter extract, and the effect of undecomposed layer on the whole radicle growth period of P. massoniana seeds was enhanced with the decrease of concentration, but increased with the decrease of concentration, and the promoting effect was the strongest at the concentration of 1 ≤ 100, and the effect of semi-decomposition layer was promoted by low concentration and high concentration, and the intermediate concentration was inhibited by the undecomposed layer. The fully decomposition layer showed promoting effect as a whole, and the promoting effect decreased with the decrease of concentration. (3) Correspondence analysis showed that different decomposition degree-concentration had no significant effect on seed germination of P. massoniana, but had significant correlation with radicle growth. Conclusion The result proves that the litter extract of different decomposition degree has a weak promoting or inhibiting effect on the seed germination of P. massoniana, promotes the growth of radicle at low concentration, and promotes the regeneration of P. massoniana, which will intensify the interspecific competition in the forest, and lead to the inhibition of the natural regeneration of C. kawakamii.