Abstract:The subtropical zonal vegetation is monsoon evergreen broad-leaved forest (altitude 300-600 m, monsoon forest), and the mountain evergreen broad-leaved forest (mountain forest) is distributed in the middle mountains (1 000-1 500 m). The ecological value of mountain forest has been paid more and more attention, but the environmental adaptability of its tree species is still not well understood. Based on fixed plots of typical mountain forest (Daming Mountain, Guangxi) and monsoon forest (Dinghu Mountain, Guangdong) in south subtropical region, leaf morphological and anatomical characteristics, mechanical strength and hydraulic properties of 57 representative tree species were measured, and leaf traits and correlation of various traits of evergreen broad-leaved forest species at different elevations were compared. The results showed that compared with monsoon forest species, the leaves of mountain forest species were thicker, the specific leaf area was smaller, and the mechanical strength was higher, which was conducive to improving the adaptability to winter freezing in the mountains at higher altitude. Under extreme hot-dry weather in 2022 summer, leaf water potential and hydraulic safety margin were significantly lower in the low-elevation forest than those in the high-elevation forest. However, leaf hydraulic safety margins were positive for most studied tree species and showed large inter-specific variations, indicating a low hydraulic risk in subtropical evergreen broadleaved forests. Leaf traits networks differed between the two forests. There was no tradeoff relationship between leaf hydraulic security and efficiency in mountain forest, while the correlation between leaf economic traits (such as specific leaf area) and other indexes was weak in monsoon forest. Based on leaf traits, the differences and diversity of adaptive strategies of evergreen broad-leaved forest species at different elevations in south subtropical region were revealed.

Abstract:With the development of urbanization, the output of wet waste is increasing, and the resource utilization of wet waste is imminent. Using earthworm to treat wet waste to make earthworm manure for farmland soil improvement is an effective way of resource utilization of wet refuse and is conducive to alleviating the obstacles of vegetable continuous cropping. Earthworm manure made from wet waste and anaerobic biogas residue was selected as the study object. The effects of earthworm manure applied for three consecutive years on soil quality and crop yield of Cucumis sativus were studied. The results showed that after three years of improvement, the organic matter content and cucumber yield treated with 60.0 t/hm²earthworm manure increased by 50.0% and 5.60%, respectively, and the effect of earthworm manure was higher than that of conventional organic manure. The soil total nitrogen content reached the highest level, which was 33.0% higher than the background value. The soil nutrient content (nitrate nitrogen, available phosphorus, available potassium) was also improved, and the available potassium content was increased by 94.0%. After 3 years of improvement, the number of bacteria in the soil increased significantly with the application of organic fertilizer, in which was the highest treated with 30.0 t/hm² earthworm manure. The ratio of soil bacteria/fungi was increased, and the biological properties of soil were improved. The soil respiration intensity increased with the application of organic fertilizer, in which was the highest treated with 60.0 t/hm² earthworm manure. Soil pH decreased slightly and salinity did not change significantly. Therefore, earthworm manure from wet waste can improve the physical, chemical and biological properties of soil, alleviate the occurrence of continuous cropping obstacles to a certain extent, and can be used as a substitute for chemical fertilizer or combined with chemical fertilizer to promote agricultural production.

Abstract:The leaves of Oxalis triangularis ‘Purpurea’ have significant nocturnal movement, which is characterized by a circadian rhythm of opening and closing. The effects of light quality, duration, and vibration on nocturnal movement of Oxalis were investigated in a climate chamber with controlled light and a time-laps camera. The results showed that light wavelength was a critical factor for the nocturnal movement pattern of Oxalis. The longer the wavelength, the faster the leaf unfolds, the shorter the wavelength, the slower the leaf closure. Under continuous light for 3 days, the leaves did not close, except that the leaves opened and closed only at 18:00 under red light. When 12 h/12 h (light/dark) photoperiod lasted for 3 days, it took 45-61 min for the leaves to unfold in the morning and 85-120 min to close completely at night. The leaves had unfolded before 8:00 AM except white light. The leaves could still unfold for 3-5 h every day under continuous dark. Horizonal rotation could change the nocturnal movement pattern of Oxalis. When the leaves were rotated at 300 r/min for 0.5-6 h, it will not close completely during rotation, only close to about 60°. The longer the rotating time, the faster the rate of leaf closure after stopping rotation. When rotation stopped after 2 h, the leaves would not close, so there was a certain range of adaptability to external stress of Oxalis. Therefore, when applying O. triangularis ‘Purpurea’ in the garden, short-wavelength illumination could be used to extend the unfolding time of leaves, increase its ornamental effect, and avoid exposure to the sun at noon.

Abstract:In order to explore climate warming could counteract the negative effects of defoliation caused by insects to some extent, the height growth of Larix gmelinii, Pinus koraiensis and Abies fabri seedlings under different defoliation degrees in current year and the budburst in the next year under different temperature were compared by using control variable method. The results showed that the height growth of L. gmelinii in the current year was significantly affected under 50% defoliation, while did P. koraiensis and A. fabri under 75% defoliation. At ambient temperature, the bud phenology of L. gmelinii in the next year advanced than that at 20 ℃ and 25 ℃, and the height growth was better. At ambient temperature (13 ℃~18 ℃), the bud phenology of P. koraiensis and A. fabri was delayed and the height growth was affected by 75% defoliation, while the adverse effect of defoliation was counteracted at 20 ℃ or 25 ℃. Therefore, in the future warming scenario, it was speculated that the adverse effects of defoliation caused by insects on P. koraiensis and A. fabri would be counteracted to some extent, and the resistance to a insects nd recovery would be significantly higher than that of L. gmelinii.

Abstract:The growth, survival, reproduction, and spread of plants are significantly influenced by functional traits. Understanding the distribution pattern of plant functional traits is helpful to reveal the process of community construction and its internal mechanism. Twelve different functional traits of woody plants in Dinghu Mountain subtropical mountain evergreen broad-leaved forest and gully rainforest were collected and measured. The quadrats of 5 m×5 m, 10 m×10 m and 20 m×20 m were used as scale units, respectively. The distribution pattern and driving mechanism of functional traits in communities were investigated by calculating mean pairwise trait distance (PW). The results showed that the 12 functional traits of the two forest types had different degrees of variation, but there was no significant difference between the communities (P>0.05). The spatial distribution pattern of functional traits in the two forest types was scale dependent, but the driving mechanism was different at different scales. With the increase of spatial scale, the main driving mechanism of spatial distribution pattern of functional traits in the mountain evergreen broad-leaved forest changed from environmental filtering to diffusion restriction. The environmental filtering and similarity restriction of ravine rainforest were changed to diffusion restriction, and both forest types were diffusion restriction at the spatial scale of 20 m×20 m. Niche differentiation and dispersal restriction were involved in the formation of community functional traits distribution pattern and community construction in the subtropical mountain evergreen broad-leaved forest and gully rainforest in Dinghu Mountain, and the contribution of both changes with spatial scale. Slope is the most important topographic factor affecting the distribution pattern of functional traits in mountain evergreen broad-leaved forest, and elevation is the most important topographic factor affecting gully rainforest.

Abstract:Hypnum plumaeforme has good landscape effect and application prospect, but its slow growth and lack of systematic cultivation technology research have a certain impact on its popularization and application. Phosphorus fertilizer (P), potassium fertilizer (K) and PK compound fertilizer were used as single-use base fertilizer, respectively, and the growth physiology and nutrient changes were studied under different fertilization treatments, and the best fertilization treatment was selected by fuzzy membership function method. The results showed that fertilization could significantly increase the coverage of H. plumaeforme, and the coverage under K₁₈ was 53.9% higher than that of control (CK). Fertilization significantly increased the contents of carotenoids, chlorophyll (except for K₁₂) and soluble protein (except P₂₄, PK₁₂ and PK₃₀), but decreased the soluble sugar content (excluding P₂₄ and PK₆). The contents of carotenoid and chlorophyll in plants treated with P₁₈ were the highest, which were 3.42 times and 2 times that of CK, respectively. P fertilizer significantly increased P content in plant, and P₁₈ had the greatest effect, which was 1.33 times that of CK. K fertilizer had the best promoting effect on the accumulation of K content in plants, and the K content in plants treated with K₁₈ was the highest (1.62 times that of CK). Fuzzy comprehensive evaluation showed that K₁₈ and P₁₈ had the best promotion effect on improving plant coverage and maintenance of greenness, respectively. Therefore, P₁₈ treatment had the best effect on enhancing growth and plant color.

Abstract:Cardiocrinum giganteum, a perennial bulbous plant of family Liliaceaeas, is an important medicinal and food homologous plant. The bulbs have typical dormancy characteristics, and low temperature is a major environmental factor to relieve dormancy of lily bulbs. In order to reveal the molecular mechanism of dormancy dissolution of Lily bulbs, metabolome and transcriptome analysis were performed on bulbs treated at 4 ℃ for 0, 30 and 60 days, respectively. The results showed that dormancy release of bud was related to the metabolism of phenols, and the degradation of phenols was beneficial to the release of dormancy, among which PALs gene might play a major role in this process. Meanwhile, members of transcription factor families such as bHLH, bZIP, MYB and MADS were all significantly related with phenolic metabolites and involved in bulb dormancy release. Co-expression analysis further confirmed that PAL, CAD and POD were important regulatory genes for phenolic metabolism, MYB4, MYB114 and ICE1 were involved in the regulatory network of phenolic metabolism, and ICE1 might be the key factor connecting temperature signals and phenolic metabolism. Therefore, the interaction of these transcription factors with phenols might play an important role in breaking dormancy of bulbs.

Abstract:In order to understand the genetic diversity and evolutionary characteristics of phenotypic traits of 89 wild tea trees from Yingde, Guangdong Province, the coefficients of variation, genetic diversity index, phenotypic differentiation coefficient of phenotypic traits were analyzed. The results showed that the variation coefficient of 18 leaf traits of 89 resources ranged from 12.90% to 43.11%, with an average of 27.86%. The average genetic diversity index was 1.12, and the phenotypic differentiation coefficient ranged from 17.07% to 45.51%, with an average of 33.40%. The cluster analysis results showed that when the Euclidean distance was 21.5, all the materials could be divided into four categories, and the classification results had correlation with the geographical distribution. The variance analysis showed that there were significant differences in quantitative traits between and within different populations. The correlation analysis showed that leaf length was significantly correlated with leaf width, leaf area, leaf vein number, ratio of leaf length to width and leaf shape. The leaf shape was significantly correlated with ratio of leaf length to width and leaf vein number. There was a significant correlation between leaf base and leaf width. The ratio of leaf length to width had negatively significant correlation with leaf tip and leaf direction. Therefore, there were abundant genetic diversity in wild tea resources in Yingde, and the types of wild tea germplasm resource were primitive, evolutionary and intermediate, but the evolutionary and intermediate types were the main ones.

Abstract:To understand the growth and photosynthetic characteristics of large polytube-raised buddings of Hevea brasiliensis under different shading environments, and to determine the appropriate light environment for the growth of large polytube-raised buddings, five shading were set, including CK (full light), S60, S70, S80 and S90 (60%, 70%, 80% and 90% shading rate, respectively), to observe the growth index and photosynthetic parameters changes. The results showed that different shading rates had significant effects on the growth, photosynthetic parameters, leaf area and relative content of chlorophyll of top-leaf-whorls of large polytube-raised buddings of H. brasiliensis, and there were significant differences between the two types of embryo seedlings. The vigorous seedling index of large polytube-raised buddings increased at first and then decreased with the increase of shading rate. Compared with full light, shading significantly affected the out-nursery rate of large polytube-raised buddings, but had little effect on the survival of planting. The interaction between embryo seedling type and shading was obvious. Full light (CK) and excessive shading (S90) could significantly inhibit the growth of large polytube-raised buddings. The optimal shading rate of large polytube-raised buddings was different among different embryo seedlings. The growth performance of small seedling buds under S60 and tissue culture seedlings under S80 was the best. Therefore, appropriate shading measures should be selected according to embryo seedling types during the cultivation of large polytube-raised buddings of rubber trees.

Abstract:In order to provide the genetic resource for accelerating the breeding in Eucalytpus, the variation of heartwood and the related candidate genes were explored in E. cloeziana. Wood discs were cut at intervals of 1 meter along the stem of felled tree in two 18-year-old families with contrasting high and low heartwood width, and each family has three individuals. The diameter outside and inside bark, overall ring number, sapwood ring number, sapwood width at two directions of northeast and southwest were measured. Radial and axial analysis were analyzed and the DNA from developing xylem tissues were harvested at breast height and used for bulk DNA sequencing, the SNP loci and the functional genes highly related with the variation of heartwood were discovered. The variation of sapwood width and heartwood radius among orientations were the highest in family 2, the average difference in family 1 and 2 were 0.7 and 5.5 cm, respectively. The decrease rate of heartwood radius and ring number with tree height were 0.40 and 0.64 in family 1, and 0.43 and 0.36 in family 2. The average basic density of E. cloeziana was significantly different between two families, with family 1 ranged from 0.80 to 0.82 g/cm³, and family 2 from 0.75 to 0.78 g/cm³. The basic density was negatively correlated with tree height, cross-section radius and heartwood radius, and positively correlated with tensile strength parallel to the grain and the hardness of tangential section, along some mechanical properties. Using Bulk DNA sequencing, a total of 1842 SNPs with high difference allele frequency were screened. Approximately 55.8% of these SNPs were distributed between genes, 18.3% in the upstream region, 16.3% in the downstream region, 5.1% in exons and 4.4% in introns using SnpEff annotation. The identified SNPs were used to locate the genes belonging to 50 terms, mainly related to plant cell division, plant cell membrane and plant protein kinase by GO enrichment analysis. By conducting the radial and axial analysis of these two families with contrasting high and low heartwood width, the trend of sapwood and heartwood variation were discussed. The SNPs and candidate genes were screened by bulk DNA sequencing, and the functions of genes involved to the process of sapwood formation were explored.

Abstract:G-box-binding protein (GBF), the transcription factors which can recognize and bind to G-box, is widely involved in the regulating gene expression in response to external stimuli. The differentially expressed gene EgrGBF was screened by RNA-seq from primary to secondary growth of Eucalyptus grandis. In order to investigate its function, EgrGBF was cloned from E. grandis, and its structure and evolution were analyzed. The results showed that the length of EgrGBF1 coding region was 984 bp, encoding 327 amino acids. There were two transcripts, named EgrGBF1α and EgrGBF1β. The real-time quantitative PCR showed that expression pattern of EgrGBF1α and EgrGBF1β were different in various tissues and hormones and stress treatments. The expression EgrGBF1α was main in shoot apex, and gradually decreased down the internode, while that of EgrGBF1β was high in phloem, and there was no significant difference among internodes. Meanwhile, the expression trend of EgrGBF1α and EgrGBF1β was opposite treated by salicylic acid and boron deficiency. Under phosphorus deficiency, the expression of EgrGBF1α and EgrGBF1β was the highest at 168 h and 6 h, respectively. Therefore, EgrGBF1 plays an important role in the growth and development of Eucalyptus and the response to stress, and the transcriptional EgrGBF1α and EgrGBF1β may have different functions.

Abstract:Lycium ruthenicum is rich in anthocyanin, and AN2 is the main gene regulating anthocyanin anmeta- bolism. In order to analyze the activity difference of AN2 gene promoter, the upstream sequence of AN2 gene start codon about 1 686 bp (LrAN2p) and 1 495 bp (LbAN2p) of L. barbarum were cloned by Tail-PCR method, respectively. Plant CARE predicted that there were 133 and 137 cis-acting elements in sequences of LbAN2p and LrAN2p, respectively, among which 11 and 15 cis-acting elements were involved in photoregulation, and 13 and 16 cis-elements involved in hormone response, respectively. The plant expression vectors pKGWFS7:LbAN2p and pKGWFS7:LrAN2p were constructed, and the transgenic tobacco was obtained by using Agrobacterium- mediated tobacco genetic transformation system. The results of GUS staining showed that LrAN2p could drive the expression of GUS in tobacco, and the leaves were blue, with stronger starting activity than LbAN2p. The results of qRT-PCR showed that GUS gene in LrAN2p transgenic tobacco had high transcription level, which might lead to high expression of AN2 gene in L. ruthenicum, and activating the anthocyanin anabolic pathway. Thus, these would provide a theoretical basis for understanding the mechanism of fruit color formation and AN2 gene expression.

Abstract:In order to understand the main volatile components of Dendrobium flowers at full bloom stage, the volatile components from flowers of D. thyrsiflorum, D. tortile, D. chrysotoxum and D. densiflorum were determined by solid phase microextraction (SPME) and gas chromatography coupled with mass spectrometry (GC-MS). The results showed that there were 70 volatile components identified in 4 Dendrobium flowers, including 8 types of esters, alcohols, phenols, ketones, alkanes, alkenes, aldehydes and others, among which alkenes was the main volatile component with the highest content. The main aromatic constituent was caryophyllene in D. thyrsiflorum and D. densiflorum with relative contents of 0.46 and 6.91 μg/(g·h), respectively, and acetic acid [6.11 μg/(g·h)] in D. tortile; and β-ocimene [5.23 μg/(g·h)] in D. chrysotoxum. Thus, it was helpful to evaluate and screen valuable germplasm resources of Dendrobium, and provide reference for the cultivation of aromatic Dendrobium species and the development and utilization of orchid essential oil.

Abstract:To study metabolites of endophytic fungus Aspergillus fumigatus isolated from Paris polyphylla var. yunnanensis, thirty-one compounds were obtained from fermentation broth and mycelium by several chromato- graphic techniques, such as silica gel column chromatography, sephadex LH-20 and semi-preparative HPLC. Based on physicochemical properties and spectral data, their structures were identified as tryprostatin B (1), tryprostatin A (2), 12,13-dihydroxyfumitremorgin C (3), cyclotryprostatin B (4), 14-norpseurotin A (5), pseu- rotine F1 (6), pseurotine F2 (7), azaspirofuran A (8), pseurotin D (9), spirotryprostatin K (10), 6-methoxy- spirotryprostatin B (11), 7-deacetylpyripyropene A (12), fumagillin (13), fumagillene A (14), 5,9-dihydroxy-β- trans-bergamotene (15), 4-hydroxyphenylacetic acid (16), demethoxyfumitremorgin C (17), fumiquinazoline J (18), helvolic acid (19), ergosterol (20), ergosterol endoperoxide (21), 4,4-dimethyl-5α-ergosta-8,24(28)-dien- 3β-ol (22), lanosterol (23), linoleic acid (24), oleic acid (25), fumitremorgin C (26), fumitremorgin B (27), verruculogen (28), pseurotin A (29), fumiquinazoline C (30), and questin (31). Compounds 1-16 and 17-25 were isolated from fermentation broth and mycelium, respectively, while compounds 26-31 were isolated from both fermentation broth and mycelium. Compounds 15 and 23 were isolated from A. fumigatus for the first time. In addition, the compounds 26-29 were evaluated for their acetylcholinesterase inhibition activities and tobacco black shank inhibition activities, compounds 26 and 27 showed slight activities against pathogenic fungi of tobacco black shank with inhibition rate of 19.64% and 17.86%, respectively.

Abstract:In order to understand the chemical constituents of Dendrobium hercoglossum, fourteen compounds were isolated from the aerial parts of D. hercoglossum by using various column chromatography with silica gel, sephadex LH-20, and semi-preparative HPLC. Based on spectroscopic data, their structures were identified as 3,4,5-trimethoxyphenol (1), 3-hydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-propan-1-one (2), methyl 3-(p-hydro- xyphenyl) propionate (3), justiciresinol (4), ficusal (5), meso-secoisolariciresinol (6), threo-2,3-bis-(4-hydroxy- 3-methoxyphenyl)-3-methoxypropanol (7), (+)-pinoresinol (8), aloifol Ⅰ (9), dendrocandins T (10), 3-hydroxy- 1-(4-hydroxy-3-methoxyphenyl)-propan-1-one (11), 1,3,5-trimethoxybenzene (12), homovanillyl alcohol (13) and (−)-syringaresinol (14). Compounds 1−12, 14 were obtained from D. hercoglossum for the first time, and compounds 7, 10, and 14 were isolated from Dendrobium species for the first time. The compounds 4, 8 and 10 showed significant inhibitory activity, with IC₅₀ of (10.40±0.36), (12.16±0.18) and (9.46±0.78) μmol/L, respectively.

Abstract:Germination is the key development stage for seed plants entering the agricultural ecosystem. For light-requiring seeds, light is one of the most important environmental signals regulating germination. Red light promotes, whereas far-red light inhibits seed germination. Phytochromes are the major photoreceptors that regulate seed germination. Activated phytochromes promote the degradation of Phytochrome-Interacting-Factor 1 (PIF1), the master repressor of germination, to regulate the expression of genes related to gibberellin and abscisic metabolism and signaling pathways, leading to the initiation of seed germination. Furthermore, a series of epigenetic factors dynamically affect the chromatin structure of germination-related genes and regulate their expression to modulate seed germination process. Here, we summarize the progress, especially the transcriptional and epigenetic mechanisms in light-regulated seed germination, and discuss their applications in agricultural production in future.