Plant development is highly plastic. As ambient temperature increased， plant stems and petioles elongated， and promoted leaf surface cooling， the process known as thermomorphogenesis. High temperatures also triggered root elongation， which named as root thermomorphogenesis. There were many studies on the regulation of plant shoot thermomorphogenesis， but few investigations on the regulatory mechanisms of plant root thermomorphogenesis. In this review， we summarized the recent progresses in the field of plant root thermomorphogenesis， and proposed future research directions.
A variety of Rubus chrysobotrys Hand.-Mazz.（Rosaceae）， Rubus chrysobotrys Hand.-Mazz. var. glandulosus L.T.Lu， was described as new from southern Sichuan， China. The diagnostic differences between this new variety and Rubus chrysobotrys Hand.-Mazz. var. chrysobotrys and the key to varieties of Rubus chrysobotrys Hand.-Mazz. were given， and photos of vouchers were provided.
Based on field investigation and specimen identification in Gexigou National Nature Reserve， six families， seven genera， six species， one subspecies and one variety were identified as new records in Sichuan Province， viz. Populus wuana C. Wang et Tung（Salicaceae）， Lonicera spinosa Jacq. ex Walp.（Caprifoliaceae）， Rhododendron przewalskii Maxim. subsp. yushuense Fang et S.X.Wang（Ericaceae）， Ligularia confertiflora Chang（Asteraceae）， Rhodiola serrata H. Ohba（Crassulaceae）， Meconopsis racemosa var. spinulifera（L.H.Zhou） C.Y.Wu et H.Chuang（Papaveraceae）， Taraxacum luridum Hagl.（Asteraceae）， Taraxacum pseudoatratum Oraz.（Asteraceae）， voucher specimens（GAO20230301-08） were preserved in the herbarium of Yibin University.
In order to explore the potential suitable distribution area and the suitable living environment of Corydalis trachycarpa， and to provide a theoretical basis for resource utilization and protection of C. trachycarpa. Based on the existing distribution sites， climatic variables， and environmental variables of C. trachycarpa， MaxEnt modeling and ArcGIS software were used to simulate the potential distribution of C. trachycarpa in China for four periods under current climate condition（1970-2000） and Shared Socioeconomic Pathway（SSP） 245 scenario model（2021-2040， 2041-2060， 2061-2080， 2081-2100）， and environmental factors limiting its distribution were analyzed. The results showed that the most important environmental factors determining C. trachycarpa distribution were altitude（Alt， contribution rate was 60.9%）， standard deviation of temperature seasonality（bio4， contribution rate was 11.1%）， precipitation during the warmest quarter（bio18， contribution rate was 9.4%）， and the precipitation variation coefficient（bio15， contribution rate was 7.0%）. The cumulative contribution of these four factors was 88.4%. Under current climate conditions， the MaxEnt model predicted a total potential distribution area of approximately 1.7494×106 km2 for C. trachycarpa， primarily distributed in northwest Sichuan， southern Gansu， eastern Xizang， northwest Yunnan， and Qinghai within the eastern Tibetan Plateau. Compared with the current climate conditions the most， moderate and low suitable areas of C. trachycarpa under SSP 245 scenario might increase in the next four periods， showing a trend of expansion toward Yunnan， eastern Xizang， and other lower latitude regions.
The systematic position of Messerschmidia L. has been problematic which was ever moved into Tournefortia L. or Heliotropium L. Sporogenesis and gametogenesis in Messerschmidia sibirica were observed using conventional paraffin sectioning and light microscopy to provide embryological data for a better understanding of the systematic position of Messerschmidia. The results were as follows： （1）The anther was tetra-sporangiate， the primarily matured anther wall comprised four layers： the epidermis， endothecium， a middle layer and tapetum， the development of the anther wall was of the Dicotyledonous type， the tapetum with two-nucleate cells was secretary， the epidermis was persistent and the endothecium was irregularly 2- layered with fibrous thickening； （2）Microsporocyte undergone a meiotic division with a simultaneous cytokinesis resulting in a tetrahedral microspore tetrad， the mature pollen grains were 2-celled； （3）The ovule was unitegmic， anatropous and crassinucellate with a long thin micropyle and weak integument tapetum， some of the nucellar tissue was persistent at the stage of mature embryo sac； （4）The development of the embryo sac was of a Polygonum type， the shape of the mature embryo sac was fusiform with polar nuclei fused before fertilization and antipodal cells already degenerated. The embryological characters of Messerschmidia sibirica might be very similar to those of Heliotropium. Considering the stability of embryological characters within genus， the results suggested that it might be suitable to classify Messerschmidia into Heliotropium based on the molecular phylogenies.
Dipteris shenzhenensis is a critically endangered（CR） plant distributed only in Shenzhen. The phyto-community analysis of this dominant community was studied and analyzed， and the results showed that： there were 85 species， 73 genera and 49 families of vascular plants in Dipteris shenzhenensis community， the dominant species included Gordonia axillaris， Ilex memecylifolia， Cyclobalanopsis neglecta， Enkianthus quinqueflorus， Litsea rotundifolia var. oblongifolia， Dipteris shenzhenensis， Dicranopteris pedata； Plant individuals in this community decreased with the increase of tree height， showing an “Inverted J” type distribution， which was an obvious characteristic in subtropical areas. The diversity and evenness index of all life forms showed a trend of “high in the middle and low in the two ends”； The T test of the species diversity index of different communities in the same area proved that there was no significant difference in diversity level between different communities， which belonged to the stable stage of ecological succession； Niche analysis revealed the survival status of Dipteris shenzhenensis in the community， indicating that this species was not widespread， demanding for environment and poor competitiveness in resources， and there was a risk of extinction during community succession； Interspecific association analysis revealed the interspecific relationship between this species and other dominant herbs， and identified possible complementary and competitive plants.
To explore the effects of multi-walled carbon nanotubes in gametophyte development and sporophyte production of Ceratopteris thalictroides， and to lay a foundation for conservation and breeding of endangered ferns.C. thalictroides was used as material， and five treatment group of 0（the control）， 0.5， 1.0， 2.5， 5.0 mg·L-1 was set，and the effects of different mass concentrations of multi-walled carbon nanotubes on gametophyte development and sporophyte formation of C. thalictroides were observed by light microscope. The results showed that compared with the control group， 0.5-2.5 mg·L-1 multi-walled carbon nanotube treatment could advance spore germination by about 15 d， among them， 0.5 mg·L-1 multi-walled carbon nanotubes had the best effect on spore germination， 0.5-1.5 mg·L-1 multi-walled carbon nanotubes had the best effect on protonema and plate formation， and 2.5 mg·L-1 multi-walled carbon nanotubes had the best effect on prothallus and sporophyte formation. High mass concentration （5.0 mg·L-1） of multi-walled carbon nanotubes led to deformity of some gametophytes， and spermogonium degradation， chlorosis of chloroplasts in cells， and chlorosis of chloroplasts in some cells on the developing sporophytes cells. In addition， male gametophytes was promoted by the addition of multi-walled carbon nanotube. In conclusion，0.5-2.5 mg·L-1 multi-walled carbon nanotube treatment might significantly promote gametophyte development and sporophyte production of C. thalictroides， and the number of spermogonium increased significantly， and both monoecious and dioecious gametophytes appeared simultaneously， high mass concentration of multi-walled carbon nanotube treatment might result in‘high concentration inhibition’ of gametophyte development of C. thalictroides. In the process of practical application， the corresponding addition amount should be selected based on the specific need.
To analyze the phenotypic traits of the floral organs of Iris lactea var. chinensis germplasm resources and to clarify the pigment composition of the petals， 22 I. lactea germplasm resources under different habitat conditions in six provinces and cities of China were used as experimental materials to systematically study the phenotypic characteristics and anthocyanin of this important ornamental part of flower organs. The phenotypic traits of the floral organs were described by RHSCC colorimetry and colorimeter colorimetry， and the mass fraction of floral pigment was determined by sodium nitrite-aluminum nitrate colorimetry and pH differential analysis， and the differences in the expression of floral pigments in different color lines were analyzed. The results showed that the flower color of 22 germplasm resources could be divided into four color families： light blue， light blue-violet， dark blue-violet and violet. The brightness（L*） of the fall and standard petals was negatively correlated with a*， positively correlated with b*， and negatively correlated with color（c*） respectively. Among the four color families， violet petals were the largest， flower branch length was the highest， and fall spot was the smallest. While light blue petals were the smallest， flower branch length was the lowest， and fall spot was the largest. It indicated that the darker the petal color， the larger the petal， and the smaller the fall spot. The mass fraction of pigment in the petals of different colors of I. lactea differed significantly. The mass fraction of carotenoid in the light blue petals was significantly higher than that in the violet color， while the mass fraction of flavonoid and anthocyanin in the violet petals were significantly higher than that in the light blue color. As the petal color deepened， the mass fraction of carotenoid decreased and the mass fraction of flavonoid and anthocyanin increased correspondingly. The correlation analysis revealed that the mass fraction of carotenoid was significantly positively correlated with fall and standard petal L*（P<0.05）， and significantly negatively correlated with fall and standard petal a* and c*（P<0.05）.The mass fraction of flavonoid was highly significantly negatively correlated（P<0.01） with fall and standard petal L* and b*， highly significantly positively correlated（P<0.01） with fall and standard petal a*， significantly positively correlated（P<0.05） with fall and standard petal c*. The correlation results between the mass fraction of anthocyanin and colorimetric parameters were similar to those of flavonoids， indicating that the mass fraction of flavonoids and anthocyanins played an important role in the coloration of I. lactea.
To explore the effects of pectinase on distribution of arabinogalactan proteins（AGPs） in fruits at different developmental stages，and to provide anatomical evidence for revealing the effects of pectinase on fruit ripening and softening， the fruits of Ziziphus jujuba ‘Lingwu Changzao’ at four different development stages were treated with three different concentrations pectinase， and AGPs epitopes analysis in situ at cellular level of fruits was performed using immunocytochemistry technique. The results showed that the fluorescence intensity of the antigens recognized by JIM13 and JIM8 and MAC204 antibodies was varied in different tissues during the development of fruit at each stage. When fruit tissues were treated with 0.028 U·mL-1（E1） pectinase， there were no obvious changes in pericarp tissue structure， AGPs antigen epitopes in cell wall surface and intercellular space of pericarp and interior parenchyma cells decreased. When fruit tissues were treated with 0.056 U·mL-1（E2） and 0.084 U·mL-1（E3）pectinase， disintegration degree of cell wall in fruit tissue increased， the amount of AGPs epitopes detected in cell wall of pericarp and inner parenchyma cells decreased gradually， an increase in pectinase concentration resulted in a greater effect of AGPs on the arrangement of all epitopes in fruit and a lower fluorescence signal. After treatment with pectinase concentration up to 0.084 U·mL-1（E3）， Calcofluor White staining revealed fluorescence attenuation or reduction to varying degrees in the cell wall region， disturbance of AGPs distribution and absence of antigen epitopes were associated with changes of cellulose assembly in cells. The results indicated that the distribution of AGPs carbohydrates differed in fruits at different stages， which was related to changes in tissue structure. The absence of AGPs glycan chains in the presence of pectinase led to the block of the establishment of correlations between cell wall components and cell wall structure remodeling， and the changes in the whole cell wall structures were induced and fruit ripening was affected.
In order to explore the population structure and dynamic characteristics of Chunia bucklandioides in Diaoluo Mountain of Hainan， the local wild population of C. bucklandioides was taken as materials， and the concentrated distribution area of the population was set as a typical sample plot to survey， and construction of population age structure instead of space for time was designed. The current population structure and dynamic characteristics were analyzed by the dynamic quantitative analysis， survival curve drawing and survival function calculating， and the future development trend of C. bucklandioides was speculated by time sequence prediction model. The results showed that： （1）The age structure of C. bucklandioides population in Diaoluo Mountain was close to an irregular pyramid type. Dynamic quantitative analysis showed that the population was a growing population， but there was a decline trend from the age class Ⅰ to Ⅲ. The population had weak growth， poor stability， high sensitivity to external interference， and a trend towards a stable population. （2）With the increase of age class， the number of standardized survival individuals decreased， the life expectancy decreased， and the mortality and vanish rate showed an upward trend. The survival curve tended to be Deevey-Ⅱ type. （3）Survival analysis showed that the population of C. bucklandioides in Diaoluo Mountain increased in the early stage， stabilized in the middle stage， and declined in the late stage. （4） After two， four and six age classes in the future， there would be a gradually decreasing trend from I to Ⅲ age class， and slightly increasing trend from Ⅳ to Ⅶ age class. The self-renewal ability of young seedlings was insufficient， and there was a risk of population shrinkage and decline. Consequently， habitat fragmentation， small distribution range， low seed yield and insufficient young individuals might be the main factors leading to the endangerment of C. bucklandioides in Diaoluo Mountain. The results suggested to promote the rejuvenation and renewal of C. bucklandioides population by setting up small nature reserve， assisting seed germination， accelerating artificial cultivation technology research， artificially expanding population size and quantity， and strengthening basic research.
In order to explore the effects of nitrogen addition on the growth and non-structural carbohydrate（NSC） content of Cinnamomum bodinieri seedlings in rare earth mine tailings， one-year-old C.bodinieri cuttings were used as materials， and calcium ammonium nitrate was used as nitrogen fertilizer（containing N 15%）， and three nitrogen levels（CK（0）， N1（1.8 g per plant）， N2（3.6 g per plant）） were set up to analyze the differences in root growth， biomass distribution and NSC of C.bodinieri seedlings under three nitrogen addition levels， and to explore the response of C.bodinieri in rare earth tailings to nitrogen addition. The results showed that： Nitrogen addition increased the biomass accumulation of different tissues of C.bodinieri seedlings in rare earth tailings， and the leaf biomass and canopy biomass at N1 level were significantly increased by 44.75% and 57.43%（P<0.05）， respectively， compared with N2. Compared with CK and N1 treatment， the leaf mass ratio of N2 level was significantly increased by 123.53% and 15.85%（P<0.05）， respectively. Nitrogen addition significantly promoted the root length and root surface area of both coarse roots（diameter>2mm） and fine roots（diameter≤2mm）（P<0.05）， and the promotion effect of N1 treatment was the most significant（P<0.05）. The specific root length and specific surface area under N2 treatment were higher than those of CK and N1， and significantly different from CK（P<0.05）. For NSC， N1 treatment increased the soluble sugar mass fraction in leaves and stems， while the NSC mass fraction of fine roots under N2 treatment was significantly lower than that of CK and N1 by 46.49% and 28.61%， respectively. In summary， during vegetation restoration in rare earth mine tailings， 1.8 g per plant calcium ammonium nitrate fertilizer might be suitable for fertilization management of C.bodinieri seedlings.
To provide reference for early selection of fast-growing and adaptable varieties， the difference in growth， photosynthetic physiology， and root tip ion flux were analyzed among in five poplar varieties. The annual seedlings of Populus × euramericana ‘Bofeng 3’， P. × euramericana ‘Bofeng 1’， P. × euramericana ‘Xixiong 1’， P. × euramericana ‘Zhongxiong 7 ’， and P. deltoides × P. suaveolens cl. ‘Zhongxiong 4’ were selected as materials. Growth indexes including plant height and ground diameter were measured at 0 and 30 days under normal culture conditions， respectively. Leaf number， single leaf area， leaf length， leaf width， photosynthetic parameters including Pn， Ci， Gs， Tr， SPAD and K+， Ca2+， H+ ion flux of roots were measured at 10， 20 and 30 days， respectively. Under 30 days normal management， There were significant differences in plant height growth among the five varieties， from high to low， it was ‘Zhongxiong 4’， ‘Xixiong 1’， ‘Bofeng 3’， ‘Zhongxiong 7’ and ‘Bofeng 1’. Among them， the photosynthetic characteristics and transpiration rate of ‘Bofeng 1’ were the largest， and those of ‘Zhongxiong 4’ were the smallest. However， the single leaf area（（57.49±2.37） cm2）， total leaf area（（1 721.10±28.59） cm2）， net photosynthetic rate （（17 863.10± 910.21） μmol·m-2·s-1） and water utilization rate（（3.15±0.06）μmol·mmol-1） of ‘Zhongxiong 4’ were significantly decreased. were the largest. The efflux velocity of K+ was the slowest（（62.68±0.45） pmol·cm-2·g-1）， and the influx velocity of Ca2+ was the fastest（（-74.24±1.29） pmol·cm-2·g-1）. The net photosynthetic rate （（8 539.70±164.64） μmol·m-2·s-1） and water utilization rate（（2.64±0.07） μmol·mmol-1） of ‘Bofeng 1’ were the lowest， and the outflow velocity of K+ was（130.81±1.71） pmol·cm-2·g-1. The Ca2+ influx velocity（（-34.43±0.84） pmol·cm-2·g-1） was the slowest. In summary， among the five varieties， ‘Zhongxiong 4’ might have potential strong environmental adaptability， with the highest total leaf area， Pn and WUE， the lowest Tr， the smallest K+ efflux， largest Ca2+ influx of and most active H+ of root tip， and best plant height growth performance， which might be suitable for planting a wider range.
Bryophyte is an important component of the surface ecosystem. The physiological response of bryophyte（Syntrichia caninervis， Bryum argenteum and Plagiomnium acutum） to nitrogen deposition could provide insights into how to use bryophyte scientifically and rationally to indicate the atmospheric nitrogen deposition. Three bryophytes in the northwest of China were selected as materials， and four different nitrogen treatment concentrations（0（N0）， 2（N2）， 4（N4）， 6（N6） g·m-2） were set up， the physiological responses of three bryophytes to the above nitrogen concentration gradients were indicated by measuring the contents of chlorophyll， osmotic regulators and antioxidant enzyme activities. The results showed that：（1）P. acutum of chlorophyll a and chlorophyll b was promoted by 4 nitrogen treatments， especially by N4 treatment. However， N2 had significant inhibitory effects on chlorophyll a and chlorophyll b of B. argenteum and S. caninervis. （2）Proline（Pro）， soluble sugar（SS） and soluble protein（SP） were produced in bryophytes to regulate cell osmotic balance. The contents of Pro， SS and SP in B. argenteum and P. acutum all increased under different nitrogen concentrations， but the contents of Pro， SS and SP in mosses decreased under low nitrogen treatment， indicating S. caninervis were more sensitive to N. （3）under the given nitrogen addition treatment， the antioxidant enzyme activities of three bryophytes were promoted by low concentration of nitrogen， but inhibited by high concentration of nitrogen. （4）SOD and CAT played major role in the regulation of the antioxidant system in S. caninervis， B. argenteum and P. acutum， respectively. In conclusion， S. caninervis was the most sensitive to nitrogen increase of the three bryophytes， followed by P. acutum. And B. argenteum， suggesting that S. caninervis could be used as an indicator plant for atmospheric nitrogen deposition.
In order to investigate whether brassinosteroids（BRs）-induced chilling tolerance is regulated through nitric oxide（NO） signaling molecule， the suspension cultured cells of Chorispora bungeana were treated with 24-epibrassinolide（EBR）， NO donor SNP， NO scavenger PTIO， nitric oxide synthase（NOS） inhibitor L-NAME， EBR+PTIO and EBR+L-NAME respectively， and the effects of the above treatments on chilling tolerance， reactive oxygen species（ROS） levels and antioxidant defense system were analyzed in the cells under low temperature stress. The results showed that： （1）exogenous EBR treatment enhanced chilling tolerance in the suspension cultures and alleviated the inhibition of cell viability and aggravations of ion leakage and membrane lipid peroxidation induced by low temperature. The effects of SNP treatment on the above physiological measures were similar to those of EBR. （2）Application of PTIO or L-NAME in combination with EBR significantly decreased cell viability and increased ion leakage and membrane lipid peroxidation in C. bungeana suspension cultures under chilling stress compared with those of EBR treatment alone， suggesting that the block in NO signaling decreased the EBR-enhanced chilling tolerance. （3）EBR treatment further increased NO production and NOS activity in the suspension cells compared with those under chilling stress alone， whereas the EBR-induced NO signal was quenched by the addition of PTIO or L-NAME. （4）Both EBR and SNP obviously inhibited the increases in hydrogen peroxide（H2O2） content， superoxide radical（ O 2 · – ） production rate and hydroxyl radical （OH-）content caused by chilling， and remarkably enhanced the activities of ascorbate peroxidase（APX）， catalase（CAT）， glutathione reductase（GR）， peroxidase（POD） and superoxide dismutase（SOD） and contents of ascorbate （AsA） and glutathione（GSH） in the suspension cultured cells， thus alleviating oxidative injury caused by low temperature. However， PTIO and L-NAME blocked the protective effects of EBR. In conclusion， these results suggested that EBR-induced chilling tolerance in C. bungeana suspension cultured cells was through the promotion of NO accumulation by activating NOS activity. EBR might confer an increased tolerance to chilling stress by suppressing the accumulation of ROS caused by chilling and enhancing antioxidant defense system in the suspension cells， both of which were partially regulated by NO signal， resulting in the alleviation of chilling-induced oxidative damage and membrane lipid peroxidation. Thus， NOS-derived NO might be a downstream signaling molecule of EBR signal in C. bungeana suspension cultured cells under low temperature stress.
To analyze gene function in plants lacking stable genetic transformation system， virus-induced gene silencing（VIGS） was needed， and Iris sanguinea， a monocotyledon， was selected as materials. The specific fragment of IsPDS gene was isolated and the VIGS recombinant vector pTRV2-IsPDS was constructed and leaves were infected by injection. The results showed that the most effective infection was achieved by injecting its leaf veins with syringes when the OD600 values of the resuspension were adjusted to 0.8-1.0 after the those of pTRV1 and pTRV2-IsPDS were adjusted to 1.8-2.0. The experiment was conducted when outdoors temperature was 15-20 ℃ from 6 p.m. to 8 p.m.， and a 1 mL syringe needle pricking the outer epidermis of I. sanguinea leaves and 1 mL of heavy suspension slowly injected along parallel veins into its vascular bundles. A clear albino phenotype might appear after about 14 days. TRV1 and TRV2 virus vectors were detected in the plants with phenotypic changes and in the no-load group. The expression of IsPDS in the albino plants was significantly lower than that in the no-load group and the control group. With the concentration of agrobacterium tumefaciens carrying virus vector increased in the preparation of infection solution， the infection efficiency of the whole experiment was improved， and no shading was needed after inoculation.
To provide theoretical basis for genetic improvement of reproductive regulatory traits of Catalpa bungei， DELLAs family genes were identified and the function of CbuGRAS9 was analyzed. Based on the genomic data of Catalpa bungei， five CbuDELLAs genes homologous to Arabidopsis thaliana were identified and cloned. ExPASy， SWISS-MODEL， Plant-mPloc， PlantCare and other online tools were used to predict the isoelectric point， protein structure， sub-cellular localization and promoter cis-acting elements of CbuDELLAs protein. The expression differences of CbuDELLAs were analyzed by using Catalpa ‘Bairihua’ and Catalpa bungei ‘Luoqiu No.1’ as materials， and the molecular function of CbuGRAS9 was confirmed by heterologus transformation in Arabidopsis thaliana， and the proteins interacted with CbuGRAS9 were screened by yeast two-hybrid library. The results showed that the amino acid number of the five CbuDELLAs proteins ranged from 455 to 588 aa， the relative molecular weight of the proteins ranged from 5.04 to 6.43 kDa， and the isoelectric point value ranged from 4.81 to 5.14. All CbuDELLAs proteins contained DELLA and GRAS conserved domains and are hydrophilic proteins. Sub-cellular localization prediction showed that CbuDELLAs protein was located in the nucleus. The analysis of promoter cis-acting elements showed that the five promoter regions of DELLAs all contained cis-acting elements involved in gibberellin reaction. The results of qRT-PCR showed that the expression of CbuDELLAs in Catalpa ‘Bairihua’ were significantly higher than that in Catalpa bungei ‘Luoqiu No.1’， and CbuGRAS9 was the most significantly gene， and the flowering time of CbuGRAS9 transgenic plants were significantly delayed. Proteins interacted with CbuGRAS9 were mainly concentrated in metabolic pathways such as ribosome， amino acid synthesis， secondary metabolism， photosynthesis and TCA cycle.
In order to reveal the endangered mechanism and carry out related conservation actions of Lumnitzera racemosa， we observed the flowering dynamics of the introduced L. racemosa in Dangan Island Provincial Nature Reserve， Zhuhai， Guangdong， and investigated the breeding system of L. racemosa by using the out-crossing index（OCI）， pollen-ovule ratio（P/O）， pollen viability and stigma receptivity， and artificial pollination. The results showed that： （1）The flowering period of L. racemosa population started May 16， the full blooming period was from May 25 to July 1， and the last flowering period was from July 5 to August 31， and the flowering period of L. racemosa population was up to 106 days. The flowering duration of inflorescence was 5-18 days， and average duration was （10.80±3.58） days； The single flowering period of L. racemose lasted 7-13 days， with an average of （9.1±1.3） days. （2）Pollen viability was highest on the day of flowering， reaching 58.73%， and decreased on the second day and no longer viable was on the third day； Stigma receptivity was weakest at the first day of opening， then gradually strengthened， and was strongest at 100% at the third day， and maturity time of male and female was inconsistent. （3）OCI was 4， the breeding system of L. racemosa was mainly outcrossing with partial self-compatible， which required pollinator； P/O was 5 740.50±1 318.20， the breeding system was obligate xenogamy； pollination test showed that the breeding system was a mixed mating system with both self and xenogamy. Based on the above， the breeding system of L. racemosa was mainly outcrossing with partial self-compatibility and requiredr pollinators.
Rubber tree（Hevea brasiliensis） is one of the important tropical cash crops， and natural rubber（NR）， a secondary metabolite， is an important industrial raw material and strategic material in China. Phytohormones play important roles in regulating plant growth， development， germination， and environmental responses. Here， the research progress on application of four phytohormones， Ethylene， Abscisic acid， Brassinolides， and Gibberellin in the growth and development of rubber trees， NR biosynthesis， rubber yield， latex flow， and quality formation， was summarized in detail， and the application prospect of four phytohormones in mechanism research of improving rubber production and latex flow was looked forward to provide theoretical support for the rubber industry development.
To explore the potential suitable distribution and ecological adaptability of Rhodiola tangutica on the Qinghai-Xizang Plateau， based on 38 distribution sites of Rhodiola tangutica across the plateau and seven environmental factors across current and future five periods， a relationship model between the distribution of Rhodiola tangutica and environmental factors was constructed using the MaxEnt model. The potential geographical distribution patterns for the current period（1970-2000） and four future periods（2030s， 2050s， 2070s and 2090s） under the SSP245 scenario were simulated and verified. The findings revealed that： （1）Altitude（Alt） and precipitation of the driest month（Bio14） were the most important ecological factors influencing the geographical distribution of Rhodiola tangutica， contributing rates of 89.3% and 4.9%， respectively. （2）under the current climatic context， the total suitable distribution area of Rhodiola tangutica on the Qinghai-Xizang Plateau was approximately 195.21×10? km2， predominantly situated in the southern and northeastern parts of Qinghai， northwestern Sichuan， and central Xizang. （3）compared with the current period， the total suitable distribution area of Rhodiola tangutica in the next four periods would not change obviously； however， the area of high suitability would increase， with a tendency of concentrated distribution to the central Qinghai-Xizang Plateau.
To understand the distribution characteristics of Amygdalus mongolica， a rare and endangered Tertiary in the Mongolian Plateau， and its response to future climatic change， climate and soil variables with 121 population distribution points of A. mongolica were selected， and the comprehensive habitat suitability model（CHS） in the R software Biomod2 modeling platform was constructed， which was used to simulate and predict suitable habitat under the current climatic condition and three different future climate scenarios（SSP1-2.6、SSP3-7.0 and SSP5-8.5） in the future（2050S and 2090S）， and the spatial and temporal evolution characteristics was analyzed， and the migration pattern of suitable habitat was explored. The results showed that the TSS of the climate suitability model （ensemble model） was >0.75， the ROC of the distribution limitation model was >0.90， which indicated that the comprehensive habitat suitability model selected in this study might accurately simulate the potential geographical distribution characteristics of A. mongolica under different climate scenarios. The suitable habitat area of A. mongolica at present was 64.00×104 km2， mainly distributed in Inner Mongolia， Gansu and Ningxia， a small number distribution in Qinghai， Xinjiang， Shaanxi， Shanxi， Hebei and other places. The suitable habitat area of A. mongolica showed a decreasing trend under three climate change scenarios（SSP1-2.6， SSP3-7.0， SSP5-8.5） in the future， and the suitable habitat area under different climate scenarios in 2090S was smaller than that in 2050S. Its suitable distribution area extended to the west and higher latitudes as a whole.
The Northeastern region of China is one of the important distribution areas of wild Ribes， and many records of the genus in this region are incomplete or even incorrect. There is an urgent need to summarize the species and distribution of the wild Ribes in this region. Field investigation on the wild Ribes in northeast China was conducted， and the Flora of China， the northeast plants search contents， and the Northeast vascular plants survey were consulted， and related papers and electronic documents and websites were reviewed respectively. The results showed that there were six subgenus and 22 species（including eight varieties） of the wild Ribes in northeast China. Heilongjiang Province had the largest number of wild Ribes， with 12 species and two varieties， Jilin Province had eight species and four varieties， Liaoning Province had five species and four varieties， and the eastern part of Inner Mongolia Autonomous Region had seven species and two varieties. The wild Ribes in the northeast China mainly distributed in the Greater Khingan Mountains， the Lesser Khingan Mountains， the Changbai Mountains， and the coast and islands of the Liaodong Peninsula； the number of species and subgenus of this genus in the northeast China was consistent in horizontal distribution. The wild Ribes in the Lesser Khingan Mountains had the largest number of species and subgenera， and was the modern distribution center of the wild Ribes in northeast China. The Ribes in the northern part of the northeast was dominated by hermaphroditic groups， while in the southern part of the Northeast Most of them were unisexual groups. This genus was distributed from low altitude（≤200 m） to high altitude（1 800-2 100 m）， and most species were concentrated at an altitude of 300-800 m. The endemic phenomenon of this genus was very obvious. There were as many as 15 species（including six variants） endemic to domestic regions， accounting for 68%. The wild Ribes in northeast China had many species， rich resources， wide distribution and huge development potential. However， its living environment was under threat. We should pay close attention to the dynamic changes of its population and distribution area in order to take measures to protect it in time.
To explore the composition and phylogenetic diversity of species， endemics， and threatened species in different geographic units of Yunnan， and to provide scientific basis for biodiversity conservation and sustainable resource utilization in Yunnan. Based on the comprehensive Yunnan monocotyledon species database， the spatial distribution pattern of monocotyledon plants in Yunnan was revealed by using species richness， weighted endemic， threatened index， phylogenetic diversity， phylogenetic endemic， and evolutionary distinctiveness and globally endangered index， respectively， and the distribution of nature reserves was integrated， and the key areas for biodiversity conservation in Yunnan was identified. The results showed that species richness of Yunnan monocotyledons was significantly（P<0.001） and positively correlated with phylogenetic diversity， weighted endemism with phylogenetic endemism， threatened index with evolutionary distinctiveness and globally endangered； northwestern， southern， and southeastern Yunnan possessed the highest diversity and endemism in terms of species composition and phylogenetic composition； and the standardized phylogenetic diversity was higher in all regions except for northwestern and southeastern Yunnan； Northwestern， southern and southeastern Yunnan were the key conservation areas for monocotyledonous plants， and effective measures to protect them would help maintain the evolutionary history and evolutionary potential of biodiversity in the region.
Protected plants usually have high utilization value or a small population size， and are the plant groups facing the highest survival threat， and are also one of the focus objects of biodiversity conservation. Based on the systematic survey of key protected wild plants in Wenshan Prefecture， the abundance and geographic distribution of them were analyzed， and the weights were determined by using four indicators， including endangerment coefficient， genetic value coefficient， protection coefficient， and utilization value coefficient， and then the integrated value of priority protection for these plants were calculated， and the different levels of priority protection to species were classified. The results showed that the387 species of wild plants were identified under priority protection in Wenshan Prefecture， including 36 species under national-level priority protection， 259 species at the second level， 24 species under priority protection at the second level in Yunnan Province， and 78 species at the third level， respectively. Orchidaceae family accounted for 38%（112 species） of the wild plants under national-level priority protection， was an important protected taxon in Wenshan Prefecture. From the horizontal distribution level， Malipo， Maguan and Xichou Counties in the south had high species richness with 228， 224， and 200 species， respectively. On the other hand， Guangnan， Qubei and Yanshan Counties in the north-central part had lower species richness with 87， 68 and 52 species， respectively. In terms of vertical distribution， the elevation range of 1 301 to 1 500 m was the most concentrated area for wild key protected plants. Therefore， biodiversity protection efforts should focus on the southern region and areas with an altitude of 1 301 to 1 500 m. The combined value of priority protection ranged from 0.372 to 0.940， resulting in 39 species classified as Class Ⅰ， 142 species as Class Ⅱ， 123 species as Class Ⅲ， and 83 species as Class Ⅳ. Eight species， including Begonia gulinqingensis， Camellia fascicularis， Horsfieldia tetratepala， Cymbidium qiubeiense， Camellia crassicolumna var. multiplex， Dysosma pleiantha and Cypripedium henryi， were not listed as threatened species in the “China Biodiversity Red List-Higher Plants Volume（2020）”， but were assessed as Class Ⅰ Priority Conservation due to their small number of distribution individuals， and significant human disturbance and high conservation value. These species should be considered urgent targets for rescue and protection.
In order to clarify the phenotypic variation degree and regularity of flower organ traits in distant hybrids of Catalpa bungei， 12 distant hybrid species of C. bungei were used as materials， statistical analysis methods such as variance analysis， correlation analysis， and cluster analysis were used to study their phenological characteristics， inflorescence traits， flower traits， and color traits during flowering. The results showed that there were significant differences in phenological characteristics during the flowering period of the distant hybrid species of C. bungei. The hybrid of C. bungei and C. ovata was pseudo three-branch， with strong differentiation ability of flower buds， and multiple rounds of flowering in the year of grafting， and the flowering period of over 100 days， exhibited maternal traits. The floral organ characteristics of hybrid species of C. bungei were significantly different， with seven to nine rounds of lateral branches in the inflorescence axis， and the main axis was an infinite inflorescence， and the lateral branches were dichasium， and the transition from the bottom to the top was a cyme inflorescence， which was a transitional trait from a limited inflorescence of C. bungei to an infinite inflorescence of C. ovata. The variation ranges of total flower length， flower tube diameter， flower tube length， corolla width， peduncle length， pistil length， anther length， stamen length， and sterile stamen length were 35.42-50.36， 10.84-16.13， 16.57-24.68， 31.58-44.87， 9.07-31.99， 19.44-27.52， 4.85-5.89， 13.93-21.10， 3.66-6.79 mm， respectively. The variation coefficient ranged from 10.88%-31.02%， and the diversity index ranged from 1.36-1.93. Based on the nine traits， the 12 hybrids were clustered into three types： large flower type， medium flower type and small flower type. There were significant differences in flower color among C. bungei hybrids. The values of L*， a* and b* were used to cluster the labellum flower spots color of the 12 hybrids into three categories， namely pinkish purple， purplish red and purple.
Leaf is the main photosynthetic organ， and the leaf morphology beneficial for photosynthesis has become an important breeding target. atscamp was screened from the Arabidopsis thaliana mutant library（about 6 000 lines） with wide leaves. Tail-PCR analysis revealed a T-DNA insertion at the AT1G11180 locus， which encodes a secretory carrier membrane protein（SCAMP）. RT-PCR showed that the transcriptional expression level of the gene was basically zero. The leaf width and area of the mutant were significantly larger than those of wild type plants（P<0.01）， while the crown diameter was essentially unchanged. Additionally， chlorophyll content， chlorophyll maximium fluorescence， and photosystem II potential photochemical efficiency were all increased in the atscamp mutant（P<0.05）. Correspondingly， the mutants showed significant increases in transpiration coefficient（Tr）， net photosynthetic rate（Pn）， and leaf water use efficiency（WUE）（P<0.05）. Spatial-temporal specific expression analysis of the AT1G11180 gene revealed that the gene was highly expressed only in leaves， with low expression levels in other organs， and the gene expression gradually increased with the development and maturity of plants. The results suggested that AtSCAMP might play an important role in leaf shape development.
To explore whether the fungi from Parametarhizium， namely P. hingganense or P. changbaiense， a newly discovered fungus from forest litters in northeast China， could improve plant growth under salt and alkali stress， the mung bean seeds were treated with the fungi， followed by the examinations on the phenotypic changes， and alterations on the photosynthesis， chlorophyll fluorescence parameters， osmolyte contents， ROS levels， and antioxidant enzyme activities were detected respectively. The results showed that the biomass of mung bean plants treated with P. hingganense or P. changbaiense were higher under no-stress， salt and alkali stress conditions than untreated plants. Under salt and alkali stress， two fungus-treated plants maintained a high photosynthetic activity， elevated proline content， decreased malondialdehyde（MDA） content， and increased the activities of antioxidant enzymes POD， SOD and CAT in different degrees. In conclusion， through maintenance of photosynthesis， raising osmotic potential， and antioxidant capacity， treatment of the fungi from Parametarhizium alleviated the salt and alkali stress on mung bean. P. hingganense might significantly alleviate salt stress damage， while P. changbaiense might significantly improve the growth of mung bean under alkali stress.
To explore the effects of different thinning intensity on the growth and wood properties of Populus pseudo-cathyana×Populus deltoids plantation， and to provide a theoretical basis for cultivating high-quality industrial resources of poplar in northeast China， the 18-year old Populus pseudo-cathyana×Populus deltoids was used as the material， and the initial plant row spacing of 2 m×3 m was used as the control， and the thinning treatments of 3 m×3 m， 6 m×3 m， 4 m×6 m were set up. The growth characteristics（tree height， DBH， 2 m diameter， crown width） and wood properties（basic density， fiber length， fiber width， hemicellulose content， cellulose content， semi-cellulose content， lignin content） of the experimental forest were measured in the 5th year after thinning， and the volume per tree and the storage per unit area were calculated using tree height and DBH. The results of variance analysis showed that all indexes were significantly different except basic density （P<0.01）. The results of mean analysis showed that the mean values of each growth index and lignin content reached the maximum when the row spacing was 6 m×3 m， and the other wood indexes reached the maximum when the row spacing was 4 m×3 m or 6 m×4 m. The variation of phenotypic coefficient of each index ranged from 3.35% to 29.87%. In addition to the basic density， the repetitive force of each index exceeded 0.590. The results of correlation analysis showed that there were significant positive correlations among the growth indicators（0.690<r<0.993）， but the correlation between wood traits and growth traits was weak. It was found that Qi reached the maximum when the row spacing was 6 m×3 m， 4 m×6 m and 4 m×6 m， respectively， by using growth traits， wood traits and combined growth and wood traits as evaluation indexes. Thinning might promote the growth of stand and improve the wood property of the forest， and the wood property and the comprehensive improvement effect of the forest growth and wood would be better when the row spacing of the trees is 4 m×6 m. The best growth results were obtained when the row spacing was 6 m×3 m. Therefore， suitable thinning intensity might be selected according to different cultivation objectives for the cultivation of poplar high quality industrial resources in northeast China in the future.
To investigate the vertical distribution of root biomass（diameter≤2 mm） and root length density of Pinus tabulaeformis and Cupressus chengiana plantations in the arid valleys of the upper Minjiang River， and to analyze the carbon allocation strategy of fine root system in different soil layers， and to provide reference for vegetation restoration in the arid valleys of the upper Minjiang River. P. tabulaeformis and C. chengiana plantations were sampled by soil corer method， and the root biomass and root length density of absorptive roots（first to third order） and transport roots（≥fourth order） in different depth（h）（0 cm<h≤15 cm and 15 cm<h≤30 cm） were measured， as well as the proportions biomass and length density of absorptive roots to the total fine roots. The results showed that： the absorptive root biomass and root length density of P. tabulaeformis and C. chengiana were significantly higher in 0 cm<h≤15 cm than those in 15 cm<h≤30 cm， and the transport root biomass and root length density were not significantly different between soil layers； the proportions biomass and length density of absorptive roots to the total fine roots in 0 cm<h≤15 cm were significantly higher than that in 15 cm<h≤30 cm（P<0.05）； the proportions biomass and length density of absorptive roots to the total fine roots in 0 cm<h≤15 cm and 15 cm<h≤30 cm of C. chengiana were significantly higher than those of P. tabulaeformis（P<0.05）. These findings suggested that more carbon was allocated to the absorptive roots in the surface soil layers with the highest nutrient availability in P. tabulaeformis and C. chengiana root system.
Since the regeneration of Tilia amurensis is difficult under full light conditions， and vegetation control can promote the growth of target species by changing light conditions and soil quality. In order to provide the support for the cultivation of T. amurensis， the effects of vegetation control intensity on root traits and soil factors of seedlings were investigated. T. amurensis monocultures（Five-year-old） with inter-row and intra-row spaces of 1.5 m×1.5 m were used as materials， and vegetation control treatments with different intensities T30， T50 and T75（clearing vegetation in the radius of 30， 50， 75 cm around T. amurensis seedlings） and control treatment（CK） were set. The morphological traits， total nutrient content， and non-structural carbon content in the absorptive roots and transport roots of T. amurensis seedlings， as well as soil variables were measured under different treatments， and the effects of vegetation control on root traits and soil conditions were revealed. Vegetation control significantly changed the light intensity in the environment of T. amurensis seedlings， among which the light intensity under T75 treatment was the maximum， and the light intensity decreased with the weakening of vegetation control intensity（P<0.05）. Vegetation control significantly reduced the contents of total carbon， total nitrogen， available nitrogen， and available phosphorus in the soil. With the decrease of vegetation control intensity， the fine root diameter， carbon to phosphorus ratio， soluble sugar and starch contents decreased， while the specific surface area， specific root length， total carbon， total nitrogen and total phosphorus contents increased. Soil variables factors to the variation of root traits for absorptive roots and transport roots were 43.2% and 37.9%， respectively. The greater the vegetation control intensity， the greater the light intensity obtained by T. amurensis saplings， and the root morphology， stoichiometry and physiological traits of T. amurensis saplings took adaptive changes with the change of vegetation control intensity. The root specific surface area， specific root length， total carbon， total nitrogen and total phosphorus contents were increased to enhance the adaptability to low light conditions. The changes of light conditions and soil factors under vegetation control might be the two main factors to explain the root trait changes of T. amurensis saplings.
In order to explore the difference and influencing factors of the number of regenerated seedlings of Pinus schrenkiana on different decomposed grades of fallen wood， the relationship between the number and height levels of regenerated seedlings on different decomposed grades of fallen wood， and the water content， surface area， slope， slope direction and elevation of fallen wood were investigated respectively. The results showed that the probability of seedlings appearing on fallen wood with different decay grades was different， but the seedlings survival rate increased with the increase the decay grade of fallen wood. The height level structure of fallen wood seedlings with different decomposition grades showed obvious growth characteristics， with seedlings at height of 0-5 cm being the most. The water content of fallen wood had a significant impact on the number of seedlings on grade Ⅰ and grade Ⅱ decayed fallen wood（P<0.05）， while the surface area of fallen wood had a significant impact on the number of seedlings on grade Ⅱ， Ⅲ and Ⅳ decayed fallen wood（P<0.01）， but the slope and altitude had no significant impact on the number of regenerated seedlings on each grade of decayed fallen wood（P<0.05）. Further analysis of the influencing factors on the number of seedlings at different height levels showed that water content had a very significant impact on the number of A1（0-5 cm） and A2（5.1-10.0 cm） height level regenerated seedlings on fallen wood with grade Ⅱ decay（P<0.01）， and the surface area of fallen wood had a significant impact on the number of A1 height level seedlings on fallen wood with grade Ⅱ and Ⅲ decay（P<0.05）； On the fallen wood with grade Ⅳ decay， these factors had no significant impact on the number of regenerated seedlings at different height grades（P<0.05）. The surface area and slope direction of fallen trees had a significant impact on the number of dead seedlings on fallen trees. The water content on low-level decomposed fallen wood was the main factor affecting the number of regenerated seedlings， while for high-grade fallen wood， the surface area was the main factor. In contrast， seedlings with lower heights were more susceptible to the impact.
Understanding the growth dynamics of tree xylem in arid and semi-arid areas of China and its response to climatic factors is crucial for assessing and predicting forest productivity and carbon sequestration potential under climate change. In this study， the intra-annual xylem formation of four Quercus mongolica in Liupan Mountain Nature Reserve of Ningxia were monitored by micro-core sampling technique in two growing seasons（2019 and 2020）， and mixed linear model was used to explore the effects of temperature and precipitation on xylem growth rates. The results showed that there was no significant difference in intra-annual xylem formation dynamics between the two years（P>0.05）. The onset of xylem formation started from early April and ceased from mid-to-late September， resulting in a growing season length of （177±17） days（2019） and （165±24） days（2020）. The results of the mixed linear model showed that the annual xylem growth rate of Q. mongolica was positively correlated with the maximum， mean， minimum temperatures， as well as total precipitation in the preceding 7， 10 and 15 days（P<0.01）. Under global change， the xylem growth of Q. mongolica may benefit from future warm and humid climate conditions in Liupan Mountain Nature Reserve， Ningxia.
FERONIA （FER） receptor kinase plays an important role in pollen and stigma recognition in flowering plants. To analyze the function of receptor-like kinase FERONIA（FER） in the pollination in ornamental kale（Brassica oleracea var. acephala）， BoFER gene was cloned from the stigma of the self-incompatibility line（S13-bS13-b ） of ornamental kale by RT-PCR， and the cloned cDNA sequence was 2 682 bp， which encoded 893 amino acids containing the highly conserved kinase domain and Ser/Thr kinase binding site， and the expression level of BoFER was analyzed by qRT-PCR. The results showed that the expression of BoFER in stigmas gradually increased after incompatible pollination， but gradually decreased after compatible pollination. Furthermore， the interaction between BoFER and known proteins related to self-incompatibility were analyzed by yeast two-hybrid. The results suggested that BoFER interacted with the kinase domain of S-locus receptor kinase BoSRK13-b.
To explore the mixing effect of Cunninghamia lanceolata and Elaeocarpus sylvestris， 20-year-old pure and mixed C. lanceolata and E. sylvestris plantations in Fengshushan Forestry Farm in Jingdezhen were selected as test objects， and three slope positions（up slope position， middle slope position and down slope position） were set for each stand type， and the effect of mixed tree species on the plantation growth was analyzed， and the responses of the mixed effects on site condition and on environmental factors was investigated， respectively. The results showed that the volume of the mixed forests ircreased by 5% compared with the expected volume， showing a slightl increase. Compared with pure stands， the diameter distributions of the two species showed opposite trends to the mixed， the peak of diameter distribution of C. lanceolata in mixed stands moved towards higher order， however， the peak of diameter distribution of E. sylvestris in mixed stands moved towards lower order. The allometric analysis of coarse root diameter-stem diameter of pure and mixed plantations showed that C. lanceolata allometry in mixed forests was focused on stem growth， while E. sylvestris allometry in mixed forests was focused on root growth， regardless of forest type and tree species， tree growth would focus on stem growth from slope position to bottom. There was a significant negative correlation between the mixed effect of C. lanceolata and E. sylvestris and the site index， the soil available phosphorus was the main limiting factor for the growth of the mixed forests. The mixed forest of C. lanceolata and E. sylvestris might improve stand growth， and the mixed stands had better adaptability to poor site conditions.
