Through investigation and analysis of the landscape quality and ecological function of farmland protective forest network in eastern Henan Plain, it was found that there were some problems such as broken forest network structure, single tree species and lack of management. In view of the problems existing in farmland protective forest in the eastern Henan Plain, adhering to the plant application principle of "high protection, strong adaptation, low management, large grid", the quality of farmland forest network in the main grain producing areas of the plain is improved from the following four aspects: (1) build water conservation forest, form a complex water forest space; (2) improve the forest quality around the village and display the rural characteristics; (3) construct the framework of forest network to enrich the public space; (4) connect the veins of forest network and maintain ecological balance. The paper aims to help form both functional and landscape ecological complex forest network, and to provide reference for the construction of regional farmland shelter forest.

The stem segment of axillary bud were used as experimental materials, the effects of fungicides, medium and growth hormone on explant sterilization, cluster bud induction, rooting and transplantation of tissue culture were studied by tissue culture method with different concentration and types of agents, culture media and hormone, to provide reference for the construction of comprehensive and efficient rapid propagation system of Acer truncatum× A. platanoides ‘Warrenred’ system. The results showed that the best sterilization method for explants was 10% NaClO solution disinfection for 12 minutes, the pollution was reduced to 19.6%, and the number of germination was 8.76. The optimum medium for bud induction was WPM+ 0.2 mg/L NAA+ 1.0 mg/L 6-BA+ 0.2 mg/L TDZ+ 2.0 mg/L PVP+ 30 g/L sucrose; the optimum combination of strong culture was WPM+ 0.8 mg/L ZT+ 1.0 mg/L 6-BA+ 2.0 mg/L PVP+ 30 g/L sucrose; 1/2WPM+ 0.8 mg/L IBA+ 0.2 mg/L NAA+ 0.5 g/L AC+ 15 g/L sucrose was available to culture rooting. The best transplanting substrate was mixture of humus soil: vermiculite=2:1, the survival rate was maximal for 89%. This study established a rapid propagation system for the shoots of Acer truncatum ×A. platanoides ‘Warrenred’, and could lay a foundation for the subsequent transplanting, culture expanding and popularizing of the fine germplasms.

To explore the rapid clone propagation technology in cutting and grafting of Camellia mingii and realize the permanent preservation of superior germplasm resources and valuable genetic resources of C. mingii, the cutting propagation of C. mingii was carried out, and the seedlings of C. mingii were grafted and propagated with rootstock seedlings of C. osmantha, C. oleifera, C. japonica ‘Heimudan’ and C. ‘Maozi-3’, etc. At the same time, the rapid propagation experiment of C. osmantha with big stock grafting was carried out. The experimental results showed that the cutting of C. mingii was rooted from cortex, the comprehensive effect of cutting with 750 mg/L IBA growth regulator was the best. The cutting survival rate, shooting rate, new shoot length, new shoot diameter, leaf number, and the fresh weight and dry weight of the cutting were the highest, reaching 94.59%, 60.00%, 3.42 cm, 2.18 mm, 4.80 pieces, 1.83 g and 0.63 g, respectively. And the rooting rate of the cutting, the number of primary rooting, the average root length, the longest adventitious root, and the fresh weight and dry weight of root were also the highest, reaching 93.81%, 7.60 roots, 3.18 cm, 7.02 cm, 0.25 g and 0.075 g, respectively. Secondly, the effect of the cutting with 1500 mg/L IBA growth regulator was also better. C. osmantha had better affinity in seedling grafting and propagation. Its grafting survival rate, shooting rate, new shoot length, new shoot diameter, and the leaf number were the highest, reaching 94.18%, 90.52%, 11.85 cm, 4.01 mm and 7.42 pieces, respectively. C. ‘Maozi-3’ was also a good rootstock variety. The propagation effect of C. osmantha grafting on C. mingii with big stock in spring was the best, but the effect in winter was poor. Comparing the grafting tests by big pile and big pile sprout of C. osmantha, the grafting effect of big pile sprout rootstock under the shade of kraft paper was the best. The cutting of C. mingii belongs to cortex rooting type. And it is relatively easy to cut and propagate, which can be achieved by using lower concentration IBA treatment for cuttings. C. osmantha and Camellia ‘Maozi-3’ are better rootstock varieties to carry out the grafting propagation of C. mingii, and it will obtain the best effect to carry out big pile grafting propagation of C. osmantha in spring.

To establish the cutting propagation technology system of Viburnum brachybotryum, the effects of three cutting substrates, growth regulators, treatment concentrations and treatment time on the softwood cutting of V. brachybotryum were studied by L₉(3⁴) orthogonal design. The semi-lignified branches of the 5-8 years old V. brachybotryum seedlings were used as the experimental materials. The results showed that the cutting rooting type of V. brachybotryum was mixed rooting type, both bark and callus could take root. Under suitable external environmental conditions, the cutting could take root at the 15th day, and a large number of adventitious roots were formed after 60 days, and the mature roots with brown color could be formed after 80 days. Cutting substrate had no significant effect on the rooting rate of V. brachybotryum cuttings, but had significant effect on adventitious root number and extremely significant effect on the longest adventitious root length. The types of growth regulators had significant effect on the longest adventitious root length, and extremely significant effect on the rooting rate and adventitious root number. Treatment concentration had no significant effect on adventitious root number and the longest adventitious root length, but had very significant effect on the rooting rate. Treatment time only had significant effect on adventitious root number. Comprehensive analysis by membership function method showed that V (peat): V (perlite)= 1:1 as the cutting substrate, and IAA as the growth regulator at 200 mg/L for 2 h ranked the third, but its rooting rate was as high as 95.96%, ranking the first, and the number of adventitious roots was 14.67, the longest adventitious root length was 6.37 cm, and the quality of cuttings was also high. Therefore, the treatment is the best combination for the cuttings of V. brachybotryum.

The paper aims to explore the linkage relationship of colour of pepper organs. 18 botanical traits of 113 pepper cultivars were investigated and statistically analyzed. Correlation analysis showed that corolla colour, style colour and filament colour had high correlation, while ovary colour, young fruit colour, immature fruit colour and mature fruit colour had no significant correlation. Phylogenetic clustering analysis indicated that purple immature fruit colour was linked to fruit shape and filament colour, stem pubescence was linked to disease-resistance. In this study, we elucidated 18 botanical traits of 113 pepper germplasm, especially the correlation between immature fruit colour and mature fruit colour, which laid a solid foundation for the subsequent research on the genetic law of fruit colour and the gene mapping of fruit colour in pepper.

The aim of this study was to explore the differences and relationships of main metabolites in leaves of celery under traditional soil cultivation and comprehensive cultivation mode, and to explore the effects on medicinal components metabolites. Oenanthe javanica was used as experimental material, and the number of metabolites of O. javanica under different cultivation modes was determined by means of soil and water quality index determination, leaf sample collection, metabolite extraction and mass spectrometry. The results showed that different cultivation methods had significant effects on leaf metabolites of celery. The accumulation of metabolites of celery planted in cage floating bed was better than that of celery cultivated in soil, mainly involving flavonoids, alcohols and polyols. It is beneficial to the extraction of flavonoids from O. javanica and can provide experimental materials for future research on therapeutic drugs or functional products.

To appropriately select potassium fertilizer for seed lotus (Nelumbo nucifera) production, a micro-plot experiment was conducted to study the effects of different types of potassium fertilizer on growth, yield, quality and nutrient uptake of seed lotus by using ‘Taikonglian No.36’as test material, with three treatments of no potassium (CK), potassium chloride (MOP) and potassium sulfate (SOP). The results showed that potassium fertilizer application significantly increased the yield of lotus seed cotyledon (LSC) and developed rhizome (DR) in the lotus field with 32.2 mg/kg available sulfur (S) and 10.0 mg/kg available chloride (Cl) in the soil. Compared with CK treatment, yield of LSC and DR in MOP treatment increased by 29.7% and 21.5%，respectively, and that in SOP treatment increased by 41.3% and 71.2%, respectively. Compared with MOP treatment, the yield of LSC and DR in SOP treatment increased by 9.0% and 40.9% respectively, the harvest index of LSC and DR increased by 0.6 and 5.0 percentage points, and the starch content increased by 2.6 and 7.9 percentage points, respectively, and the yield, harvest index and starch content of DR increased significantly. The Cl content in most organs of seed lotus plant decreased significantly by 34%-77%, therefore the total Cl absorption decreased by 55.2%; S content in the organs of seed lotus plant increased by 0.4%-57%, and the total S absorption increased by 23.0%. The recovery efficiency of K of SOP treatment increased by 2.4 percentage points when compared with MOP treatment. SOP was slightly better than MOP in increasing yield and improving quality of LSC, and significantly superior to MOP in increasing yield and improving quality of DR. Therefore, a fertilization strategy of ‘MOP in early stage and SOP in late stage’ was preliminary proposed for seed lotus production in Guangchang County, Jiangxi Province.

To clarify the effect of microbial inoculants on watermelon continuous cropping obstacles, 4 treatments including ordinary organic fertilizer+ inactivated microbial inoculants (CK), ordinary organic fertilizer+ microbial inoculants (T₁), biological organic fertilizer+ inactivated microbial inoculants (T₂), bio-organic fertilizer+ microbial inoculants (T₃) were set, and the change of watermelon growth, yield and quality, and soil biological characteristics were tracked. The results showed that T₃ could effectively promote the growth and development of watermelon. Compared with CK, the main vine length, stem thickness and chlorophyll of T₃ increased by 18.04%, 17.21% and 20.09% from seedling stage to fruit expansion stage, respectively. T₃ had a significant inhibitory effect on watermelon vine blight and Fusarium wilt, with protection effect of 12.81% and 9.32%, respectively. T₃ increased the yield of each batch of watermelon fruits by 18.59% and 19.11%, respectively, and increased the soluble solids by 10.67% and 13.26%, and vitamin C by 6.42% and 5.32% comparing with CK. In addition, the microbial inoculum fertilizer was also conducive to improving the biological characteristics of the soil. Compared with the data before the test, activity of acid phosphate monoesterase, urease, catalaseby and sucrose of T₃ treatment were increased by 6.65%, 9.61%, 3.23%, and 3.43%, respectively. Furthermore, the biomass of soil bacteria and actinomycetes were increased, and the biomass of fungi was reduced, the flora characteristics changed from “fungal type” to “bacterial type”. In summary, using bio-organic fertilizer as a base fertilizer and topdressing microbial inoculants could promote watermelon growth, increase watermelon yield and quality, inhibit soil-borne diseases, and improve soil biological characteristics, which has a positive effect on alleviating watermelon continuous cropping obstacles.

The paper aims to solve the problems of landscape fitness, extension of ornamental time and ecological adaptability of rock garden plants. Taking the rock garden plants in Perennial Plants Garden of Beijing Botanical Garden, a total of 49 genera and 60 species of 22 families (including varieties) as the research objects, the Analytic Hierarchy Process (AHP) was used to evaluate the maintenance difficulty, ornamental value and resistance. A total of 32 species of rock garden plant resources with good garden application prospects were selected such as Chelidonium majus, Iris lactea var. chinensis, Potentilla anserina, Physostegia virginiana and et al., including 20 species of perennial plants, which enriched the plant selection of rock garden, added color to the landscape of rock garden in four seasons, and provided reference and demonstration for the construction of rock garden in northern China.

To study the characteristics of soil nutrients and the ecological stoichiometric ratios of carbon (C), nitrogen (N), phosphorus (P) and potassium (K) under different land use types, the distribution of soil nutrients in the surface layer (0-20 cm) of paddy fields, drylands, grasslands and woodlands and the differences were analyzed by bibliometric methods. The results showed that the four land use types were relatively rich in total potassium and fast-acting potassium, but generally deficient in total phosphorus, with significant differences (P<0.05); soil total nitrogen was positively significantly correlated with total phosphorus (P<0.05), and negatively significantly correlated with adequate phosphorus (P<0.05), soil organic matter showed a highly significant positive correlation with total nitrogen (P<0.01), and total soil phosphorus showed a highly significant positive correlation with total potassium (P<0.01). Soil C:N values were highest in paddy fields, soil C:K, C:P and N:K values were highest in grasslands, N:P values were highest in woodlands and P:K values were highest in drylands; based on the integrated soil nutrient pool index, it could be concluded that the overall soil nutrient levels of the four different land use types showed paddy fields>grasslands>drylands>woodlands. The four land use types effectively presented the differences between soil nutrient content and ecological stoichiometric ratio of elements, which could provide theoretical support for the revegetation and soil improvement of different land-use types.

It's of great significance to find out the status of nitrate nitrogen in the soil of protected vegetable fields for the nitrogen management of regional protected vegetable fields and the sustainable development of protected vegetable industries. Based on sampling and testing, the study adopted a large sample survey method to comprehensively analyze and evaluate the status of nitrate nitrogen in the soil of protected vegetable fields in Xi’an. The results showed that: (1) the average content of nitrate nitrogen in the soil of the protected vegetable fields was 55.22 mg/kg, and the abundance and deficiency level was medium. (2) The regional variation of soil nitrate nitrogen content in the protected vegetable fields was obvious, among which the average value of soil nitrate nitrogen content in Lantian County was the highest (92.40 mg/kg), and the average value of soil nitrate nitrogen content in Zhouzhi County was the lowest (28.10 mg/kg). (3) WIth the increase of planting years, the content of nitrate nitrogen in the soil of protected vegetable fields generally presented a downward trend, and the average value of nitrate nitrogen in the soil of protected vegetable fields in 1-5 years (57.67 mg/kg) was the highest. (4) The content of nitrate nitrogen in the soil of protected vegetable fields showed obvious regularity with the change of soil texture. The coarser the soil texture, the lower content of nitrate nitrogen, and the finer the soil texture, the higher the content of nitrate nitrogen. (5) There was a very significant positive correlation between nitrate nitrogen and available phosphorus, but no significant correlation with organic matter, alkali-hydrolyzable nitrogen, available potassium, pH, soil electronic conductivity, etc. In general, there was no excessive accumulation of nitrate nitrogen in the surface soil of the protected vegetable fields in Xi’an, but attention should be paid to nitrogen reduction and balanced fertilization in the process of fertilization management.

Based on the daily meteorological observation data of seven meteorological stations in southern Tibet from 1980 to 2021 (April-October), the temporal and spatial variation characteristics and influencing factors of dry and wet index (AI) in the growing season of major grain producing areas in Tibet were studied by using climate propensity rate, Mann-Kendal test, Morlet wavelet analysis, GIS hybrid interpolation method, Pearson correlation coefficient, contribution rate analysis and other methods. The results showed that the average AI in the main grain producing areas of Tibet was 1.7, which belonged to the semi-arid area, and the overall trend was decreasing (humidifying) (-0.036/10 a). The linear decreasing trend was different in different regions, and the area around Lazi County was the most significant (-0.26/10 a). AI had no obvious mutation, and had long and medium term oscillation characteristics of 24 a, 6 a. The spatial distribution was uneven, and had the characteristics of ‘shrinking the dry area and expanding the wet area’. the contribution rate of the main climate influencing factors of AI varied in different regions. In general, the contribution degree after quantification was as follows: precipitation (34.9%)> relative humidity (28.4%)> sunshine (19.9%)> maximum temperature (12.4%).

Based on the meteorological data of Yingshan National Meteorological Station from 2013 to 2021, taking Yingshan tea as the research object, the Changchong Tea Factory was selected as the observation area, the change characteristics of the growth period and yield factor index in different tea rounds were analyzed. The correlation analysis and significance test were used to explore the correlation between meteorological factors and yield at different growth periods. The results showed that the duration of growth period of different rounds of tea was the first round tea> the third round tea> the second round tea. Bud density, average 100 bud weight and theoretical fresh leaf yield all were three round tea> two round tea> first round tea, while the actual fresh leaf yield was two round tea> three round tea> first round tea. The average temperature and relative humidity during the key growth period of different rounds of tea in Yingshan was the third round tea> the second round tea> the first round tea. The precipitation was the third round tea> the first round tea> the second round tea. The sunshine was the second round tea> the first round tea> the third round tea. The number of foggy days reached 50%. The above conditions were suitable for tea plant growth. The precipitation, relative humidity, temperature and sunshine hours of the first round tea decreased with the change of the year. The precipitation, relative humidity and sunshine hours of the second round tea decreased with the annual change, while the average temperature increased. However, the precipitation and temperature of the third round tea showed an upward trend with the change of the year, while the relative humidity and sunshine hours showed a downward trend. Through correlation analysis, it was found that temperature was the first important meteorological factor affecting the growth, development, yield and quality of tea, followed by precipitation and relative humidity, while sunshine played the opposite role.

To clarify the pathogens of the tomato leaves exhibiting curling, mottle and mosaic symptoms in Guangxi, four samples suspected of virus infection were collected, and small RNA deep sequencing (sRNA), reverse transcription-polymerase chain reaction (RT-PCR), sequence analysis and phylogenetic trees construction were applied for the viruses detection and genetic and evolutionary analysis. The results showed that 41 contigs from sRNA were annotated as tomato mosaic virus (ToMV) and tomato chlorosis virus (ToCV), respectively. The results of sRNA were also confirmed by RT-PCR, and all the samples were mix-infected by ToMV and ToCV. Nearly complete genome sequences of ToMV and ToCV RNA2 Guangxi isolates were obtained by multiple DNA fragments splicing. The length of the nearly complete genome sequence of ToMV was 6383 bp, named as ToMV-GX. The nearly complete genome sequence of ToCV RNA2 was 8031 bp, named as ToCV-GX. Phylogenetic analysis showed that the ToMV-GX isolate clustered with the ToMV isolates from Shanxi, Inner Mongolia and Hohhot in a big branch, indicating their close evolutionary relationship. ToCV-GX isolates clustered with the ToCV isolates from Taiwan and Guangdong in a big branch, indicating their close evolutionary relationship. The above results showed that ToMV and ToCV were the pathogens that infected tomato showing curling, mottle and mosaic symptoms, and this was the first report of ToMV and ToCV co-infected tomato in Guangxi.

To identify the pathogen types and biological characteristics of root rot, the pathogen samples were collected from Annona squamosa, and 9 chemical fungicides were tested for their toxicity effects on this disease. This study will provide material and theoretical basis for further research on pathogenic mechanism, and resistance breeding program in A. squamosa. Root rot diseased samples were collected from A. squamosa in Guangdong production fields, and the pathogen was isolated and determined by Koch's rule, with combining methods of morphological observation by optical microscope and molecular identification. The pathogenicity was measured with in vitro inoculation tests, and 9 fungicides were tested for their toxicity effects. The results showed that 5 isolated pathogen strains were identified as Fusarium sp., in which SJF1-4 was F. solani, and SJF5 was F. nematophilic. Based on in vitro tests, strains of SJF3 showed highest pathogenicity, followed with SJF4, then SJF2, and the lowest were SJF1 and SJF5. 28℃ was optima temperature for pathogen growth, and the mycelium lost its vitality after treated at 75℃ for 10 min. No significant difference was observed among different carbon sources compared to the sucrose control. The utilization rates of urea, ammonium sulfate, and ammonium chloride were significantly lower as nitrogen sources than the control of sodium nitrate, while peptone, beef extract, potassium nitrate showed no significant difference compared to the control. Nine fungicides were selected to detect the toxicity for pathogen strain SJF3. The results of toxicity test showed that all selected fungicides showed inhibition effects on pathogen growth rate. Prochloraz and benazoxystrobin, phenyl ether- methiconazole showed best inhibition effects with the EC₅₀ of 0.08, 0.86 and 1.27 mg/L, respectively. The followings were hymexazol, quinoline-copper and methyl metalaxyl. The lowest toxicity was metalaxyl-mancozeb, and enoylmorpholine, with EC₅₀ of 678.29 and 1313.92 mg/L, respectively. This study laid material and technology base for early prevention and control of root rot disease, and related researches on pathogenic mechanism, and resistance breeding program in A. squamosa.

To clarify the biological characteristics of Fusarium oxysporum, the pathogen of gerbera root rot in Sanming, Fujian Province, the effects of temperature, pH, light, carbon and nitrogen sources on the mycelial growth of the root rot pathogen were determined by mycelial growth rate method, and the field control effects of 11 tested pesticides were tested to screen safe and effective fungicides against gerbera root rot. The results showed that the optimum growth temperature of pathogen was 25℃. It prefers alkaline environment, and the optimum pH value for mycelial growth is pH 8. Light had no significant effect on mycelial growth, and the optimum carbon and nitrogen sources were glucose and peptone, respectively. The results of field experiments showed that 3% metalaxyl-hymexazol AS, 100 billion cfu/g Bacillus compound WP and 300 million cfu/g Trichoderma harzianum WP had good control effects on root rot, and the control effects were more than 75%. Among them, 3% metalaxyl-hymexazol AS 800 times solution had the best control effect, and the control effect was 81.41% after 21 d of application. Clarifying the biological characteristics of the pathogen of gerbera root rot and screening safe and efficient fungicides in the field will provide theoretical support for the safe production and cultivation of gerbera and the comprehensive prevention and control of gerbera root rot.

In order to clarify the community structure and dynamics of Solenopsis invicta, the community structure and occurrence dynamics of S. invicta in Yiliang County of Kunming City were investigated by counting method and weighing method in 2016. The results showed that the sterile ants and sexual ants of the above-ground parts of nests accounted for 98.15% and 1.85% respectively, in 2016. Among the sterile ants, the number of adult worker ants and soldier ants was the largest, accounting for 83.38%. In the sexual ants’ group, the number of eggs, larvae and pupae was the largest, accounting for 52.15%. In 2016, the peak duration of S. invicta's dynamics was from June to September, with the largest number in August, mainly on sterile ants. The peak period of sexual ants’ dynamics was from June to August; for adults, the peak was in June; and the peak period of eggs, larvae and pupae occurred in August. Therefore, the key period for S. invicta control is from May to September. In the winter and spring of 2016-2017, the proportion of maximum number of sterile ants was 99.34%, and that of sexual ants was 0.66%. The number of S. invicta in the underground part of the nest was higher than that in the above-ground part. The number of S. invicta in the underground part accounted for 59.19%, and that in the above-ground part accounted for 40.81%. It provides a basis for the local control technology of S. invicta.

The paper aims to find a method suitable for determining the color pigment content of different pear peels. The chlorophyll content and total carotenoid content were determined for five pear varieties with different peel colors, namely ‘Xinli No.7’, ‘Akizuki’, ‘Yali’, ‘Yuluxiang’ and ‘Xianghongli’ by two methods. The results showed that for ‘Xinli No.7’ and ‘Yuluxiang’, the total chlorophyll content, chlorophyll a content, chlorophyll b content and total carotenoid content measured by the 80% acetone extraction method and the 95% ethanol extraction method weren’t significantly different. For ‘Yali’, ‘Xianghongli’ and ‘Akizuki’, the total carotenoid content measured by the 80% acetone extraction method and the 95% ethanol extraction method wasn’t significantly different, but the total chlorophyll content, chlorophyll a content and chlorophyll b content measured by the 80% acetone extraction method were significantly higher than the content measured by the 95% ethanol extraction method. The chlorophyll content and total carotenoid content of pear peels of all varieties can be determined by 80% acetone extraction. When determining the chlorophyll and total carotenoids of pear peel with green color and green as the background color with red halo, the 95% ethanol extraction method can be preferred. If the total carotenoid content is only required, all peel colors can be extracted with 95% ethanol.

To analyze the quality of cultivated and wild Gardenia jasminenoides from different habitats, the contents of medicinal components (gardenoside, chlorogenic acid, crocin-Ⅰand gardenia yellow pigment) among G. jasminenoides from different localities were determined by HPLC, and taking each component as indexes for cluster analysis. The results showed that the 13 different kinds of G. jasminenoides fruits were all containing gardenoside, chlorogenic acid, crocin-Ⅰand gardenia yellow pigment, but the content of each ingredient was different, in which the content of gardenia yellow pigment was the highest, and the content of chlorogenic acid was the least. The contents of gardenoside and chlorogenic acid in No.7 (Dawu County) were the highest, reaching 125.95 mg/g and 2.71 mg/g respectively. The contents of crocin-Ⅰand gardenia yellow were the highest in No.2 (Liuyang County). G. jasminenoides No.7 (Dawu County) and No.2 (Liuyang County) had relatively high content of main components, which could be used as research materials for breeding.

In order to study the application of polyamines for cherry preservation during storage, the effects of spermidine (Spd) and spermine (Spm) on the quality characteristics and antioxidant properties of peduncle, peel and sarcocarp were investigated by using cherry ‘Crystal’ as the test material. The results showed that: (1) exogenous Spd could effectively delay the decrease of chlorophyll content and maintain its freshness index of peduncle. (2) Both exogenous Spd and Spm reduced the rate of superoxide anion (O₂^·-) and the content of hydrogen peroxide (H₂O₂), thus alleviating the peroxidation degree of plasma membrane. (3) Exogenous Spd and Spm substantially enhanced superoxide dismutase (SOD) activity, ascorbic acid (ASA) and glutathione (GSH) contents, and improved the antioxidant capacity of sarcocarp. (4) The storage time of cherry preservation was extended, and the weight loss rate and the degree of decay were also effectively retarded after Spd and Spm spraying. In conclusion, exogenous polyamines (Spd and Spm) can effectively improve the antioxidant and storage properties of cherries. The study can provide important theoretical support for the application of polyamines in the maintenance of postharvest quality and fresh-keeping.

The disease index (DI) survey of powdery mildew for winter wheat at flowering stage was carried out in different regions. Canopy spectral measurement and field sampling were conducted simultaneously during this process. Three factors that played an important role in wheat growth were selected, namely leaf chlorophyll content, leaf water content and air temperature. These factors were statistically analyzed with DI to build a prediction model of wheat powdery mildew and obtained a thematic map. The results showed that there was a certain correlation between the three factors and DI. Leaf chlorophyll content and leaf water content were negatively correlated with DI with correlation coefficients of 0.6316 and 0.633 respectively, and leaf area index (LAI) and air temperature were positively correlated with DI with correlation coefficients of 0.6372 and 0.561 respectively. The change of wheat powdery mildew disease index can be obtained through changes of leaf chlorophyll content, leaf water content, air temperature and LAI (converted by NDVI), which proves that it is feasible to monitor the disease index based on remote sensing technology, and the constructed model can better retrieve the disease index of wheat powdery mildew. On this basis, this study drew the thematic map of wheat powdery mildew disease index monitored by remote sensing technology.

In order to conduct a comprehensive and in-depth analysis of the research status of ancient trees at home and abroad, and identify the hotspots and frontiers of ancient trees during 2012 and 2021, this paper took the relevant research literature as the data foundation, which was included in the CNKI database and the core collection of Web of Science. This paper fully integrated the advantages of CiteSpace and VOSviewer visualization software, and used comprehensive literature co-author network, co-citation network and co-word network to carry out the visualization analysis of scientific knowledge map. This paper found that the attention of researchers at home and abroad on ancient trees was on the rise year by year. In China, the main research institutions included Shanghai Green Management Guidance Station, Taiyuan Garden Plant Research Center, etc. The main domestic research contents involved four aspects, respectively: investigation of ancient tree resources, ancient tree protection measures, the soil impact on ancient tree growth and analysis of ancient tree ecological characteristics. Internationally, the most influential research country was the United States, and the second was China. Among the international research institutions, the most influential research institution was the Chinese Academy of Sciences, and Yang Y, et al. were highly influential authors in this field. The main research contents of international ancient trees involved four aspects, namely: the biological and cultural heritage value of ancient trees, the extensive ecological value of ancient trees, the value of ancient trees in the protection of regional biodiversity, and the unique advantages of ancient trees in genetic diversity.

The aim of this research was to investigate the molecular evolutionary characteristics of histone H2 and its role in the immune regulation in pearl oyster Pinctada fucata martensii, and to provide a theoretical basis for further elucidation of the physiological functions of histone H2 in Pinctada fucata martensii. Bioinformatics methods were used to identify histone H2A and H2B from nine species, such as Pinctada fucata martensii, Homo sapiens, and Crassostrea gigas, and their molecular evolution was analyzed. Using the data available in our previous research, the functions of histone H2A and H2B in the development, tissue and immunity of Pinctada fucata martensii were also analyzed. The main results showed that the human genome contained 27 histone H2A and 20 histone H2B, the C. gigas genome contained 12 histone H2A and 8 histone H2B, and the genome of Pinctada fucata martensii contained only two H2A (H2A-1 and H2A-2) and one H2B, which showed a contraction phenomenon compared with other species. Sequence analysis revealed that there were 6 H2A and 2 H2B variants in human genome, 3 H2A and 1 H2B variants in C. gigas, and 1 H2A variant (H2A-2) in Pinctada fucata martensii. The expression of H2A-1 and H2B were changed after transplantation in Pinctada fucata martensii, indicating that they were involved in the immunological regulation of the transplantation immune response. The expression level of H2A-1 gene was higher in the gastrula stage, H2A-2 was highly expressed in trochophore stage and type D larvae, and the expression level of H2B was higher in the egg and fertilized egg. H2A-1 was relatively high in pearl sac, the expression level of H2A-2 was relatively high in blood cell, foot, and mantle pallium, and H2B gene was relatively high in gonad and pearl sac. The genome of pearl oyster Pinctada fucata martensii contained only two H2 genes, and both of them involved and played a different role in the regulation of transplantation immune response in Pinctada fucata martensii.

To analyze the composition of microbial community in integrated rice-crayfish farming system at different time in spring, Illumina Miseq high-throughput sequencing technology was used to analyze the bacterial community composition in the intestinal tract and culture environment of Procambarus clarkii. The results showed that a total of 16966 operational taxonomic units (OTUs) were detected in all samples. The maximum OTUs of sediment samples in April were 3677, and the minimum OTUs of intestine were 757. Alpha diversity analysis showed that the abundance and diversity of the sediment microflora were high. The dominant bacteria groups in the integrated rice-crayfish farming system were Proteobacteria, Actinobacteria, Bacteroidetes and Firmicutes. Proteobacteria was the predominant group in all samples in April and May, and Firmicutes was the predominant group in P. clarkii intestinal tract in June. The proportion of Actinomycetes in water was higher than that in intestinal tract and sediment. Principal coordinates analysis (PCoA) and unweighted pair group method with arithmatic mean (UPGMA) analysis showed that, microbial communities of the sediment and water in different months were clustered together according to species, but the microbial community structure of intestines and the sediment in June were relatively similar. These results suggested that in spring integrated rice-crayfish farming system, the composition of intestinal microflora of P. clarkii was correlated with the external culture environment. The diversity and composition of microflora in each sample were different but relatively stable in different months.