This study examined three 45-year-old Aigeiros varieties, ‘I-63’, ‘I-69’, and ‘I-72’, introduced in the Jianghan plain. Tree trunk analysis was performed by sampling discs at varying heights to compare the growth processes of different varieties in terms of diameter at breast height, tree height, and wood volume. The data and technical support provided by this study could contribute to the cultivation of large-diameter Aigeiros varieties timber in the Jianghan plain. The results indicated that the bark-stripped diameters of ‘I-63’, ‘I-69’, and ‘I-72’ reached 58.35, 61.70 and 53.60 cm, respectively, after 45 years of growth. The tree heights were 24.84, 22.14 and 27.79 m, respectively, and the bark-stripped wood volumes were 3.92, 3.93 and 3.11 m3, respectively. The maximum annual growth in diameter for ‘I-63’, ‘I-69’, and ‘I-72’ occurred in the 5th, 6th, and 5th years, respectively, with a significant slowdown in diameter growth after the age of 17. The diameter growth slowed down significantly. The maximum annual growth in tree height for ‘I-63’, ‘I-69’ and ‘I-72’ occurred in the 8th, 4th, and 6th years, respectively, with tree height growth approaching its peak after the age of 20. The maximum annual growth in wood volume for ‘I-63’, ‘I-69’, and ‘I-72’ occurred in the 18th, 15th, and 16th years, respectively, corresponding to the maturity age of wood volume for these three varieties. The statistical data revealed that the fast-growing period of wood volume for ‘I-63’, ‘I-69’ and ‘I-72’ was from 8 years to 18 years, 6 years to 15 years, and 7 years to 16 years, respectively. Overall, all three varietied had long lifespans and growth period, demonstrating excellent adaptability in the Jianghan plain. However, ‘I-69’ had a superior stem type and superior growth performance, making it more valuable for promotion.
This study aimed to explore the endophytic bacterial resources of Catalpa bungei tissue culture seedlings, to develop agricultural microorganisms with application potential, promoting the rapid growth and propagation of tissue culture seedlings. The endophytic bacteria were isolated and identified from C. bungei tissue culture seedlings by selective medium in this paper. The nitrogen content in the culture solution was determined to evaluate the nitrogen fixing effect after preliminary screening with Ashby solid medium, and the phosphorus solubilization effect was evaluated using phosphorus content in the culture solution after preliminary screening with Nbrip solid medium, then the inhibitory effect of endophytic bacteria was measured with Alternaria alternate and Fomitopsis semiolaccatus as test objects. 24 strains of endophytic bacteria were isolated from the seedling of C. bungei, and they were identified as Rhizobium zeae by morphological and 16S rRNA sequence analysis. The results indicated that the nitrogen fixing capacity of strain NF6 was best as its nitrogen concentration in the Ashby liquid medium reached 111.97 mg/L, and strain NF11 had the best phosphorus solubilization effect due to the phosphorus concentration in Nbrip culture medium reached 1007.95 mg/L. Furthermore, most of the endophytic R. zeae had inhibitory effects on the tested pathogens, and more than 20% of inhibitory rates against A. alternate and F. semiolaccatus respectively had obtained for the 6 and 2 strains of endophytic R. zeae. In this study, the resources of endophytic bacteria with the potentials of promoting growth and resistance to pathogens were obtained, which provided theoretical basis for the potential application of endophytic bacteria in tissue culture seedlings.
In order to establish a set of flow cytometry application methods that can rapidly and accurately identify the ploidy of tetraploid Chinese cabbage, 12 vegetable crops with known ploidy were used to verify the results of ploidy detection by flow cytometry. At the same time, diploid Chinese cabbage ‘Jibai 4’ and tetraploid Chinese cabbage ‘Duowei 462’, ‘Duo 505’ and ‘Duoyu 2’ were selected as materials, and the ploidy identification was carried out in different periods and parts of the plant, so as to screen out the suitable sampling periods and parts. The results showed that 12 vegetables with known ploidy verified the accuracy and reliability of the flow cytometry results used in this experiment; the ploidy detection results of young cotyledons taken from ‘Jibai 4’, ‘Duowei 462’, ‘Duo 505’ and ‘Duoyu 2’ during the cotyledon stage were consistent with known ploidy. Therefore, the young cotyledons at the cotyledon stage are the best time and place for ploidy sampling in Chinese cabbage.
In order to explore the physiological response mechanism of Cucumis melo to antimony (Sb3+) stress, waterlogging tolerant melon strain ‘10-06-3’ was used as experimental materials to study the effects of Sb3+(0, 30, 60, 100 mg/L) stress at different concentrations on melon seed germination and seedling physiology through dish germination and hydroponic experiments. The results showed that low concentration antimony had a promoting effect on seed germination of muskmelon, but had an inhibitory effect on root growth and was also beneficial for seedling growth. However, high concentration antimony had a significant inhibitory effect on seed germination and seedling growth of muskmelon, affecting its development and growth. The concentration of MDA increased with the increase of antimony concentration, and the soluble sugar content and CAT activity were significantly positively correlated with MDA concentration, leading to a regulatory increase. When the concentration of Sb3+ was lower than 60 mg/L, the soluble protein content, POD activity, SOD activity, and relative chlorophyll content significantly increased with the increase of antimony concentration. However, when the concentration was higher than 60 mg/L, its activity and content sharply decreased. A certain concentration of Sb3+ could stimulate the antioxidant regulation reaction of muskmelon, while high concentration antimony inhibited antioxidant enzyme activity. High concentration of Sb3+ led to a decrease in stomatal conductance and intercellular CO2 concentration in melon leaves, which comprehensively affected the photosynthetic rate and transpiration rate of the melon. Principal component analysis showed that the weight coefficients of soluble sugar content, MDA concentration, and CAT activity in principal component PC1 were relatively high, while the weight coefficients of soluble protein and SOD in principal component PC2 were relatively high. This indicates that under low concentration Sb3+ (30 mg/L) stress conditions, sweet melons enhance their stress resistance by increasing the content of soluble sugars and soluble proteins as osmoregulatory substances. However, under high concentration Sb3+ (60 mg/L), nickel stress can damage their defense system, leading to unstable growth and development of seedlings.
This study aimed to investigate the occurrence and development mechanism of internal browning in Prunus salicina var. cordata, specifically focusing on the impact of environmental factors, soil nutritional factors, and leaf mineral element contents on P. salicina var. cordata internal browning. Orchards with varying degrees of P. salicina var. cordata fruit internal browning at different elevations were selected for investigation. The results indicated that the bagged treatment significantly increased internal browning, and thicker fruit bagging treatments exhibited more severe internal browning than non-bagged treatments. Additionally, there was an observed increase in internal browning at lower altitudes. Furthermore, orchards with a lower incidence of internal browning demonstrated better soil conditions, with a significant increase in the content of organic matter and various elements. Correlation analysis revealed significant positive correlations between the incidence of internal browning and the contents of soil pH, phosphorus, magnesium, iron, copper in soil, and magnesium in leaves. Conversely, the contents of soil organic matter, calcium, zinc, manganese, and boron in soil were significantly negatively correlated with the incidence of internal browning. Finally, appropriately reducing orchard ambient temperature during fruit ripening and increasing the content of organic matter, soil pH, calcium, and boron in soil may reduce the incidence of internal browning.
The paper aims to study the effects of exogenous bioactive substances on the fruit quality of ‘Black Monukka’ grape, and to provide a reference basis for the production of high-quality fruit of Xinjiang table grapes and the research and development of fruit quality control technology. Taking ‘Black Monukka’ as the test material, five kinds of bioactive substances, including iron dihydroporphyrin, chitosan, rape lactone, gamma-aminobutyric acid and plant source enzyme nutrient solution, were used for fruit surface spraying process from the fruit expansion period to color-turning period, with water treatment as a control (CK), and determine the quality indicators, such as spike weight, grain weight, soluble solids, hardness, tensile, chromatism and dehiscent fruit rate, etc, during the fruit ripening period. The results showed that the spike weight, spike length, spike width and grain weight of ‘Black Monukka’ grape under the treatment of plant source enzyme nutrient solution were higher than those of CK, reaching 968.42 g, 25.82 cm, 15.83 cm and 4.49 g, respectively, and the differences among them reached a significant level. The soluble solids content of ‘Black Monukka’ grape was significantly increased by 12.30% and 19.14% compared with CK under the treatment of rape lactone and plant source enzyme nutrient solution, respectively. Plant source enzyme nutrient solution was beneficial to the color formation and reduction of fruit cracking rate of ‘Black Monukka’ grapes. ‘Black Monukka’ grapes under the treatment of plant source enzyme nutrient solution had the lowest fruit cracking rate of 20.00% after 24 h of immersion, which was reduced by 77.77% compared with that of CK. The fruit surface spraying treatment with plant derived enzyme nutrient solution from the fruit expansion stage to the color change stage could help to improve the quality of ‘Black Monukka’ grapes.
The paper aims to investigate the effects of drought stress on the growth and physiological indexes of Echinacea purpurea seedlings. The seedlings were treated with 5%, 10% and 15% polyethylene glycol (PEG 6000) simulated drought stress, respectively, to study the effects of simulated drought stress with different concentrations of PEG on biomass, chlorophyll content, and the accumulation of proline, soluble protein and soluble sugar in leaves and roots of E. purpurea. With the extension of drought stress time and the severity of drought, the growth and dry and fresh weight of E. purpurea seedlings showed a decreasing trend. The proline and soluble protein in leaves and roots of E. purpurea seedlings showed an increasing trend. On the 6th day after stress, when the PEG concentration reached 15%, the proline, soluble protein in leaves and roots of E. purpurea seedlings began to decrease. The soluble sugar increased with the duration and severity of drought stress. Chlorophyll content maintained normal synthesis at first, and showed an upward trend when PEG concentration reached 15%. E. purpurea seedlings have strong tolerance to mild and moderate drought stress, and can adapt to drought stress by various mechanisms such as morphological change, material metabolism, physiological regulation, etc., but the tolerance to long-term and high concentration stress is poor, protein decomposition is accelerated, cell damage is serious, and growth is significantly inhibited.
To explore the possibility of using conventional plant growth data to evaluate and measure the anti-degradation ability of turfgrass, this study took six common turfgrasses as the research objects, established two experimental treatments as “maintaining natural state” (MNS) and “manually removing weeds” (MRW), to investigate three sets of data for five consecutive years, including the diversity of plant species, the number of plant individuals, and the annual production of plants per unit area, and analyzed their changing tendencies and patterns with the increasing years after the lawns were cultivated. The results showed that the management measures of MRW could significantly reduce the number of weeds in various types of lawns, ensuring the neatness and ornamental value of the lawn. With the increasing years after the lawns were cultivated, the plant diversity per unit area of six types of lawns was all distributed following a decay exponential modal; the decay rate of Trifolium repens was the fastest one among the six lawns in the MRW experimental treatment, indicating that the management measures of MRW had the most obvious effects on the management of T. repens lawn; the decay rates of Festuca elata and Cynodon dactylon were the fastest in the MNS experimental treatment, and they still were dominant plant species in the experimental plots, indicating that they had strong competitiveness. Due to different reproductive methods, the number of plant individuals per unit area was distributed following a binomial model in the experimental plot of C. dactylon, and was distributed following a decay exponential model in the experimental plots of the other five lawns. The data of plant annual production were distributed following a binomial model in all six lawns. The time required to reach the maximum value was the longest in the experimental plot of Agrostis stolonifera in the experimental treatment of MRW, and was the longest in the experimental plot of C. dactylon in the experimental treatment of MNS, indicating that the management measures of MRW had the most significant effects on delaying the degradation of A. stolonifera lawn and C. dactylon had the strongest competitive ability in the natural state. The study results indicate that the three sets of data, including the diversity of plant species, the number of individual plants, and the annual production of plants per unit area, can be used to evaluate and measure the anti-degradation ability of turfgrasses. This can provide scientific suggestions and reasonable opinions for selecting corresponding turfgrasses in different regions based on local climate conditions and the purpose of lawn construction for improving lawn quality, delaying lawn degradation, and extending lawn service life.
By investigating the dynamic changes of Cyclocodon lancifolius fruit in different growth periods under light conditions, it provides a scientific basis for the determination of the reasonable harvest period of C. lancifolius and the selection of artificial cultivation light conditions. The external quality and internal quality indexes of C. lancifolius fresh fruit under different growth periods and light conditions were measured and the correlation analysis was carried out. The fruit quality of C. lancifolius was the best under the condition of no shading light. In general, from October, with the delay of harvest time, fruit size, single fruit weight, soluble solids, soluble sugar, total acid and Vc all increased to varying degrees, and fruit hardness gradually decreased. Most of the indicators reached the best in early January, so early January was determined as the best mature harvest period. This study basically proved the cultivation light conditions and the best harvest time of C. lancifolius, which laid a theoretical foundation for the standardized planting of C. lancifolius.
Based on the domestic and international literature related to the management of agricultural non-point source pollution in Chaohu Lake, the dynamic changes in the field were analyzed, including its development process, research hotspots, dynamic frontiers and possible future research directions. Taking 394 relevant literatures included in CNKI, Wanfang data, Wipro database and Web of Science core ensemble published between 1998 to June 2023 as data sources, CiteSpace visualization and analysis software were employed to draw the knowledge map of Chaohu Lake’s non-point source pollution research. This allowed for an analysis of the distribution of authors, institutions and journals involved in the research as well as a study of the development from a dynamic viewpoint. The results indicated that (1) the development process could be divided into four stages and the paper issuance numbers were correlated with trends in total nitrogen and total phosphorus changes in Chaohu Lake. Furthermore it was found that there was room for improvement regarding overall knowledge levels within this field. (2) The research hotspots identified within Chinese literature mainly focused on nitrogen and phosphorus loss, livestock and poultry farming, spatial distribution and countermeasures. Conversely English literature focuses on runoff, impacts of pollutants, analyzing sources and management measures of pollutants. The research on non-point source pollution in artificial wetlands was still a blank field. (3) The prominent direction of future research was to use “3S” and other technologies to quantitatively characterize the complex spatiotemporal processes of pollution occurrence, revealing the mechanism of migration and transformation of agricultural non-point source pollution, and predicting changes in the “water environment” under pollutant load. Under the premise of stabilizing yield, the whole process involved implementing targeted fertilization, precise fertilizer control, and reducing nitrogen and phosphorus loss. The management of agricultural non-point source pollution in Chaohu Lake is a long-term and continuous endeavor that requires increased collaboration between various departments and institutions to establish a unified information database. This also requires more understanding and participation from domestic and foreign scholars in the management of Chaohu Lake.
To investigate the phosphorus leaching capacity of pepper straw biochar in different regions, biochar were prepared from pepper straw in different regions (Taikang County of Henan Province, Xinjian District of Nanchang City, Dingxi City of Gansu Province and Bijie City of Guizhou Province) using two pyrolysis temperatures (400℃ and 700℃). The concentrations of four phosphorus fractions (H2O-P, NaHCO3-P, NaOH-P and HCl-P) in the biochars were extracted by distilled water, 0.5 mol/L sodium bicarbonate, 0.1 mol/L sodium hydroxide and 1 mol/L hydrochloric acid, respectively. Additionally, the kinetic dissolution experiments of phosphorus from biochars and the effect of pH on phosphorous leaching were carried out in the study. The results indicated that the content of H2O-P was the highest among the four fractions of phosphorus in biochars and NaHCO3-P was the lowest. The content of H2O-P in the biochar prepared at 400℃ in Guizhou was the highest, reaching 7.89 mg/g. The content of NaHCO3-P in the biochar prepared at 700℃ in Henan was the lowest, which was only 0.13 mg/g. The higher the temperature of carbonization, the lower the concentration of phosphorus dissolution in biochar. The biochar prepared at 400℃ in Guizhou had the strongest phosphorus dissolution ability, and the maximum dissolution amount was 1.58 mg/g at 10 min. The higher the initial pH of the solution, the lower the leaching of phosphorus from the biochar. When the initial pH 2.0, the maximum phosphorus leaching rate was achieved, the dissolved concentration of the biochar prepared at 400℃ in Guizhou was 3.21 mg/g. Our finding would provide a reference for the use of biochar to improve soil nutrients by enhancing phosphorus availability.
To explore the water consumption law of Chinese cabbage under microspray irrigation in Kunming regions, using cloud intelligent soil water meter in Yunnan Irrigation Experiment Center Station, the water consumption law of Chinese cabbage during summer and autumn of 2019 year under microspray irrigation was studied by using local planting experience, and the water saving potential in this regions was revealed under microspray irrigation. The results showed that the evapotranspiration of Chinese cabbage were 119.23 and 102.57 mm during the whole growth period, and the average daily evapotranspiration intensity was 1.66 and 1.27 mm/d, in which the average evapotranspiration was the highest in rosette stage, reaching 47.54 mm, and the average evapotranspiration was the smallest in seedling stage, only 2.36 mm. The evapotranspiration of Chinese cabbage in different growth stages showed heading stage> rosette stage> harvesting stage> group tree stage> seedling stage. The curve of evapotranspiration of typical Chinese cabbage showed a single peak change, and the high value of evapotranspiration mainly concentrated in 11:00-14:00, and there was an obviously ‘lunch break’ phenomenon. The evapotranspiration of Chinese cabbage decreased with the increase of soil depth. The evapotranspiration of Chinese cabbage was the highest at 0-10 cm, the average proportion reached 45.25%, and the lowest at 30-40 cm, the average proportion was 7.74%. According to the suitable range of soil water content in different growth stages of Chinese cabbage, there were two times and three times of over-irrigation respectively in the two crops of Chinese cabbage. Under the condition of avoiding over-irrigation, the two crops of Chinese cabbage could save water by 160.0 m3/hm2 and 180.0 m3/hm2 respectively.
In order to improve the utilization rate of recycled water for potted flowers in Hongta District and explore effective ways of integrated fertilization, 42 irrigation water samples and 85 backflow water samples were collected regularly from 3 potted flower planting enterprises. Seven nutrient indicators, such us pH value, EC value, and available nitrogen, were tested to analyze the correlation between backflow water EC value and nutrient content. The results showed that: (1) the EC value of irrigation water for potted flowers ranged from 82.10 to 2170.00 µs/cm, with an average of 544.40 µs/cm and a coefficient of variation of 119.42%. (2)The EC value of the backflow of potted flowers ranged from 85.00 to 2960.00 µs/cm, with an average of 1115.99 µs/cm and a 95% confidence zone of 980.65 to 1251.33 µs/cm. (3)Compared with irrigation water, the EC value of return water increased by 571.58 µs/cm, the available nitrogen increased by 362.43 mg/L, the available phosphorus increased by 102.81 mg/L, the available potassium increased by 50.93 mg/L, the available sulfur increased by 27.73 mg/L, and the exchangeable magnesium increased by 15.59 mg/L. This indicates that there is a large amount of residual available nitrogen, available phosphorus, available potassium, available sulfur, and exchangeable magnesium in the return water, and there is a great potential for utilization. (4)The EC value of the return water was positively correlated with the content of five nutrients, including available nitrogen, available phosphorus, available potassium, exchangeable magnesium, and available sulfur, all of which were above a significant level. Therefore, in the production of potted flowers in Hongta district, the content of available nitrogen, available phosphorus, available potassium, available sulfur, and exchangeable magnesium in the recycled water can be quickly determined by measuring the EC value when using the recycled water, and timely guidance can be provided for the fertilization of potted flowers.
This study predicts the potential suitable areas for Oenothera biennis in Heilongjiang Province and its changing patterns under future climate conditions, providing a basis for further monitoring and control efforts. This study focused on the invasive plant O. biennis and used software such as MaxEnt and ArcGIS to predict the changes in its distribution under three carbon emission scenarios (ssp126, ssp370, ssp585) for the present and two future periods (2021-2040, 2041-2060). The study also analyzed the dominant environmental factors and expansion trends that affected the distribution of O. biennis in Heilongjiang Province. The results showed that: (1) the MaxEnt model predicted an AUC value of 0.864, indicating accurate predictions. (2) The environmental factors with the greatest impact on the habitat of O. biennis were annual average precipitation (26.5%), coldest month minimum temperature (21.3%), and annual average temperature (16.9%). (3) The suitable area for O. biennis in Heilongjiang Province was 231600 km2, with high suitability accounting for 9.11% of the province. (4) Under the future climate change scenario of the 2040s, the suitable area for O. biennis increased by 5.78%, 5.16%, and 8.52% under the ssp126, ssp370, and ssp585 climate conditions, respectively. Under the 2060s scenario, the suitable area increased by 7.51%, 8.95%, and 8.66% under the three climate conditions. Under future climate change, the suitable area for the invasive plant O. biennis showed a trend of spreading from the center to the periphery, with average annual rainfall being the main influencing factors for its distribution.
‘Jingying F1’ was used as scion and ‘Jingxin rootstock No.9’, ‘Yuyi rootstock No.1’, ‘Luqing Sturdy’ and local pumpkin seed were used as rootstocks, the most suitable rootstock-scion combination was screened. At the same time, an experiment was carried out by directly transplanting self-rooted seedlings and applying biological bacterial fertilizer to explore the effects of different rootstocks and the application of biological bacterial fertilizer on soil-borne diseases and quality of small-scale watermelons in early spring greenhouses in Dongming County. The survival rate, plant growth, fruit quality, resistance to anthracnose, wilt and other soil-borne diseases of watermelon were investigated after grafting and transplanting. The results showed that the four rootstocks could almost control the watermelon soil-borne diseases and the quality of watermelon plants was improved effectively. ‘Jingxin rootstock No.9’ and ‘Jingying F1’ were the best combination, the graft survival rate was 94%, the incidence of watermelon anthracnose and the root-knot nematodiasis were reduced 23 and 57 percent respectively and the yield reached 19350 kg/hm2 and the soluble sugar content reached 10.56 Brix and no soil-borne diseases occurred after grafting compared with the self-rooted seedlings. The incidence of root-knot nematodiasis decreased significantly and the yield reached 19500-19800 kg/hm2 with the soluble sugar content reaching 12.5 Brix on average after grafting with biological bacterial fertilizer. Rootstock grafting has significant effect on increasing yield and disease resistance, but will reduce watermelon sweetness. Applying bio-fertilizer is beneficial for disease resistance, growth, and flavor improvement.
This study aims to investigate the herbicidal activity of coumarin against the invasive plant Bidens pilosa var. radiata in agricultural and forestry settings. Seed germination tests and pot experiments were carried out to study the inhibitory effects and physiological impacts of coumarin on seed germination and plant growth of B. pilosa var. radiata. The results showed that the inhibitory activity of coumarin on seed germination of B. pilosa var. radiata (IC50=108.16 mg/L) was higher than three common allelochemicals: methyl jasmonate, salicylic acid and pyrocatechuic acid. During the germination process of B. pilosa var. radiata seed, treatment with coumarin (50 and 100 mg/L) induced the accumulation of O2·- and H2O2 in the seedlings, with a particularly notable accumulation of O2·- in the cotyledons and roots of the seedlings. Additionally, coumarin treatments significantly affected the activities of POD and SOD in B. pilosa var. radiata seedlings. The addition of coumarin (100-1000 mg/kg) to the growth substrate had a significant impact on the growth, photosynthesis, and respiration of B. pilosa var. radiata plants; after 15 days of treatment, the dry weight of B. pilosa var. radiata plants decreased by 18.4%-67.6% compared to the control, net photosynthetic rate decreased by 22.1%-40.5%, and dark respiration rate decreased by 20.9%-41.7%. These results indicate that coumarin effectively inhibits seed germination and plant growth of B. pilosa var. radiata by inducing the accumulation of reactive oxygen species and inhibiting photosynthesis and respiration. Therefore, coumarin has the potential to be developed into effective agents for controlling B. pilosa var. radiata.
The outdated view of “three species of peony viruses” was corrected at first, whereas 17 species of viruses infecting peony (including tree peony and herbaceous peony) in the world was counted and analyzed. The research work on viral disease of peony dedicated by Chinese scholars was reviewed, including investigation about tobacco rattle virus (TRV) infecting peony; discovering several new viruses of peony such as peony leafroll-associated virus (PLRaV) and new host records for peony infected by some known virus such as apple stem grooving virus (ASGV) in recent years; a series of research progress about study on peony gene function using VIGS (virus induced gene silencing) technology. There were still many deficiencies in the basic research of peony viral disease in China, such as the lack of special funding opportunities for national projects; unknowing the background of viral disease occurrence in traditional peony cultivation centers; lacking deep research on the infection and transmission mechanism of the virus. Compared with western countries, the obvious disadvantages in the application of viral disease detection and diagnosis technology was that lower level technicians could not update the knowledge of disease diagnosis in time and could not completely understand the recent development of molecular detection technology for viral diseases. Therefore, it is suggested that molecular detection technology should be applied to carry out nationwide survey of peony viral disease, risk analysis and risk management of peony viral disease.
The content status and changing trend of conventional chemical components of tobacco leaves in Changsha tobacco area were evaluated and analyzed to provide reference for the rational distribution and quality improvement of tobacco production in this area. From 2020 to 2023, 370 tobacco samples were collected from 20 representative monitoring sites of Liuyang and Ningxiang tobacco planting units in Changsha tobacco area, and the contents of conventional chemical components were statistically analyzed. The results showed that except for slightly higher total sugar (26.14%) and lower total nitrogen (1.39%), the average contents of reducing sugar, nicotine, chlorine and potassium in the Changsha tobacco area were all within the appropriate range of high quality tobacco leaves. The main derivative indexes, the ratio of sugar to nicotine, nitrogen to nicotine, and potassium to chlorine also met the standard of high quality tobacco leaves. According to the analysis of different monitoring sites of tobacco planting units, the total sugar content should be controlled in Liuyang tobacco area and the total nitrogen content should be increased in Ningxiang tobacco area. According to the analysis of different parts of tobacco leaves, the total sugar and the ratio of sugar to nicotine in middle tobacco leaves were higher, and the total nitrogen in upper and middle tobacco leaves was lower. According to the analysis of different years, the ratio of total sugar and sugar to nicotine increased year by year, while the ratio of nicotine and potassium to chlorine decreased year by year, and other component indexes fluctuated from year to year. According to the analysis of different varieties, the total sugar of ‘Xiangyan 7’ and ‘G80’ were higher, and the total nitrogen content of ‘Xiangyan 7’, ‘Yunyan 87’ and ‘G80’ were lower. According to the correlation coefficient analysis of conventional chemical components, except for the ratio of total sugar, reducing sugar and sugar to nicotine, total sugar and total nitrogen, potassium and the ratio of potassium to chlorine, the others reached a very significant level. To sum up, the overall quality of the tobacco leaves in Changsha tobacco area is better, but attention should be paid to controlling the total sugar content of tobacco leaves in the central part of Liuyang tobacco area and to improving the total nitrogen content of the middle and upper tobacco leaves in Ningxiang tobacco area. The quality of ‘Yunyan 87’ performs better in Changsha tobacco-growing area.
To address the issues of complex data preprocessing, low prediction accuracy, and poor generalization capability of existing methods for predicting the soluble solid content (SSC) of plums, a one-dimensional convolutional neural network (1D-CNN) model specifically for plum varieties is proposed. Near-infrared (NIR) spectral data were constructed for 300 samples of Sanhua and Sanyue plums to predict their SSC. And the multi-layer structures such as input layer, one-dimensional convolution layer, pooling layer and full connection layer and output layer were designed to construct 1D-CNN model. Comparative experiments demonstrated that the model achieved a coefficient of determination (R2) of 0.980 and a root mean square error (RMSE) of 0.192, outperforming traditional machine learning methods such as support vector regression and random forest. As a lightweight model, it offers simplicity in the modeling process and strong generalization capability, making it suitable for practical applications.
In order to provide a theoretical foundation for the production of high-quality Jingshan black tea, this study clarified the quality characteristics of Jingshan black tea and selected suitable cultivars for its production. Tea leaves of 9 representative cultivars were used to make tea, including ‘Zuijinhong’, ‘Huaxiangchun’, ‘Yujinxiang’, ‘Jiukeng Population’, ‘Maolv’, ‘Zhenong 113’, ‘Baiye No.1’, ‘Zijuan’ and ‘Jiaming No.1’. By sensory quality evaluation and chemical analysis, the quality characteristics and the main biochemical components of Jingshan black tea of different cultivars were obtained. The results showed that the appearance of Jingshan black tea was wiry and tight (heavy), slightly tippy, black bloom, the liquor color was bright and red, the aroma was pure and flowery, the taste was mellow and refreshing, the infused leaves were red even bright. It was found that the quality of black tea made by ‘Huaxiangchun’ and ‘Maolv’ was the best. There were significant differences in the biochemical components contents of the 9 kinds of Jingshan black tea, where the catechins, theaflavins, thearubigins, theabrownins, water extract, tea polyphenols, caffeine and Tp/Aa (the ratio of tea polyphenols to amino acids) ranged from 3.71%-6.63%, 0.07%-0.84%, 1.82%-8.20%, 0.65%-7.39%, 44.23%-49.06%, 8.73%-13.55%, 2.46%-3.92% and 5.06-10.97, respectively. Based on bivariate correlation analysis, it was indicated that the total sensory evaluation score of Jingshan black tea was significantly (P<0.05) or extremely significantly (P<0.01) positively correlated with the content of EGC, ECG, total catechins, amino acids and tea polyphenols. Also, it was significantly (P<0.05) negatively correlated with theaflavins content and Tp/Aa. In comparison, the cultivars of ‘Jiukeng Population’, ‘Maolv’, ‘Baiye No.1’, ‘Jiaming No.1’, ‘Huaxiangchun’, ‘Yujinxiang’ and ‘Zuijinhong’ are more suitable for making Jingshan black tea than ‘Zhenong 113’ and ‘Zijuan’.
This study used geostatistical methods and GIS technology to divide tobacco fields into different fertility zones based on soil nutrients content. A recommended fertilization model was established using key parameters obtained from multiple field experiments. The digital tobacco field system and tobacco nutrient management system will push the results of soil testing and formulated fertilization to tobacco farmers to guide fertilization practice. The results showed that the soil alkaline hydrolyzable nitrogen content was at a moderate level, while the available phosphorus and available potassium content were moderate or higher in Fengjie County tobacco growing area. Fertilization zoning showed that the proportion of medium nitrogen, medium or high phosphorus, and medium or high potassium tobacco fields was the largest in the area. The proportion of low nitrogen, low phosphorus, high potassium and medium nitrogen, high phosphorus and medium potassium tobacco fields took the second place. The proportion of low nitrogen, high phosphorus, high potassium, and medium nitrogen, low phosphorus, low potassium tobacco fields was the smallest of them. The digital tobacco field system and tobacco field nutrient management system were developed through research. The systems could conveniently convey soil nutrient information and fertilization formula results to users in real-time for guiding precise fertilization. The research results had opened up the “last kilometer” of soil testing and formulated fertilization, providing technical support for scientific fertilization in tobacco fields.
The article first outlines two methods of image acquisition, namely, the capture of RGB images and spectral images. Subsequently, it explores image preprocessing techniques, including steps such as image denoising, enhancement, and segmentation. In terms of feature extraction, principal component analysis (PCA) and linear discriminant analysis (LDA) methods are employed to efficiently extract the color, texture, and shape features of rice seeds. Additionally, the article discusses the practical applications of machine learning and deep learning in processing spectral and RGB images of rice seeds, as well as the performance optimization and improvement methods of deep learning models in rice seed recognition and classification. Overall, machine vision technology demonstrates its efficiency and accuracy in the field of rice seed recognition. In the future, the development of a low-cost image acquisition platform and more lightweight rice seed recognition software can be anticipated, promoting rice seed data sharing and continuously exploring emerging deep learning techniques to further optimize the effectiveness of rice seed recognition.
To study the effects of Bacillus on the growth performance, digestion, non-specific immunity and disease resistance of Procambarus clarkii, a total of 270 P. clarkii with body weight of (9.36±1.40) g were selected and divided into 3 groups of CK (without Bacillus) group, T1 (with B. coagulans) group and T2 (with B. subtilis) group, for a 4-week culture experiment. The results showed that there were no significant differences in final body weight among all groups (P>0.05), while WGR, SGR, SR and HSI in groups T1 and T2 were significantly higher than those in group CK (P<0.05). The activities of ACP, ALP, LZM and SOD in groups T1 and T2 were significantly higher than those in group CK (P<0.05). The LPS and TPS activities of groups T1 and T2 were significantly higher than those of group CK (P<0.05), and the AMS activity of group T1 was significantly higher than that of groups CK and T2 (P<0.05), but there was no significant difference between groups T2 and CK (P>0.05). After WSSV challenge, the survival rate of P. clarkii in groups T1 and T2 was significantly higher than that in group CK (P<0.05). In conclusion, the two species of bacilluscan significantly improve the growth performance of P. clarkii, increase intestinal digestive enzyme and serum non-specific immunoenzyme activity, enhance disease resistance and reduce mortality when infected with WSSV.
