Current Issue http://journals.caass.org.cn/zgnxtb EN-US http://journals.caass.org.cn/zgnxtb/EN/current.shtml http://journals.caass.org.cn/zgnxtb 5 In order to reveal the effect of PBOG on yield and yield-related traits of soybean, and to investigate its suitable application concentration, we chose the sub-limited podding habits soybean variety ‘Kenfeng 16’ as the material, and conducted foliar spray with five different concentration gradients of PBOG: 0, 0.5, 1, 2 and 3 g/L at the early flowering stage of soybean. The effects of PBOG on soybean plant height, node number of main stem, bottom pod height, number of effective pods, kernel number per plant, 100-kernel weight and yield were investigated. The results showed that the plant height and bottom pod height decreased the most and significantly at PBOG concentration of 3 g/L, with a decrease of 41.9% and 44.1%, respectively; while 100-kernel weight reached the maximum of 19.05 g at this concentration, with an increase of 13.3%. The node number of main stem, number of effective pods, and kernel number per plant increased significantly at PBOG concentration of 1 g/L. The yield showed a trend of first increase and then decrease with the increase of PBOG concentration, with the maximum increase of 21.6% at the concentration of 1 g/L, and then gradually decreased, and was lower than that of control at 3 g/L. In conclusion, the optimum application concentration of PBOG is 1 g/L for the sub-limited podding habits variety ‘Kenfeng 16’, the yield can be increased by 21.6% at this concentration, and the lower plant height can improve the lodging resistance.

]]> The effects of ridge cultivation pattern on potato growth, photosynthesis and yield were explored to provide a scientific basis for the popularization and application of ridge cultivation without film mulching in dry land of shallow mountainous area in Qinghai Province. In the 2-year positioning experiment, the treatment of ridge cultivation without plastic film mulching was set up, and the control treatment was the ridge cultivation with plastic film mulching. The growth, photosynthesis and yield of potato under different treatments were analyzed. The results showed that there was no significant difference of plant height, leaf chlorophyll content, leaf photosynthetic characteristics, yield and commodity rate between the treatments. In the dryland of the shallow mountainous area in Qinghai Province, the ridge cultivation without film mulching can be popularized and applied in potato production, but it still needs multi-point verification to control the risks.

]]> Abiotic stressors, such as water, saline-alkali, temperature and heavy metals, stress the growth and development of tobacco, and current research has found that exogenous substances play a very important role in tobacco stress mitigation. This paper summarizes the adverse effects of abiotic stress on tobacco growth, and the pathways of the action of exogenous substances in alleviating abiotic stress, analyzes the optimal concentration of exogenous substance application, and points out the possible adverse effects of exogenous substance application on tobacco. It also points out that the effect of multiple exogenous substances in combination is better than the effect of single exogenous substance, and discusses future prospects of tobacco abiotic adversity research, aiming to provide a theoretical basis for the exploration and application of new exogenous substances in tobacco cultivation and the elucidation of their regulatory mechanisms to mitigate the abiotic adversity.

]]> This paper summarized the existing preparation technologies of nano-selenium, and compared the advantages and disadvantages of different preparation technologies. The research of nano-selenium’s role in improving crop growth, product quality and crop resistance to diseases and pests, and extending shelf life was reviewed. At the same time, the alleviation effects of nano-selenium on crop physiology and biochemistry, plant primary and secondary metabolite synthesis, and agricultural product quality under heavy metal stress were explored. While increasing the selenium content of crops, nano-selenium can continuously improve the quality and efficiency of agricultural industry, which is reflected in regulating the content of trace elements in crops, enhancing plant health, preventing and controlling pests and diseases, reducing the risk of crop yield reduction and fruit quality deterioration, and inhibiting the accumulation of heavy metals. Summarizing previous scientific research achievements is conducive to understanding the benefits of nano-selenium, which is easy to be absorbed by animals and plants, to agriculture and other fields, providing technical ideas for the development of healthy and green agriculture and functional agricultural products, and impelling the modern industrial system construction with scientific and technological strength.

]]> To explore the light intensity suitable for the growth of purple leaf lettuce seedlings in plant factories and greenhouses, the effects of light intensity of 6000, 12000, 18000, 24000 and 30000 lx on growth morphology, nutritional quality, photosynthetic pigment and photosynthetic characteristics of purple leaf lettuce seedlings were studied with ‘Beizisheng 3’ as the experimental material under the condition of white light quality unchanged. The results showed that under the light intensity of 30000 lx, purple leaf lettuce seedlings grew well and the biomass, chlorophyll a content, chlorophyll b content, carotenoid content, total chlorophyll, soluble protein content, soluble sugar content, vitamin C content, anthocyanin content, net photosynthetic rate, transpiration rate and stomatal conductance were the largest, while the nitrate content and intercellular CO₂ concentration were the lowest. However, chlorophyll b content, carotenoid content, soluble protein content and transpiration rate had no significant difference compared with those under 24000 lx light intensity, and the plant height was the highest under 24000 lx light intensity. Under the condition of white light quality, the most suitable light intensity for the growth of purple leaf lettuce seedlings is 30000 lx.

]]> By studying the effect of planting density on different varieties of chili pepper, we aim to investigate the optimal planting density of chili pepper in Kuitun of Xinjiang. ‘Yanjiao No.1’, ‘Yanjiao No.808’, ‘Yanjiao No.52’, ‘Yanjiao No.408’, which are main chilly pepper varieties in Kutun, were used as test materials, and the effects of different planting densities on growth period, plant characters, leaf area coefficient and yield of chili pepper were studied. With the increase of the planting density, the initial flowering period, fruiting period and harvest beginning period of chili pepper were delayed by 0-6 days, but the final harvest period was earlier by 0-9 days. The plant height increased with the increase of the planting density, while the stem diameter, branch number and spreading degree decreased with the increase of the planting density. In the range of the planting density of this study, the fruit number per plant, fruit longitudinal diameter and transverse diameter, fresh weight per fruit, dry weight per fruit and dry pepper weight per plant of the 4 varieties decreased with the increase of the planting density. The leaf area coefficient increased with the increase of the planting density. In the range of 25000-65000 plants/hm², the highest yield of the 4 varieties was obtained when the planting density was 48000 plants/hm². The relationship between the planting density and yield showed a quadratic curve. The optimum planting density of ‘Yanjiao No.1’ was 48700 plants/hm², and its optimum yield was 9304.74 kg/hm². The optimum planting density of ‘Yanjiao No.808’ was 49700 plants/hm², and its optimum yield was 9787.95 kg/hm². The optimum planting density of ‘Yanjiao No.52’ was 47800 plants/hm², and its optimum yield was 8565.07 kg/hm². The optimum planting density of ‘Yanjiao No.408’ was 48000 plants/hm², and its optimum yield was 8012.09 kg/hm², which is consistent with the actual yield measured in field.

]]> To screen the most suitable Chinese medicine residue compound substrate cultivation mode for watermelon in greenhouse, in this study, main small-fruit watermelon varieties planted in greenhouse were used as the test materials. Five cultivation modes were adopted, including pit cultivation (T₁), substrate bag cultivation (T₂), substrate pillow cultivation (T₃), aboveground trough cultivation (T₄) and underground trough cultivation (T₅), to explore the effects of different substrate cultivation modes on the growth, yield and quality of watermelon in greenhouse. The results showed that in the flowering and fruit setting stage, compared with those of T₃, the plant height, internode length, number of leaves, SPAD value, net photosynthetic rate (Pn) and intercellular CO₂ concentration (Ci) of T₄ significantly increased by 60.81%, 20.63%, 25.49%, 13.77%, 6.34% and 8.56%, respectively; while the stomatal conductance (Gs) and transpiration rate (Tr) of T₃ increased significantly by 65.71% and 14.99%, respectively, compared with those of T₄. In the fruit enlargement stage, the plant height, stem diameter and number of leaves of T₄ increased significantly by 86.75%, 22.42% and 16.79%, respectively, compared with those of T₃. At the maturity stage, the plant height, stem diameter, internode length, number of leaves, fresh weight of aboveground part, fresh weight of underground part, dry weight of aboveground part, dry weight of underground part, and fruit yield of T₄ reached the maximum value, and were significantly higher than those of T₃. The content of center sugar and edge sugar were the highest in T₃, the center sugar content was significantly higher than that of other treatments, and the edge sugar content was significantly higher than that of T₁, T₄ and T₅ treatments. In summary, the five cultivation modes can all be used for the production and cultivation of watermelon in greenhouse, but the aboveground trough cultivation mode is more conducive to promoting the growth and development of watermelon and increasing the fruit yield, and the watermelon growth is the best and the fruit yield is the highest. The substrate pillow cultivation mode is beneficial to increasing the sugar content of fruit, and the watermelon fruit quality is the best.

]]> To gain an in-depth understanding of the genetic diversity of the Prunus salicina ‘Fengtang’ cultivated population, a quantitative classification study was conducted on 26 fruit traits of 74 single plants in the P. salicina cultivated population (12 quantitative and 14 descriptive traits). The fruit traits were compared with those of P. salicina ‘Fengtang’ to provide reference for scientific conservation and rational exploitation of local plum resources in Guizhou. The trait distribution frequencies, coefficients of variation, Shannon-Wiener information index, Simpson genetic diversity index, epistatic clustering, principal component analysis and significant difference analysis were used to analyze and study the traits according to the Specifications and Data Standards for the Description of Plum Germplasm Resources. The results are as follows. (1) The ranges of Shannon-Wiener diversity index and Simpson genetic diversity index for the 26 fruit traits were 0.3425-2.1838 and 0.1928-0.8775, respectively. Among the 14 descriptive traits, no variation type was found for kernel shape, while 2.9 average variation types occurred for the remaining descriptive traits. The coefficients of variation for 12 quantitative traits ranged from 0.50% to 31.92%. Among them, the coefficient of variation of Vc was the largest, followed by single fruit weight. (2) The results of the Q-cluster analysis showed that at the Euclidean distance of 16.65, the 74 materials could be divided into four clusters, A, B, C and D. The number of materials in each cluster was 16, 12, 28 and 18 in order. Among them, group A, group B and group C were more closely related to P. salicina ‘Fengtang’. Group D was more distantly related to P. salicina ‘Fengtang’, and most of the fruit quantitative traits of group D and P. salicina ‘Fengtang’ were significantly different. (3) The results of R-type cluster analysis showed that at the correlation coefficient of 2.08, the 26 fruit traits could be divided into two major groups, and the first major group was group A. At the correlation coefficient of 1.35, the second major group could be divided into group B, group C and group D. Combined with the correlation analysis of quantitative traits, it was found that most of the traits showed pairwise correlations with each other, and some of the traits showed obviously logical correlations with each other. (4) Principal component analysis revealed that there were nine principal components with eigenvalues greater than 1.0. Their cumulative contribution rate reached 70.79%, among which the contribution rate of each trait was more dispersed. This indicated that the classification of the probable P. salicina ‘Fengtang’ germplasm was influenced by several traits together. In conclusion, it can be concluded that the 74 individual plants of the P. salicina ‘Fengtang’ cultivated population were rich in fruit trait diversity, with more types of descriptive trait variation, more obvious quantitative trait variation, and rich genetic diversity. There were strong correlations in 26 fruit phenotypic traits, and it was a reasonable method to use fruit traits for quantitative classification study of the test material. The study yielded 18 germplasm resources that are distantly related to P. salicina ‘Fengtang’, which can be conserved and utilized as important resource materials.

]]> The purpose of this study is to analyze the relationship of the occurrence of grape fruit cracking with the cell wall metabolism substances and apoptosis under different concentrations of plant growth regulators in ‘Black Monukka’ grape production, explore the main physiological reasons for the difference of fruit cracking characteristics, and find the most suitable plant growth regulator spraying concentration for ‘Black Monukka’ grape. The easy-to-crack variety ‘Black Monukka’ was used as the test material, different concentrations of plant growth regulators were sprayed 10-15 days after flowering, and the fruit cracking rate was induced by soaking in water for 24 hours after the berries were picked at the mature stage. The water-soluble pectin, protopectin, hemicellulose, and PG, PEP, CE and PL enzyme activities were determined by enzyme-linked immunoassay, and the apoptosis rate was observed and counted by TUNEL staining. The results showed that there were significant differences among different treatments after the berries were soaked in water for 24 h. The fruit cracking rate under the treatment of 100 mg/L gibberellins plus 5 mg/L forchlorfenuron was 56%, which was the lowest and significantly lower than that under other treatments, and the apoptosis rate was relatively low. Protopectin and hemicellulose were very significantly and negatively correlated with the fruit cracking rate, and the PEP enzyme activity had a significantly negative correlation with the fruit cracking rate. Water-soluble pectin/protopectin had very significantly positive correlations with the fruit cracking rate. The results of this study indicate that proper spraying of gibberellin and forchlorfenuron can improve the activities of PEP and CE, increase the contents of hemicellulose and protopectin, and reduce the rate of apoptosis and alleviate the occurrence of fruit cracking.

]]> By studying the interaction of the phenotypic traits of safflower with the application rates of nitrogen, phosphorus and potassium (NPK), we aim to provide reference for rational application of fertilizers in safflower production. 21 phenotypic traits of safflower at full-bloom stage and mature stage were recorded based on three-factor and three-level orthogonal design method, the data was investigated by correlation analysis and principal component analysis (PCA), and the requirement rule and amounts of NPK fertilizers at different safflower growth stages were studied by DTOPSIS method. The results showed that 7 traits of fresh root weight per plant, number of flowering balls, number of all balls, fresh weight per plant, branch height, fresh weight of all balls, and main root length at full-bloom stage, and 4 traits of dry weight of all balls, dry weight per plant, number of seeds in top ball, and dry weight of root at mature stage varied with the application rates of NPK, and the variation coefficients were all higher than 10%, accounting for 53.8% and 50.0% of the tested phenotypic traits. 13 traits at full-bloom stage and 8 traits at mature stage had different degrees of responses to different NPK fertilizer rates, but the traits were coordinated with each other, and some traits showed significant or extremely significant correlation. 4 principal components at full-bloom stage and 3 principal components at mature stage were identified by PCA, accounting for 84.61% and 85.70% of the total variation, suggesting that proper application rates of NPK fertilizers could lay a foundation for high flower and seed yield of safflower by changing yield related traits. The requirement of N and P fertilizers at full-bloom stage and mature stage of safflower was relatively high. Therefore, it is suggested that N and P fertilizers should be applied with proper rates and at proper time for the high yield of safflower.

]]> To explore the prevention and control effect of biological fungus Trichoderma on the diseases of cutting-rose, 300 times Trichoderma wettable powder was used at the seedling stage of cutting-rose. The results showed that Trichoderma could promote and enrich the distribution of fungal species in the rhizosphere and roots of rose, and had a great impact on the diversity of fungi and microorganisms in the soil. The number of OTU increased, and the rhizosphere fungal indexes, namely Shannon, Simpson and PD indexes, were higher than those of the control and chemical agent thiophanate methyl treatment, indicating that Trichoderma could enrich the species of soil fungi and increase the abundance of some beneficial bacteria. From the perspective of the control effect on rose downy mildew, 300 times of Trichoderma and 800 times of 50% thiophanate methyl showed significant differences compared with the control. The disease prevention and treatment effect of Trichoderma was 87.35%, which was slightly higher than that of chemical agent thiophanate methyl.

]]> The present study is focusing on the soil bacterial community structure and diversity of Morchella inferred from the high-throughput sequencing in Jianchuan of Dali in Yunnan Province, aiming to provide data support for revealing the mechanism of continuous cropping obstacle of M. sextelata. The results indicated that the phylum Proteobacteria, genus Pseudomonas, species Bradyrhizo biumelkanii were dominant individually. Sphingomonas was the dominant genus in one-year soil, and Candidatus Jettenia was an additional genus, in which the species Streptomyces puniciscabiei significantly decreased, and Ignavibacteriales bacterium and Chlorobi bacterium were additional taxa, and Ignavibacteriales bacterium showed dominant in one-year soil. The OTUs and Alpha diversity analyses index in the original soil of M. sextelata were higher than those in one-year soil. The result revealed that the soil bacterial community structure changed significantly at the genus and species level, and the diversity and uniformity of species distribution in the community decreased after continuous cropping of M. sextelata. The analyses proposed that the continuous cropping obstacle of M. sextelata might be related to the decrease of relative abundance of various beneficial bacterial taxa in the soil, such as Acidobacteriota (phylum), Verrucomicrobiota (phylum), Pedosphaeraceae (family), Streptomyces puniciscabiei (species) and Candidatus Koribacter (genus).

]]> To reveal the distribution characteristics of pH values and available potassium (AK) contents in Guizhou tobacco fields with different soil types and guide soil conservation, the thickness of plough layer, the distribution of pH values and AK contents were analyzed in typical tobacco-planting fields in Guizhou, and the changes of pH values and AK contents were evaluated after 30 cm deep ploughing. The results showed that the average thickness of soil plough layer was 18.88 cm, which was generally shallow. The average pH value was 6.21 with anthrosols>argosols>cambosols>ferrosols>primosols, and there was no significant difference among the soil types. The average AK content in soil plough layer was 332.81 mg/kg with argosols>ferrosols>anthrosols>cambosols>primosols, AK in argosols and ferrosols were significantly higher than that in anthrosols and cambosols, and there was no significant difference between argosols and ferrosols, and anthrosols and cambosols. The soil pH value and AK content were defined as three modes: decreasing type, increasing type and uniform type, pH was mainly increasing type (72.21%), and AK was mainly decreasing type (72.21%). After deep ploughing, the pH value increased by 0.12 units on average, and the AK content decreased by 49.43 mg/kg. The thickness of plough layer was generally shallow and acidification phenomenon could be observed, but the AK content was generally high in Guizhou tobacco-planting fields. Different soil types had different pH values and AK contents and the profile distribution characteristics affected the changes of soil pH value and AK content after deep ploughing.

]]> To study the correlations between seedling cultivation effect of different strawberry varieties and meteorological factors, a field experiment was conducted on four strawberry varieties in Cixi of Zhejiang Province by descriptive statistics and LSD multiple comparative analysis. The results showed that ‘Hongjia’ had the shortest seedlings and the highest SPAD value of leaves with the number of seedlings of 114.0 plants/m². ‘Mengjing’ had the lowest SPAD value of leaves with the number of seedlings of 90.3 plants/m², which was prone to brown angular leaf spot at the later stage of growth. ‘Yuexiu’ was close to ‘Mengjing’ in the capacity of seedling propagation, but the former had the highest mortality of mother plant and was more susceptible to anthracnose and brown angular leaf spot. The seedlings of ‘Mengxiang’ formed the latest, with only 65.5 plants/m². In terms of the germination capacity of stolon, the four varieties were in an order of ‘Hongjia’> ‘Yuexiu’> ‘Mengjing’> ‘Mengxiang’, among which the stolon of ‘Mengxiang’ germinated about 20 days later than that of the other three varieties. In conclusion, the quantity of stolon stabilizes after a period of rapid outbreak with the rise of external temperature. The rate of stolon germination decreases and the seedlings enter the stage of flourishing germination with the accumulation of temperature. Although precipitation inhibits the germination of stolon, it can speed up the germination of seedlings, which has a more significant influence on ‘Mengjing’ and ‘Yuexiu’. ‘Yuexiu’ requires a relatively cool and dry environment for the germination of its stolon.

]]> As a major agricultural province in China, Shandong is one of the most important grain-producing areas in the country. The province is affected by the monsoon climate and is prone to drought disaster. Therefore, the disaster risk assessment and zoning of drought in Shandong Province can prevent drought disasters more scientifically, which is of certain guiding significance to improving drought disaster risk management, enhancing decision-making and reducing economic losses. Based on the principle of natural disaster risk assessment, this paper used the basic data of meteorology, soil and topography, and high-precision data of land use type and normalized differential vegetation index in Shandong, adopted the methods of weighted comprehensive evaluation and analytic hierarchy process, as well as GIS spatial analysis technology, to assess and zone the risk of drought. The results showed that the risk of drought in Shandong was high, areas with medium and high risk accounted for 59.40% of the total, and the high risk areas were mainly located in the northwestern part of Shandong and the eastern part of Jiaodong peninsula. The exposure of disaster-bearing bodies was high, areas with medium and high exposure accounted for 70.66% of the total, and the high exposure areas were mainly located in the western and southern parts of Shandong, and some areas in the central part were also highly exposed. The vulnerability of disaster-bearing bodies was slightly high, areas with medium and high vulnerability accounted for 48.1% of the total, and high vulnerability areas were mainly located in the southwestern part of Shandong. The disaster prevention and mitigation capacity of Shandong was strong, areas with medium and high disaster prevention and mitigation capacity accounted for 50.87% of the total, and areas with high disaster prevention and mitigation capacity were mainly located in the Jiaodong peninsula and some areas in the north of the province. The comprehensive risk of drought in Shandong was high, areas with medium and high comprehensive risk accounted for 54.04% of the total, and mainly located in the western and central parts of Shandong, and the eastern part of the province had relatively low comprehensive risk of drought.

]]> To clarify the application effect of Grapholitha molesta (oriental fruit moth, OFM) in Linqu cherry orchards, a field survey was conducted to monitor the occurrence dynamics of the oriental fruit moth and compared the mating disruption effect and rate of shoot decay in Linqu cherry orchards in 2021 by hanging disorientated wire. The results showed that the occurrence of G. molesta was from early April to July, and the occurrence of G. molesta adults was the highest on April 26 and June 14, with 33 and 38 adults per trap, respectively. After comparing different numbers of disorientated wire, it was found that the mating disruption rate under 300 clips/hm² treatment was the lowest, while that under 450 clips/hm² and 600 clips/hm² treatments had no significant difference, both were above 89%. The shoot decay rate of the treated orchards was obviously lower than that of the control area, and the control effect on shoot decay was more than 80%. According to the critical periods of the occurrence of G. molesta, hanging 450 clips/hm² of disorientated wire can basically control the occurrence and avoid the damage of G. molesta.

]]> To evaluate the safety of cyromazine used on celery, dynamic test and final residual test of 75% cyromazine wettable powder on celery were carried out in Lhasa of Tibet from 2019 to 2021. The ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis method was used to analyze the residues of cyromazine and its metabolite melamine in celery. The degradation rule and half-life were clarified, and the safety evaluation of the residual amount of cyromazine and its metabolite melamine were carried out. The results showed that the degradation of cyromazine on celery complied with the first-order reaction kinetics equation, with a half-life of 3.18-3.40 d, which was an easy-to-degrade pesticide. The residual amount of melamine on celery decreased first and then increased. After 2-3 days of cyromazine application, the residual amount of melamine reached the maximum, and then showed a gradual decrease trend over time. The preliminary regression analysis showed that the residual degradation dynamics of melamine was in line with the first-order kinetic relationship after its residual amount reached the maximum in celery, with a half-life of 5.13-6.24 d. According to GB 2763-2021, the maximum residue limit (MRL) value of cyromazine on celery is 4 mg/kg. Under the condition that 75% cyromazine wettable powder is applied twice or three times on celery according to the recommended dose (168.75 g a.i./hm²) and seven days after the last application, cyromazine and its metabolite melamine have no significant risk of exceeding the standard. It is suggested that the safe harvest interval for cyromazine applied to celery should be 7 days．

]]> The study aims to analyze the growth and development law of the hybrid F₁ generation between German Simmental bulls and Chinese Holstein cows, build model of the body size growth law of hybrid F₁ generation cows, and explore the difference of body size between hybrid F₁ generation cows and Holstein cows at 3, 6, 13 and 18-month-old levels under the same condition. The body size data, including body height, cross height, body oblique length, chest circumference, abdominal circumference and maximum hip breadth of hybrid F₁ generation bulls (0-6 months)，hybrid F₁ generation cows (0-23 months) and 3, 6, 13, and 18-month-old Holstein cows were measured. Logistic, Brody, Gompertz and Bertallanffy were used as models to fit the relationship between body size and month age of hybrid F₁ cows, and the curve fitting effect was evaluated by curve fitting degree R². The results showed that the body size indicators of hybrid F₁ generation cattle all showed an increasing trend with the increase of months, but the growth rates of different body size indicators were different. Before the age of 5 months, the average growth of body height, cross body height, body oblique length, chest circumference and abdominal circumference of F₁ generation cows was 5.31, 5.99, 8.33, 11.11 and 16.29 cm/month. At the age of 6 months, the growth rate of each indicator became smaller, increased by 1.76, 2.99, 6.34, 7.81 and 7.56 cm/month, respectively. However, this slow growth trend was alleviated at the age of 7 and 8 months. After the age of 9 months, the body size indicators increased relatively steadily, and after reaching the age of 17 months, the indicators increased slowly. The average growth rate of body height, cross body height, body oblique length, chest circumference and abdominal circumference of hybrid F₁ generation bulls at 6 months of age was 4.29, 4.76, 6.76, 9.34 and 14.73 cm/month. After 3 months of age, all the body size indicators of hybrid F₁ generation cows were higher than those of Holstein cows. The body size index curves fitted in this experiment can be used as a model for estimating the growth law of hybrid F₁ generation of German Simmental and Holstein, and provide basic data for the hybridization improvement of Chinese Holstein cattle with the introduction of German Simmental cattle.

]]> The purpose of the study is to investigate the effects of hormone treatment and donor age on superovulation and production efficiency of sex control embryos for high yielding Holstein cows in vitro, and provide technical support for the establishment of stable and efficient superovulation schedule and the improvement of production efficiency of sex control embryos for high yielding Holstein cows in vitro. A total of 60 high yielding Holstein cows were randomly selected and divided into 3 groups. OPU-IVF for embryo production was performed according to FSH injection schedule: bi-weekly (BW), once weekly (OW) and no injection (CON) in vitro. The best schedule was used to further study whether there was difference in embryo production efficiency in vitro between young cattle and postpartum cattle. The superovulation effect of BW group was better than that of OW and CON groups. The number of available ovum (15.30±0.60), the proportion of available ovum (68.83%±1.92%), the number of grade A ovum (9.86±0.38) and the number of grade B ovum (5.44±0.37) in BW group were significantly higher than those of OW group. The in vitro development of IVF early embryos in BW group was better than that in OW and CON groups. The cleavage rate (77.80%±1.08%) and the number of embryos per cow (5.11±0.27) in BW group were higher than those of OW and CON groups, and the differences were significant. The proportion of grade B embryos (13.95%±1.23%) in BW and CON groups was significantly lower than that in OW group. The number of average ovum (27.10±1.35) and embryo per cow (5.29±0.28) in postpartum cattle group were significantly higher than those of young cattle group, but the ovum availability was significantly lower than that of young cattle group, which was 64.44%±1.81% and 75.01%±2.33%, respectively. The BW group had the best superovulation schedule, under which the production efficiency of sex control embryos in vitro of postpartum cattle was significantly higher than that of young cattle.

]]> The objective is to investigate the differences of fruit color indexes and internal quality of Mollera rubra ‘Dongkui’ at different maturity levels, and explore the correlation between fruit color indexes and internal quality, so as to provide reference for the appearance color evaluation and high quality harvest of M. rubra fruits. M. rubra ‘Dongkui’ cultivated in open field, greenhouse and high mountain net room were used as test materials. The fruit color indexes L^*, a^*, b^*, a^*/b^*, C, H, CIRG values of M. rubra ‘Dongkui’ at different maturity levels were measured and analyzed, so were the fruit weight, firmness, soluble solid content, titratable acid content, and solid-acid ratio. The results showed that with the increase of fruit maturity, the fruit color deepened from red to dark red, violet red and dark violet, the fruit color indexes L^*, a^*, b^*, C and H decreased, while the values of a^*/b^* and CIRG increased, the titratable acid content decreased, and the solid-acid ratio increased. Among them, the CIRG value showed significant differences among the four different fruit colors in the four bases, which could better reflect the color difference of M. rubra fruits. The fruits were red when the CIRG value ranged from 2.36 to 3.43, were dark red when the CIRG value ranged from 3.69 to 4.14, were violet red when the CIRG value ranged from 4.80 to 5.46, and were dark violet when the CIRG value ranged from 5.58 to 7.69, and the CIRG value was significantly and positively correlated with the solid-acid ratio of fruits in the four bases. It is suggested that CIRG value can be used as a quantitative evaluation index for fruit appearance color, maturity and internal quality of M. rubra fruits.

]]> The cultivation of Oenanthe javanica in China has achieved great results, but still not yet made a breakthrough in the field of deep processing and consumption. With the booming of the pre-cooked food consumption market, O. javanica as the raw material of pre-cooked food has a great development prospect. Based on the development status of pre-cooked food and the processing of O. javanica, the authors reviewed the types of traditional consumption and processing of O. javanica, and described the innovation in O. javanica product processing. Then, the authors proposed that the processing of O. javanica pre-cooked food could be the key to improving the overall benefit of O. javanica industry. Therefore, it is necessary to continuously explore the processing methods of O. javanica, and promote the value-added O. javanica industry for achieving good price and economic benefit.

]]> The purpose of this study is to accurately extract spatial information of lotus root cultivation in the basin area of Sichuan Province and to grasp the hotspot areas for this crop. First of all, we used the remote sensing images of GF-6 and ground survey data as data sources, analyzed spectral characteristics of lotus root fields in order to determine the best period of remote sensing, and extracted spatial information of lotus root cultivation in the area. Then, the spatial distribution characteristics and hotspot areas of lotus root cultivation in Sichuan were analyzed by Moran's I index and Getis-Ord G_i^* index. The results showed that: (1) the total accuracy of extracting spatial information of lotus root based on the maximum likelihood classification method was 92.35%, and the Kappa coefficient was 0.9045; (2) the area of lotus root cultivation in Sichuan basin based on remote sensing was about 128.57 km², which was distributed in 1374 townships, and some areas had aggregation phenomenon; the area of lotus root cultivation in 73 hotspot townships was 54.31 km², accounting for 42.24% of the lotus root cultivation area in the Sichuan basin, with obvious spatial polarization, mainly in Anju of Suining, Lezhi of Ziyang, Jianyang of Chengdu, etc. The results of the study can provide reference for the development of specialized lotus root cultivation in townships and the optimization of lotus root industry in Sichuan Province.

]]> This paper explored the research hotspots and future directions of Tinospora by bibliometric analysis based on China National Knowledge Internet (CNKI). Relevant research literature of Tinospora was combed by bibliometrics, the selected literature was visually analyzed by VOSviewer software, and the data of annual published papers, research institutions, subjects and disciplines, publishing periodicals, fund support and so on were compared. The research on Tinospora mainly involves chemical constituents, biological activity and clinical application. The research institutions are mainly concentrated in higher educational institutions and scientific research institutions. At present, foreign research on Tinospora focuses on basic research, resulting in a lot of high-level papers, while domestic research focuses on the germplasm resources, planting technology, extraction process, processing, pharmacological effects, clinical application, quality control and evaluation of Tinospora, and the research scope is more extensive. With the deepening of the research, more new components will be found from plants of Tinospora based on plant phylogeny and chemical component specificity in the future. Therefore, new drugs related to Tinospora will be applied to the market.

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