Based on the global rapeseed trade data from 2000 to 2020, this paper used social network analysis method to explore the evolution characteristics of global rapeseed trade network in recent 20 years and its policy implications for China's rapeseed foreign trade. The results showed that the direct trading path among the rapeseed trading partners in the world was constantly shortening, and the rapeseed trade among the core countries, marginal countries and semi-marginal countries had a certain degree of substitution, but it remains relatively stable on the whole. Germany, France, the Netherlands, China, Canada, Japan and other countries were the world's important rapeseed trade hubs in the past twenty years. China's rapeseed import will pick up in a short time, and its dependence on foreign countries is still strong. Due to the further diversification of the development trend of rapeseed import source market, China's rapeseed industry will face both challenges and opportunities in the future development. Therefore, China should improve the rapeseed production level, improve the rapeseed import policy, expand the foreign trade and economic cooperation relations and channels of rapeseed industry, and ensure the stable supply of rapeseed.
Low self-sufficiency rate and the higher foreign dependence rate of about 87% have seriously threatened the soybean safety in China. In recent years, with the changes of the international situation and the COVID-19 epidemic, soybean production, processing and consumption in China have attracted more attention at home and abroad. China unveiled "No. 1 central document" proposed a soybean revitalization plan in 2019, putting forward the goal of "one expansion and two improvements" to strengthen the competitiveness of China's soybean industry in the international agricultural market. This paper reviewed the current situation of soybean production, processing, trade and consumption in China in recent years, and upgraded strategies to enhance China's soybean industry and enhanced the self-sufficiency rate according to China's national conditions.
Limited by natural resources, reducing post-harvest loss has become an important method to protect national food security. Based on the survey data of 784 rural households in 22 provinces, we first estimated the harvest and storage loss of three major oil crops in China, include soybean, rapeseed and peanut. Second, we compared the differences of harvest and storage loss of three oil crops between different regions, harvesting methods and storage facilities. Third, we measured the impact of the harvest and storage losses of oil crops on resources and environment. The results showed that: (1) the harvest losses of soybean, rapeseed and peanuts were 4.75%, 4.97% and 4.02%, respectively; and the storage losses of these three oil corps were 2.67%, 1.11% and 1.15%, respectively. (2) There are significant differences in harvest and storage loss of oil crops between different regions, harvesting methods and storage facilities. (3) The harvest and storage losses of three major oil crops are equivalent to waste 0.86 million tons of oil, 1.26 million hectares of land, 160 thousand tons of chemical fertilizers, 7.15 billion m3 of water, and 1.37 million tons of carbon emissions.
At present, the decline of rape planting income has become a direct factor that frustrates farmers’ planting enthusiasm and hinders the development of rape industry in China. The multi-functional development of rape provides a potential and feasible way to improve the income of rape planting. In this regard, this study explored the way to improve the income of rape planting from the perspective of rape tourism. Using the rape fixed observation point data of the national rape industry economic research laboratory and the inverse probability weighted regression adjustment method （IPWRA）, it is found that rape tourism can significantly promote the rape planting income of Chinese farmers, and the promotion is realized by improving the commercialization rate of rape products, improving the quality of rape products, and optimizing the rape planting scale. Based on the research conclusions, this study puts forward the following policy suggestions: first, continue to promote the appropriate “seed tourism integration” of rape, that is, give consideration to the attributes of product supply of rape planting and the tourism. Second, take multiple measures to open up the three mechanisms of rape tourism and enlarge its income increasing effect.
In order to find the key financial factors affecting the price fluctuations of rapeseed products, the monthly price data of rapeseed products from January 2004 to July 2020, oil and fat agricultural products futures trading volume, currency liquidity, international crude oil prices, RMB exchange rates and the short-term capital flow were selected to construct the TVP-SV-VAR model and analyze the impact of five types of factors on the price fluctuations of three rapeseeds and time-varying effects. The research results showed that, in different time intervals, the impact of five types of financialization factors on the price fluctuation of rape products had obvious time-varying characteristics. First, the equally spaced impulse response showed that the impact of the five types of factors on the price of rapeseed products was mainly concentrated in the short-term, and the oil and fat agricultural product futures were conducive to calming the impact of external shocks on the price of rapeseed products. Second, the timing impulse response showed that currency liquidity had a significant pulling effect on the spot prices of three rapeseed products. International crude oil prices had a greater positive impact on the prices of rapeseed, rapeseed meal and rapeseed oil. The impact of volatility was relatively small, and the impact of RMB exchange rate and short-term capital flows on the price of rapeseed products had strong time-varying and structural mutations. On the basis of above analysis, this article proposes to continually improve the "insurance + futures" financial early warning system for rapeseed products to stabilize price expectations, promote advanced practical technologies through agricultural technological innovation to improve comparative advantages, and improve rapeseed subsidies with a green and large-scale orientation.
In order to make full use of the introduced rapeseed germplasm, genetic diversity of 144 rapeseed （Brassica napus L.） resources （including 124 exotic lines and 20 local spring rapeseed lines in Qinghai Province） was analyzed using 50K SNP microarray. In addition, 13 important phenotypic traits, including flowering time, stem strength-related traits, yield-related traits and quality traits, were identified in spring rapeseed planting environment. Results showed that mean value of genetic distances among 144 germplasm resources was 0.4683. 36.45% germplasm resources had genetic distance greater than or equal to 0.5. It indicated that the genetic diversity of these resources was relatively rich. 144 resources were divided into 6 groups according to their geographical origin. Among them, the group of spring rapeseed resources from northwest China had great genetic differences with other groups. Although had less diversity than other groups, it still had more than 0.4 inside. Cluster results showed that geographical origin of materials could not be really valid for judging their genetic differences. Some elite resources were identified with at least one excellent traits including large stem diameter （greater than 17 mm）, thick xylem （≥ 1 mm）, strong stem （breaking strength ≥ 80 N, or stem strength ≥ 40 N/cm2）, large TSW （thousand seed weight ≥ 6 g）, high oil content （≥48%）. Among them, 22 germplasm with excellent comprehensive traits were found and could be constructed into 2 hybrid parent resource groups. One group was from northwest China and abroad, the other is from the Yangtze River Valley in China.
The nodulation and nitrogen fixation of legumes have a great significance in agriculture, such as production, nutrient efficiency, and soil improvement. WUS gene plays an important role in meristem function in plants. The bioinformatics analysis shows that the protein encoded by the soybean WUS gene （GmWUS） and the ArabidopsisWUS gene （AtWUS） share a high conserve amino acid sequence, even though there is a big difference at C-terminal. The promoter sequence GmWUS2pro, 3000 bp upstream of the transcription start site, was amplified from the genome of soybean Tianlong 1, and fused with the reporter gene GUS to obtain the GmWUS2pro:GUS expression vector. qRT-PCR analysis revealed that GmWUS2 gene was highly expressed in soybean flowers and nodules. Through hairy root transformation mediated by Agrobacterium rhizogenes and GUS staining, it was found that the GmWUS2 promoter was active in both the roots and the nodules in soybean. The knockout vector of GmWUS2 was constructed using CRISPR/Cas9 technology, while overexpressing vector was constructed at the same time, and both vectors were transformed into soybean hairy roots, which was further inoculated with rhizobia HH103. The phenotypic differences between Gmwus2 mutant hairy roots and GmWUS2 overexpression hairy roots were statistically analyzed compared to an empty vector. It was found that the knockout of GmWUS2 significantly promoted the nodule and leaf development, suggesting the GmWUS2 gene affected growth of both the above-ground and underground parts of plants. Our results indicate that the WUS gene plays an important role in soybean nodule development, providing useful clues for both studying soybean nodulation and improving biological nitrogen fixation in agricultural production.
The pod thickness of soybean (Glycine max L.) is an important factor affecting the yield of soybean. Soybean pod is also rich in protein, cellulose and other nutrients, which can be used as stockfeed. Therefore, the research on pod thickness is of great significance to the special variety breeding of soybean and the further processing of soybean. In this study, ICIM method was used to locate QTL in CSSLs population, and a high-low mixed pool was constructed. BSA was used to analyze the re-sequencing results. Finally, the confidence interval was reduced to 0.03 Mb (2 970 674 bp-3 000 004 bp) on chromosome 03. All the genes in the consensus QTL interval were annotated, and the four candidate genes were obtained. Through gene annotation information and related biological analysis, two target genes directly related to pod thickness trait were predicted. The results of this study will have a certain reference value for soybean fine breeding.
The identification methods of soybean maturity group in previous studies were compared to provide reference for selecting appropriate identification methods. Interval method, clustering methodology and regression analysis method were used to identify 90 soybean varieties in their growth period groups. The results showed that the three methods could group the tested varieties well. Clustering analysis method is applicable to the situation that the maturation period of materials to be grouped is rich and balanced, its number of standard varieties is small, and the value of the maturity group is not accurate. The critical value of the grouping needs to be corrected according to the distance between the maturity group. Interval method is suitable for the growth period of standard varieties in each group strictly according to the median distribution of the maturity group, and the definition of the grouping critical value is more accurate. Regression analysis method is applicable to the situation that the value of standard variety maturity group is accurate and the number of standard variety is large, so it can accurately identify the growth period group of tested variety. The results of any identification method should be based on the premise of determining the standard identification site, and the identification results should meet the requirements such as the distance of the maturity group defined by the growth period group. Through the comparison of three identification methods, the applicability and results of each method were analyzed, which provided theoretical basis for the identification of soybean maturity groups in different region.
Arachis hypogaea L. is one of the most important oilseed and cash crops. The nitrogen utilization efficiency (NUE) is an important factor of peanut yield. In previous study, a candidate gene related to peanut yield was identified, belonging to high-affinity nitrate transporter genes (NRT2) family. In this project, the conserved domain of NRT2 protein was used to obtain the members of the NRT2 gene family based on the whole genome and transcriptome of peanut database. The phylogenetic tree, physicochemical properties, chromosomal distribution, genetic structure, conserved domain and gene expression pattern from 22 tissues were analyzed. The results showed that a total of 10 family members of the peanut NRT2 gene were identified. Chromosomal location analysis showed that these members were unevenly distributed on the 20 chromosomes. Genes located on chromosome 03 and chromosome 13, chromosome 06 and chromosome 16 had significant homology relationships. The expression pattern analysis indicated that the expression levels in tissues were different. Four genes, AhNRT2.4，AhNRT2.5a，AhNRT2.5b and AhNRT2.5c had higher expression in the root, which indicated the NRT2 members played important roles in root functions. This study provided the theoretical evidence for further revealing the function of NRT2 protein in peanut.
In order to rapidly identified peanut seed coat color, an accurate, simple and economical seed coat color recognition system was established. In this experiment, the color recognition system of Aliyun intelligent cloud computing platform was used to determine the HSV （Hue, Saturation, Value color mode） color spatial data of peanut seed coat with different colors such as black, purple, pink and white. At the same time, combined with the anthocyanin content data of peanut seed coat, the correlation model between color index （p） and anthocyanin content （i） was constructed, and the accuracy was verified by population. The results showed that the correlation coefficient between p and i was 0.932. According to p value, peanut seed coat color was divided into four groups : black （≥0.6000±0.0238）, purple （0.6000±0.0238~0.4000±0.0238）, pink （0.4000±0.0238 ~ 0.2000±0.0238） and white （≤0.2000±0.0238）. Using AI intelligent seed coat color recognition system can quickly and accurately identify the seed coat color of RIL population offspring, with high accuracy and obvious upper and lower bounds.
Cytochrome P450 (CYP450s) superfamily is the largest family of enzyme proteins in plants, widely involved in the biosynthesis of primary and secondary metabolites. In this study, 303 sesame CYP450 genes were identified, which were randomly distributed in 16 linkage groups, and classified into 9 clans， and 43 gene families. The CYP703 family was one of the members of the 71 Clan. It has been reported that CYP703 genes were involved in anther development in Arabidopsis and rice. Thus the sesam SiCYP703A2 gene, which might be the only member of sesame CYP703 family, was cloned. Phylogenetic analysis of P450 genes in sesame and Arabidopsis showed that SiCYP703A2 and AtCYP703A2 were clustered together, with amino acid sequence identity of 77%. Expression analysis indicated that SiCYP703A2 was highly expressed in flower buds of sesame, and especially highly expressed at the tetrad stage of anther development. Moreover, SiCYP703A2 in Arabidopsis transgenic
The miR396-GRF plays an important role in regulation of plant growth and development, biotic and abiotic stress processes. Currently, there are few studies on miR396 and GRF in castor. In this study, 4 miR396 and 11 GRF members were identified in the castor genome using BLASTP and PFam. It was found that RcGRFs were composed of 318-619 aa, the theoretical isoelectric point ranges from 5.54 to 9.34, the minimum molecular weight is 35 179.57 Da and the maximum molecular weight is 67 639.97 Da. The conserved domain and motif analysis showed that all RcGRFs contain the conserved domain of QLQ and WRC. Phylogenetic analysis showed that
WD40 protein family in plants participates in many biological processes as platforms for protein-protein and protein-DNA interactions. TTG1, an important member of the WD40 family, inhibits the premature accumulation of seed fatty acids in Arabidopsis thaliana. To reveal the sequence and expression characteristics of RcWD40 gene family and RcTTG1 gene in oil crop castor, 182 members of the RcWD40 family, including RcWD40-181 as RcTTG1 gene, were identified at genome-wide scale using bioinformatics methods. Their phylogenies, conserved domains, and expression patterns were also analyzed. RcWD40 family members were divided into 8 clusters and 28 subfamilies based on phylogenetic tree structure and conserved domain composition, respectively. Furthermore, transcriptome analysis revealed that the expression patterns of RcWD40s in flowers, leaves, roots, stems and seeds at different developmental stages of castor were diverse, predicting that they might regulate the growth and development of these tissues. Promoter region transcription factor binding sites prediction and seed development expression analysis imply that RcTTG1 gene might play a similar role in negative regulation of fatty acid accumulation as AtTTG1.
The aim is to compare the differences of seed oil quality among different germplasm of Akebia, and evaluate the quality of different germplasm comprehensively, so as to provide reference for its development and utilization. In this experiment, Akebia plants in the same habitat and growth years were used as materials. The shape and yield traits of 21 Akebia germplasm were measured and recorded. The oil content was determined by Soxhlet extraction method, and fatty acid types and contents were determined by gas chromatography. The yield and quality differences between species and within species were analyzed by coefficient of variation. Through correlation analysis, principal component analysis and grey correlation analysis, comprehensive analysis and evaluation were also carried out. Results showed that oil content, acid value, peroxide value, iodine value and saponification value of 21 accessions of Akebia were 33.86-47.08%, 2.64-11.72 KOHmg·g-1, 0.03-0.38 g·100g-1, 47.33-81.85 g·100g-1 and 237.87-281.53 KOHmg·g-1, respectively. The relative mass fraction of saturated fatty acids ranged from 13.56% to 18.51%. Oleic acid and linoleic acid were the main unsaturated fatty acids, and their relative mass fraction ranged from 45.75% to 66.17%. Differences were found among interspecific and intraspecific. The yield traits of Akebia trifoliate (Thunb) Koidz was significantly different, and that of Akebia trifoliatr (Thunb) Koidz.var. australis (Diels) Rehd was larger in oil quality. Correlation analysis showed that the fruit quality and shape index were correlated with some quality indexes of seed oil (single fruit quality was significantly negatively correlated with saturated fatty acids; fruit shape index was positively correlated with oil content, oleic acid, monounsaturated fatty acid, saponification value, and negatively correlated with peroxide value), and the higher the two, the higher the quality of seed oil. Principal component analysis and grey weighted correlation analysis showed that the best germplasm was Akebia trifoliatr (Thunb) Koidz.var. australis (Diels) Rehd (B1-B8). At the same time, S6 and S8 of Akebia trifoliate (Thunb) Koidz ranked above the middle in the two kinds of analysis, which was worthy of development and utilization. Fruit color and shape had little effect on the comprehensive quality of seed oil. The comprehensive quality of seed oil from B1 to B8, S6 and S8 was better, thus has higher utilization value.
In order to increase cold resistance of rapeseed and to improve germination rate and growth, Brassica napus cv. Zhongyouza 19 was used to study on effects of exogenous trehalose under low temperature by seed soaking. Results showed that under 10℃, rapeseed germination was inhibited. Germination potential, germination rate, germination index and vigor index were significantly reduced. Average germination period was significantly extended. Activity of isocitrate lyase, consumption of soluble sugar and soluble protein were significantly reduced during germination. Increase of proline content was turned down. Seedling length, main root length and dry weight and fresh weight of seedlings were significantly reduced. However, after seed soaking with exogenous trehalose, rapeseed growth was significantly increased by higher germination rate and increased root development under cold stress. 10 mmol/L trehalose treatment was the best among different concentrations. By promoting soluble protein and soluble sugar consumptions, increasing proline accumulation, and increasing the activity of isocitrate lyase, the 10 mmol/L trehalose increased the germination rate and germination potential by 19.4% and 61.8%, with the average germination period shortened by 21.7%. It also promoted root growth, increased nutrient content and seedling fresh weight, which enhanced seedling cold resistance. Correlation analysis found that germination indexes had significant correlation with 3 physiological indexes (soluble sugar, soluble protein and proline) after 24 h of seed-soacking. Thus the 10 mmol/L trehalose seed soacking for 24 h might improve the cold resistance of rapeseed. In summary, seed soaking with 10 mmol/L trehalose alleviated the inhibition of low temperature on seed germination by promoting seed energy metabolism and osmotic regulation of rapeseed, improving rapeseed production and its cold resistance.
To explore the germination differences of different peanut varieties under low temperature stress, and provide a theoretical basis for low temperature tolerance and cold resistance of peanut, low temperature tolerant varieties Yuhua 22 and intermediate varieties Luohua 16, low-temperature sensitive varieties Quanhua 6 and Luhua 11 were used as experimental materials to determine the physiological indexes related to germination under cold treatment. The results showed that, compared with CK, low temperature treatment 2℃ significantly reduced the radicle emergence rate, germination rate and relative germination rate of each peanut variety, and there were significant differences among the varieties. The decline reats of low temperature-tolerant peanut varieties were less than 10%, while that of intermediate and sensitive varieties was 30% to 100%. Under 2℃ stress for 24 h, the electrical conductivity of sensitive varieties was significantly higher than that of low temperature resistant and intermediate varieties. With the extension of stress time, SOD, POD activity increased, CAT activity decreased. Under 2℃ stress for 48 h, the content of Ss （soluble sugar） was higher than CK, the content of SP （soluble protein） was lower than CK. MDA content of sensitive varieties increased significantly, while that of low-temperature tolerant varieties increased slightly. The SOD activity of low-temperature-tolerant varieties was higher than that of intermediate and sensitive varieties, and the CAT activity decreased more significantly than that of intermediate and sensitive varieties. During recovery period, MDA content of all varieties was lower than CK, SP accumulation was higher than CK, Ss accumulation of low temperature resistant varieties and intermediate varieties was higher than sensitive varieties. The activities of antioxidant enzymes SOD, POD and CAT showed the same trend. With the extension of germination time, the enzyme activity of peanut varieties with stronger cold resistance was higher. The differences in each index well reflected the differences in low temperature tolerance of different resistant peanut varieties. The results of this study provide a basis for further improving the agronomic measures to prevent chilling injury in peanut and conducting peanut breeding for low temperature tolerance.
In order to explore the effects of calcium fertilizer application on soil acidity and harmful metal elements Al, Mn, Cd and Pb contents in peanut planting soil, this study selected three typical seed type peanut varieties in Hunan: Xianghua2008 (large seed size)，Xianghua55 (medium seed size)，Lanshan Xiaozi (small seed size) to carry out soil column test in typical calcium deficient barren acid red soil, and set up two treatments of calcium (hydrated lime) and no calcium application, rhizosphere soil and 0-20 cm topsoil were measured. The results showed that the overall average value of each index was affected by lime calcium as the pH increased by 4.93%, the content of Al, Cd, and Mn decreased by 3.85%, 2.13%, 1.59% respectively, and the Pb content increased by 0.66%. The increase of pH of calcium application was obviously greater in rhizosphere soil than in topsoil, midium seed > large seed > small seed. The decreasing amplitude of soil Al content by calcium application was rhizosphere soil > topsoil, large seed > medium seed > small seed. The Mn content decreased in the order of medium seed > large seed > small seed in the topsoil; large, medium seed increased, and small seed decreased in the rhizosphere soil. The Cd content in the topsoil and rhizosphere soil decreased the most in small seeds, large seeds increased slightly, and medium seeds decreased or increased. The soil Pb content in the rhizosphere soil of the large and medium seed varieties increased more than that in the topsoil, while the small seeds decreased. There was a stable positive correlation between pH and Mn content. The correlation between pH and Al, Cd, Pb contents was significantly affected by Ca application and soil position.
A field experiment with two-factor split-plot design was conducted to realize the effects of phosphorus and exogenous gibberellic acid on dry matter accumulation and yield formation of dry-land flax. We studied the effects of different phosphorus levels （0 kg P2O5·hm-2, 67.5 kg P2O5·hm-2 and 135 kg P2O5·hm-2） with and without spraying 15 mg·L-1 and 30 mg·L-1 GA3 at the budding and anthesis stages on the dry matter accumulation and transportation at pre-anthesis and post-anthesis, and the yield formation of flax. Results showed that both phosphorus and GA3 significantly promoted the yield formation of flax, and had a positive interaction effect between them. The contribution of phosphorus to the seed yield of oilseed flax was greater than that of GA3. Phosphorus application alone significantly increased the 1000-grain weight and fruit number of flax. Spraying GA3 had a significant effect on the effective capsule number and 1000-grain weight, and the interaction between phosphorus and GA3 significantly increased the seed yield of flax. Dry matter accumulation and yield of flax increased with the increasing GA3 concentration at 0 and 67.5 kg P2O5·hm-2. Spraying 15 mg·L-1 GA3 at the phosphorus level of 135 kg P2O5·hm-2 had the highest average dry matter growth rate, which was significantly increased by 55.51% compared with the treatment without fertilizer and hormone. The dry matter accumulation after anthesis and its contribution to grains was increased by 58.69% and 139.32% （2019）, 52.23% and 25.10% （2020）, respectively. The dry matter accumulation and yield reached the maximum, which were significantly higher than the P0G0 treatment by 55.51% and 17.25% on average. Our results showed that the interaction of phosphate and exogenous hormones promoted the dry matter accumulation and the contribution rate of seed at post-anthesis, increased the 1000-grain weight and fruit number, and then the grain yield of flax increased. It was determined that phosphorus application 109.35-111.26 kg·hm-2 combined with 22.37-23.08 mg·L-1 GA3 spraying might be a suitable high-yield cultivation technique in dry farming areas.
The aim of this study was to understand the effects of potassium (K) and silicon (Si) fertilizers on main carbohydrate components content and lodging resistance characteristics of oil flax stalks, and to explore the regulatory mechanism of these two fertilizers on lodging resistance of flax stalks. Split plot design was used, with two varieties as main treatment, three potassium fertilizer dosage (K0: no potassium; K1: 52.5 kg K2O/hm2; K2: 105 kg K2O/hm2) as split-treatment, two silicon fertilizer dosage (Si0: no silicon; Si1: 90 kg SiO2/hm2) as sub-split treatment. The results showed that lodging resistance capability of oil flax stem mainly depended on both total carbohydrate (TC) content and proportion of non-structural carbohydrate (NSC). TC content, NSC proportion, the content of soluble sugar and starch were all significantly and positively correlated with breaking resistance and lodging resistance index. Potassium increased the content of stalk cellulose, lignin, soluble sugar, starch, TC and NSC percentage by 11.74-32.27%, 12.18-68.78%, 12.48-33.59%, 23.96-121.65%, 8.95-35.09% and 17.48-20.29% respectively, and increased lodging resistance index by 19.80-86.37%. Meanwhile, higher potassium had better increase effects. Silicon promoted cellulose, lignin and TC contents significantly. Content of structural carbohydrate (SC) was not affected by K-Si interaction. But NSC content was affected. NSC increased under higher K level without Si. Compared with K0Si0, K2Si0 and K1Si1 increased soluble sugar content by 38.08-46.15% and 21.60-40.83% respectively, and starch content by 56.13-176.54% and 50.00-61.41% respectively, and TC by 44.18-53.40% and 34.08-36.73% respectively. Higher K without Si, or lower K accompanied by Si could both improve the proportion of NSC and then enhanced lodging resistance. K application significantly increased grain yield, while Si fertilizer had no significant main effect on yield. Applying K alone had a significant effect on lodging resistance and yield increase. Combined positive interaction of K and Si to lodging resistance could be manifested only under low K condition.
In order to understand the effect of harvest time on seed quality of oil sunflower, the vitality related indexes and quality indexes of dried seeds derived from different harvest time (30, 35, 42, 47 days after flowering) of three oil sunflower cultivars (‘67×Zao R’, ‘36×Zao R’ and ‘Zaoshuaidatou’ ) were detected. The results showed that the seed vigor from ‘67×Zao R’ and ‘Zaoshuaidatou ’ was the highest harvested at 42 days after flowering than other harvest times. However, seed vigor reached the highest for ‘36×Zao R’ harvested at 47 days after flowering. Oleic acid content and oil content of oil sunflower kernels decreased with the later harvest, but linoleic acid content increased. Moreover, vigor and quality of three oil sunflower’s seeds （derived from different harvest time） were evaluated comprehensively by membership function method, it was showed that high-quality seeds could be obtained when delaying the harvest for about 7 days. Therefore, the time （days） after flowering can be used as a reference for sunflower harvest when planting in the areas of central and southern China. When the weather is suitable (without cloudy-rainy or high-humidity) or the stubble arrangement permits, sunflower could harvest lately, and its seed quality might be effectively improved if delay the harvest for about 1 week. This research was expected to provide reference for sunflower scientific harvesting and seed safe preservation in the areas of central and southern China.
Soybean is one of the most important legume crop and the main source of plant protein and edible oil for human beings. Soybean mosaic virus
Aspergillus flavus is an opportunistic pathogen of ascomycetes, which can causes diseases on several important agricultural crops, especially peanut and maize. This fungus has the potential to produce a toxic metabolite known as aflatoxin, with carcinogenic, teratogenic and mutagenic effects to humans. A. flavus infection and aflatoxin contamination occur not only during the growing season, but also in the process of harvesting, drying, storage and transportation, which has a great impact on the safety of agricultural products and human health. Therefore, it is of great significance to analyze the infection process and molecular mechanism of A. flavus on grain and oil crops, which is benefit for resistant varieties breeding, the early warning and source control of aflatoxin contamination. This review summarized the infective process and molecular mechanism of A. flavus in peanut and maize, focusing on infection cycle, colonization site, infection process, influencing factors and infection mechanism of A. flavus. The purpose is to provide theoretical support for the prevention and control of aflatoxin contamination in agricultural products.
Nanobodies are a class of naturally deficient light chain of heavy chain antibodies produced by camelid bodies. Compared with traditional monoclonal antibodies and polyclonal antibodies, they have the advantages of small size, excellent thermal stability, high organic solvent tolerance, reversible foldability, easy expression, high affinity and specific recognition of unique epitopes. Therefore, nanobodies have attracted much attention in the fields of biology and agriculture. This article reviewed the structure, biochemical characteristics and the current research status in the field of agricultural mycotoxin detection of nanobodies, and prospects for the development prospects of nanobodies in the detection of mycotoxins in the agricultural products.
Riptortus pedestris is an important pest in soybean production. For further understanding the population dynamics, forecasting and formulating integrated pest management for R. pedestris in soybean fields, fecundity and population development of R. pedestris, biological parameters of viability and fertility were systematically observed using pod culture in vitro at a constant temperature of 24℃±1℃. The fecundity and population trend were further discussed through the analysis on life table of population. Results showed that the generation duration of R. pedestris fed on soybean pods lasted 54.69 d. The average adult life span was 49.18 d, and life spans of male and female adults were 46.26 d and 52.75 d respectively. The average pre-oviposition duration of R. pedestris was 6.60 d. The average oviposition duration was 36.97 d. The average fecundity per female was 116.62. The trends accorded with model of Logistic regression and exponential function. And its daily cumulative fecundity trends accorded with the model of exponential function and trinomial regression. The fecundity trends of female adults showed a skewed distribution. Fifty percent of fecundity were concentrated in the first 25% of the spawning period. The life table analysis showed that intrinsic growth rate (rm ) was 0.0717, net value-added rate (R0 ) was 50.53, finite rate (λ) was 1.07 d-1, population doubling time was 9.66 d, and population trend index was 48.07. Therefore, the fresh soybean pods in vitro could fully meet the nutritional needs of the individual development of R. pedestris, and the pod during podding stage could be a main source of nutrition for R. pedestris population in fields.
