To thoroughly examine the current status and challenges of peanut variety registration and application in China, and to support the breeding, registration, and promotion of peanut varieties, this paper provides a systematic analysis of the quantity, quality, resistance, and particularly the promotion and application of registered peanut varieties since the implementation of the non-main crops variety registration system in 2017. The results indicate that from 2017 to 2023, China has had an ample number of registered peanut varieties. The registration of these varieties is primarily led by research institutions, with varieties from major production regions dominating the registry, the Virginia and Spanish botanical types are predominant. Moreover, the number and proportion of high-quality varieties have been continuously increasing. In terms of the promotion and application of varieties, the currently leading varieties in production are mostly those that were previously released and have been re-registered. The newly developed and registered varieties are being accelerated in their promotion, and the primary regions for large-scale cultivation varieties highly coincide with the provinces where the breeding institutions are located. At present, there are still some prominent problems in the registration and promotion of varieties: Firstly, among the registered varieties, there are few specialized types suitable for fresh consumption or special processing purposes such as peanut butter production, and there is a lack of varieties suitable for mechanized production, resistant to soil-borne diseases, tolerant to saline-alkali conditions, and cold-resistant. Secondly, from the perspective of variety registration management, the application materials for some variety registrations are not standardized, and there is insufficient follow-up evaluation and supervision after registration. Thirdly, there are not many varieties with wide adaptability that can be promoted cross provincial borders. To address these issues, the following recommendations are proposed: Firstly, intensify innovation and research on peanut breeding for important traits, such as multi-resistant, suitable for mechanization, salt alkali resistant, cold resistant and other specialized varieties. Secondly, include the descriptions of important traits such as resistance to stem rot disease and pod rot disease, as well as specialized utilization when registering varieties. Thirdly, strengthen the linkage between the variety registration system and the variety protection system to enhance the protection of intellectual property rights in the seed industry. Finally, increase the promotion of excellent varieties, facilitate the widespread application of breakthrough superior varieties across the country, and contribute to increase yield and efficiency.
Excessive intake of very-long-chain saturated fats will affect human health.To better understand the genetic basis of peanut very-long-chain fatty acids (VLCFAs) and to improve peanut quality, correlation sites of peanut VLCFAs were explored. 390 peanut natural population germplasm resources were used to statistically analyze the contents of peanut VLCFAs in two years. A total of 18 sites related to VLCFAs content were detected by genome-wide association analysis using the mixed-model analysis (PCA+K model) in GAPIT3.0 software. Combined with peanut genome information, one significant association locus (A02_ 98650666) was found. And eggNOG-Mappe was also used to predict candidate genes and gene expression analysis. 6 candidate genes were predicted: Ahy_A02g009062, Ahy_A02g009064, Ahy_A02g009065, Ahy_A02g009066, Ahy_A02g009067, and Ahy_ A02g009069. Both Ahy_A02g009064 and Ahy_A02g009065 encoded proteins belonging to AP2 family, and both were expressed during peanut pods development.
Ralstonia solanacearum utilizes its type III secretion system to inject effector proteins into host cells, inhibiting the host's immune response or disrupting normal cellular functions, thereby causing disease. Previous studies have demonstrated that overexpressing the RipTAL gene in Nicotiana benthamiana, an effector from peanut Ralstonia solanacearum, significantly enhanced the resistance level to R. solanacearum. To further investigate the interaction mechanism between peanut and R. solanacearum mediated by the RipTAL effector protein, a normalized library of peanut root tissues induced by R. solanacearum was constructed. The candidate host target proteins interacted with RipTAL were screened using yeast two-hybrid technology. Functional annotation showed that these genes mainly involved post-translational modification, translation, ribosome structure, and biogenesis, amino acid transport and metabolism. the expression of these genes in resistant and susceptible peanut varieties induced by Phytophthora infestans, and the expression characteristics of these genes induced by different exogenous hormones. The expression patterns of these genes in different tissues and organs were elucidated based on RNA-seq analysis. Additionally, their expression level induced by R. solanacearum in resistant and susceptible peanut varieties, as well as induced by different exogenous hormones, were also investigated. Two candidate interacting proteins NPR5 and TIFY 10b, were identified using one-to-one yeast two-hybrid verification, and both of them were found to interact with RipTAL..
Off-target effects of CRISPR/Cas9 system have long been an important issue that concerns researchers. Off-target editing might be reduced among regenerated edited plants when Cas9 is driven by a callus-specific promoter. For effective reduction, we cloned a rice callus-specific promoter P OsCSPpro and investigated its expression activity and base editing efficiency in peanut callus. GUS histochemical staining revealed that P OsCSPpro was active in peanut callus. The 190th amino acid P190 encoded by AhALS2 was chosen as the target site and a base editor with its cytosine deaminase and nCas9 driven by P OsCSPpro was constructed. The base editor was transformed into peanut to determine the editing efficiency. Result showed that P OsCSPpro drove cytosine base editor and achieved 3.6% editing efficiency in peanut.
In order to reduce farmland pollution and to improve peanut nitrogen use efficiency, yield and economic benefits, we clarified the effect of nitrogen (N) reduction on peanut nitrogen accumulation and yield. 5 N nitogen levels were set up as 82.5 kg·hm-2 (normal N in Shenyang, T1), 70 kg·hm-2 (reduced N by 15%, T2), 62 kg·hm-2 (reduced N by 25%, T3), 54 kg·hm-2 (N reduced by 35%, T4), blank N (T0, CK). Peanut cultivar Qinghua 6 was used as material. Effect of N reduction on enzyme activity, N accumulation, N use efficiency and yield of peanut were investigated. The results showed that activities of arachidonic nitrate reductase and glutamine syntheses were peaked when N was reduced by 15%, which were 35.74 μg·g-1·h-1, 13.75 μg·g-1·h-1 (2019), and 36.39 μg·g-1·h-1, 15.06 μg·g-1·h-1 (2020) at seedling stage, respectively. When N was reduced by 15%, the N accumulation, N utilization rate and N agronomic utilization rate of peanut plants were higher than those of other treatments, which were 1234.91 mg·plant-1, 41.61%, 3.66 kg·kg-1 (2019) and 1649.61 mg·plant-1, 32.34%, 6.26 kg·kg-1 (2020), respectively. And those 3 indexes showed a decreasing trend compared with increase of N reduction, but N partial productivity increased. Moreover, peanut yield, full fruit number per plant, full fruit weight per plant and 100 fruit weight reached summit, with yield of 4369.58 kg·hm-2 (2019) and 4851.34 kg·hm-2 (2020), respectively. Yield and yield-related indexes showed downward trend with continuously N reduction. Considering N accumulation, utilization efficiency and peanut yield, it was suitable to promote N reduction by 15% in field, that is, 70 kg·hm-2.
To comprehensively analyze transcription factor regulatory network during peanut seeds development, this study first measured phenotypic data of seeds and pods at 3 different developmental stages (5 d, 25 d, and 45 d) after fruit needle entered to soil. Subsequently, transcriptome sequencing was performed for gene expression analysis, identifying a total of 71 044 expressed genes, of which 5198 were newly identified transcripts. The study identified 5159 (25 vs 5), 7714 (45 vs 5), and 1712 (45 vs 25) differentially expressed genes at the 3 different developmental stages. Differential genes were studied by analyzing their involvements on biological metabolic pathways. Results showed that the most metabolic pathways focused on 25 d-seeds after fruit needle entering the soil. When 45 d after needle entering, the number of metabolic pathways decreased, but oil synthesis was becoming dominant. Based on differential gene profile, 544 transcription factors were screened, and a transcriptional regulatory network was constructed, which was mainly involved in important pathways related to seed development, such as plant hormone signal transduction, circadian rhythm regulation, and MAPK signaling pathways. Further research showed that 18 transcription factors were specifically highly expressed in seeds, and were positively correlated with developmental rate of the seeds in terms of oil accumulation-related transcription factors family ABI, NFYB, and WRI, which were verified by qPCR.
In order to accurately comprehend the karyotype characteristics of wild species, make full use of favorable protein traits to create valuable germplasm resources and select new varieties, karyotypes of 26 wild species were established and studied. Chromosome patterns showed that karyotypes of 20 wild species were consistent with their genome classification, and 6 were inconsistent, indicating that some wild species might have made mistakes in the process of classification or introduction and reproduction. Based on accurate karyotype classification of wild species, the content of protein and amino acid components in seed kernel was detected by chemical analysis, and the potential analysis, correlation analysis, stepwise regression analysis and cluster analysis were carried out. Results showed that tyrosine （Tyr） had the highest improvement potential, reaching 37.51%. Coefficient of variation of protein content in different wild seeds was 11.87%, and coefficient of variation of 16 amino acid components ranged from 10.65% to 18.59%. Protein content was significantly positively correlated with various amino acid components. Arginine （Arg）, methionine （Met）, serine （Ser） and lysine （Lys） could effectively increase the protein content. In addition, 26 wild species were divided into 3 groups according to the content of protein and amino acid components. These results indicated that wild species possess considerable utilization value with regards to their protein and amino acid composition.
To improve the utilization efficiency of peanut germplasm resources resistant to bacterial wilt, we utilized 19 phenotypic traits and constructed applied core collection based on diversity evaluation of 149 peanut resources resistant to bacterial wilt. Through cluster analysis, 149 materials were divided into 5 subgroups, and core collection containing 37 peanuts was constructed using the method of "multiple cluster priority sampling method+ 25% sampling proportion+ euclidean distance+ single distance". Mean difference percentage, variance difference percentage, conformity rate of range, and variation rate in coefficient of variation were 0%, 52.63%, 100%, and 125.77%, respectively. The principal component distribution map showed that the core collection was evenly distributed among the entire collection, significantly reducing genetic redundancy. These results indicated that the core collection constructed in this study, which contains 37 germplasm, represented the phenotypic variation characteristics of the entire collection. These 37 materials included germplasm with large pod, high oil content, and resistance to other diseases, as well as commercial varieties such as Zhonghua 6 and Yuanza 9102, with excellent comprehensive traits and large-scale application in production.
To clarify genetic diversity and characteristics of local peanut germplasm resources in Guizhou, we systematically analyzed 11 agronomic traits and 9 quality traits of 108 accessions collected in Guizhou Province from 2017 to 2022 in the Third National Survey and Collection of Crop Germplasm Resources Expand. Genetic diversity, correlation, principal components and clustering were used as methods. Results showed that the tested peanut resources showed significant genetic diversity, among which the coefficient of variation of yield (fresh weight) per hectare was the highest (49.633%), fat content variation was the lowest (3.47%), and aspartic acid had the highest genetic diversity index of 2.08. Correlation analysis showed that productivity per plant had significant positive correlation with the total number of branches, the number of fruiting branches and the yield per hectare (fresh weight) respectively. Principal component analysis showed that protein content, branching characteristics, kernel quality, overall quality and yield could explain 73.10% trait information of the tested germplasm. Based on the comprehensive F-value assessment, 13 materials with F-value larger than 1 could be used as potentially important germplasm resources. The 108 peanuts were divided into 3 groups by clustering analysis, and the characteristics of each group were distinct. Among them, group II was particularly prominent in terms of comprehensive performance, and were regarded as high-quality candidate parental material and genetic resources. This study revealed the genetic diversity and correlation of agronomic traits and quality traits of 108 peanut resources in Guizhou, and screened 12 specific resources, such as Niuchang local peanut, which might lay a material foundation for future breeding.
To provide candidate gene for molecular breeding of herbicide resistant peanut, 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene AhEPSPS, predicted target of herbicide glyphosate in peanut was studied. Two peanut AhEPSPS genes and their full-length CDS were cloned, named as AhEPSPS1 and AhEPSPS2. In order to investigate their biological function, especially in response to glyphosate, the expressions of AhEPSPS1 and AhEPSPS2 in different tissues and peanut leaves under glyphosate treatment were analyzed. Their bioinformatics analysis, subcellular localization and real-time fluorescence quantitative detection (qRT-PCR) were carried out. Results showed that both full-length of AhEPSPS1 and AhEPSPS2 were 1581 bp and encoding 526 amino acids proteins with a molecular mass of 55.9 kDa and isoelectric point of 6.80. Phylogenetic analysis suggested that AhEPSPS was highly homologous to GmEPSPS. Bioinformatics protein subcellular localization prediction and transient expression analysis in epidermal cells of tobacco leaves demonstrated two types of AhEPSPS were localized in chloroplasts. Tissue expression results indicated that AhEPSPS1 and AhEPSPS2 were constitutively expressed in roots, stems and leaves, and the expression level showed an order of stems > leaves > roots in AhEPSPS2. In addition, 1% glyphosate could induce the expressions of both AhEPSPS1 and AhEPSPS2, and exhibit a pattern of first decreasing, then increasing changes, indicating that AhEPSPS1 and AhEPSPS2 could response to glyphosate phytotoxicity with dynamic transcriptional.
In order to determine optimal reduction of nitrogen fertilizer under peanut alternative sowing on small ridge with narrow two-rows, 4 different nitrogen fertilizer treatments were set up with cultivar Qinghua 6 as material. The treatments included CK (pure nitrogen 82.5 kg·hm-2, conventional nitrogen application), T1 (pure nitrogen 70 kg·hm-2, nitrogen reduction 15%), T2 (pure nitrogen 62 kg·hm-2, nitrogen reduction 25%), T3 (pure nitrogen 54 kg·hm-2, nitrogen reduction 35%). Effects of nitrogen fertilizer reduction on photosynthetic characteristics and yield of peanut were studied. Two-year experiments showed that with nitrogen fertilizer reduction accentuated, leaf area, main stem height, and dry matter accumulation of peanut first increased and then decreased, and their corresponding indices in T2 and T3 treatments were significantly lower than those in T1 treatment. Chlorophyll content, net photosynthetic rate, transpiration rate, and stomatal conductance also increased firstly and then decreased with the nitrogen reduction, and among them, T1 treatment was aggravated. Intercellular CO2 concentration in leaves decreased firstly and then increased with the reduction, with bottom value in T1 treatment and peak value in T3 treatment. Number of full pods per plant, full pods weight per plant, 100-pod weight, and 100-kernel weight increased firstly and then decreased with the decrease of nitrogen fertilizer application rate, and yield reached peak in T1 treatment with 4369.58 kg·hm-2 and 4851.34 kg·hm-2 in two years, respectively, which was significantly higher than those in CK, T2 and T3 treatments by 2.19%, 3.28%, 4.17% (2019) and 2.07%, 2.17% and 6.61% (2020), respectively. No significant difference was found between treatments and CK, and T3 was significantly lower than T1 (2019). In summary, appropriate cutting off nitrogen fertilizer (pure nitrogen 62-70 kg·hm-2) could optimize peanut growth, increase chlorophyll content, improve photosynthesis ability, and promote dry matter accumulation in various organs without affecting yield.
Soil in southern China has undergone acidification and calcium depletion due to excessive rainfall and unreasonable fertilization, which seriously affects peanut production. Calcium and ARC biological agents effects were explored on nitrogen and calcium nutrients and peanut yield, by using Xianghua 522, a major peanut cultivar in Hunan. We set 2 calcium hydroxide levels, 0 kg/hm2 (Ca0) and 750 kg/hm2 (Ca50), and 3 levels of ARC microbial agent, 0 kg/hm2 (A0), 30 kg/hm2 (A2), and 60 kg/hm2 (A4), totally 6 treatment combinations in pot experiment. With Ca0A0 as control, contents of nitrogen and calcium elements in various plant organs were determined during the main growth stages of peanut. Accumulation and distribution of the 2 nutrient as well as yield traits were analyzed. Results indicated that: accumulations of nitrogen and calcium of Ca0A2 were generally higher than those of the control in all stages, while nitrogen accumulations in leaves, stems, and roots of Ca0A4 were only higher than those of the control during flowering-peging stage. Application of calcium and its combined application with ARC could generally increase nitrogen accumulation, calcium content and accumulation in peanut organs. Average nitrogen accumulation in roots of each treatment was significantly increased by 32.53% to 44.71% compared with the control during flowering-peging stage, podding stage and mature stage. Calcium accumulation in leaves, roots and pods average increased significantly by 25.54% to 52.27% compared with control at mature stage. In the later growth stages, both the nitrogen accumulation in roots and the calcium accumulation in pods were manifested as Ca50A4 > Ca50A2 > Ca50A0. Single application of ARC microbial agent could increase the distribution rate of nitrogen in roots at all periods, among which Ca0A2 and Ca0A4 in seedling stage and Ca0A4 in pod-filling stage reached significant levels. The distribution rate of calcium in roots during podding stage significantly increased in Ca0A4, Ca50A2, and Ca50A4 compared with the control. The distribution rate of calcium in pods significantly increased in Ca0A4 compared with the control during mature stage. Both the application of calcium and ARC microbial agent could increase pod yields to varying degrees, and the combined application had a better yield-increasing effect than single application. Ca50A4 treatment had the highest yield, with a significant increase of 12.29% compared with the control. In conclusion, calcium fertilizer, ARC microbial agent, and their combination have favorable promoting effect on yield, nitrogen nutrition, and calcium nutrition. Combination of 750 kg/hm2 calcium fertilizer and 60 kg/hm2 ARC microbial agent had the best yield-increasing effect, which could be regarded as an important measure for the green, high-yield, and efficient cultivation of peanut.
Peanut southern blight is a serious soil-borne fungal disease caused by Sclerotium rolfsii Sacc. To efficiently utilize resources of Trichoderma to control peanut southern blight, we screened 2 Trichoderma strains with strong antagonistic ability against S. rolfsii, namely, T. harzianum X51 and T. asperellum X125, with the efficacies of 63.04% and 91.30% against peanut southern blight respectively, through the dual culture method, isolated leaf efficacy experiment and pot experiment. Further studies showed that both strains of Trichoderma were able to produce bacteriostatic non-volatile metabolites that inhibited growth of mycelium of S. rolfsii and had a growth-promoting effect on peanut plants, which showed important development and application potential.
To improve both yields of wheat and peanut, effect of nitrogen (N) fertilizer moving-forward to the previous crop wheat was studied on photosynthetic characteristics and peanut yield under fixed N application rate. Wheat cultivar Jimai 22 and peanut cultivar Huayu 22 were used as materials. Five treatments were established in field, including T1 (nitrogen fertilizer moving forward was 0), T2 (15% forward to wheat jointing stage for topdressing), T3 (30% forward displacement), T4 (45% forward shift), and T5 (60% forward shift). Results showed that the appropriate proportion of N fertilizer was helpful to improve root activity and photosynthetic characteristics of peanut and make the plant grow robust. Among them, the increase in T3 was the most significant. Compared with T1, root activity, SPAD value and leaf area index at pod-setting stage increased by 27.17%, 6.32% and 14.28%, respectively; net photosynthetic rate, stomatal conductance and transpiration rate increased by 6.61%, 10.34% and 8.05%, respectively; intercellular CO2 concentration decreased by 4.19%; dry matter accumulation and full fruit number per plant; 100 fruit weight and 100 kernel weight increased significantly. Thus the pod yield increased by 27.38% compared with T1. However, too high forward ratio might cause peanut to fertilizer deficient at the later stage, resulting in plant dysplasia and yield lose. For example, the pod yield of T5 was 18.54% lower than that of T1. In addition, different proportions of N fertilizer could increase wheat yield, and yields from T2, T3, T4 and T5 increased by 8.94%, 12.50%, 12.74% and 12.86% respectively compared with T1. But no significant difference among treatments was found. Therefore, under the present conditions, the appropriate proportion of N fertilizer forward could increase peanut pods yield. Among them, 30% N fertilizer forward could achieve better photosynthetic characteristics of peanuts and obtain high yield of both wheat and peanut.
Peanut is an important oil and cash crop in China. In recent years, stem rot caused by Sclerotium rolfsii, has become one of the most important soil-borne diseases of peanut. Biological control is an effective measure to manage plant soil-borne diseases. In order to explore the biocontrol agent with inhibitory effect on the Sclerotium rolfsii highly virulent strain ZY2, bacteria were isolated from the roots and stems of peanuts in this study. Ten bacterial strains with obvious inhibitory effect on ZY2 were obtained by quantitative plate confrontation assay, and the inhibition rate ranged from 66% to 81%. The control effect of ZS5-1 strain to S. rolfsii ZY2 was 60.72% in the pot test, and was 33.73% in the field test. The bacterial strain ZS5-1 was identified as Bacillus velezensis by morphological, physiological, biochemical and sequence determination. ZS5-1 could induce ZY2 mycelium shorter, twisting and tangling, apical enlargement and protoplasma degradation by microscope and electron transmission microscope observation. ZS5-1 could produce protease, amylase, pectinase, cellulase and xylanase, but did not produce chitinase. The results of this study can provide an elite bacterial resource for the management of peanut stem rot.
To improve soil quality and land productivity, effects of peanut rotation patterns on soil organic carbon components, carbon mineralization and carbon sequestration were investigated. Based on 2 initial plots of paddy field and dry field, 2 rotation patterns of wheat-peanut and rapeseed peanut were set up, with winter idle field and spring peanut as control. Totally, 6 traits were in 0-20 cm and 20-40 cm soil layers were investigated through a 4-year localization experiment in Huanggang, Hubei Province. The traits included TOC (total organic carbon), DOC (dissolved organic carbon), MBC (microbial biomass carbon), AMC (accumulated mineralized carbon), organic carbon retention, and CSR (carbon retention rate) under different peanut rotation patterns. Results showed that TOC, DOC, MBC, mineralization rate and AMC in 0-20 cm soil layer were higher than those in 20-40 cm soil layer under 2 starting fields. At the beginning of paddy field, TOC content in rotation of peanut and oilseed rape Brassica napus was significantly higher than that in wheat-peanut rotation mode, and TOC content in 20-40 cm soil layer was 36.34% higher than that in wheat-peanut rotation mode. Compared with rapeseed-peanut rotation mode, MBC content in the soil of winter-spring peanut planting mode was increased by 60.57%. Under 2 starting fields, rapeseed and peanut rotation showed higher carbon mineralization, among which, under paddy field, AMC was significantly increased by 11.86% and 6.85% compared with wheat-peanut and winter-idle field-spring peanut, respectively. In paddy field and dry land, CSR of rapeseed and peanut rotation was 137.66% and 58.51% higher than that of wheat and peanut rotation, respectively. Multi-factor analysis showed that soil depth and planting mode had significant effects on TOC, DOC, MBC and AMC, and soil organic carbon sequestration rate was significantly affected by the initial plot and planting mode. Rapeseed-peanut rotation had higher organic carbon sequestration rate and active carbon content such as DOC and AMC, which was more conducive to promoting soil organic carbon sequestration and improving soil quality.
For high-yield and efficient cultivation of peanut in Fujian Province, application effects of ARC (aflatoxin rhizobia couple) microbial agents combined with nitrogen (N) fertilizer on peanut yield were investigated in field trial. A new red-skin and high-protein cultivar Quanhonghua 1 was used as material. N fertilizer doses effects were observed on peanut agronomic traits, quality, and yield by setting up reduced-N fertilizer and ARC microbial agents. Results indicated that ARC microbial agents promoted nodulation and early nodulation, thus promoted peanut growth. Significant differences were found in agronomic traits of peanuts among different treatment groups, with the highest total number of branches per plant and the highest number of fruiting branches per plant in treatment T3 (basal fertilizer with a 30% reduction in N combined with ARC microbial agents). The total number of fruits per plant and number of full fruits were the highest in treatment T0 (using ARC microbial agents without reducing N in base fertilizer). The treatment of T4 (basal fertilizer with a 40% reduction in N combined with ARC microbial agents) was the heaviest in terms of fruit weight. The full fruit rate of each treatment with ARC agent was higher than control. The protein content was the highest in T1 treatment (basal fertilizer with a 10% reduction in N combined with ARC microbial agents), reaching 32.59%. Overall analysis showed that the treatment of reducing 30% nitrogen fertilizer and 40% nitrogen fertilizer, combined with the application of ARC microbial agent, had better effect and better planting economic benefits. Compared with the control, the pod yield has significantly increased, with an increase of 17.53% and 16.33%, respectively. The application of microbial agents to reduce nitrogen fertilizer is an effective measure to increase peanut yield and economy in Fujian Province. This study can provide theoretical basis for high-yield and efficient cultivation of peanuts and scientific and rational fertilization in Fujian Province.
To reveal the physiological mechanisms of peanut seedlings adapting to cold, drought, and combined stresses, this study used tolerant varieties NH5, HY22 and sensitive varieties NH16 and HY20 as test materials. Artificial climate chamber simulation experiments were used to analyze the effects of cold, drought and combined stresses on the growth and physiological characteristics of peanut seedlings. The results showed that under stress conditions, the plant height, leaf area, fresh weight of aboveground and underground parts, dry weight of aboveground and underground parts and root vitality of each variety significantly decreased. The overall degree of inhibition on the growth of peanut seedlings showed composite stress>cold stress>drought stresses, with cold being the direct dominant factor inhibiting the growth of peanut seedlings, especially affecting the growth of aboveground parts. Drought mainly affects the growth of peanut seedlings by accelerating water loss and reducing root vitality; The content of malonaldehyde (MDA), superoxide anion (O2 -), and H2O2 (superoxide dismutase) in peanut seedlings shows a continuous increasing trend, with an overall increase in composite stress>single stress. The content of MDA and O2 - is more affected by drought than other stresses, and the content of H2O2 is more affected by cold than others; The activities of superoxide dismutase, peroxidase and catalase all showed a trend of first increasing and then decreasing. The duration of the upward trend was tolerant varieties>sensitive varieties, and the amplitude of the increase was single stress>compound stress. Among them, catalase activity was more affected by cold than other stresses, superoxide dismutase activity was more affected by drought than others, and peroxidase activity was more affected by compound stress than others; The results of principal component analysis showed that the contents of MDA, O2-, and H2O2 were significantly negatively correlated with the growth indicators of peanut seedlings, while CAT activity was significantly positively correlated with the growth indicators of peanut seedlings, which can be used as evaluation indicators for identifying stress resistance in peanut seedlings.
To clarify the effect of rapeseed/wheat peanut rotation, the problem of soil quality decline and peanut continuous cropping obstacles caused by the wheat corn rotations in Yellow River Basin has been addressed, a long-term field experiment was carried out to study the effects on the yield, disease occurrence, and soil quality of different rapeseed/wheat peanut rotations. The results indicated that after 7-years of crop rotation, the incidence rate and incidence index of sclerotinia sclerotiorum were significantly reduced by 61.2% -76.5% and 69.4% -81.6% under rapeseed/wheat peanut rotations, respectively. The incidence rate of peanut pod rot under rapeseed-peanut (R-P) was significantly reduced by 46.47% -57.82%, and the disease index was reduced by 48.98% -70.48%, compared with wheat-peanut (W-P). The incidence rate and disease index of peanut pod rot in rapeseed/wheat intercropping were between R-P and W-P. Both sclerotinia sclerotiorum and peanut pod rot have a trend of decreasing gradually with rotation years. Rapeseed yield in rapeseed/wheat-peanut rotation pattern was significantly improved with an increase of 0.93% -15.79%, and which was mainly due to significant increase of effective pods number. Compared with wheat followed by peanut cultivation, peanut yield after rapeseed cultivation has a significant increase, and with the rotation years, peanut yield shows a gradually increasing trend. Soil organic matter and available NPK nutrient increased significantly under different rotation patterns, with an increase of 22.08% -47.05%, 45.5% -88.1%, 91.2% -224.0%, and 8.8% -35.5%, respectively. Among them, the increase of available P nutrient was even greater under R-P, with an increase of 224.0%. Therefore, the rapeseed/wheat-peanut rotations pattern is beneficial for increasing the yield of rapeseed and peanuts in Yellow River Basin, and controlling sclerotinia sclerotiorum and peanut pod rot, and improving cultivated land quality.
Screening peanut genotypes with high yield and high nodulation efficiency suitable for Northeast China is of great significance for improving nitrogen (N) fixation efficiency and promoting peanut production under green development. In this study, 120 peanut germplasm suitable for Northeast China were classified according to their yield and nodule capacity. Characteristics of peanut nodules, nodule structure, dry matter accumulation and distribution, N accumulation and distribution, and N efficiency were measured. Differences in physiological characteristics among peanut genotypes with different yield and nodule capacity were analyzed. Results indicated that based on two years’ field investigation, 120 germplasm could be classified into 4 types: high yield and high nodulation efficiency type (HYHN), high yield and low nodulation efficiency type (HYLN), low yield and high nodulation efficiency type (LYHN) and low yield and low nodulation efficiency type (LYLN). Among them, 4 representative genotypes were selected, including Nonghua 12 (HYHN), Shuangying 8 (HYLN), Tangyou 4 (LYHN) and Jinhua 28 (LYLN). As the both high-yield and high-nodulation efficiency genotype, Nonghua 12 had significantly more nodule, as well as high nodule fresh weight, high nodule urea content and more leghemoglobin content than other 3 genotypes under no N fertilizer application, and ite nodule N-fixation area increased, which showed stronger N fixation ability. Moreover, Nonghua 12 improved dry matter and N accumulation to pods and root distribution rate to improve N efficiency, which was conducive to yield formation. In summary, HYHN peanuts we selected suitable for planting in Northeast China, and it was founded that due to their strong ability of N absorption and assimilation, they had obvious advantage of N fixation and yield potential.
To investigate the differences in flowering peg formation and pod setting habits of peanuts with extreme flowering period traits and their correlation with yield, the experiment selected 4 peanut varieties (DL123 and Anhua Hongpi Xiaozi with redundant flowering period, Huayu 9130 and Tianfu 22 with concentrated flowering period) as materials. Study focused on flowering period, flowering dynamics, peg formation, pod setting performance, and their correlation with yield. Results showed that: for the redundancy varieties, their durations to 10%, 50%, 70% and 100% flowering were significantly earlier than the concentrated types, and the durations to 90% flower cessation was very late than the latter. The average flowering duration of redundant varieties was 85.5 d, the average low effective flowering duration was 82.2 d, and the average low effective flowering duration rate was 96.06%, which were significantly higher than those of concentrated varieties. The average number of high-position-flowers per plant was 96.90, high-position-flowers rate was 66.06%, high-position-pegs were 50.72, and high-position-pegs rate was 59.49% of the redundant types, which were significantly higher than the concentrated types at respectively 37.09, 27.87%, 29.28, and 40.45%. Both amount and rate of high-position-pods were significantly lower than those of the concentrated types. Average 52.31% of the high-position-flowers formed into pegs in the redundant types, with 21.06% of the total flowers into pods, 2.95% high-position-flowers into pods, 36.71% total pegs into pods, 5.69% high-position-pegs into pods, 14.14% effective flower rate, and 24.87% effective peg rate. These data were significantly lower than the concentrated types. Total number of pods per plant was significantly negatively correlated with durations to 90% flower cessation, flowering duration, and low effective flowering duration. It exhibited negative correlation with high-position-flowers rate, high-position-pegs, and high-position-pegs rate. Yield per plant was significantly negatively correlated with the durations to 90% flower cessation, flowering duration, low effective flowering duration, and number of high-position-flowers, and was significantly positively correlated with duration to 100% flowering. In summary, spatial and temporal redundancy of the three sinks of flowers, pegs, and fruits severely affects pod setting performance and individual plant yield, especially in redundant types. In contrast, varieties with concentrated flowering, a moderate number of flowers, and low position-pegs exhibit elite sink capabilities.
Drought stress during pegging stage seriously affects peanut yield and quality. To accurately reflect comprehensive drought resistance of different genotypes of peanut, 27 cultivars were selected and investigated. Their net photosynthetic rate, SPAD value, water use efficiency (WUE), 100-pod weight, 100-seed weight, pod per plant, and shelling percentage were investigated under 3 conditions/environments, including rain shelter, pot planting and hydroponics. Membership function method, principal component analysis, correlation analysis and systematic cluster analysis were used to evaluate drought resistance of the cultivars. Results showed that Pn of the stressed peanuts decreased by 1.0%-92.6%, while Gs by 0.9%-67.9%, Ci by 1%-42.8%, Tr by 0.5%-82.7%, and SPAD by 1.3%-14.7% respectively. The WUE decreased by 0.4%-80.1%, while 100-pod weight by 2.3%-19.3%, 100-seed weight by 3.5%-36.8%, shelling percentage by 0.9 %-20.1%, yield per plant by 6.4%-63.1%, pod per plant by 5.4%-60.6%, full pods by 4.0%-78.6%, pods per kilogram increased by 1.4%-12.1%, respectively. The overall trend of both comprehensive drought resistance coefficient and D values of the selected material were consistent. Jinonghua 3 had the largest D value and the strongest drought resistance. Principal component analysis retained 88.96% of the information in the original variables through 4 factors. Thus the 27 cultivars were divided into 3 major categories according to their strength of drought resistance, intermediate type and drought sensitive type. In conclusion, D value could accurately reflect comprehensive drought resistance of different peanuts.
An analytical method for detecting the amount of tryptophan in peanuts was developed using enzyme hydrolysis coupled with high performance liquid chromatography-fluorescence. Peanut samples were hydrolyzed by Pronase and immediately diluted with pure water. Under gradient condition, the extract was separated by chromatography column C18 (4.6 mm×150 mm, 3 μm) and acetic acid solution (0.2%) - methanol. Tryptophan was quantified using fluorescence detector. The results indicated that a satisfactory linear equation Y=826.2178X+109.5198 was constructed ranging from 0.5 to 25 mg/g, and a satisfactory coefficient was achieved as 0.9998. The limit of detection and the limit of quantification were 0.14 mg/g and 0.46mg/g. The recoveries were ranged from 94.8% to 104.3%, and the relative standard deviations were less than 3.4%. The proposed method was performed under mild hydrolysis condition, time-saving and cost-effective, which could provide the accurate content of tryptophan in peanut and oilseeds.
A total of 100 single peanut seed samples from diverse geographical origins were scanned using two Fourier transform near-infrared (FT-NIR) spectrometers to collect spectral data. Reference sucrose content was determined by high-performance liquid chromatography (HPLC). Partial least squares (PLS) regression was used to construct a near-infrared (NIR) analysis model for sucrose content in single peanut kernels on each of the two NIR instruments, which after optimization demonstrated excellent performance with calibration coefficients of determination (R²cal) of 0.9637 and 0.9379, and root mean square errors of cross-validation (RMSECV) of 0.2840% and 0.4330% for Matrix-I and MPA instruments, respectively. External validation using an independent set of 40 samples confirmed model robustness, yielding prediction coefficients of determination (R²p) of 0.9842 and 0.9458, with corresponding root mean square errors of prediction (RMSEP) of 0.1485% and 0.5094%. These results meet the stringent criteria for excellent NIR calibration models. This study established predictive models suitable for different NIR instruments based on the same set of peanut samples with measured sucrose content data. These models, along with the team's existing models, will jointly support specialized peanut germplasm innovation and variety breeding.
In order to explore the application of infrared drying technology in peanut pods, this experiment took fresh peanut pods as materials, and investigated drying characteristics and moisture migration characteristics of pods under different infrared temperatures. Peanut pods were dried at a slow descending rate during infrared drying process. We found that when different infrared temperatures (30, 40, 50, 60, 70℃) were set, the time required to reach the safe moisture content was 25, 19, 14, 11, and 7 h. At the same time, pods moisture decreased, kernels’ hardness increased, and shells’ hardness showed a tendency of elevated-decreased-elevated. In addition, the infrared heating temperature had a significant effect on crude fat, L* value and a* value of kernels (P< 0.05). Rresults of low-field nuclear magnetic resonance showed that T2 relaxation peak migrated to the left overall during pod drying process. The dispersed water was dominated by free water, followed by weakly bound water. The higher the temperature, the more favorable it was to the increase of water migration rate. The simultaneous observation of the microstructure by scanning electron microscopy revealed that during the drying process, pore size of peanut surface contracted and their porosity increased, which contributed to impediment of water migration. Logarithmic model could better describe and predict relationship between moisture and drying time during pods infrared drying (R2= 0.9977). The Deff was 9.10×10-11- 3.12×10-10 m2/s. The coefficient increased with the increase of infrared temperature. Pods drying activation energy (Ea) was 25.91 kJ/mol.
