NetWork
Screening of Peanut Germplasms Tolerant to Low Calcium
LIANG Qi;WU Gongming;GAO Sheng;LUO Zinan;LI Lin;LIU Dengwang;YANG Zemao;ZENG Ningbo;Peanut is a calcium-preferring crop,and calcium deficiency is common in acidic soils,which severely affects the yield and quality of peanut.Breeding low-calcium-tolerant peanut varieties is an economic and efficient solution.In this study,170 peanut germplasms from domestic and foreign sources were used as experimental materials.A field experiment was conducted using a randomized complete block design with three replications in acidic low-calcium soil(pH 5.6,exchangeable calcium 3.9 cmol/kg) located in Liuyang City,Hunan Province,and the calcium oxide(CaO) was adopted as the calcium source.Two treatments were set up as:low calcium treatment(0 kg/ha) and normal calcium treatment(750 kg/ha).Twenty-five key traits,including plant morphology,physiological characteristics,yield components,and nutritional quality were determined from the seedling stage to the mature stage.Through correlation analysis,principal component analysis(PCA),cluster analysis,and comprehensive evaluation,it was aimed in this study to provide high-quality germplasm resources for the improvement of low-calcium-tolerant peanut varieties.The results are summarized as follows:(1)Correlation analysis showed that the low-calcium tolerance coefficient of pod yield per plant was extremely significantly and positively correlated with the low-calcium tolerance coefficients of full pod number per plant and total pod number per plant.(2)Principal component analysis revealed that 16 evaluation indices of low-calcium tolerance coefficients were reduced to 5 principal components,with a cumulative contribution rate of 77.21%.Based on the analysis of the contribution rate and eigenvector of each principal component,it was found that full kernel mass ratio,kernel-fruit ratio,100-pod mass,and total pod number per plant are the core factors influencing yield formation,while oil content is the key trait determining the quality.(3)The results of cluster analysis and comprehensive evaluation indicated that the 170 peanut germplasm resources were divided to 5 categories by 16 indicators through cluster analysis,and 20 peanut germplasm resources with excellent comprehensive traits were screened out.According to the D value,the resources were classified into 5 grades,resulting in the selection of 12 peanut germplasm resources with better low-calcium tolerance.
Effects of Calcium Application on Calcium Absorption and Utilization in High-Yield Peanut Cultivars with Different Seed Types
GAO Sheng;YIN Jianhui;YANG Zhixiang;TANG Daojian;WU Gongming;LIANG Qi;LIU Dengwang;YANG Zemao;LI Lin;Peanut is a typical calcium-preferring crop,and the widespread calcium deficiency in acidic red soils of southern China often results in empty and shriveled pods,thereby reducing yield.The calcium requirements of different seed-type highyield peanut varieties was investigated in this study to explore the customized fertilization strategies.Using Xianghei xiaoguo(V1),a popular edible-purpose small-seed peanut variety in Hunan,and Xianghua522(V2),a large-seed oil-purpose peanut variety,as test materials,a pot experiment was conducted under typical acidic and low-calcium red soil conditions(pH 5.27,soil exchangeable Ca 700 mg/kg),with calcium oxide as the fertilizer source.Three calcium oxide application levels were established as 0 kg/ha(Ca0),750 kg/ha(Ca50),and 1,125 kg/ha(Ca75),representing low(soil background),medium,and high calcium levels,respectively.Plant calcium accumulation,distribution,and utilization were assessed at key growth stages of the peanuts.The leaf calcium content(5.89—15.01 mg/g) and calcium distribution rate(69.89%—78.38 %) of V1 were significantly higher than those of V2(3.36—11.09 mg/g and 60.11 %—73.02%,respectively) throughout the whole growth period,and the calcium accumulation in leaves and the whole plant were also significantly higher than those of V2 after the pegging stage;the apparent utilization efficiency of calcium fertilizer(12.21%) was significantly higher than that of V2(8.85%).In contrast,under calcium application,the calcium distribution rate in shells(3.47%—6.87%),calcium accumulation in kernels(1.44—12.45 mg/plant),and calcium distribution rate in kernels(0.83%—4.84%) of V2 were significantly higher than those of V1(1.62%—5.00 %,0.88—8.05 mg/plant,and 0.43%—2.55%,respectively)throughout the whole growth period.Additionally,V2 exhibited significantly higher calcium pod production efficiency(142.65 g/g) and calcium pod harvest index(17.04%) than V1(86.82 g/g and 11.09 %).In terms of the effects of calcium application,it increased the calcium kernel production efficiency of V2,with the medium calcium treatment significantly increasing it by 20.62%,while V1 showed no significant change.The promoting effects on kernel calcium accumulation and distribution rate at the maturity stage were both greater for V2 than for V1,with kernel calcium accumulation and distribution rate increasing by 159.7 % and 101.3 % for V2,respectively,and 81.7% and 18.9% for V1,respectively.The decrease in the apparent utilization efficiency of calcium fertilizer with increasing calcium application rate was smaller for V2 than for V1.In summary,the two varieties differed in their calcium absorption and utilization strategies,but the difference in whole-plant calcium accumulation of both varieties between the medium and high calcium treatments was consistently small in this experiment,and the medium calcium treatment showed superior calcium utilization efficiency.Therefore,from an economic and efficiency standpoint,a calcium fertilizer application rate of 750 kg/ha is recommended for both varieties in the southern acidic and low-calcium red soil region of China.
The Effect of Layered Fertilization on Nutrient Absorption and Utilization of Peanut
ZHOU Chen;CHI Haorui;JI Wenxuan;ZHANG Caijun;SI Tong;ZOU Xiaoxia;Investigating the effects of layered fertilization on nutrient uptake and utilization of peanut can provide a theoretical basis for optimizing layered fertilization strategies and improving nutrient use efficiency.In this study,the commonly used conventional rotary tillage fertilization was adopted as the control(CK).Two layered fertilization modes,including a twolayer fertilization mode(10 and 25 cm) and a three-layer fertilization mode(10,15 and 25 cm),were established under the conventional fertilizer rate and a 10% reduced fertilizer rate,resulting in four treatments:two-layer fertilization without fertilizer reduction(T1),two-layer fertilization with a 10 % fertilizer reduction(T2),three-layer fertilization without fertilizer reduction(T3),and three-layer fertilization with a 10 % fertilizer reduction(T4).In the two-layer fertilization treatments,fertilizer was applied at a ratio of 1(10 cm):4(25 cm) to the two soil layers,whereas in the three-layer fertilization treatments,fertilizer was applied at a ratio of 1(10 cm):2(15 cm):2(25 cm) to the three soil layers.Dry matter accumulation,as well as the contents of nitrogen(N),phosphorus(P),potassium(K),and calcium(Ca) at major growth stages of peanut,were determined to evaluate the effects of layered fertilization on nutrient uptake and utilization.The results showed that,with the progression of plant growth,nutrient contents in vegetative organs such as stems,leaves,and roots of peanut first increased and then decreased,whereas nutrient content in shells gradually declined,which may be associated with the translocation of nutrients from shells to kernels.Compared with CK,kernel contents of N,P,K,and Ca at harvest stage were significantly higher under T1 and T3 treatments,with the greatest increases observed under T3,reaching 6.25%,30.58%,12.22%,and 5.48%,respectively.In addition,under T3 treatment,nutrient accumulation in stems,leaves,pegs,and pods at harvest stage was significantly higher than that in CK,and the total plant accumulation of N,P,K,and Ca increased significantly by 27.12%,56.44%,20.18%,and 17.06%,respectively.Under the same layered fertilization pattern,plant nutrient accumulation tended to decrease with reduced fertilizer application;however,total N and P accumulation in plant at harvest stage under T2 and T4 treatments remained significantly higher than that of CK,with increases of 13.60%-13.68% and 11.19%-21.42%,respectively.For all treatments,pods accounted for the highest proportion of N,P,and K accumulation,while Ca was mainly accumulated in leaves.Layered fertilization increased the allocation proportions of N and K to pods while reducing those in leaves,thereby promoting nutrient translocation to pods and laying a foundation for yield formation.Compared with CK,pod and kernel yields under layered fertilization treatments were significantly increased by 13.61%-23.08% and 16.20%-27.99 %,respectively.In conclusion,layered fertilization can improve nutrient content and accumulation in peanut plants.Considering both peanut yield and field mechanization efficiency,the two-layer fertilization mode is recommended for practical production.
Effects of Exogenous Melatonin on Growth and Physiological Characteristics of Peanut Seedlings and Roots under Salt Stress
WANG Jiaxin;HU Guoqing;WAN Yongshan;LIU Fengzhen;ZHANG Kun;LIU Zhaoxin;DONG Yuanjie;In order to explore the alleviation effects of exogenous melatonin(MT) on the growth of peanut seedlings and their roots under different salt concentration stress,the peanut cultivar Shanhua9 was taken as the test material,and five treatments were set up by nutrient solution culture method:CK(1/2 Hoagland nutrient solution);T1(1/2 Hoagland nutrient solution+150 mmol/L NaCl);T2(1/2 Hoagland nutrient solution+200 mmol/L NaCl);T3(1/2 Hoagland nutrient solution+ 150 mmol/L NaCl+15 μmol/L MT);T4(1/2 Hoagland nutrient solution+ 200 mmol/L NaCl+15 μmol/L MT).The growth,root activity,photosynthetic pigments,antioxidant system,osmotic adjustment substances and electrical conductivity of seedlings under different treatments were determined,and the correlation analysis between seedling growth and physiological indices was conducted to study the effects of exogenous MT on the growth and physiological characteristics of peanut seedlings under salt stress.The results showed that the application of exogenous MT significantly improved the growth and physiological indices of peanut seedlings under salt stress and effectively relieved the inhibitory effect of salt stress on peanut seedling growth.Among which, the MT exhibited stronger alleviating effect under high salt stress:Compared with T2,the plant height increased by 10.7%,fresh mass increased by 11.4%,root activity increased by 27.85%,chlorophyll a content increased by 19.58%.SOD activity increased by 21.97 %,while hydrogen peroxide content decreased by 17.13 % and the soluble protein content increased by 28.01% under T4 treatment.In conclusion,the exogenous MT can enhance the salt tolerance of peanut seedlings by increasing the content of photosynthetic pigments to improve photosynthetic performance,regulating the activity of the antioxidant system and reducingthe accumulation of reactive oxygen species to alleviate oxidative stress,and optimizing osmotic adjustment metabolism to relieve osmotic damage.Moreover,the stress alleviating effects of exogenous MT on peanut growth was better under the 200 mmol/L NaCl condition.
Research on Water Absorption and Metabolic Responses of Peanut Seed Germination under Salt Stress
XU Yang;QIN Feifei;GUO Qing;ZHANG Zhimeng;DING Hong;In this study,physiological index determination and liquid chromatography-tandem mass spectrometry(LC-MS/MS) analysis methods were utilized to explore the primary water absorption patterns and the variation characteristics of differential metabolites in peanut seeds during germination under salt stress.Peanut seeds absorb water rapidly during germination,however,both the total water uptake and the absorption rate were significantly decreased after being inhibited by salt stress.The difference in the total water uptake between the salt treatment and the control was the greatest at 72 h,reaching21.71 %,and the rate of water absorption in the salt treatment group decreased the most at 3 h, by 11.58%.Principal component analysis and partial least squares discriminant analysis showed a distinct separation of metabolites between the salt-stressed group and the control group,indicating that salt stress exerts a significant impact on metabolism during peanut seed germination.VIP value analysis and KEGG pathway prediction revealed that L-glutamic acid was the most active differential metabolite,followed by L-glutamine,L-aspartic acid,and glucose-1-phosphate.These metabolites are primarily involved in diverse metabolic processes such as amino acid metabolism,carbon-nitrogen metabolism,lipid metabolism,and glucose metabolism.Additionally,key stress-responsive metabolic pathways,including secondary metabolite biosynthesis,flavonoid biosynthesis,purine metabolism,and ABC transporter pathways,exhibited significant enrichment of differential metabolites,which may play a vital role in peanut seed germination under salt stress.In summary,during the early germination stage under salt stress,peanut seeds may enhance their salt tolerance by activating metabolic pathways such as secondary metabolite biosynthesis,purine metabolism,and ABC transporter pathways,thereby adapting to external salt stress.Among these,L-glutamic acid is likely to act as a key regulatory factor enabling peanut seeds to adapt to salt stress during germination.
Effects of Salt Stress on Root Morphology and Physiological Characteristics of High Oleic Acid Peanut Seedlings
LIU Ruiqi;SU Wanyu;LUO Lu;LIU Fengzhen;BAI Shengsheng;GU Mingxuan;ZHANG Kun;WAN Yongshan;To investigate the effects of salt stress on seedling growth of the high oleic acid peanuts,seven cultivars were selected as experimental materials.Utilizing an indoor hydroponic cultivation method,salt stress(200 mmol/L NaCl)was applied during the seedling stage,and the changes of the dry matter accumulation,root morphology,and leaf physiological characteristics of the different high oleic acid peanut cultivars under salt stress treatment were examined in this study.The results demonstrated that the salt stress significantly reduced the peanut root length,root surface area,root volume,number of root tips,root activity,shoot dry mass, root dry mass,and total dry mass,while increasing the rootshoot ratio.Under salt stress,high oleic acid peanut cultivars generally exhibited lower salt tolerance indices and relative values for root morphological traits compared to conventional peanut cultivars.The salt tolerance index of the large-kernel type high oleic acid cultivars ranged from 0.78 to 0.88,and about the small-kernel type high oleic acid cultivars,it ranged from 0.70 to 0.86.The large-kernel type high oleic acid cultivars showed lower relative values for superoxide dismutase(SOD) activity but higher relative values for peroxidase(POD) and catalase(CAT) activities compared to conventional large-kernel type peanuts.The small-kernel type high oleic acid cultivars generally exhibited lower relative values for the leaf antioxidant enzyme activities than the conventional small-kernel type peanuts.The relative malondialdehyde(MDA) content in leaves was generally higher for both large-and small-kernel types of high oleic acid cultivar groups compared to their respective conventional peanut groups.Among the high oleic acid cultivars evaluated,Jihua19,Shanhua21,Kainong308,and Jihual8 demonstrated relatively strong adaptability under salt stress and can be recommended as preferred varieties for cultivation in medium and mild saline-alkali soils.
Effects of Environmental Factors on Seed Germination and Seedling Emergence of Solanum nigrum L.
ZHAO Xingrui;TIAN Dongdong;QU Mingjing;LI Ying;ZHANG Zhaowei;DU Long;YAO Yongsheng;Solanum nigrum L is a widespread annual weed infesting in peanut fields in China,and it causes severe damage to peanut production in Xinjiang.In this study,the seed germination biological characteristics of S.nigrum populations collected from Kashgar,Xinjiang(KS) and Qingdao,Shandong(QD) were determined under laboratory conditions.The results showed that the optimal germination temperature for both populations was 25-30℃ within which the time required for 50% germination(t50) was the shortest as only 2.02 d.Compared with constant temperature,fluctuating temperature slightly decreased the seed germination rate.Seed germination was sensitive to light and photoperiod,with germination rates of 96.5 %-97.5 %,76.0%-78.0 %,and54.0 %-58.0% under 12 h light/12 h dark,full light,and full dark conditions,respectively.Both populations maintained germination rates above 86.5% under pH 4-10.NaCl stress and osmotic stress significantly inhibited seed germination,and 280 mmol/L NaCl and-0.9 MPa osmotic stress completely inhibited germination,respectively.The highest seedling emergence rate(91.0%-93.5 %) was observed at a burial depth of 1.0 cm,and the emergence rate still exceeded 81.5 % at burial depths ranging from 0.5 to 2.0 cm.Comparison between the two populations revealed that the KS population had a significantly higher germination rate than the QD population under several temperature regimes,especially under suboptimal temperatures(constant temperatures of 15,20,and 35℃;alternating temperature of 20/10℃).The KS population also exhibited significantly higher germination rate than the QD population under 20-240 mmol/L NaCl or-0.7 to-0.3 MPa osmotic stress.The KS population showed strong germination resistance to low temperature,drought,and high-salt stresses,which may be one of the critical reasons for its dominance as a weed population in peanut field in Xinjiang.
Genome-Wide Identification and Analysis of the DOF Gene Family in Peanut
ZHAO Xiaobo;LI Chunjuan;MOU Yifei;WANG Juan;YUAN Cuiling;SHAN Shihua;The DOF(DNA binding with one finger) genes represent a class of plant-specific transcription factors,which play a crucial role in various stages of plant growth and development,as well as in response to environmental stresses.In this study,61 DOF transcription factors were identified from the peanut genome, and a systematic bioinformatics analysis was conducted.The results indicated that the members of the DOF family are distributed across all 20 chromosomes, but their distribution is uneven.Amino acid sequence alignment revealed that DOF proteins primarily contain 10 types of Motif sequences.Analysis of tissue expression patterns demonstrated that some members including Ah DOF4 exhibit strong tissue specificity.Additionally, AhDOF3、AhDOF31、AhDOF46 showed varying degrees of positive responses to drought stress.In this study,it is demonstrated that peanut DOF protein sequences showed both similarity and conservation,while their regulatory mechanisms are diverse.Consequently,this research provides a theoretical foundation for further investigations into the functions of related genes and their potential application in breeding.
Effects of Low-pH Stress on Mineral Nutrition Absorption and Transport in Peanut
LIU Ling;ZHANG Xiang;SUO Yanyan;LI Liang;DUAN Xianjie;LI Qian;YAN Meng;CHENG Peijun;To investigate the effects of low-pH stress on mineral nutrition absorption and transport in peanut,the peanut cultivar Yuanza9307 was utilized as material and a hydroponic culture system was employed in this study to analyze the growth phenotypes,nutrient accumulation,and transport efficiency under different pH conditions(pH 3.0-6.0).Based on the transcriptomic data,genes involved in nutrient absorption and transport responsive to low-pH stress(pH 3.5 vs.pH 6.0) were identified,and the expression levels and tissue-specific expression patterns of the candidate genes were further analyzed.The results showed that low-pH stress significantly inhibited the growth and development of peanut,leading to markedly reduced absorption of nitrogen,phosphorus,potassium,calcium,magnesium,manganese,zinc,and boron,as well as decreased transport efficiency of copper,calcium,and boron to the shoots.Under extreme low-pH conditions(pH 3.0),the transport efficiency of phosphorus and magnesium was relatively enhanced,while manganese transport exhibited a pH-dependent accumulation pattern.At the molecular level,low-pH stress induced widespread down-regulation of genes associated with the absorption and transport of nitrogen,phosphorus,potassium,boron,and other metal ions.Among these,the root-and root tip-specifically expressed genes AH03 G00930/AH13 G02820(AhNRT2;4 s),AH13 G53580(AhHAK5),AH09 G00730/AH08 G06010(AhRAMP6) and AH09 G33130(AhNIP5;1) were identified as key candidate genes regulating nutrient absorption under low-pH stress.It is revealed in this study that low-pH stress disrupts peanut growth and mineral homeostasis through coordinated inhibition of root development,differential regulation of element transport systems,and dynamic regulation of gene expression.These findings provide a theoretical foundation and genetic resources for breeding of acid-tolerant peanut cultivars.