Transcription factor CabHLH035 promotes cold resistance and homeostasis of reactive oxygen species in pepper

Plant basic helix-loop-helix(bHLH)transcription factors(TFs)play central roles in various abiotic stresses.However,its role in plant cold resistance is largely unknown.Previously,we characterised CaNAC035 in pepper,which positively regulates tolerance to cold,salt and drought stresses tolerance.Here,we identified CabHLH035,a CaNAC035-interacting protein in pepper.To explore its functions in cold stress tolerance,we silenced the gene in pepper via virus-induced gene silencing(VIGS)and overexpressed the gene in Arabidopsis.The results showed that CabHLH035 expression was induced by cold treatment,and silencing of CabHLH035 decreased cold stress tolerance.Conversely,overexpression of CabHLH035 in Arabidopsis increased cold stress tolerance.To investigate homologs genes of C-repeat binding factor(CBF)pathway proteins and reactive oxygen species(ROS)marker gene expression blocking by CabHLH035,we performed yeast one-hybrid(Y1H),dual luciferase and electrophoretic mobility shift assay experiments.The results showed that CabHLH035 bound to the region upstream of the CaCBF1A and CaAPX promoters.Additionally,CaCBF1A bound to the CaDHN4 promoter.Taken together,our results showed that CabHLH035 plays a crucial role in cold stress tolerance and its potential as a target for breeding cold-resistant crops.The findings provide a basis for studying the functions and regulatory network of cold stress tolerance in pepper.

Melatonin mitigates cold-induced damage to pepper seedlings by promoting redox homeostasis and regulating antioxidant profiling

This study assessed the influence of exogenous ME in the mitigation of cold damage in pepper seedlings. Melatonin(ME) is a dynamic molecule that helps plants cope with stress in several ways. Cold stress(CS) is one of the most important environmental factors that restrict plant growth and yield. Pepper(Capsicum annuum L.) is a valuable commercial crop, highly sensitive to CS. Thus, identifying an efficient strategy to mitigate cold damage is critical for long-term pepper production. For this purpose, the roots of pepper seedlings were pretreated with ME(5 μmol · L^(-1)) and exposed to CS for 7 d. The results indicated that CS suppressed pepper growth, hampered photosynthetic capacity, and damaged root architecture in pepper plants. In contrast, the production of reactive oxygen species(ROS), malondialdehyde(MDA), electrolyte leakage(EL), proline, and soluble sugars were enhanced in plants under CS. ME(5 μmol · L^(-1)) pretreatment reduced the negative effects of CS by recovering plant growth, root traits, gas exchange elements, and pigment molecules compared to CS control treatment. Furthermore, ME application efficiently reduced oxidative stress markers [hydrogen peroxide(H_(2)O_(2)), superoxide ion(O_(2)^(·-)), EL, and MDA] while increasing proline and soluble sugar content in pepper leaves. ME application combined with CS further increased antioxidant enzymes and related gene expression. Collectively, our results confirmed the mitigating potential of ME supplementation for CS by maintaining pepper seedling growth,improving the photosynthesis apparatus, regulating pigments, and osmolyte content.

Hydrolytic and Antimicrobial Activities of Bacteria Isolated from Fermented Peppers Sold in Markets at Brazzaville, Republic of the Congo

Microorganisms are omnipresent in all environments and play mainly the role of transformers, thanks to the multiple enzymes they are able to produce. In order to valorize fermented foods in the Republic of the Congo, this work aimed to characterize and study some properties of microorganisms isolated from samples of peppers sold in three markets of Brazzaville. A numeration of the total aerobic mesophilic flora (TAMF) was made in a solid medium, allowing the evaluation of each sample’s microbial concentration. The microbial mass varied from 2.8 × 105 CFU/g for the Ouénzé sample to 1.8 × 104 CFU/g for the Total sample and 2 × 104 CFU/g for the Moungali market sample. The evaluation of the enzymatic properties of the Bacillus isolates showed that 68.42% were capable of producing cellulases and 78.94% were capable of producing amylases and proteases. Antimicrobial activities revealed that 63.15% of the isolates were able to secrete inhibitory substances against E. coli and Staphylococcus aureus. Molecular analysis by PCR amplification, sequencing of the 16S rRNA gene and BLAST bioinformatics analysis provides newly identified bacteria strains with new accession numbers in GenBank: Bacillus thuringiensis MBCBR322 (OP474008), Bacillus megaterium MBCBJ1822 (OP476493), Bacillus thuringiensis MBCBR222 (OP476494), Priestia megaterium MBCBJ2022 (OP476495) and Lactobacillus paraplantarum MBCBR1522 (OP476496). Multiple sequences alignment of identified sequences with their homologs of GenBank has shown high similarities. The phylogenetic inference assay has provided the two groups of strains observed in this study, and the two groups are very coherent with the phylogeny of the reference.

Analysis of Fourteen Mycotoxins in Chili Peppers in Guizhou Province Combining DES-DLLME and UHPLC-MS/MS and Their Risk Evaluation

Mycotoxins exist widely in food and have a serious impact on human health.At present,most detection methods of mycotoxins are costly and time-consuming.Most of these methods are aimed at detecting a single type of mycotoxin,and the efficiency is not high.On this basis,in this study,QuEChERS-deep eutectic solvent liquid-liquid microextraction was applied to extract and enrich 14 mycotoxins in chili peppers from the concept of green chemistry.A simple,time-consuming and environment-friendly multi-flux pretreatment method was established,and 100 chili pepper samples were randomly sampled from farmers'markets and supermarkets in major urban areas of Guizhou Province for detection,and risk assessment was carried out according to the detection results.

Effects of Full-Element Bio-Organic Fertilizer on Growth,Yield,and Rhizosphere Soil Nutrients of Pepper

A field experiment was conducted to evaluate the effects of self-developed full-element bio-organic fertilizer on the growth,yield,and rhizosphere soil nutrients of pepper.Four treatments were designed,including full-element bio-organic fertilizer+conventional fertilizer reduced by 50%(T1),inactivated full-element bio-organic fertilizer+conventional fertilizer reduced by 50%(T2),conventional fertilizer(T3),and no fertilizer(CK).The results showed that T1 significantly increased the plant height,crown width,fruit number per plant,and yield of pepper.T1 had higher pH value,total nitrogen,total phosphorus,total potassium,available nitrogen,available phosphorus,and available potassium in the rhizosphere soil than T3 and CK,and it had higher available phosphorus and available potassium than T2.The disease index of bacterial wilt in T1 was 21.74,which was 10.37,20.19,and 35.48 lower than T2,T3,and CK,respectively.The control effect of T1 reached 56.71%.The above results indicated that whole bio-organic fertilizer promoted the growth to improve the yield and benefit of pepper.Moreover,the fertilizer activated soil nutrients to improve soil fertility and reduced soil-borne diseases.Therefore,the full-element bio-organic fertilizer can be promoted in the pepper fields with continuous cropping obstacles.

Variety Selection and Green Cultivation Technology of Courtyard Ornamental and Edible Peppers

In order to comply with the development trend of the multifunctional use of peppers,we conducted an investigation into the characteristics and features of varieties,potting management techniques,and the methods of extending the fruit ornamental period and other aspects of courtyard ornamental and edible peppers.A set of cultivation techniques suitable for courtyard ornamental and edible peppers has been developed,including timely sowing and seedling,nutrient soil preparation,water and fertilizer management,trimming and pruning,preservation of flowers and fruits,green prevention and control of diseases and pests,harvesting,and so on.

AFLP Analysis of Cytoplasmic Male-sterile Line and Its Maintainer Line of Pepper

[Objective] The aim of this study was to analyze the cytoplasmic male sterile line 21A and its maintainer line 21B of peppers by AFLP,and lay the foundation for further studies on molecular mechanism of the cytoplasmic male sterility in peppers.[Method] Cytoplasmic male sterility(CMS)line 21A and its maintainer line 21B were analyzed by AFLP to obtain the specific amplified fragments of cytoplasmic male sterile line 21A,while the specific amplified fragments were recovered or sequenced,and analyzed by BLAST...

Effect of Slow and Controlled Release Fertilizers on the Yield and Nutrient Use Efficiency of Hot Pepper in Qiu-bei

[Objective] The aim of this study was to investigate the impacts of slow and controlled release fertilizers（SCRF）on the yield of qiubei hot pepper,its nutrient use efficiency and environment.[Method] Using Qiubei hot pepper（Capsicum frutescens L.）as the experimental material,we studied the fertilization effect and environment-protecting effect of SCRF.[Result] The result showed that SCRF could improve the agronomic characteristics of hot pepper.Compared to singly applied common fertilizers,SCRF increased economic yield by 20.90% and economic benefit by 13 234.35 Yuan/hm2,and the ratio of output to input was improved by 47.93%.In comparison with common straight fertilizers at same NPK proportion and rate,SCRF increased economic yield by 5.26% and economic benefit by 5 554.80 Yuan/hm2,and the ratio of output to input was improved by 9.91%.Under the reduced use of SCRF by 20%,SCRF increased economic yield by 12.38% and economic benefit by 9595.20 Yuan/hm2 compared with singly applied common fertilizers,and the ratio of output to input was improved by 65.95%.SCRF improved nitrogen,phosphorus and potassium use efficiencies by 12.42-17.53,3.35-5.24 and 5.37-14.02 percents respectively.[Conclusion] As the result of much reduced N and P application rates,SCRF would significantly economize fertilizer resources and minimize the pollution caused by the loss of fertilizer nutrients,which is of practical importance for environment protection.

Screening of SSR Core Primers for Purity Identification of Pepper(Capsicum) Hybrids

[Objective] This study aimed to screen a set of SSR core primers suitable for purity identification of pepper （Capsicum） hybrids. [Method] DNA fingerprint of 100 pepper hybrids was analyzed using 17 SSR primers. [Result] According to the polymorphism and heterozygosity, Hpms1-214, Es395 and Hpmsl-5 were determined as three preferred core primers for purity identification of pepper hybrids. By using these three preferred core primers, 97 pepper hybrids （accounting for 97%） had heterozygous band pattern with at least one primer. Es330, Es363, Epms923, Es120 and Es64 were determined as candidate core primers for purity identification of pepper hybrids. Specific primers of 14 varieties were obtained, which could be used to further screen parent-complementary primers of each pepper hybrid. [Con- clusion] This study laid the foundation for constructing standard DNA fingerprints for purity identification of pepper hybrids.

Screening of Low Temperature Resistance Germplasm Resources of Pigment Pepper

Objective The aim of this study was to explore the method and standard for rapidly screening low temperature-resistant pepper germplasm resources and provide a theoretical basis for the breeding of low temperature-resistant pepper. [ Method ] With 110 pigment pepper seeds as the materials, their germination vigor under optimum temperature and suboptimal temperature were determined by means of roll rapid germination, and seeds with different genetic types were evaluated from aspects of germination vigor and its interval division. [ Result ] 37 pepper seeds with stronger low temperature resistance were screened. [ Conclusion]This study provides an important basis for screening low temperature-resistant pepper germplasm resources.

Discussion on AFLP Molecular Markers in Piper methysticum and Pepper

The aim of the research was to discuss the genetic relationships between Piper methysticum, Pepper and other wild species in Pepper genus. DNA was extracted from leaves which belonged to 28 germplasms including 6 materials of P. methysticum, 21 maerials of cultivated and wild Pepper, 1 material of Peperomia pellucida belonged to different genus. Premiers with good band-type and high polymorphism and resolution were selected from 64 pairs of primers for AFLP amplification and the clustering analysis was conducted with MVSP3.13f software. 191 bands were amplified by 4 pairs of premiers, 189 of which had polymorphism, being 98.6%. 28 germplasms were classified into 6 different groups at the genetic similarity coefficient of 0.52 by silver staining AFLP, in which 6 materials of Piper methysticum were clustered into a single group, indicating that P. methysticum belonged to Pepper family of Pepper genus but were distantly related to the others. The research provided the basis for selecting rootstocks for P. methysticum graft, molecular identification of P. methysticum and the fingerprint construction of P. methysticum.

Current Situation and Countermeasures of Breeding for Processing Pepper in China

Research progress on the heterosis, cytoplasmic male sterility and biotechnology breeding of processing pepper （Capsicum annuum L.） was introduced, and the problems of limited germplasm resources and varieties of processing pep- per, large gap with the foreign companies were pointed out. Some suggestions were proposed on strengthening innovation and collection of germplasm resources, breed- ing processing pepper varieties, enhancing breeding level of processing pepper and its market competitiveness.

Relationship between SSR Genetic Distance and Heterosis in Hot Pepper

[Objective] This study aimed to predict the heterosis of hot pepper using SSR genetice distance. [Method] Twenty-five hybridized combinations between 10pepper parents were obtained through NCⅡ incomplete diallel cross to analyze the relationship between SSR genetic distance and heterosis. [Result] The genetic distance of the parents varied in a range from 0.13 to 0.33, and the average genetic distance was 0.25, indicating that the genetic difference was not obvious among the parents, namely, they shared a close genetic relationship. In addition, the SSR genetic distance was closely related to yield per plant and fruits per plant, but showed no obvious correlation with other traits. [Conclusion] This study proved that in a certain range the combinations between the parents with a distant genetic distance possessed stronger heterosis and a larger possibility to produce a high yield and vice versa.

In vitro Regeneration Culture of Pepper and Its Application in Breeding

This paper summarized the technology of haploid production, protoplast culture, organ regeneration culture of pepper and the key factors affecting in vitro regeneration culture of pepper, including explants, seedling age, medium,genotype and plant growth regulator, then pointed out several main problems, in order to provide the reference for building an efficient in vitro regeneration culture system of pepper and its application in breeding.

Effects of Slow-release Fertilizer and Balanced Fertilization on Nitrogen, Phosphorus and Potassium Uptake in Peppers

Field plot experiment was conducted to study the effects of two slow-re- lease fertilizers and balanced fertilization on dry matter accumulation, yield, fertilizer use efficiency, nitrogen, phosphorus and potassium uptake of peppers at Jiangna Town, Yanshan County, Yunnan Province in 2011. The results showed that the dry matter accumulation in dried pepper plant, pepper yield, nitrogen, phosphorus, potassium uptake in peppers were significantly increased in all the fertilizer treat- ments, compared with those in control （no fertilizer）. Compared with conventional fertilization, balanced fertilization, slow-release compound fertilizer and slow-release urea fertilizer significantly increased dried pepper economic output by 20.94%, 17.5% and 14.54%, nitrogen uptake in dried peppers by 21.53%,18.46% and 13.19%, phosphorus uptake in dried peppers by 14.08%, 15.76% and 10.44%, potassium uptake in dried peppers by 22.66%, 15.73% and 16.28%; they also in- creased nitrogen and potassium use efficiency, but reduced potassium use efficiency due to the increased potassium addition. In treatments with balanced fertilization, slow-release compound fertilizer and slow-release urea fertilizer, the nitrogen utiliza- tion was 5.84%, 7.14% and 8.33% higher and the phosphorus utilization was 3.32%, 3.27% and 2.47% higher than those in treatment with conventional fertiliza- tion. In addition, the nitrogen application could be reduced by 20%-50% by bal- anced fertilization and the two slow-release fertilizers, thereby reducing environmen- tal pollution. Slow-release fertilizers could also reduce the frequency of fertilization and labor costs.

Influences of Carbon Sources and Plant Growth Regulators on Anther Culture Efficiency of Pepper

[Objective]In order to increase anther culture efficiency of pepper.[Method]MS culture media and Bolajiaohong were used in this experiment to study the influences of carbon sources and concentrations on anther callus induction of pepper.Jiayu was taken as a material to study influences of plant growth regulators and concentrations on anther callus induction of pepper according to L16（4^5） orthogonal design.[Result]The average callus and embryoid induction rates of maltose at all concentrations were higher than these of sucrose but the difference was not significant.Taking maltose or sucrose as a carbon source,3% to 6% concentration was good for increasing induction frequencies of calli and embryoids.However,If the concentration was over 6%,the induction rates were declined dramatically with the increase of sugar concentration.The influences of growth regulators on induction rate of calli were listed as 2,4-D﹥ZT﹥NAA﹥KT﹥6-BA;the influences on induction rates of embryoids were listed as 2,4-D﹥NAA﹥ZT﹥KT﹥6-BA.The 2,4-D,ZT,NAA and KT had signficant or extremely significant influences on induction rates of calli and embryoids.2,4-D,ZT at 1.0 mg/L and NNA,KT at 0.5 mg/L had the best effects.The influences of ZT on calli and embryoids were better than those of KT and 6-BA.1.0 mg/L 2,4-D ＋1.0 mg/L ZT ＋0.5 mg/L KT ＋0.5 mg/L 6-BA was the best regulator combination for induction culture of Jiayu anther.[Conclusion]The experiment provided research basis for anther culture of pepper.

Studies on Thermo-sensitivity of Ningxia Hot Pepper Male Sterile Line

[Objective] This study was conducted to identify the thermo-sensitivity of the male sterile line （NYB） of Ningxia hot pepper. [Method] The pol en abortion rates of pepper male sterile line under artificial y control ed temperature condition and nature temperature condition were measured and compared. [Result] The pol en abortion was the sign of NYB male sterility. The pol en abortion rate changed little under different temperature conditions, while pol en amount greatly reduced at low temperature, indicating that NYB was genetical y stable in field. [Conclusion] The re-sults can provide some theoretical references for the application of NYB pepper male sterile line in breeding work.

Investigation of Main Fungal Diseases of Pepper (Piper nigrum L.) in Hainan Province and Their Pathogen Identification

[ Objective ] The paper was to confirm the current major diseases of pepper in Hainan Province and their corresponding pathogens. [ Method ] The pep- per gardens in 13 main cultivation regions of pepper in Hainan Province were systematically investigated, and the pathogens of the obtained specimens were isolated and identified. [ Result] Seven fungal diseases in pepper were totally investigated, including blast, anthracnose, blight, slow wilt, root rot, basal rot and scleretin- ia disease. Currently, the diseases with serious damage on pepper include blast, anthracnese, blight and slow wilt. [ Conclusion] The result provides the theoreti- cal basis for the integrated control of diseases in pepper, and is also benefit for scientific research workers to master the latest dynamic of diseases.

Relationship between Pepper Cultivars' Yields and High Temperatures with Pepper in Different Genotypes

[Objective] The aim was to research effects of high temperature stress on pepper yield by cultivation of peppers in different genotypes and provide theoretical references for pepper breeding and high-yield cultivation. [Method] Four pepper va- rieties were studied with varied genotypes to explore effects of temperatures on pepper fruiting and yield in the whole growth stage. [Result] The optimal-temperatre term for pepper blooming and fruiting were shorter. For example, the periods from June 16 to July 15 and from August 16 to September 15 would be the best, with temperature ranging from 20.70 ℃ to 30.74 ℃. In the stage from July 16 to August 15, the temperature range of 24.22 ℃-32.17 ℃ would severely affect pepper growth and yield. Pepper No. 1 and pepper No. 1-1＇s yields were just 38.21% and 51.74% of the yields in the stage 1st and 52.01% and 62.35% in the stage 3rd and eady No. 1 and late No. 1 were 48.1% and 72.38%, respectively. Under high tem- perature stress in summer, pepper No. 1, pepper No. 1-1, and late No. 1 showed extremely significant differences with early No. 1 （P〈0.01）. The yield ratios of pep- per No. 1 and pepper No. 1-1 in stage 1st （May 25-July 15） and the later three stages were 42.34：57.66 and 39.50：60.50; the ratio was 47.99：52.21 of early No. 1; the ratio of late No. 1 was 20.25：79.75. [Conclusion] The cultivation approaches should vary upon pepper variety, necessitating the focus on pepper management, fertilization, and irrigation, and locating peak-blooming term in moderate-temperature stage to accelerate pepper growth.

Application Technology of Biocontrol Agents against Pepper Blight（ Phytophthora capsici） in Greenhouse in Qinghai Province

[ Objective ] The paper was to explore the combined application technique of organic fertilizer and two biocontrol agents against pepper blight in green- house hot pepper in Qinghai Province. [Method] By L4 （23）orthogonal design, the effects of combined application of two biocontrol agents against pepper blight and organic fertilizer on control effects against pepper blight and the yield of hot pepper were studied in greenhouse hot pepper base in Ledu County of Qinghai Province. [ Result] The effects of various factors affecting the relative control effect against pepper blight in sequence were biecontrol agent A5 〉 biecontrol agent B2 〉 organic fertilizer, and the optimal combination was organic fertilizer 1 800 kg/hm^2, agent B2 30 kg/hm^2 and agent A5 45 kg/hm^2. The effects on hot pepper yield in sequence were organic fertilizer 〉 biocontrol agent B2 〉 biocontrol agent AS, and the optimal combination was organic fertilizer 900 kg/hm^2 , agent 132 15 kg/hm^2, agent A5 22.5 kg/hm2. [ Conclusion] Combined with control effect of pepper blight and yield benefit, the application technique of biocontrol agents pro- moted in local hot pepper production could be confirmed as follows ： agent A5 45 kg/hm^2, agent B2 15 kg/hm^2, organic fertilizer 900 kg/hm^2 ; the field control effect at this moment could reach 76.31%, the yield could reach 35 573 kg/hm^2 , and the newly increased output value could be 13 029 yuan/hm^2 with input and output ratio of 1： 7.9.