Fine-mapping and primary analysis of candidate genes associated with seed coat color in mung bean(Vigna radiata L.)

Seed coat color affects the appearance and commodity quality of mung beans(Vigna radiata L.).The substances that affect mung bean seed coat color are mainly flavonoids,which have important medicinal value.Mapping the seed coat color gene in mung beans would facilitate the development of new varieties and improve their value.In this study,an F2 mapping population consisting of 546 plants was constructed using Jilv9(black seed coat)and BIS9805(green seed coat).Using bulk segregated analysis(BSA)sequencing and kompetitive allele-specific PCR(KASP)markers,the candidate region related to seed coat color was finally narrowed to 0.66 Mb on chromosome(Chr.)4 and included eight candidate genes.Combined transcriptome and metabolome analyses showed that three of the eight candidate genes(LOC106758748,LOC106758747,and LOC106759075)were differentially expressed,which may have caused the differences in flavonoid metabolite content between Jilv9 and BIS9805.These findings can provide a research basis for cloning the genes related to seed coat color and accelerate molecular markerassisted selection breeding in mung beans.

Nitrogen, Phosphorus, and Potassium Interactive Effects for Improving Drought Resistance on Mung Bean Varieties

The planting areas of mung bean are mostly arid and semi-arid areas, and lack of irrigation conditions. Many studies have reported that fertilization can increase drought resistance. In our previous research, optimized nitrogen (N), phosphorus (P) and potassium (K) combined fertilization model was established in mung bean. In the present study, the optimal fertilization was conducted in pot trails, and mung bean varieties Bailv9 and Bailv11 were used as materials, while the four water regimes, and three fertilization ratios of F120 (optimal fertilization), F100 (conventional fertilization), F50 (half of conventional fertilization) treatments were set, to compare each fertilization ratio effects and non-fertilization condition under each water regimes respectively. Under different water conditions, the investigation of N, P, and K effects of optimal fertilization showed that the yield of Bailv9 was not sensitive to water stress and had strong drought resistance;their water sensitivity index and drought resistance coefficient were BaiLv9 as Di = 0.89 and DC = 0.79. The yield of Bailv11 was sensitive to water stress, and their drought resistance was weak;their water sensitivity index and drought resistance coefficient were BL11 Di = 1.76 DC = 0.59, and under different water treatment conditions, Bailv9 and Bailv11 all had the best yield and other related traits increase in the F120 fertilization mode compared with other fertilization and non-fertilization conditions, and the average yield increases were 31.56% and 28.08%, respectively. The pot trails conduct the drought stress treatments in mung bean varieties Bailv9, Bailv11, Bailv935 and Bailv985 to determine the function of NPK optimized fertilization for improving plants growth in drought stress condition. Compared with the mung bean varieties treated with F50, F100, and F120, the yield of Bailv9 increased by 56.20%, 81.27%, and 107.22%, respectively;compared with that of F0, the yield of Bailv11 increased by 10.18%, 19.42%, and 45.88%, respectively;Bailv935 increased by 26.52%, 61.90%, 74.16% respectively, and Bailv985 increased by 23.78%, 56.92%, 87.62% respectively. The significant performances of optimized fertilization were also verified in 20 mung bean varieties in our filed trails. The research establishes a theoretical basis for introducing the model into production practice in the next step.

Drought Tolerance in Mung Bean is Associated with the Genotypic Divergence, Regulation of Proline, Photosynthetic Pigment and Water Relation

Drought is one of the critical conditions for the growth and productivity of many crops including mung bean(Vigna radiata L.Wilczek).Screening of genotypes for variations is one of the suitable strategies for evaluating crop adaptability and global food security.In this context,the study investigated the physiological and biochemical responses of four drought tolerant(BARI Mung-8,BMX-08010-2,BMX-010015,BMX-08009-7),and four drought sensitive(BARI Mung-1,BARI Mung-3,BU Mung-4,BMX-05001)mung bean genotypes under wellwatered(WW)and water deficit(WD)conditions.The WW treatment maintained sufficient soil moisture(22%±0.5%,i.e.,30%deficit of available water)by regularly supplying water.Whereas,the WD treatment was maintained throughout the growing period,and water was applied when the wilting symptom appeared.The drought tolerant(DT)genotypes BARI Mung-8,BMX-08010-2,BMX-010015,BMX-08009-7 showed a high level of proline accumulation(2.52–5.99 mg g^(−1) FW),photosynthetic pigment(total chlorophyll 2.96–3.27 mg g^(−1) FW at flowering stage,and 1.62–2.38 mg g^(−1) FW at pod developing stage),plant water relation attributes including relative water content(RWC)(82%–84%),water retention capacity(WRC)(12–14)as well as lower water saturation deficit(WSD)(19%–23%),and water uptake capacity(WUC)(2.58–2.89)under WD condition,which provided consequently higher relative seed yield.These indicate that the tolerant genotypes gained better physiobiochemical attributes and adaptability in response to drought conditions.Furthermore,the genotype BMX-08010-2 showed superiority in terms of those physio-biochemical traits,susceptibility index(SSI)and stress tolerance index(STI)to other genotypes.Based on the physiological and biochemical responses,the BMX-08010-2 was found to be a suitable genotype for sustaining yield under drought stress,and subsequently,it could be recommended for crop improvement through hybridization programs.In addition,the identified traits can be used as markers to identify tolerant genotypes for drought-prone areas.

Integrated Transcriptome and Small RNA Sequencing Analyses Reveals Insights into the Molecular Mechanism of Seed Germination in Mung Bean

During the life cycle of a plant,seed germination is crucial.Upon ingestion of water,the dry seeds resumed energy metabolism and cellular repair.To dissect the complex mechanisms at the very beginning of seed germination,two approaches including transcriptome and small RNA sequencing were conducted during the water imbibition process of mung bean seeds compared with dry seed.The transcriptome sequencing analysis identified 10,108 differentially expressed genes(DEGs)between dry and imbibed mung bean seeds.KEGG enrichment analyses demonstrated numerous DEGs involved in hormone signaling pathways,carbohydrate,and energy metabolism.Out of the total DEGs,129 genes were investigated to involve in abscisic acid,gibberellin,and ethylene pathways,with 56 genes involved in glycolysis and TCA cycle.Through the analysis of small RNA sequencing among different samples,there were 284 miRNAs found in the imbibed and dried seeds of mung bean containing 213 known and 71 novel miRNAs.From comparison between the two types of seeds,51 miRNAs were differentially expressed.The integrated analyses of transcriptome and miRNAome data showed that 23 DEGs are the putative target genes of 8 miRNAs including miR156,miR171b-3p,miR166e-3p,miR169-1,etc.QRT-PCR was used to validate several DEGs and miRNAs.The data suggested that the seed imbibition process is regulated by a variety of DEGs and microRNAs.Meanwhile,we hope to gain a deeper insight into how mung bean seeds germinate in order to optimize seed growth.

Cloning and Functional Validation of Mung Bean VrPR Gene

For the purpose of functional validation,the mung bean(Vigna radiata)VrPR gene was cloned and overexpressed in Arabidopsis thaliana.Thefindings revealed that the ORF of VrPR contained 1200 bp,in which 399 amino acids were encoded.Bioinformatics analysis showed that the VrPR protein belonged to the NADB Rossmann superfamily,which was one of the non-transmembrane hydrophilic proteins.VrPR was assumed to have 44 amino acid phosphorylation sites and be contained in chloroplasts.The VrPR secondary structure comprised of random coil,αhelix,βangle,and extended chain,all of which were quite compatible with the anticipated tertiary structure.Moreover,analysis of the phylogenetic tree indicated that the soybean PR(Glyma.12G222200)and VrPR were closely related.Furthermore,chlorophyll content in leaves is markedly increased in Arabidopsis when VrPR is overexpressed.Ourfindings will serve as a reference for more functional studies on the PR genes in mung bean.

Effects of Variety and Planting Density on Mung Bean Eco-Physiology and Yield in the Southeastern US

Mung bean (Vigna radiata L. Wilczek.) is a warm-season, C3 pulse crop of the legume family that has been widely cultivated in Asian countries. As the demand for mung bean continues to increase in the United States, the ecophysiology, growth, and yield of mung bean varieties in the southeastern US need to be assessed. A field experiment was conducted at the Agricultural Research and Education Center of Tennessee State University to investigate the effects of four varieties (OK2000, Berken, TSU-1, AAMU-1) and three planting densities (5, 10, and 15 cm spacing) on the ecophysiology and yield of mung bean. Results showed that the relative chlorophyll content, plant height, pod dry biomass, pod number, crop yield, and harvest index significantly varied among the varieties. Density only influenced transpiration, relative chlorophyll content, and plant dry biomass. OK2000 had 101.0% more pods per plant and a 42.4% higher harvest index and produced a 45.3% higher yield than other varieties, but no significant difference in yield was found among the other three varieties. This study demonstrated that the mung bean variety OK2000 with a high yield would be ideal for commercial production in the southeastern US.

Current Status and Development Strategy of Mung Bean Production in Chongqing Municipality

[Objective] This paper presented the current status of mung bean produc- tion in Chongqing, and put forward the corresponding development strategies. [Meth- ods] By overviewing the status of mung bean production in Chongqing Municipality, the main problems, advantages of mung bean production in Chongqing were pre- sented, and based on corresponding development strategies were put forward.[Re- suits] Currently, the main problems of mung bean production in Chongqing area in- clude insufficient attention, serious variety degradation, lag in cultivation technology, low scientific research level. However, the region has strengths in growing mung beans which would have broad prospects by appropriate adjustment and planning. [Conclusion] This study laid the foundation for the development of mung bean pro- duction and promotion of economic development in Chongqing Municipality.

Effects of Magnetic Stress on the Delayed Luminescence of Mung Bean Leaves

[Objective] The research aimed to study the effects of magnetic stress on the delayed luminescence of mung bean leaves.[Method]With mung bean leaves as the experimental materials,the delayed luminescence curve of mung bean leaves under the same magnetic field intensity at different processing time was measured by using BPCL-type weak luminescence measuring instrument.[Result] The absorption of the magnetic field stimulation within the leaves had its own rules.A certain magnetic field intensity and a certain...

Contents of D-chiro-Inositol,Vitexin,and Isovitexin in Various Varieties of Mung Bean and Its Products

Mung bean （Vigna radiata L.） is rich in bioactive compounds including D-chiro-inositol （DCI）, vitexin, and isovitexin, which have beneficial effects on patients with diabetes. To find a better source for these valuable chemicals, we have collected 110 varieties of mung bean seed samples and 8 mung bean products to determine the levels of these bioactive compounds. We also measured the DCI content in mung bean sprouts at different germination stages. Content of DCI, vitexin, and isovitexin in all mung bean varieties ranged from 0.43 to 5.79, 0.12 to 3.00, and 0.03 to 1.16 mg g-~, respectively. The varieties of C0001321, C0003522, and C0004485 have the highest DCI, vitexin, and isovitexin contents, respectively. The mung bean products in the market contained relatively lower level of these bioactive components. Contents of DCI, vitexin, and isovitexin in all mung bean products ranged from 0.119 to 0.717, 0 to 0.547, and 0 to 0.923 mg g-~, respectively. During the 112 h of germination test, DCI level steadily increased at first stage and reached the highest level at 80 h of germination （4.79 mg g-~）. These results provide useful information for the selection of suitable varieties and proper germination stages to obtain functional ingredients from mung beans.

A critical review on phytochemical profile and health promoting effects of mung bean (Vigna radiata)

The seeds and sprouts of mung bean are very common cruise in Asia.Evidence showed that bioactive compounds in mung bean have emerged as an increasing scientific interest due to their role in the prevention of degenerative diseases.All data of in vitro,in vivo and clinical studies of mung bean and its impact on human health were collected from a library database and electronic search.Botanical,phytochemical and pharmacological information was gathered and orchestrated.Remarkable studies have been demonstrated,showing the enhancement of metabolites in mung bean during the sprouting process,which possesses various health benefiting bioactive compounds.These compounds have been frequently attributed to their antioxidant,anti-diabetic,antimicrobial,anti-hyperlipidemic and antihypertensive effect,anti-inflammatory,and anticancer,anti-tumor and anti-mutagenic properties.In this critical review,we aimed to study the insight of the nutritional compositions,phytochemistry,and healthpromoting effects of mung bean and its sprouts.The various curative potential of mung bean provides successive preclinical outcomes in the field of drug discovery and this review strongly recommends that mung bean is an excellent nutritive legume,which modulates or prevents chronic degenerative diseases.

Effects of Different Population Densities on Yield and Agronomic Characteristics of Mung Bean

With the methods of crop population physiology,the effects of different population densities on growth,development and yield of mung bean as well as the relationship between these indexes and density were studied.The results showed that the morphology indexes of mung bean plant changed significantly with planting density increasing：the plant height showed increasing trend,while the stem diameter of the basal intemode were gradually decreased.And these two indexes were sensitive to the density.The effects of planting densities on valid branch number and the height of the first branch had reached significant level.In the yield components,the effects of planting densities on the pod number per plant,the grain weight per plant and the hundred grain weight had achieved significant level.

Research Progress of Quality Characteristics and Comprehensive Utilization of Mung Beans

Mung bean is one of the major legume crops in China, and its nutritional quality and processing quality directly affect the development of mung bean processing industry. In order to promote the development of mung bean processing industry, the research progress of mung bean quality characteristics, including physical quality, nutritional quality, medicinal value and the processing quality, were summarized based on literatures both at home and abroad, and the current exploitation status of starch, protein, dietary fiber, resistant starch, flavonoids and superoxide dismutase of mung bean was also reviewed. In order to promote the development of mung bean processing industry, it should strengthen the research on quality characteristics and functional ingredients of mung bean, pay attention to the development of healthy products, improve the processing technology, and cultivate a group of leading mung bean processing companies with strong competence in the market.

Physiological Response of Mung Bean to Polyethylene Glycol Drought Stress at Flowering Period

The study was carried out on the basis of the flowering period of mung bean (Phaseolus radiatus). The polyethylene glycol 6000 (PEG6000) was used to stimulate water stress. Four mung bean varieties with different drought resistances were used as materials in this experiment, in which the physiological indexes of mung bean for the identification of drought resistance were selected, and the response analysis of seven physiological indexes to different degrees of drought stress was measured by using polyethylene glycol 6000 (PEG6000) on different concentrations of 5%, 10% and 20%. The physiological mechanism was analysed on drought tolerance of mung beans. This test was to set up identification system for drought tolerance of flowering mung bean. The results showed that the relative conductivity after 6 days of 5% PEG treatment, the SOD activity after 6 days of 5% PEG treatment, the POD activity after 6 days of 10% PEG treatment and the ABA content after 6 days of 10% PEG treatment could be used as drought-tolerant identification for mung beans at flowering period. These four physiological indexes and drought-resistant index weighted grey correlation analysis results showed that the correlation order was successively SOD activity (0.8589) > ABA content (0.8290) > conductivity (0.7160) > POD activity (0.6637);and the grey correlation degree was greater than 0.6500 among the four physiological indexes.

Physiochemical, Nutritional and Technological Properties of Instant Porridge Supplemented with Mung Bean

The present study was undertaken to prepare instant porridge from some useful and available ingredients such as bulgur powder, potato, tomato, carrot, mung bean (unsoaked, soaked and germinated), then seasoned with onion, garlic, salt, black pepper, cumin and coriander to make B1, B2 and B3 formulas. Chemical, physical properties, amino acids and sensory evaluation of instant porridge formulas were determined. The data showed that B2 formula which contained soaked mung bean had the highest calories value, total essential amino acids, biological value and water absorption index (WAI) compared to the other formulas, also it is recorded the highest degree of lightness L* values (82.39 and 56.65), least redness a* values (0.98 and 1.45) and intermediate in yellowness b* values (25.91 and 24.45) before and after rehydrated, respectively. Regarding to sensory evaluation, there was a significant increase in color, taste and overall acceptability in B2 compared to the other formulas. Based on these results, revealed that the soaked mung bean was a good source of essential amino acid and calories to enhance nutritional and technological quality of the resultant porridge.

Effects of Different Proportions of Spent Pleurotus ostreatus Substrate on Seed Germination and Seedling Growth of Mung Beans

[Objectives] This study was conducted to investigate the effects of different proportions of spent Pleurotus ostreatus substrate on the germination and seedling growth of mung beans. [Methods] The cellulose-degrading bacteria HB8 and HF1 were mixed with a commercially available microbial composting agent, respectively, for the composting of spent P. ostreatus substrate. Mung beans were cultivated with different proportions of spent mushroom substrate compost and soil. The seed germination rate, plant height, fresh weight and chlorophyll content of mung bean were used as indicators to investigate the effects of the organic fertilizer from spent P. ostreatus substrate on the growth of mung bean seedlings. [Results] The addition of cellulose-degrading bacteria can significantly improve the composting effect of the spent mushroom substrate. After 8 d of cultivation of mung beans with different ratios of the mushroom substrate organic fertilizer, 50% of the organic fertilizer can make the plant height, fresh weight and leaf chlorophyll content of mung bean seedlings reach the highest value and was suitable for mung bean breeding and cultivation. [Conclusions] This study provides scientific basis and technical indicators for the rapid and harmless treatment of spent mushroom substrate and its application in crop cultivation and nursery.

Nondestructive classification of mung bean seeds by single kernel near-infrared spectroscopy

Near-infrared spectroscopy(NIRS)in the range 900-1700 nm was performed to develop a clas-sifying model for dead seeds of mung bean using single kernel measurements.The use of the combination of transmission-absorption spectra and refection-absorption spectra was deter-mined to yield a better classification performance(87.88%)than the use of only transmission-absorption spectra(81.31%).The effect of the orientation of the mung bean with respect to the light source on its absorbance was investigated.The results showed that hilum-down orientation exhibited the highest absorbance compared to the hilum-up and hilum-parallel-to-ground orientations.We subsequently examined the spectral information related to the seed orientation by developing a classifying model for seed orientation.The wavelengths associated with classi-fication based on seed orientation were obt ained.Finally,we determined that the re-developed classifying model excluding the wavelengths related to the seed orientation afforded better ac-curacy(89.39%)than that using the entire wavelength range(87.88%).

Application of Near-Infrared Reflectance Spectroscopy to the Evaluation of D-chiro-Inositol,Vitexin,and Isovitexin Contents in Mung Bean

Mung bean （Vigna radiata L.） is rich in D-chiro-inositol （DCI）, vitexin, and isovitexin, which has beneficial effects on antidiabetic and inhibits the formation of advanced glycation end-products. In this study, near-infrared reflectance spectroscopy （NIRS） was used to predict the contents of DCI, vitexin, and isovitexin in mung bean. The spectra data were linearized with those determined by high-performance liquid chromatography （HPLC）. The models for predicting the DCI, vitexin, and isovitexin contents in mung bean were developed using partial least-squares （PLS） algorithm. Cross-validation procedures indicated good correlations between HPLC data and NIRS predictions （R2=0.90 for DCI, R2=0.81 for vitexin, and R2=0.90 for isovitexin）. The predictive contents of DCI, vitexin, and isovitexin ranged from 2.082 to 3.084%, 1.277 to 1.307%, and 0.5998 to 0.6286%, respectively. The results showed that NIRS, a well-established and widely applied technique, could be applied to rapid detection of DCI, vitexin, and isovitexin contents in mung bean.

Quality enhancement and microbial reduction of mung bean(Vigna radiata)sprouts by non-thermal plasma pretreatment of seeds

Mung bean(Vigna radiata)sprouts are widely consumed worldwide due to their high nutritional value.However,the low yield and microbial contamination of mung bean sprouts seriously reduces their economic value.This study investigates the effects of non-thermal plasma on the quality and microbial reduction of mung bean sprouts by pretreatment of seeds in water for different times(0,1,3 and 6 min).The quality results showed that short-time plasma treatment(1 and 3 min)promoted seed germination and seedling growth,whereas long-time plasma treatment(6 min)had inhibitory effects.Plasma also had a similar dose effects on the total flavonoid and phenolic contents of mung bean sprouts.The microbiological results showed that plasma treatment achieved a reduction of native microorganisms ranging from 0.54 to 7.09 log for fungi and 0.29 to 6.80 log for bacteria at 96 h incubation.Meanwhile,plasma treatment could also efficiently inactivate artificially inoculated Salmonella typhimurium(1.83–6.22 log)and yeast(0.53–3.19 log)on mung bean seeds.The results of seed coat permeability tests and scanning electron microscopy showed that plasma could damage the seed coat structure,consequently increasing the electrical conductivity of mung bean seeds.The physicochemical analysis of plasma-treated water showed that plasma generated various long-and short-lived active species[nitric oxide radicals(NO·),hydroxyl radicals(·OH),singlet oxygen(1O2),hydrogen peroxide(H_(2)O_(2)),nitrate(NO_(3)^(-)),and nitrite(NO_(2)^(-))]in water,thus the oxidizability,acidity and conductivity of plasma-treated water were all increased in a treatment timedependent manner.The result for mimicked chemical mixtures confirmed the synergistic effect of activity of H_(2)O_(2),NO_(3)^(-)and NO_(2)^(-)on bacterial inactivation and plant growth promotion.Taken together,these results imply that plasma pretreatment of mung bean seeds in water with moderate oxidizability and acidity is an effective method to improve the yield of mung bean sprouts and reduce microbial contamination.

Basal Application of Zinc to Improve Mung Bean Yield and Zinc-Grains-Biofortfication

Worldwide,the dietary deficiency of zinc(Zn)is prevailing in almost all arid and semi-arid regions.Zinc deficiency is not only the major constraint of lower yield,but also dietary Zn deficiency in cereals grains may cause increasing malnutrition and chronic health problems in human.Exogenous application of Zn through basal soil nutrition might be a useful option to recover Zn deficiency in mung bean.Therefore,field study was conducted to optimize the optimum level and method of Zn nutrition to enhance crop yield and Zn biofortification of mung bean through basal application.Zinc was applied at 0,5,10 and 15 kg/ha as basal application and side dressing,and in combination(50%basal application+50%side dressing).The results highlighted that Zn nutrition prominently improved the mung bean yield as compared with control(no Zn applied).The maximum grains yield and Zn concentration in grains were obtained where Zn was applied at 15 kg/ha as basal application as compared with all other combinations.Better improvement in grain yield was due to significant increase in more number of pods and grain size owing to well-developed root system,improved leaf area index and high chlorophyll contents in mung beans leaves.Amongst all applied Zn nutrition’s the basal application of Zn(15 kg/ha)was a viable option to get higher yield and Zn biofortification of mung bean.

Extraction Technology of Flavonoids from Mung Bean Hull and Antioxidant Activity

[Objectives]The research aimed to study extraction technology of flavonoids from mung bean hull and determine their antioxidant activity.[Methods]Mung bean hull was taken as raw material,and extraction technology was freeze thaw assisted ultrasound,and ethanol aqueous solution was taken as solvent.Solid-liquid ratio,ethanol volume fraction,ultrasonic power and time were taken as variables to carry out single-factor experiments,to determine scavenging abilities of flavonoids from mung bean hull to DPPH radical and hydroxyl radical.[Results]The optimal extraction process of flavonoids was as below:1∶15 of solid-liquid ratio,70%of ethanol volume fraction,120 W of ultrasonic power and 80's of ultrasonic time.At this time,extraction rate of flavonoids was 4.07 mg/g.Scavenging activities of flavonoids from mung bean hull to DPPH radical and hydroxyl radical were 57.64%and 42.19%,respectively.[Conclusions]Freeze thaw assisted ultrasound was suitable for extracting flavonoids from mung bean hull.