To provide technical supports for marker assisted breeding and accelerate the cloning and functional verification of candidate genes of node numbers on the main stem in soybean, high throughput sequencing was used to detect the association region (QTL), fine mapping of the QTL were then conducted with the InDel markers developed based on the re-sequencing of parents. In this study, 102 recombinant inbred lines (RIL) derived from the cross between C025 with few node numbers on the main stem and Zhong119 with many node numbers on the main stem were used as experimental materials. Two mixed pools were constructed from 30 inbred lines with extremely few or extremely many node numbers on the main stem respectively. Five quantitative trait locus (QTL) related to the node number on the main stem of soybean were detected on chromosome 4 by the Bulked segregant analysis (BSA) and specific-locus amplified fragment sequencing (SLAF-Seq) high throughput sequencing method. In order to further narrow down the association regions, insertion-deletion (InDel) information between the association regions were obtained according to the re-sequencing of parental lines and the InDel markers were developed. The genotype of F 2 population was firstly analyzed by the InDel markers, and the major locus was mapped in the third associated region. Then eight co-dominant InDel markers were developed in the major region and all RIL lines were genotyped, nine individuals were obtained and the major region was divided into six exchange types. Combined with phenotypic analysis, the node number on the main stem was mapped between InDel markers Chr04-38 and Chr04-46, a region with only 171.9 kb, including six candidate genes. Therefore, the major locus of the node number on the main stem of soybean main stem was fine mapped. In short, the combination of BSA and high-throughput sequencing can effectively and rapidly detect the association regions of the node number on the main stem of soybean, furtherly combined the re-sequencing of parents to develop the tightly linked InDel markers can realize fine mapping of the major region. The developed InDel Markers Chr04-38 and Chr04-46 are tightly linked with the node numbers on the main stem of soybean, which can be used in the molecular marker assisted breeding for node numbers on the main stem in soybean.
To explore the mechanism of high photosynthesis efficiency of millet mutant with yellow leaf colour. The photosynthetic pigment, photosynthetic rate, stomatal traits, fluorescence parameters,activity of key photosynthetic enzymes and yield characteristics of two yellow leaf colour mutant lines ylm-1 and ylm-2 were studied, the wild type of “Yugu 1” was used as the control. The results suggested that the contents of photosynthetic pigment in mutants were 50%~60% of that in Yugu1. The photosynthetic rates of mutants were higher than that of the control under high light intensity and had no obvious “Midday depression phenomenon”. The stomatal conductance of ylm-1 and ylm-2 were increased significantly. The fluorescence parameters suggested that light energy efficiency and conversion efficiency of mutants were obviously higher than that of the wild type. The activity of key photosynthetic enzyme ribulose-1,5-bisphosphate carboxylase (Rubisco) in mutants were significantly lower than that in control, but the activities of phosphoenolpyruvate carboxylase (PEPCase) and NADP-malic enzyme (NADP-ME) were 23.3%, 24.4% and 12.9%,15.5% higher than those of the control, respectively. The results of yield characteristics showed that the weight per spike, seed weight per spike and thousand grain weight were increased significantly compared with control. These results provide an important theoretical basis for high light efficiency and molecular marker assisted selection breeding in millet.
Rice is one of the most important food crops in the world. In order to explore the genes associated with low temperature to lerant in rice at the bud bursting period, the chromosome segment substitution lines (CSSLs) derived 9311 (recipient)/Nipponbare (donor) was used to study the rice cold tolerance. The CSSLs was treated at low temperatures of 7℃ and 15℃ for 7 days after the emerge of rice bud respectively, and then recovered at 28℃ for 3 days. After the treatments, the QTL associated with seed survival rate were detected. Under low temperature treatment at 7℃, two major QTLs, qCS7T10 and qCS7T11 on chromosome 10 and 11, affecting seed survival rate, were detected, with LOD values of 7.26 and 5.87, and contribution of 18.85% and 14.92%, respectively. Under 15℃ low temperature treatment, one major QTL, qCS15T5, was detected. qCS15T5 was located on chromosome 5 of rice, LOD value was 7.61, and the contribution rate was 25.69%. The results showed that the QTLs controlling seed survival rate under different low temperature reatments at the bud bursting period were different. It has laid a certain foundation for future breeding and pyorarniding of more low temperature tolerance QTLs to improve the adaptability of rice to different low temperatures and reduce the impact of low temperature stress on rice bud stage.
The purpose of this paper was to confirm the core indices to evaluate the quality of weak gluten wheat, and optimize weak gluten wheat quality evaluation system. In this study, nine weak-gluten wheat cultivars from the region of middle and lower reaches of Yangtze River were used to carry out four-year planting experiments. Quality parameters, including grain protein content, kernel hardness, wet gluten content, gluten index, SDS sedimentation value and solvent retention capacity (SRC), farinograph parameters and alveograph parameters were investigated after harvesting. Cookies were processed in the laboratory and quality parameters such as diameter and thickness were tested. Results indicated that most quality traits of weak gluten wheat were affected by both genotype and environment, and gene effects were greater than environment effects for grain protein content, kernel hardness, SDS sedimentation value, water SRC, sodium carbonate SRC, lactic acid SRC, alveograph parameters, degree of softening, and cookie diameter and thickness. There was no significant difference in protein content, wet gluten content, water absorption, development time, stability time, farinograph quality number among the cultivars tested. Whereas hardness, gluten index, water SRC, sodium carbonate SRC, P value, P/L value and degree of softening showed significant differences among weak gluten wheat varieties(P<0.05), and were significant or extremely significant correlated with cookie quality, which indicated their potential applications as the quality evaluation indices for weak-gluten wheat. It can be concluded from this study that the recommended quality evaluation standards of weak-gluten wheat are: hardness≤25, gluten index≥80%, water SRC≤60%, sodium carbonate SRC≤75%, P value of alveograph≤40mm, L value of alveograph≥95mm, P/L ratio of alveograph≤0.45, 75≤degree of softening≤95.At the same time, results from the cluster analysis showed that Yangmai13, Yangmai9 and Yangmai19 are elite weak-gluten wheat cultivars. The results provided support for weak gluten wheat breeding.
In order to explore the important role of WRKY transcription factors in plant resistance to adversity stress. This study obtained the PpWRKY18 gene in peach, and bioinformatics analysis showed that the PpWRKY18 protein contained a typical WRKY functional domain. Phylogenetic tree analysis showed that PpWRKY18 in peach was more closely related those in to Rosaceae species. PpWRKY18 was predicted to be a nucleolus localization protein, and was confirmed to be located in nucleus using transient expression in tobacco leaf through Agrobacterium tumefaciens injection. Fusion protein PGEX-PpWRKY18 was expressed after induction, and showed that the PpWRKY18 was mainly expressed in the inclusion body. Real-time PCR showed that the expression of PpWRKY18 was induced by drought, and the expression of PpWRKY18 decreased after rehydration. The protein phosphatase protein family (Protein Phosphatase 2C), C2H2 protein family (PpZAT5), ERF protein family (PpERF9), and BHLH protein family (PpBHLH92) were predicted to interact with PpWRKY18, therefore we speculate that PpWRKY18 regulates drought stress by interacting with these proteins, and may provide a theoretical basis for investigating the molecular mechanism of PpWRKY18 response to drought.
S-adenosylmethionine synthetase is a key enzyme in plant metabolism. In order to explore the mechanism in response of biotic and abiotic stresses, a full cDNA sequence of CtSAMS1 gene was cloned from Carthamus tinctorius L. cultivar Yuhonghua1hao based on the transcriptome data. Meanwhile, the bioinformatics analysis, tissue-specific expression analysis, and expression analysis under different abiotic stresses and hormone treatments were performed. The open reading frame (ORF) of CtSAMS1 gene was 1 173 bp, encoding a protein containing 390 amino acids with a calculated molecular mass (MW) of 42.7 kDa. Protein conserved domain analysis indicated CtSAMS1contained the conserved domain of methionine adenosyltransferase which belonged toS-adenosylmethionine synthase family. The phylogenetic analysis indicated that CtSAMS1 protein had the highest homology with SAMS protein from family Compositae. The results of real-time quantitative PCR showed that the expression of CtSAMS1 gene was the highest in flowers and stems, but very low in other tissues. The transcript level of CtSAMS1 gene increased with the degree of petal senescence. The transcript level of CtSAMS1 was induced by various abiotic stresses including salt, drought and cold. The transcript level of CtSAMS1 also induced by jasmonate (MeJA), salicylic acid (SA) and abscisic acid (ABA), but gibberellin 3 (GA3) can inhibited moderately the transcript ofCtSAMS1. These results provided valuable insights into the resistance mechanism of CtSAMS1 and cultivation of new varieties of Carthamus tinctorius L. stress resistance.
In order to develop SSR molecular markers and to study the universality of SSR primers in Lycoris spp., in this study, six species of Lycoris spp. including Lycoris radiata, Lycoris aurea, Lycoris chinensis, Lycoris longituba, Lycoris sprengeri, and Lycoris incarnata were RNA sequenced. SSR loci were detected and primers were designed. The validity and polymorphism of primers were detected by PCR amplification and capillary electrophoresis. The fingerprints of 17 species of Lycoris were drawn, and early detection of offspring authenticity in hybrids was carried out. The results showed that, a total of 404 481 Unigenes were obtained after de novo assembly. Five public databases were used for homology comparison and functional annotation. A total of 59 612 SSR loci were detected by simple sequence repeat analysis. Among them, the number of single nucleotide repeats>dinucleotide repeats>trinucleotide repeats, which accounted for 62.88%, 20.06%, and 14.66% of the total SSRs, respectively. There were relatively few repeats of four bases or more. Eight pairs of fluorescent primers were selected and synthesized for PCR amplification. In total, 60 polymorphic alleles were detected using eight SSR fluorescent labeling markers, with an average of 7.50 alleles per locus. The polymorphism information content ranged from 0.148 0~0.940 8, with an average of 0.593 0. The fingerprints of 17 species ofLycoris spp. were constructed according to the combinations of amplified bands. Primer QZ209 could distinguish all tested materials, and which could be used for the identification of hybrid offspring. In conclusion, the SSR markers developed in this study are rich in polymorphisms, which are of great significance in genetic diversity analysis, hybrid identification, and construction of a genetic map of Lycoris spp.
Auxin response factor (ARF) can specifically bind to the promoter region of response gene to regulate plant growth and development. In order to understand furtherly the number, basic characteristics, evolutionary relationship of ARF gene family in maize and the expression pattern of ARF in response to abiotic stress and hormone. In this study, the ARF gene family in maize was identified by bioinformatics, and the physiochemical properties and the phylogeny of proteins were analyzed. RT-qPCR was used to analyze the temporal and spatial expression patterns and their expression under high temperature, drought, salt and ABA treatment of fourZmARFs. The results showed that 36 ARFs genes were randomly and unevenly distributed on 9 chromosomes, and the amino acid length, molecular weight, isoelectric point and secondary structure of the encoding protein were quite different. The protein phylogenetic tree of sorghum, rice, Arabidopsis and maize showed that these ARF proteins are divided into four categories Ⅰ~Ⅳ. Maize ARF has the closest genetic relationship with sorghum ARF, and the farthest genetic relationship with Arabidopsis ARF, and there were intragenic and intergenic duplication occurs in maize.The cis-acting elements of promoter are main elements in response to drought, low temperature, oxidation and hormones. RT-qPCR results showed that the expression of ZmARF1,ZmARF6,ZmARF13 and ZmARF22 were higher in the tassel branches and embryos, but lower in the pollen. The four genes were significantly up-regulated when induced by high temperature, drought, salt and ABA, except that ZmARF22 gene had decreased expression after high temperature treatment. Subcellular localization indicated that the proteins encoded byZmARF1, ZmARF6, ZmARF13 and ZmARF22 are localized in the nucleus. The results of this study provide a theoretical basis for revealing the function of maize ARF protein and mining stress resistant genes, and also provide molecular resources for stress resistant breeding.
In order to obtain a highly resistant tomato material against Tomato yellow leaf curl virus (TYLCV), two double-stranded RNA (dsRNA) were designed to target the TYLCV virus genes V1 and C1, and were transformed in tomato by Agrobacterium-mediated, to explore the defense effect of RNAi technology in tomato against TYLCV. The results showed that interfering with V1 and C1 gene of TYLCV through RNAi can delay the occurrence of virus symptoms and improve the resistance of tomato plants to TYLCV. Field experiments found that RNAi strains, RNAi-CP-2 and RNAi-Rep-12, targeting TYLCVV1 and C1 gene, respectively, can not only interfere with the expression of V1 and C1, but also interfere with the other four genes of TYLCV, V2, C2, C3 and C4, which indicate that RNAi technology can ‘pass’ RNA interference along the target gene and affect the expression of other adjacent genes. This research lays a foundation for tomato antiviral research.
In order to investigate the structure and roles responding to microcystin-LR (MC-LR) Rab1A, one member of small GTPases family, the cDNA sequence of Rab1A gene in grass carp (Ctenopharygodon idella) was amplified using rapid amplification of cDNA ends (RACE). Grass carp Rab1A gene was 806 bp in length and had an ORF coding a predicted 202 amino acids protein. Sequence analyses showed that grass carp Rab1A gene was homologous to common carp (Cyprinus carpio) Rab1A3 gene. Phylogenetic analyses showed that grass carp Rab1A was assigned to a clade with common carp, zebrafish (Danio rerio) and other teleost. The grass carp Rab1A gene was ubiquitously expressed in all analyzed tissues from healthy grass carp as revealed by quantitative real-time (qRT-PCR), and was highly expressed in blood and gill. A special segment coding 1-202 AA of Rab1A was selected and cloned into pGEX-4T-1 vector to construct the prokaryotic expression vector pGEX-4T-1-Rab1A, and the polyclonal antibody of Rab1A was prepared. The antibody titer obtained by ELISA was higher than 1∶512 000. Western blot results showed that the antibody had specificity. The expression of Rab1A protein of grass carp liver was significantly down-regulated 100 μg·kg-1 for 96 h(P<0.05), but the expression were not significantly changed with 25 and 75 μg·kg-1 groups (P>0.05), which suggest thatRab1A gene might play an important role in defending grass carp against MC-LR stress. The above research results will provide a basis for further studies of the function of Rab1A and its roles in response to MC-LR.
Sucrose metabolism plays a critical role in plant development, stress response and yield formation. The growth and development process of the plant is promoted through the synthesis and decomposition of a series of sugars. As a signal factor, it participates in regulating the expression of related genes, and can interact with other genes, hormones, and defense signals. However, the coupling mechanism of sucrose metabolism and signal transmission between intracellular and external is different from the signal transduction mechanism of sucrose metabolizing enzymes. This article reviews the function of crucial sucrose metabolism enzymes in plant development and response to abiotic stresses. Combining with the current researches, the future research direction of sugar metabolism and its signal transduction has being proposed, which will contribute to understanding and improving the characteristics of plant growth and development as well as stress resistance.
The aim of the present study was to explore the distribution of stable isotopes in Chinese organic tea, and correlations with δ 15N indicator. 145 organic tea samples produced in certified companies were collected from different regions, and the stable isotope ratio (δ13C、δ15N、δ2H、δ18O) of organic tea were determined by elemental analyzer-stable isotope ratio mass spectrometry. The distribution of stable isotope characteristics was investigated using one-way analysis of variance and normal distribution model. The results showed that δ 13C values in organic teas were -31.0‰ ~ -23.7‰, with no significant differences among regions. The range of δ2H and δ 18O were -107.1‰ ~ -24.8‰ and 17.2‰ ~ 32.0‰, respectively, showing significant differences in organic teas produced from different regions. The range of δ15N values was -4.6‰ ~ 7.0‰ for normal distribution, and the average was 1.2‰. The tea samples produced from regions with large production area had significant higher δ15N values with the range of 1.6‰ ~ 5.8‰, than samples produced from regions with small production area (-2.5‰ ~ 0.4‰,P<0.01). This study suggested that δ15N value as an indicator of organic teas was correlated with the production area. The present study provides research basis for the application of stable isotopes in discrimination of organic teas, which also supplies theoretical basis for the certification and supervision of organic teas.
In order to explore the degradation of starch in postharvest fruit, the change of starch contents and the expression pattern of genes related to starch degradation in postharvest Hongyang and Cuiyu kiwifruits were compared and analyzed. Results showed that the firmness of Hongyang fruit decreased rapidly with the occurrence of ethylene climax, but the firmness of Cuiyu fruit decreased slowly without ethylene release peak. The starch content decreased with the prolongation of storage time. SEM results showed that with the increase of storage time, the smooth surface of the starch was digested and broken to different degrees, indicating the enzymatic degradation of starch occurred in the two varieties of kiwifruit. Meanwhile, it was found that the ethylene production of Hongyang fruit was significantly higher than that of Cuiyu fruit(P<0.001). During storage, the starch content in the outer pericarp of Hongyang fruit was significantly higher than that of Cuiyu fruit in the early storage period (0-2 d)(P<0.01), but significantly lower than that of Cuiyu fruit in the later storage period (8-12 d)(P<0.001); The starch content in the core of Hongyang fruit was not significantly different from that of Cuiyu fruit in the early storage period (2-4 d), but it was significantly lower than that of Cuiyu fruit in the later storage period (6-12 d). These results provide a theoretical basis for further revealing the mechanism of starch degradation in the postharvest of kiwifruit.
In order to investigate the effect of high relative humidity (HRH) storage on reducing chilling injury of eggplant fruit and its relationship to changes in antioxidant system, eggplant fruit were respectively stored in 4℃ dry-fog humidity controlled cold storage (96%~99% RH) and low relative humidity (LRH) cold storage (70%~75% RH) for 15 days in this experiment. Fruit samples were taken every 3 days during storage to compare and analyze the changes of related parameters. The results showed that, compared with LRH storage, HRH storage significantly inhibited the increase of chilling injury index, relative electrical conductivity and weight loss rate, maintained higher fruit firmness and total phenolics as well as total anthocyanin contents (P<0.05). Meanwhile, HRH storage significantly increased the activities of antioxidant enzymes like as superoxide dismutase (SOD), ascorbate peroxide (APX), catalase (CAT) and peroxidase (POD) (P<0.05), inhibited the production of hydrogen peroxide and superoxide anion, and maintained higher scavenging activity against 1,1-diphenyl- 2-dinitrophenylhydrazine (DPPH) and hydroxyl radicals. The above results suggested that HRH storage could maintain higher antioxidant system activity to inhibit the detrimental effects of reactive oxygen species, and thus reduce chilling injury of eggplant fruit during low temperature storage. This work provided a theoretical basis for the application of HRH storage in quality maintenance of postharvest eggplant fruit.
In order to study the effects of abscisic acid(ABA) on fruit quality of Cerasus humilis, two cultivars of Nongda 6 and Nongda 7 were used as experimental materials by spraying different concentrations and different times of ABA to determine the single fruit weight, soluble solid content (SSC), titratable acid content (TAC), total phenol content (TPC), total flavonoid content (TFC) and antioxidant capacity. The results showed that the content of TAC, TFC, TPC and antioxidant capacity of Nongda 6 fruit were all decreased by all treatments. For TAC, the effect of decreasing acid was more obvious after sprayed twice than that of sprayed once. However, TFC, TPC and antioxidant capacity were not affected by the changes of ABA concentration and sprayed times. The single fruit weight and SSC of Nongda 7 fruit were increased under all treatments. The TFC, TPC and antioxidant capacity of Nongda 7 fruit were greatly influenced by the changes of ABA concentration and sprayed times. After ranking according to principal component analysis, the comprehensive score of Nongda 6 fruit after different concentrations and different times of ABA treatment was lower than that of control group(CK), and the fruit comprehensive quality decreased. The comprehensive score of Nongda 7 fruit was higher than that of CK. When the concentration of ABA was 25 mg·L-1and sprayed once, the improving effect on fruit quality was the best. This study provided a theoretical basis for selecting the appropriate concentration and times of ABA spraying for improving the quality of Cerasus humilis fruit.
In order to determine the optimal extraction process of polygonatum polysaccharide (PPP), Polygonatum was used as the raw material using ultra-high pressure technology after processed. The effect of pressure strength, pressure holding time, solid-liquid ratio on PPP extraction rate were analyzed. Box-Behnken response surface analysis (RSM) was used to optimize the PPP extraction conditions, and the obtained polysaccharides were tested in vivo to analyze the changes in the content of related enzymes in serum, liver and left leg skeletal muscle in mice. The mechanism of improving exercise endurance was investigated. The results showed that the optimal extraction process conditions for PPP were: liquid-material ratio 23 pressure holding time 6.73 min, pressure intensity 293 MPa. Under these conditions, the PPP yield was 13.46%; which could significantly improve the exhausted swimming time of mice (P<0.05). Compared with the swimming control group, the contents of SUN, Lac and MDA in mice were significantly decreased (P<0.05), At the same time lactate dehydrogenase (LDH) decreased, ATPase and CK increased, which had a better effect of improving exercise endurance, and provided data support for the mechanism of PPP to improve exercise endurance.
In order to reduce the mould loss of peanut caused by drying in time after harvest, tianfu 9 fresh peanuts was used as the raw material. The fresh peanuts was dried to safe moistureby three different drying methods: hot air drying (AD), microwave drying (MD) and microwave couple with hot air drying (MWAD). The effects of different drying methods on nutrition and sensory quality of peanut were investigated. The results showed that the total drying time of AD、MD、MWAD to dry peanut to safe moisture content was 24h, 14h and 10h, respectively. Compared with the two drying methods of HD and WD, the contents of amino acid, fat and unsaturated fatty acid in MWAD peanuts were significantly higher (P<0.05), while the acid value and peroxide value were significantly lower (P<0.05). The peanut color was uniform and consistent which was the most similar to the natural fruit color of peanuts. The red coat is complete without shrinkage and shedding, and had better flavor qualities. The results of this study provide a theoretical basis for the mechanized drying of peanuts, and have a good application prospect in the field of loss reduction.
The Pushu32 sweet potato was used as material to explore the effect of postharvest humidity on the wound healing of sweet potato. After an artificially mechanical damage, the sweet potato was stored at 25℃ under different humidity(RH50% and RH80%). The lignin accumulation, weight loss rate, respiratory intensity, key enzyme activity, total phenol and flavonoid content during the healing process of the sweet potato were measured to evaluate the effect of humidity on the wound healing of sweet potato. The results showed that RH80% enhanced the formation of healing tissues for mechanical damaged sweet potato than RH50%; lignin accumulation peaked after 4d of healing. Compared with RH50%, RH80% treatment could significantly increase the activity of phenylalanine ammonialyase(PAL), peroxidase(POD) and polyphenol oxidase(PPO)(P<0.05), elevate the content of total phenols and flavonoids, bring-forwards the respiration peak and reduce the weight loss of the sweet potato. The correlation analysis revealed a significant correlation between lignin content with PAL, POD, PPO activity, total phenol and flavonoid content under RH80% healing treatment(P<0.05). This study provides the theoretical support to the wound healing of postharvest sweet potato.
To optimize the industrial production mode of dried Hypsizygus marmoreus by studying the effect of different drying methods vacuum freeze-drying without heating, heating vacuum freeze drying, heat pump drying and heat air drying on physical and nutritional quality. Nutrition components (protein, amino acids, reducing sugar, fat, ash, crude fiber), active components (polysaccharide, total phenolics, total flavonoid), physical characteristics (color, hardness, chewingness, microstructure) were taken as evaluation indices. The gray correlation analysis method was used for comprehensive evaluation. The results indicated that there were no significant differences in nutrition components (protein, amino acids, reducing sugar, fat, ash, crude fiber)of Hypsizygus marmoreus among different drying methods, while the content of total flavonoid (7.04%) and phenolics(0.6%) was the highest in vacuum freeze drying without heating, while the heat pump drying had the highest contents of polysaccharide (0.43%). The bright color and good texture profile, organization structure were found in vacuum freeze-drying. Grey correlation analysis results indicated that the quality of Hypsizygus marmoreus obtained by different drying methods were as follow: vacuum freeze-drying without heating > heating vacuum freeze drying> heating vacuum freeze drying >heat pump drying. In conclusion, heating vacuum freeze drying had the potential to be used to produce high-quality dried Hypsizygus marmoreus. These results could provide theoretical basis for further processing and utilization of Hypsizygus marmoreus.
Field experiments were conducted to explore the effects of tillage and fertilization on soil moisture and yields of forage maize (Zea may L.) in the semi-arid area of Northwest China. Taken forage maize Longsi 1 as the experimental material, four treatments were designed, including two tillage methods of traditional rotary tillage and vertical rotary subsoiling tillage and two fertilization methods of organic fertilizer and chemical fertilizer application, to investigate the effects of difference tillage and fertilization methods on soil water storage, water consumption before and after flowering, fresh and dry weight per plant, yield and water use efficiency of forage maize. The results showed that, compared with traditional tillage (T), vertical rotary subsoiling (VT) decreased 0-300 cm soil water storage, and water consumption after flowering, while increased water consumption before flowering, reduced the water consumption after flowering, and increase the total water consumption during the growth period. Organic substitution decreased the total water consumption of VT appreciably. Besides, VT increased dry- and fresh-weight per plant by 1.3%-10.6% and 4.9%-21.9%, respectively, at maturity. Plant height, ear length, ear diameter, grain number per row, 100-grain weight and double ear rate of forage maize also increased at various levels by VT, whereas bald head length decreased significantly. Compared with VT and chemical fertilizer (VTC), VTO increased grain yield by 1.8%-38.6%, and biomass yields by 1.2%-15.1% in wet years. VTO increased biomass yields by 4.9%-21.9%, WUE based on grain yield by 6.3%-34.8% and WUE based on biomass yield by 7.1%-21.5%, respectively, compared with other treatments in dry years. The results demonstrate that vertical rotary subsoiling tillage combined with organic fertilizer replacement technology can improve soil environment for crop growth, promote dry matter accumulation, enhance forage maize grain and biomass yields in wet years, and significantly increase biomass and water use efficiency (WUE) in dry years. The study provides a theoretical basis for high yield and high efficiency of forage maize in the semi-arid area of Northwest China.
In order to investigate the effects of slow-release fertilizer application stage on the yield and grain quality of fresh waxy maize, the yields of ears and grains, and contents of protein and starch in grains, iodine binding capacity, thermal and pasting properties of Suyunuo 11 under one-time application of slow-release fertilizer at sowing stage (SN15-0), three-leaf stage (SN15-3) and six-leaf stage (SN15-6) were studied, taking conventional fertilization mode (N15CK, basal compound fertilizer + topdressing urea in six-leaf stage) at the same fertilization level and zero fertilization as controls. Results indicated that fertilization increased the yield, the yields of fresh ears and fresh grains of the slow-release fertilizer treatments were significantly higher than that of N15CK. In comparison to SN15-0, the fresh ear yields were increased by 14.0% and 7.4%, and the fresh grain yields were increased by 14.6% and 2.0% for SN15-6 and SN15-3. The contents of starch, soluble sugar and protein in grains of SN15-6 were the highest among all the treatments. Postponing the application stage of slow-release fertilizer reduced the size of starch granules. The starch iodine binding capacity and maximum absorption wavelength of SN15-6 and N15CK were significantly higher than that of other treatments. Fertilization increased pasting and gelatinization (onset, peak, and conclusion) temperatures and decreased retrogradation enthalpy and percentage. The peak, trough, breakdown, and final viscosities of SN15-3 were the highest, whereas the setback viscosity, retrogradation enthalpy and percentage of SN15-6 were the lowest among all the treatments. In spring-sown fresh waxy maize production, postpone the slow-release fertilizer fertilization stage could increase yields of ears and grains, improve the contents of protein, starch and soluble sugar in grains, and reduce the size of starch granules. One-time application of slow-release fertilizer at three-leaf stage could improve grain pasting viscosities, while applying it at six-leaf stage could reduce retrogradation tendency. The results can provide theoretical basis and technical support for green, high-yield, high-quality and simple cultivation of spring-sown fresh waxy maize.
In order to investigate the variation of micro-ecological environment in rhizosphere soil and yield increasing mechanism of winter potato under different mulching cultivation. The effects of different mulching cultivations (Black Film Mulching, BFM; Rice Straw Mulching, RSM and Conventional Cultivation, CK) on soil bacterial community structure diversity, enzyme activity, physical and chemical properties and potato growth were analyzed by using the method of combining high-throughput sequencing with soil science. The results showed that, compared with RSM and CK, the influence of BFM on the above aspects was mainly as follows: first, BFM could improve the index of Chao1 bacteria in rhizosphere soil and the relative abundance of Proteobacteria in early growth stage, Acidobacteria and Genmmatimonadetes in the later growth stage, and Sphingomonas in the whole growth stage.At the same time, BFM significantly increased the activity of acid phosphatase and the content of available potassium. The contents of organic and available phosphorus content of BFM were significantly higher than RSM and CK in seedling stage, of which the organic content raised by 28.45% and 13.29%, and the content of available phosphorus increased by 29.62% and 16.62%, respectively. And the tuber swelling stage, the activities of sucrase and catalase of BFM were significantly higher than RSM and CK, of which the activities of sucrase raised by 18.71% and 158.32%, and the activities of catalase raised by 17.44% and 45.54%, respectively; At the same stage the rate of big potato and yield of BFM were increased by 20.15% and 17.90% more than that of RSM and CK, respectively. It was showed that soil bacterial diversity index was positively correlated with alkali hydrolyzable nitrogen, available potassium, organic matter and pH value. In conclusion, the bacterial diversity and enzyme activities of rhizosphere soil under different cultivation modes were mutually affected to maintain soil quality;black film mulching could improve the microecological environment of rhizosphere soil, increase soil biological activity and nutrient availability, and enhence the plant growth and development, the end result was an eventual increase in potato production. This study provides a theoretical basis for the effective guidance of winter potato production in Guangxi.
In order to investigate the mitigative effect of prohexadione-calcium (Pro-Ca) on soybean (Glycine max) root growth under saline-alkali stress, soybean variety Hefeng 50 (salt-tolerant) and Kenfeng 16 (salt-sensitive) were employed as the experimental material to study the effects of foliar spraying 100 mg·L-1 Pro-Ca on root growth characteristics of soybean, metabolism of reactive oxygen species, antioxidant enzyme activity, and osmotic regulation substances content under saline-alkali stress. The results showed that spraying exogenous Pro-Ca could alleviate the inhibition on root growth of Hefeng 50 and Kenfeng 16 under saline-alkali stress, and the root length, root fresh weight, and root dry weight were increased by 11.2% and 23.6%, 3.2% and 19.8%, 38.0% and 37.6%, respectively. Exogenous application of Pro-Ca up-regulated the activities of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), increased the levels of ascorbate (AsA) and glutathione (GSH), inhibited
To discover the biological effects of different phosphorus-releasing microorganisms on the seedlings of Chinses walnutCarya cathayensis Sarg., we isolated three phosphate-solubilizing strains (Pectobacterum cypripedii R7, Burkholderia sp. R8, and Enterobacter sp. R9) and four nitrogen-fixing strains (Paenibacillus glycanilyticus G2, Staphylococcus sp. G3, Pseudomonas sp. G4, and Bacillus sp. G5) from the rhizosphere of C. cathayensis. The four mixing inoculums (R7G5, R8G4, R8G5, R9G4) were prepared to use for soil inoculation on C. cathayensis seedlings, to measure the growth and physiological indexes and evaluate the inoculum effects on C. cathayensis seedlings. The treatment with distilled water was included as blank control. The results showed that the release of phosphorus of R9G4 and R8G5 mixture was significantly higher than that of other combinations after cultured in PVK liquid medium for 5 days. The mixing inoculums in the potted inoculation test could promote the growth ofC. cathayensis seedlings, R8G5 was substantially effective than other compound bacteria in promoting the growth of C. cathayensis seedlings. Root indexes such as length, surface area, total biomass, total phosphorus content, and soluble sugar content of C. cathayensis were significantly increased by 105.53%, 89.07%, 52.94%, 55.23% and 91.99% under R8G5 treatment compared with control treatment, resectively. Meanwhile, the R9G4 treatment improved the total phosphorus contents by 58.16% and net photosynthetic rates by 79.47% compared with control treatment, respectively. The results of this study provide an important basis for the further development of growth-promoting mixing microbial agents on C. cathayensis seedlings.
In order to investigate effects of extraction methods on extraction rate, three different extraction methods (hot water extraction, ultrasonic extraction and dilute acid hydrolysis) were used to extract polysaccharides from Agrocybe cylindracea spent mushroom substrate. The results showed that extraction methods had a great influence on the extraction rate of polysaccharides, and the dilute hydrolysis method had the highest efficiency among three methods. The optimum parameters were sulfuric acid 2%, extraction time 60 min, the ratio of material to liquid 1∶25 g·mL-1, extraction temperature 121℃. Under this condition, the polysaccharide extraction rate was up to 29.29%, which was 6.72 and 13.88 times higher than that of hot water extraction and ultrasonic extraction, respectively. The polysaccharides prepared by three extraction methods had good antioxidant activity and biological activity. Among them, the hot water extracting polysaccharide had better ABTS free radical and hydroxyl radical scavenging ability, while the dilute acid hydrolyzed polysaccharide had better DPPH free radical scavenging ability and reducing power. Polysaccharides prepared by different methods could effectively promote the germination of rice seeds and alleviate the inhibitory effect of copper ion on rice seed germination, especially on the root’s development. When the concentration of dilute acid hydrolyzed polysaccharide was 1 000 mg·L-1, the growth ratio of rice seed root length increased by 37.75% and 112.10% under control group or copper ion stress. The results of this study indicated that the extraction method not only affected the extraction rate of polysaccharides, but also had a great influence on its biological activity, which had a certain reference value for the development and utilization of polysaccharides from spent mushroom substrate.
In order to reduce the phytotoxicity of nicosulfuron on sweet maize (Zea mays L. seccharata Sturt), the response mechanism of the antioxidant system of sweet corn seedlings to nicosulfuron stress was explored. In this study, a pair of sister lines of sweet corn (sweet corn inbred line HK301 with resistance to nicosulfuron and sweet corn inbred line HK320 with sensitivity to nicosulfuron) were used to study the effects of nicosulfuron stress on oxidative stress, antioxidant enzymes, antioxidant non-enzymatic substances and key gene expression levels on sweet corn seedlings. The results showed that compared with control treatment (HK301-CK), in HK301, after nicosulfuron stress, the superoxide anion (
Drought stress is the most important abiotic stress factor affecting the growth and development and yield formation of wheat. With the adverse effects of excessive use of chemical fertilizer and global climate change, the harm of drought stress in the growth of wheat is becoming more and more serious. Plant growth promoting rhizobacteria (PGPR) can not only help wheat improve its nutrient utilization efficiency and promote its growth, but also help wheat to resist drought stress through its own action or various metabolites. In this paper, the mechanism of PGPR promoting growth was summarized, and the research progress of PGPR in improving wheat drought resistance was summarized from two aspects of physiological and molecular mechanism, which laid a theoretical foundation for the application research of using PGPR to improve wheat growth promotion and drought resistance.