13 March 2015, Volume 29 Issue 3
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 413-420. https://doi.org/10.11869/j.issn.100-8551.2015.03.0413Rice lesion mimic mutant is useful material for studying systemic resistance mechanism. 156 lesion mimic mutants were acquired through irradiating the dry seeds of indica rice 93-11. These mutants can be divided into 9 types based on the shapes of the lesions. Most lesion mimics began to appear in 4 to 5 weeks after sowing. Two mutants spl078 and spl104 have displayed enhanced resistance to both rice blast and bacterial blight disease comparing with the wild-type 93-11 in vivo experiment. The expression profiles of disease resistant related genes PBZ1,POC1,PR1,PAL3 and POX22.3 in spl 073, spl078 and spl104 investigated by the real-time PCR assay showed that the genes in spl078 and spl104 were up-regulated. The relationship between the lesions formation and the expression of the disease related genes indicated that the expressions of the disease related genes were significantly changed when the lesions brought out. While they were almost stable after lesions formation. This research has provided the useful rice materials for understanding the broad-spectrum resistance to the multiple pathogens and disease resistant breeding.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 421-427. https://doi.org/10.11869/j.issn.100-8551.2015.03.0421To further find an effective way of delaying or resolving the rice premature senescence, we isolated an early leaf senescence mutant from ‘Zhehui7954’ with 350Gy gamma ray irradiation. It was investigated that the mutant, named els-R7954, kept normal at seedling stage but leaves showed etiolating at tiuer stage, and the whole plant withering at the later filling stage. Genetic analysis and gene mapping suggested that this trait was controlled by a single locus which was preliminarily mapped between SSR marker RM530 and RM3774 on chromosome 2, with a distance of 5.0cM from RM530. This study not only lays a foundation for els gene cloning and explanation of molecular mechanism of leaf senescence, but also provides a possibility of improving the yield and quality of rice.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 428-434. https://doi.org/10.11869/j.issn.100-8551.2015.03.0428A brittle stem mutant ‘Zhejing 88GH’ was obtained from japonica rice variety ‘Zhejing 88’ by irradiated mutation with 60Co gamma rays. M (a) ule reagent was used to measure the composition of lignin in ‘Zhejing 88 GH’. Lignin monomer composition in cortex and vascular bundle area in the mutant is different from that in the wild type ‘Zhejing 88’. PCR and gene sequencing for the candidate genes within the target regions of 90kb on Chromosome 2 showed that there was a mutation in the 191st base in the first exon (C to G) of LOC_Os02g09490. The gene family spectrum and the three-dimensional structure of LOC_Os02g09490 protein were also analyzed. qRT-PCR result showed that this gene was constitutively expressed in roots, stems and leaves in ‘Zhejing’ 88 while has low expression level or even no expression in ‘Zhejing88 GH’. Furthermore, with subcellular localizations of two vectors using Agrobacterium-mediated transformation, LOC_Os02g09490 was first localized in both nucleus and cell membrane.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 435-441. https://doi.org/10.11869/j.issn.100-8551.2015.03.0435Germplasms with dwarf are valuable for the wheat breeding. Two dwarf wheat-Thinopyrum ponticum germplasms, 31505-1 and 31505-2 were used to do the molecular identification and genetic analysis. The results revealed that 31505-1 and 31505-2 were two different wheat-Th.ponticum translocation lines. Line 31505-1 contained the chromatin from Th. ponticum, which was translocated onto chromosome 2D of wheat. Plant heights and internode lengths of the hybrids populations of dwarf wheat-Th.ponticum lines and other varieties with different heights were analyzed. The plant height of F1 reduced 16% to 23%, which was determined by the change in the lengths of internodes. In particular, the second internode was correlated significantly with plant height.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 442-447. https://doi.org/10.11869/j.issn.100-8551.2015.03.0442In order to determine the salt and alkaline tolerance indexes of Peanut Varieties and evaluate their saline alkaline tolerance, 47 peanut varieties and breeding materials were grew in the breeding field and the saline alkali land. The 9 salt and alkaline tolerance indexes such as stem height, branch length, branching number, full fruits etc. were measured in harvest. The principal component analysis method was used to analyze their indexes. Results show that, in addition to branching number, 8 indexes are divided into 4 main factors. 41 peanut were divided into 5 categories by cluster analysis according to the score plot of all factors. The analysis showed P31、P48 were highly saline-alkaline tolerant. P45, P86, P109 etc. six cultivars were saline-alkaline tolerant. While P92, ‘Huayu 28’,G37 etc. eighteen cultivars were medium saline-alkaline sensitive and P24,G52,P29 etc. sixteen cultivars were saline-alkaline sensitive, ‘Huaxuan10',P125,P18 etc. five materials were highly saline-alkaline sensitive. A few varieties were high tolerant or sensitive, most were intermediate tolerant and the general distribution was normal. These results laid foundations for selecting and breeding salt and alkaline tolerant cultivars.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 448-453. https://doi.org/10.11869/j.issn.100-8551.2015.03.0448Mutants are important materials for investigating plant gene function and developing new crop variety. In our previous study, a non-function of the transgene and stably inherited dwarf mutant dl (dwarf line) was found in the progenies of transgenic tomato. To elucidate the phenotypic and genetic characteristics of this mutant, the differences in phenotype between the mutant dl and wild type LA4024 in different growth stages were comparatively analyzed in the present study. Compared with the wild type, the dl mutant showed shorter internodes, dwarf, more branches, underdeveloped roots, and all tissues and organs of the mutant plant become smaller, including leaf, flower, fruit, and seed. The plant height of the dwarf mutant dl could be recovered by exogenous spray application of gibberellin, but not influenced by exogenous application of auxin, suggesting dl is a gibberellin-deficient mutant. Genetic analysis of F1, F2, and BC1 population derived from the cross dl/LA4024 revealed that the mutant phenotype of dl was controlled by a single recessive gene. These results laid a basis for mapping, cloning and functional analysis of the dl gene.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 454-461. https://doi.org/10.11869/j.issn.100-8551.2015.03.0454The development of pear stone cell is closely related to the synthesis, transfer and deposition of lignin. Caffeic acid o-methyltransferase (COMT) is a key enzyme in the lignin biosynthesis pathway that mainly catalyzes Syringyl lignin. In this study, a COMT gene named PbCOMT (GenBank Accession No. KC905086) from Pyrus bretschneideri cv. Dangshan Su fruit using RT-PCR and RACE methods was cloned. The PbCOMT cDNA comprises 1371 bp, with an ORF of 1098 bp, which encodes a putative protein containing 365 amino acid residues. Phylogenetic analysis indicated that PbCOMT shared high similarity with other plant COMTs, and showed 94% homology with apples. Furthermore, a prokaryotic expression vector pET-32a-PbCOMT was constructed and transformed into E.coli BL21(DE3). Then a fusion protein with molecular mass 60.0 kD was produced. Fluorescence quantitative expression analysis showed that the change of PbCOMT expression level was similar to that of lignin content, and also had great relevance with stone cell development rules. The present study is to elucidate the molecular mechanism of stone cell development in pear, which will provide a basis for further researches on the regulation of stone cell content and the improvement of pear taste.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 462-471. https://doi.org/10.11869/j.issn.100-8551.2015.03.0462Superabsorbent polymers are a kind of novel functional polymer network that can uptake and retain a large amount of aqueous liquid. In this work, a starch-graft-polyacrylaic acid superabsorbent crosslinked by N,N’-methyl bisacrylamide (MBA) was prepared under 10 MeV simultaneously electron-beam irradiation at room temperature. The functional structure and surface morphology were confirmed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The effects of monomer-to-starch ratio, irradiation dose, crosslinker-to-monomer ratio and neutralization of monomer were evaluated via orthogonal experiments. The variation of all the above factors can affect the absorption of starch grafted copolymer significantly, with an order of neutralization > AA/St > MBA/AA > irradiation dose. Optimization treatments were carried out with a AA/St ratio of 3.5 g ·g-1, a total dose of 6 kGy, a MBA/AA ratio of 5 mmol ·mol-1 and a neutralization degree of 70%. The copolymer obtained under the above conditions showed maximum absorption of 435 g ·g-1 in deionized water. The result of this work would widen the application of EB irradiation in the field of polymer preparation.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 472-477. https://doi.org/10.11869/j.issn.100-8551.2015.03.0472Irradiation has important significance in pest prevention. In order to solve the insects on phosphine resistance problem in stored grain, the irradiation biological effects of 0 to 1 000Gy electronic beam on phosphine resistant and susceptible of Tribolium castaneum (Herbst) were studied, and the irradiation susceptibilities were compared. The results showed that the lethal effects of Tribolium castaneum (Herbst) were varied with the irradiation dose, and the lethal rules of two strains were similar. Moreover, it was found that the irradiation susceptibilities of phosphine resistant and susceptible of Tribolium castaneum (Herbst) had the diversity, but there was no significant difference between them. Furthermore, it was discovered that the adults of the two irradiated by the doses 200Gy could prevent off spring reproduce. Thus, 200Gy irradiation could be considered as a reference dose for the controlling development of Tribolium castaneum (Herbst) in stored grain. The technical support can be provided to pest prevention by electron beam irradition in this theory, and the application of irridiation technology can be promoted in the green grain storage.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 478-483. https://doi.org/10.11869/j.issn.100-8551.2015.03.0478To develop straws reasonably and reduce environmental pollution, a simultaneous irradiation technique of 60Co-γ rays is adopted to graft acrylic acid on to straws. The structural feature of straws, preprocessed straws, and graft copolymer is also analyzed, in which FTIR and XRD are used. The effects of the method of preprocessing straws, the dose of irradiation, the dosage of cross-link agent and monomer ratio on the water absorption and salt resistance of the graft copolymer is studied. The study shows that when the synthesis condition is the straw fibers processed by 9% NaOH and 6% urea solution, the irradiation dose of 4.5 kGy, the monomer ratio of 1:15 and the cross linking agent of 1.2%, a higher water absorbency ratio of 463 could be achieved, or under the condition of the dosage of 1.5% cross linking agent, an salt water absorbency ratio of 125 could be reached, which overcomes the problems of traditional method of more serious pollution, higher energy consumption, and poorer water retention.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 484-492. https://doi.org/10.11869/j.issn.100-8551.2015.03.0484Starch noodle is a popular starchy food, the nutrient value and people’s dietary structure can be enhanced through adding sweetpotato flour. The AOAC methods, scanning electron microscope (SEM), differential scanning calorimetry (DSC), swelling power, solubility and retrogradation rate were used to evaluate the influence of the amount of purple sweetpotato flour (0%, 5, 8%, 10%, 12%, 15%) on the properties of sweetpotato starch, and the texture and cooking properties of starch noodle were also investigated. The result showed that with the increasing of the amount purple sweetpotato flour, the swelling power, solubility, retrogradation property and the a* value of sweetpotato starch were significantly increased, gel strength, viscosity and brightness of sweetpotato starch were significantly decreased, and the thermal properties of sweetpotato starch was also significantly changed. At the same time, the color, texture and cooking properties of sweetpotato starch noodle were significantly decreased with the increasing of the percentage of purple sweetpotato flour. The effect of the percentage of purple sweetpotato flour on the physico-chemical properties of sweetpotato starch was significant. Furthermore, the quality properties of starch noodle were better when the percentage of purple sweetpotato was 12%. This study provided basic data for the research and development of sweet potato nutritional starch noodle.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 493-498. https://doi.org/10.11869/j.issn.100-8551.2015.03.0493In order to study the quality of three breeds sweet potato under the storage temperature of 4℃and 10℃ (refrigeratory storage), the moisture, starch, reducing sugar content, PPO activity and structure index were measured.Through the study of quality sweet potato storage at different temperatures change, provide reference for sweet potato storage and processing.Result showed that, the storage temperature on the moisture, the content of starch and reducing sugar and PPO activity, and the indices such as hardness, chewiness of the sweet potato has significant difference (P<0.05), and on the springiness, gumminess of the sweet potato has no obvious effects (P>0.05). Therefore, it could keep the quality of the ipomonea batatas Lam more effectively under the storage temperature of 4℃.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 499-505. https://doi.org/10.11869/j.issn.100-8551.2015.03.0499The feasibility of using near infrared (NIR) spectroscopy and multivariate analysis as tools to identify the extracts of Ganoderma lucidum and Versicolor was studied for the purpose of supervising the extracts. In the wavelength range of 800 to 12 500nm, a set of pure and real extracts of Ganoderma lucidum and Versicolor collected from different companies were used as the representative training set of authentic objects. Indentification models based on the NIR spectra were developed using principal component analysis (PCA) and partial least squares (PLS).146 samples were used to build the model, 48 external samples were used to test the model. By the PCA model, the results showed that excellent classification could be obtained after optimizing spectral pre-treatment with the correct rate of 87.5%. By the PLC model, the correct rate was100%. The results indicated that NIR combined with classification techniques could be a suitable technology for the classification of the extracts of Ganoderma lucidum and Versicolor,at the same time, the investigation provides the theoretical support and practical method for rapid identification of the extracts of Ganoderma lucidum and Versicolor.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 506-512. https://doi.org/10.11869/j.issn.100-8551.2015.03.0506Pneumatophorus japonicus meat is easy to rotten. To extend the shelf life of fresh P. japonicus meat, the histamine content, total volatile basic nitrogen (T-VBN) value, sensory quality and the indexes of lipid oxidation such as peroxide value(POV) and relative content of unsaturated fatty acid (UFA) were measured, then the effects of packing mode and potassium sorbate on the freshness, lipid oxidation and histamine generation of P. japonicus meat during refrigeration were evaluated. The results showed that during refrigeration at 4℃, vacuum packaging was slightly more effective than common packaging for controlling the lipid oxidation and increase of T-VBN value, but the difference was not significant. During the late period of storage, common packaging was better than vacuum packaging in the control of histamine generation. Under refrigerated conditions, lipid oxidation process of P. japonicus meat was relatively slow, relative content of unsaturated fatty acid had not significant decrease. Before common packing, P. japonicus meat were soaked in potassium sorbate solution of 5%, its shelf life could prolong 4d than the control group. So fresh P. japonicus meat was soaked with potassium sorbate before refrigeration, its shelf life could be extend. The purpose is to improve its edible quality and safety.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 513-520. https://doi.org/10.11869/j.issn.100-8551.2015.03.0513Rice resistant starch has attracted more and more attentions for its important physiological functions and values in food industry. The classification and determination of resistant starch were briefly introduced, and the latest research progress on determination, physicochemical properties and physiological functions of resistant starch in rice as well as rice resistant starch industry were reviewed. It was intended to provide some references for breeding of rice rich in resistant starch and the development of resistant starch rice industry.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 521-527. https://doi.org/10.11869/j.issn.100-8551.2015.03.0521To provide an excellent plant resource for vegetation restororation in salve land region. In this study, The potential mechanism of saline resistance in three shrubs, i.e., Atriplex nummularia, Atriplex canescens, Lycium barbarum L.was investigated by accessing the growth, carbon isotope discrimination, photosynthetic parameters and mineral element contents under NaHCO3stress in pot experiments. The results showed that three shrubs exhibited a high capacity to induce net growth accumulation., as well as a higher net photosynthetic rate(Pn), stomatal conductance (Gs), transpiration rate(Tr), water use efficiency(WUE), stomatal limitation(Ls) and a low intercellular CO2 concentration of Atriplex nummularia and Atriplex canescens supplied with 150mmol ·L-1 NaHCO3, whereas Lycium barbarum L. showed a relative lower accumulation. A high carbon isotope discriminationΔ13C of three shrubs was observed with 150 mmol·L-1 NaHCO3 treatmentwhen compared with that of control. The higher concentration NaHCO3 treatment, the lower mineral element K and Ca contents and the more Na connect were detected in leaves of Atriplex nummularia and Lycium barbarum L.On the contrary, the 150mmol.L-1 NaHCO3 treatment induced mineral element K and Ca accumulation and decreased Na accumulation. Carbon isotope discrimination Δ13C of three shrubs was positively correlated to water use efficiency, and significant negative correlations was found between Δ13C and Na of Atriplex nummularia and Lycium barbarum L. The results suggested the growth, biomass and photosynthetic efficiency of Atriplex nummularia and Atriplex canescens might be achieved by adaptable alakali stress.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 528-537. https://doi.org/10.11869/j.issn.100-8551.2015.03.0528In order to reveal the effect of sowing date on yield and characteristics of photosynthesis and matter production of different types in mechanical transplanted rice. A comparative study of effect of sowing date on yield and characteristics of photosynthesis and matter production of different types in mechanical transplanted rice was conducted, through setting six sowing dates based on the annual-yield of rice and wheat production conditions in the Lixiahe rice district, by using blanket seedling mechanical transplanting method with three types of hybrids between Indica and Japonica rice variety ‘Yongyou 2640’ (large panicle-type) and super rice variety ‘Wuyunjing 24’ (multiple panicle-type) as materials. Results showed that both the grain yields decreased significantly with the delayed sowing date, but the decrements varied. Along with the delayed sowing date, the growth date was delayed, the growth stage was shortened and the accumulative temperature of the key growth stage was declined. Field experiments proved that the yield components of different rice were influenced by sowing date as follows. The panicles and 1 000-grain weight were almost not influenced by sowing date, but the spikelets per panicles and seed setting rate varied greatly. Different types showed different response to the sowing date. Along with the delayed sowing date, the photosynthetic potential in each key growth period decreased. The crop growth rate and net assimilation rate rise at the early growth stage but obviously descended at the middle and late growth stage. The leaf area index and dry matter accumulation increased slightly in the jointing stage, but relatively reduced at heading and maturity stages. The Decreasing rate of leaf area displayed a rising trend. The harvest index declined. To attain high yield, both the rice cultivars should be sowed early according this research. Because Early sowing could establish a solid matter fundamental for high yield or super-high yield, through properly adjusting the rate of dry matter accumulation in key growth period of mechanical transplanted rice, and form a high-quality-group that the population is smaller in the early period, population structure is optimized more properly in the middle period, and potential of photosynthesis and matter production is more strong during the late period". But from the view point of the security for reproduction, Every cultivar should be seeded no later than June 15. If the sowing date is delayed, the large large panicle-type rice should not be used, to avoid the risk of planting and lower the cost of production, yet the delayed sowing date of large panicle-type rice should be advanced to June 5. Conclusions about sowing date of the different varieties of mechanical rice was tentatively set in this paper, in order to provide a reference for the high yield and high efficient production of mechanical rice.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 538-548. https://doi.org/10.11869/j.issn.100-8551.2015.03.0538To investigate the effects of irrigation amount on the growth and physiological indexes of drip irrigated spring wheat, test-pit experiments were carried out with four treatments of different water supply: 315, 360, 405, and 450 mm. The influences of irrigation amount on the spatial and temporal distribution characteristics of soil moisture and the growth and photosynthetic physiological indexes of drip irrigated spring wheat were evaluated. The results showed that: Treatment W3 displayed the smallest differences of spatial and temporal distributions in soil moisture. Increase in irrigation amount can enhance the growth and photosynthesis of wheat, but over-irrigation can cause decreases in leaf area, above-ground biomass, ear quality, net photosynthetic rate and stomatal conductance, namely with the order W3>W4>W2>W1. Regression analyses showed that plant height and transpiration rate were significantly related to irrigation amount (R2=0.99). With the smallest differences in the spatial and temporal distributions in soil moisture, the maximum above-ground biomass and leaf area and ear quality, and fairly high water utilization rate, the quota of 405 mm was considered the best irrigation amount for the accumulation and reasonable allocation of photosynthate, The results can provide theory basis to the production practice for scientific and reasonable efficient irrigation management.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 549-556. https://doi.org/10.11869/j.issn.100-8551.2015.03.0549This article explores the DCPTA(2-(3,4-dichlorobenzene oxygen radicals)-ethyl-diethylamine) regulation mechanism on improving the cold resistance of maize and the optimal spraying concentration, thus to slow down the persecution of low temperature on maize seedling stage. Two maize varieties,Fenghe1 (low temperature sensitive) and Jiulong5 (cold resistance) as experimental materials, under the low temperature condition of 14℃/5℃ (day/night). The effects of different concentrations DCPTA on the activity of three kinds of antioxidant enzymes (CAT、SOD and POD),cell membrane permeability and MDA content, DPPH(1,1-Diphenyl-2-picrylhydrazyl radical 2,2-Diphenyl-1-(2,4,6-trinitrophenyl)hydrazyl) clearance rate of reactive oxygen species, soluble protein content and soluble sugar content. Under low temperature stress, the results showed that different concentrations DCPTA can improve SOD、POD and CAT activity in maize; reduce the content of MDA; significantly improve soluble protein content, soluble sugar content in maize and DPPH clearance rate of Reactive oxygen species. Under low temperature stress, appropriate concentrations DCPTA can improve the activity of antioxidant enzymes, the contents of antioxidants and osmotic regulation substances, thereby reducing the accumulation of reactive oxygen species (ROS) and membrane lipid peroxidation products MDA in leaf, enhancing the resistance of two different types of seedlings against low temperature stress. The most suitable concentration is 50 mg ·L-1, and it is more effective to improve the cold resistance range of cold sensitive maize to low temperature stress. Providing theoretical evidence for the physiological mechanisms of exploring the effect of increasing cold resistance of maize seedlings by DCPTA.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 557-562. https://doi.org/10.11869/j.issn.100-8551.2015.03.0557For research the effects of nitrogen uptake and distribution in soybean, Using soybean cultivar ‘HeFeng50’ in Sanjiang Plain in Heilongjiang as test materials and taking15N tracer method for leaves nitrogen application in R5 to study the nitrogen uptake and distribution of different soybean organs. The results show that there were no signification increments in dry weight, nitrogen content and nitrogen accumulation if the nitrgen application rates were over 4.5kg·hm-2(N3)and the percentages of soybean seeds dry weight increase over contral were 2.51%,5.01%,9.55% and 0.51%. The seeds weight had the highest value of 21.8 g ·plant-1 in 4.5kg·hm-2 (N3)treatment. The different organs15N accumulation were seed > leaf > pod > petiole > root under the same nitrgen application rate. The15N accumulation of different organs were increased with the nitrgen application rates increased and the seed 15N nitrogen accumulation had the highest value of 8.17 mg ·plant-1 under the different nitrgen application rate. The 15N distribution in seeds reduce with nitrogen application rates from N1 to N3 treatment, but there was a reverse trend in leavse and the seed 15N nitrogen accumulation was increased at the same time. This research theoretically proved that the nitrogen main accumulated to the seeds when leaf nitrogen application in R5 period and in favour of the seeds dry weight accumulation and got high yield at last.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 563-570. https://doi.org/10.11869/j.issn.100-8551.2015.03.0563Millet is small seed which has poor ability of ground-breaking and always exist lacking seedings in production. In order to investigate effects of Polyacrylamide on millet seed germination under drought stress, an experiment was conducted using foxtail millet cultivar ‘Jingu 21’ to study the influence of seed soaking with different Polyacrylamide concentrations (0.1%,0.5%,1.0%,5.0%,7.0%,10.0%) on seed germination and physiological characteristics of millet seedlings under 18% PEG-6000 of water stress and soil drought stress. Under water stress, the germinating ability of foxtail millet was significantly lower than that of the ck1(P<0.05), and the activities of superoxide dismutase (SOD),peroxidase (POD) and catalase (CAT), proline content (Pro), superoxide anion content (O2-) and malondialdehyde content (MDA)were increased but the soluble protein contents decreased in millet seedlings. By soaking seed with 1.0% to 7.0% PAM, the seed germination and seedlings growth were promoted significantly, the activity of antioxidant enzymes in active oxygen scavenging system and the contents of osmotic adjustment substances increased effectively, but O2- and MDA content apparently decreased under drought stress. The study indicated that the optimum concentration of PAM is 5.0％. The results showed that seed soaking with suitable Polyacrylamide concentrations could mitigate the injury of drought stress to seeds germination and seedling growth of millet, and enhance the plant's drought resistance. This results provides a theoretical basis for the application of PAM in production.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 571-576. https://doi.org/10.11869/j.issn.100-8551.2015.03.0571Hydroponic experiment was focused on the effect of aluminum (Al) and cadmium (Cd) single and combined treatments on the plant growth, toxic metals accumulation and physiological metabolisms for stress resistance in water spinach after cultured well for 3 weeks in pH 4.5 solution simulating acid soil. The results showed that seedlings growth, presented as dry weight of roots and shoots, as well as chlorophyll content were enhanced by 10 μmol·L-1 Al or 0.5 μmol·L-1 Cd single treatments. However, the stress treatments of 100 μmol·L-1 Al and 5.0 μmol·L-1 Cd both increased Al or Cd accumulation in plants, enhanced the activities of peroxidase (POD) and superoxide dismutase (SOD), as well as the contents of malondialdehyde (MDA) in leaves, but decreased leaf chlorophyll content and plant dry weight. Furthermore, the combined stress of Al and Cd caused more the accumulations of Al and Cd both in roots and shoots, and induced more severe growth inhibition and oxidative stress as compared with metals single treatment, indicating that Al and Cd was synergistic in inhibiting plant growth and inducing oxidative stress in water spinach.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 577-586. https://doi.org/10.11869/j.issn.100-8551.2015.03.0577With the large-scale development of aquaculture industry, a large number of roxarsone (ROX, a kind of veterinary drug)-containing manure are being applied to vegetables as organic fertilizer. Whether ROX's large application will reduce the yield and quality of vegetables or not is noteworthy. The common leafy vegetable, Amaranthus mangostanus, was selected in this paper to suspect these effects. Results showed that ROX treatment inhibited the elongation of radicles and root systems which led to the decrease of the height, leaf area and biomass of seedlings. The results of chlorophyll fluorescence parameters (Fv/F0 and Fv/Fm) implied that ROX could damage the PSII structure and function of A. mangostanus leaves, which led to a decrease in photosynthetic capacity. Contents of reductive ascorbic acid (AsA), glutathione (GSH) and anthocyanin increased with the increase of ROX, While contents of inorganic nutrient, soluble sugar and soluble protein were relatively stable. ROX treatment promoted the accumulation of As and nitrate in A. mangostanus. The As content in the edible parts was beyond the arsenic content limits of food and vegetable in WHO, FAO and China, and the nitrate content had reached moderate and severe pollution level. Given all that, veterinary drug ROX residue in the soil, will not only inhibit seed germination and seedling growth, reduce vegetables' yield, but also may reduce the vegetables' quality, improve human cancer risk through the accumulation of arsenic and nitrate.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 587-594. https://doi.org/10.11869/j.issn.100-8551.2015.03.0587In order to examine the phytoremediation potentiality of perennial ryegrass to heavy metal Cd2+, the accumulation characteristics, growth and physiology response of perennial ryegrass to Cd2+ stress were illustrated in this paper. The plants were treated with 0,5,10,20 mg ·L-1 Cd2+ solution for 6 days, when 6 days after treatment(dat), the growth of perennial ryegrass was significant inhibition by Cd2+,Cd content of leaf and root were significantly elevated with increasing Cd2+ concentration, perennial ryegrass represented hyper-accumulative ability for Cd. When 6dat exposed to 5mg ·L-1 Cd2+, the root, shoot biomass and the ratio of root to shoot were significantly decreased by 36.83%,12.17%,27.59% compared with control. The net photosynthesis rate(Pn) was significantly decreased by 23.38% compared with control when 6dat under 5 mg/L Cd2+ stress, whereas other gas exchange parameters, the photosynthetic pigment content and the maximum photochemical efficiency(Fv/Fm), potential photochemical efficiency(Fv/ Fo) were not affected significantly. When photosynthetically active radiation(PAR) exceeded 580μmol ·m-2 ·s-1 after 6 days treatment by 5 mg ·L-1 Cd2+ concentration, the effective photochemical efficiency(ΦPSII) and relative electrons transport rate(rETR) were lower than control, and the inhibition degree strengthened with the increasing PAR, when the PAR reached to the higest intensity(1 465μmol ·m-2 ·s-1), they were both significantly decreased by 15.46%.,whereas the regulatory energy dissipation [Y(NPQ)] was significantly higher than control all the time, this would alleviate the damage of photosynthetic agency induced by the excess excitation energy. When 6dat exposed to 5 mg ·L-1 Cd2+ concentration, the activity of superoxide dismutase(SOD) and ascorbic acid peroxidase(APX) were both inhibited, the activity of catalase(CAT) was promoted, and the content of Malondialdehyde (MDA) was significantly increased. The Pn, rETR, and SOD,APX activity could be taken as the physiological indexes to indicate the impair extent of perennial ryegrass by Cd2+. The conclusions of this study would provide reference for remedy plants breeding on the heavy metal pollution.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 595-604. https://doi.org/10.11869/j.issn.100-8551.2015.03.0595The work investigated the effects of different cadmium stress on the growth and nutrient characteristics in white clover. A controlled pot-experiment was arranged with different treatments of six cadmium concentrations to investigate the growth characteristics, biomass production and accumulation and distribution of carbon (C), nitrogen (N), phosphorus (P) and potassium (K) in white clover. The results indicated that the petiole length in white clover declined with increased cadmium supplies, while the laminae size, taproot length, fiber number, fiber length and shoot height showed the trend of increased at first, and then decreased. The cadmium accumulation of plant roots, stems and leaves increased with increased cadmium supplies. Moreover, cadmium distribution pattern under different cadmium treatments showed the same order as root>stem and/or root >leaf. Meanwhile, the plant organs biomass production and C, N, P and K accumulation showed the trend of increased at first, and then decreased. The treatments with higher cadmium concentrations (50.00, 100.00 and 200.00 mg ·kg-1) significantly inhibited white clover biomass and C, N, P and K accumulation, as well as altered their distribution patterns, while the treatment with lower cadmium concentration (control) had no significant effects. Treatments with lower cadmium concentrations (12.50 and 25.00 mg ·kg-1) decreased N, P and K use efficiency, and both the highest use efficiency of N, P and K were observed under the treatment with the highest cadmium concentration (200.00 mg ·kg-1). To a certain extent, white clover has stronger tolerance to cadmium contamination. These results suggested that white clover has some potential applications in the remediation of cadmium-contaminated soil, which also provide some scientific reference for forage security monitoring and evaluation.
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Journal of Nuclear Agricultural Sciences. 2015, 29(3): 605-615. https://doi.org/10.11869/j.issn.100-8551.2015.03.0605The stable isotopes have many features, like with a long period of stable isotopes decay, without experimental time limit, high sensitivity, the external environment impact and so on, The applications of stable isotope in animal scientific research are primarily in two ways: stable isotope tracer methods(SITM) as a tracer; analysis the stable isotopes in animals by the stable isotope ratio analysis (SIRA). This paper provides an overview of research progress of stable isotope in animal tissues and organs on studies of animal feeding and the establishment of trophic level, animal food traceability, animal product quality identification, animal nutrition and medicine and so on, as well as the amount and distribution of commonly used stable isotopes of carbon, nitrogen, hydrogen, oxygen and other elements in animal tissues and organs. This paper has pointed out some problems of stable isotope studies in animal food traceability and inadequate surviving, and the aspects of stable isotope using in animal tissues and organs in the future has been discussed.
