10 October 2017, Volume 31 Issue 10
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1873-1880. https://doi.org/10.11869/j.issn.100-8551.2017.10.1873In order to increase the growth rate of strain wswshg-10 at low temperature and inhibitory activity to pathogens, atmospheric and room temperature plasma (ARTP) was applied for the screening of mutants. The results showed that the optimal irradiation time was 120s, at which the lethal rate was 95.4% and the large colony mutation rate was 24.5%. Two positive mutants WM4 and WM7 with rapid growth rate at low temperature and high inhibitory activity to pathogens were selected from 19 mutants by plate culture and dual culture methods. The growth rate of mutants WM4 and WM7 at 15 °C was 1.94 and 2.09 times the original strain and the inhibitory activity to pathogens was 26.2% and 29.8% higher than that of the original strain, respectively. Furthermore, strain WM4 and WM7 exhibited excellent genetic stability in terms of growth rate at low temperature and inhibitory activity to pathogens after 10 reproduction. Strain WM7 showed 70.8% control effect on maize basal stalk rot in greenhouse test, which was 15.1% higher than that of the original strain. This study will provide the potential strain to develop biocontrol agent for use in cold area.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1881-1888. https://doi.org/10.11869/j.issn.100-8551.2017.10.1881In order to establish an efficient genetic transformation system for stem apexes of brown cotton, Zongcaixuan 1 that belongs to upland cotton was used as materials for genetic transformation using Agrobacterium-mediated method. In this paper, the shoot tips from 7-day-old seedlings of Zongcaixuan 1 were selected as receptors, and co-culture time, co-culture temperature, bacteria OD600 and infection time were optimized by orthogonal test. In addition, the effects of the size of the shoot tip and the vacuum infiltration on the transformation efficiency were also studied, and the genetic transformation system of stem apexes from brown cotton was initially established. The results showed that the stem apexes with 0.5 cm hypocotyl were suitable for transformation, and the suitable conditions for Agrobacterium-mediated transformation were Agro bacteria concentration of OD600=1.0, infection time for 20 min, co-culture time for 72 h and co-culture temporature for 24℃. Moreover, vacuum osmotic treatment was helpful to the occurrence of resistant seedlings. At first, plantlets were screened on the medium containing 100 mg·L-1 kanamycin, and 102 resistant plants were obtained. Subsequently, these plants were further detected by PCR and Southern blot, and in total 24 transgenic plants were obtained with a single copy gene insertion. The transformation rate was 0.4 %. Furthermore, the optimization conditions for Agrobacterium-mediated genetic transformation of stem apexes of Zongcaixuan 1 were established in this study, which laid a foundation for the genetic transformation of brown cotton.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1889-1895. https://doi.org/10.11869/j.issn.100-8551.2017.10.1889In order to evaluate the breeding value of Aegilops comosa and Aegilops mutica for wheat improvement, the disease resistance and grain quality of Triticum turgidum-Aegilops comosa amphiplid and Chinese Spring-Ae. mutica amphiploid are identified or determined by artificial inoculation and near-infrared spectrometer, respectively. As a result, both amphiploids are nearly immune to wheat stripe rust and powdery mildew. Moreover, grain protein and wet gluten contents are significantly higher than those of control. Therefore, both amphiploids are excellent gene sources for backcrossing with current cultivated wheat varieties. In order to establish cytogenetic markers for the identification of relative cross progenies, both amphiploids are analyzed by oligo-nucleotides probe-fluorescence in situ hybridization (FISH), the result showed that probe (GAA)8could be used to detect Ae. comosa chromatin in wheat background, Oligo-pSc119.2-1, Oligo-pTa-535-1 and (GAA)8 combined together a could efficiently distinguish Ae. mutica from wheat chromosomes. The specific cytogenetic markers developed in this study could be used in screening and identifying of relative cross progenies containing Ae. comosa and Ae. mutica chromosome and laid a foundation for assistance selection of new wheat germplasm harboring useful genes of Ae. comosa and Ae. mutica.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1896-1903. https://doi.org/10.11869/j.issn.100-8551.2017.10.1896To provide basis for studying the mechanism underlying grafting induced wax content change, the 3461 cucumber was chosen as the scion and grafted onto Cucurbita ficifolia or Cucubita moschata. The expressions of wax synthetic genes (CsCER1, CsCER3, CsCER4, CsCER6, CsCER8 and CsCER10) were analyzed in cucumber/ Cucurbita ficifolia grafted strain, cucumber/ Cucubita moschata grafted strain and self-rooted cucumber at different fruit growth periods (2 days before flowering, the flowering day, 4 days after flowering, 6 days after flowering, and 8 days after flowering), and the miRNAs regulating the 6 waxy genes were also predicted by RNAhybrid, psRNATarget and RegRNA software. The main differences of the waxy genes' expression in cucumbers grafted onto different rootstocks were observed in the fruits at 4 days after flowering. The expressions of CsCER1, CsCER3, CsCER6, CsCER8 and CsCER10 genes were significantly higher in cucumber/ Cucurbita ficifolia grafted strain, compared with cucumber/ Cucubita moschata grafted strain and self-rooted cucumber. MiRNA projections suggest that cme-miR164 may regulate the expression of CsCER1, CsCER3, CsCER4, CsCER6 and CsCER10, cme-miR168 may regulate the expression of CsCER3, CsCER4, CsCER6 and CsCER10, and cme-miR390 may regulate the expression of CsCER6, CsCER8 and CsCER10. CsCER1, CsCER3, CsCER6, CsCER8 and CsCER10 are predicted to be the genes related with increased wax content in cucumber/ Cucurbita ficifolia grafted strain. Cme-miR164, cme-miR168 and cme-miR390 may regulate waxy genes, the results could provide theoretical basis for studying the mechanism underlying grafting induced wax content increase.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1904-1912. https://doi.org/10.11869/j.issn.100-8551.2017.10.1904In order to reveal the drought tolerance difference in seedling stage of sweetpotato from protein level, and to explicit the mechanism of drought tolerance, Jishu21 (JS) with strong drought tolerance and Jizishu1 (JH) with weak drought tolerance were chosen as research material. Dimensional electrophoresis and mass spectrometry were used to reveal differential expression proteins in seedling roots treated by hydroponic PEG-6000 to simulate a gradient drought stress in the field. As a result, total 567 differential expressed proteins were screened out in four comparable groups, and 302 differential proteins were up-regulated. The percentage of the protein which exceeds 20% coverage was 58.6% of the total protein number. GO analysis showed that differential proteins of JS in seedling stage were mainly focused on stress and abiotic stimulus response process, however, glycosyl compound metabolic and coenzyme metabolic process are involved in JH. Drought mainly affected the cytoplasm and cytosol of both varieties, and the molecular function of differential proteins are all refer to catalytic and oxidoreductase activity. Compared to the variety with weak drought tolerance, POD and CAD were up-regulated in roots of variety with strong drought tolerance in seedling stage under normal condition. Under drought treatment, the up-regulated differential proteins are mostly involved in phenylpropanoid biosynthesis pathway. Stress response proteins were mainly presented in seedling roots of JS, while energy metabolic proteins were mainly presented in JH. In one word, biosynthesis of secondary metabolism and energy metabolic process were greatly affected by drought in cytoplasm of sweetpotato roots in seedling stage, and oxidoreductase expression level was up-regulated in JS with strong drought tolerance. Physiological regulation ways responded to drought between sweetpotato with different drought tolerance in proteomic level were significantly different. The study can provide clues for physiological identification of drought tolerance sweetpotato and exploration of tolerance related genes.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1913-1920. https://doi.org/10.11869/j.issn.100-8551.2017.10.1913To improve the theoretical basis of reproductive biology and genetic improvement of jujube tree, megasporogenesis, microsporogenesis and development of female and male gametophyte of Zizipltus jujube Mill.cv. Dongzao were studied by means of squashing and routine paraffin section technique. The results showed that Dongzao consists of five anthers and each anther has four cavities. The wall of anther is composed of epidermis, endothecium, one or two middle layers and glandular tapetum, the development of anther wall belongs to fundamental form. Cytoplasmic division of microsporocyte is simultaneous type and most of the tetrads are tetrahedron after reduction mitosis. The mature pollen grain has three germ pores and three grooves, belongs to two-cell type. Dongzao has 2-locular ovary, anatropous ovule, ovules numerous, double integument and crassinucellate ovule. The tetrads from meiosis of megasporocyte spread linearly along nucellus. The chalazal megaspore is the functional one which undergoes three times mitosis and develops into amature embryo sac with 7 cells and 8 nucleus. Embryo sac is polygonum-type. The development of stamens is obviously earlier than pistil. There are abnormal and asynchronous phenomena in the development of microspore. The stamens and pistil are accord when flowers bloom. The development stage of megaspore and microspore is related to the morphological characteristics of flower. This study reveals that the basic phenomenon and rules in megasporogenesis, microsporogenesis and development of female and male gametophytes of Dongzao, and provides important reference for future embryology research and ploidy breeding in jujube tree.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1921-1930. https://doi.org/10.11869/j.issn.100-8551.2017.10.1921In order to investigate the regulatory mechanism of miR393 in the Betula luminifera under nitrate-starvation condition, the responses of miR393 and its target gene BlTIR1 and BlAFB2 to nitrate-starvation condition were detected. The tissue culture seedlings of clone G49-3 were used in the present study, which were divided into two groups. For the control (CK, normal N) treatment, we used liquid MS medium containing 15 mmol·L-1 KNO3. For the low nitrate (LN) treatments, we used MS formulation with 0.03 mmol·L-1 KNO3. Roots, stems and leaves were sampled at 1, 2, 4, and 21 d after CK and LN treatment, which also had the Re treatment. The complete cDNA sequences of BlTIR1 (GenBank number: KX771075) and BlAFB2 (GenBank number, KX771074) was cloned by RACE, the length of BlTIR1 was 2 387 bp,coding 582 AA,and BlAFB2 had 2 373 bp in length,coding 572 AA. Both of BlTIR1 and BlAFB2 contain a highly conserved F-box domain at N terminal, and five LRR domains. The BlTIR1 and BlAFB2 were validated to be the target genes of miR393 via 5'-RACE, and the cleavage site was between the 10th and 11th base. The expression patterns of miR393 and target genes BlTIR1 and BlAFB2 under low nitrogen stress were investigated through RT-qPCR. The results showed that miR393a had the highest expression level among three miR393 members, suggested it might play main regulatory role under low nitrogen stress. The expression level of miR393a was repressed at the beginning of nitrate-starvation treatment (2 d and 4 d), then ascended in roots and leaves. The abundance of miR393a was significantly upregulated in the Re treatment. The expression pattern of BlAFB2 was significantly negatively correlated to miR393a. The expression of miR393a in shoots increased significantly on day-4 nitrate starvation, while decreased significantly in Re treatment. Therefore, the expression patterns of miR393 and their target genes under low-nitrogen stress indicated that miR393 and its target genes BlTIR1 and BlAFB2 may play a regulatory function in response to low nitrogen stress. This study contributed to elucidating the regulation function of miR393-BlTIR1/BlAFBs in responses to low nitrate stress and the molecular mechanisms of responses to nitrate-starvation in B. luminifera.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1931-1937. https://doi.org/10.11869/j.issn.100-8551.2017.10.1931For excising redundant and potentially security concerned selectable marker genes in transgenic crops, the ubiquitin promoter, loxP sequence, coding regions of Cre-GR infusion gene and NPTⅡ selectable markder gene were amplified respectively. Afterwards, they were ligated into backbone vector pBRACT806 through restriction enzymes to construct a new vector for inducible deletion of selectable marker genes. The sequencing results showed that new plant expression vector pBLCK was constructed successfully. This vector includes Gateway cloning components for target gene recombination, NPTⅡ gene for screening positive transgenic plants, Cre-GR components for the inducible excisions of NPTⅡ and Cre-GR expression cassettes between two loxP sites, while keeping target gene in the host plant genome. Target gene with NPTⅡ and Cre-GR genes are under control of powerful ubiquitin booster, allowing the contitutive overexpression of these genes in crops. Hence, this study provide a new vector system to ensure the security of transgenic crops with the breeding value.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1938-1945. https://doi.org/10.11869/j.issn.100-8551.2017.10.1938To improve the quality control production of traditional fermented aquatic products during standardized producing process, the quality variation of solid-state fermented Chinese herring (Ilishaelongata Bennett) inoculated with L. sakei was studied. During the solid-state fermentation, physiochemical characteristics, chromaticity and texture of the hering were determined, respectively. Taste characteristic were analyzed by electronic tongue, sensory quality was evaluated by panels, and the correlation between the indicators were analyzed. The results demonstrated that during the fermentation, the pH decreased first and then increased, the minimum value was 4.88, and the water content was reduced. The total acidity increased first to the maximum of 13.4 g·kg-1 and then decreased, while the contents of amino nitrogen (ANN) and volatile basic nitrogen (TVB-N) increased. The coherence, hardness and chewiness were all increased at the beginning and then decreased, and reached the maximum of 0.6, 437.4 g and 217.8 g at day 9, respectively. However, the springiness and resilience were both steadily decreased. The color of the herring changed significantly (P<0.01), the L* value increased first and then decreased, a* value decreased and then increased while b* value increased continuously, and the product gradually showed a bright yellow fermentation color. Analysis of taste characteristics based on electronic tongue technique showed that the sour, bitterness, sweetness and compound taste were mainly formed during fermentation, while the freshness and salty ingreadients were relatively less. And the principal component analysis model (PCAM) we constructed could clearly distinguished samples in different fermentation time. The synthetic evaluation of sensory quality reached the maximum 72.8 on the 9th day. In conclusion, during the solid-state fermentation of L. sakei, physio-chemical characteristics, texture, chromaticity and taste quality of fermented fish were correlated, and each of them reached the best condition in the middle of fermentation. The optimum fermentation period was 9 days, which provided the theoretical basis for the processing of the fermented aquatic products.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1946-1954. https://doi.org/10.11869/j.issn.100-8551.2017.10.1946In this paper, for further development of corn silk, key factors related to the extraction yield of carotenoid from abandoned corn silk were studied such as extraction solvent, ultrasonic time, surfactant, extraction temperature, extraction time, liquid-solid ratio and stirring speed. The effects of light, pH value, nutrition element, and ultrasonic time on stability were also researched in this paper. The results showed that the optimum technology conditions were extraction solvent of acetone, ultrasonic time of 6 min, SDS disage of 1.6%, extraction temperature of 35℃, the extraction time of 45 min, liquid-solid ratio fo 13 mL·g-1 and stirring speed of 125 r·min-1, the extraction rate is 311.21 mg · kg-1, which is consistent with the theoretical prediction (value of 313.96 mg·kg-1). The carotenoid is sensitive to in bright light, extraction temperature, high acid-base property, nutrition elements such as Ca2+, Mg2+, Fe2+, Fe3+, Zn2+, and ultrasonic treatment for a long time. What the carotenoid relatively stable under dark surroundings, neutral environment, and nutrition elements such as Na+, K+were favorable for its preservation. Appropriate ultrasonic treatment can improve the extraction efficiency and save time and without significantly affecting the stability of carotenoids in maize.The efficient use of carotenoids in corn beetles is of great significance for deep processing of corn and reduction of environmental pollution。
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1955-1962. https://doi.org/10.11869/j.issn.100-8551.2017.10.1955The effect of the heat-shock treating on the color and texture properties of asparagus lettuces was determined. Central composite design (CCD) was employed to analyze the effect of the heat-shock treating temperature and time on the a* value, b* value, hardness, fracturability and chewiness of asparagus lettuces. Quadratic mathematical model was established after statistical analysis. The results indicated that the regression equations of a* value,hardness, fracturability and chewiness value were significant, but b*value was not significant. The heat-shock treatment temperature was the major influence factor of a* value and the heat-shock treatment time was the major influence factor of firmness, fracturability and chewiness. The optimum heat-shock treatment on asparagus lettuces was under 49.52℃ for 13.14 min,under conditions the indexes of a* value, firmness, fracturability and chewiness were-12.97, 40.86 N, 44.69 N, 17.96 mJ, respectively. In practical, relatively favourable colour and textures of asparagus lettuces could be obtained at heat-shock treating temperature of 50℃ with treating time of 14 min. The results provided technical supports for the application of heat-shock treatment on fresh-cut asparagus lettuces.
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Effect of Exogenous Melatonin on Sucrose Metabolism in Peach Fruit Exposed to Low Temperature StressJournal of Nuclear Agricultural Sciences. 2017, 31(10): 1963-1971. https://doi.org/10.11869/j.issn.100-8551.2017.10.1963In order to explore the mechanism of exogenous melatonin for chilling tolerance induction in postharvest peach fruit, the sugar contents and enzymes gene expression related to sucrose metabolism of Hujingmilu (Prunus persica L. Batsch.) fruit treated with 100 μmol·L-1 melatonin and stored at 4℃ were investigated. The results showed that application of melatonin with the concentration of 100 μmol·L-1 can significantly reduce the chilling injury of peach fruit after harvest. Peaches treated with 100 μmol·L-1 melatonin represented higher levels of glucose and sucrose than the untreated peaches. In addition, melatonin treatment inhibited the expression of sugar metabolism related genes, such as PpSPS3, PpSPP1, PpSUS1, PpSUS5, PpHK1, PpFK1 and PpFK3, and enhanced the expression of sugar synthesis related genes, including PpSPS1, PpSPS2, PpSUT1 and PpNI1 during storage. The chilling tolerance and storage quality of harvested peaches induced by melation treatment are associated with higher levels of sucrose and glucose. These results revealed that melatonin treatment could be used as a useful technique to alleviate chilling injury for cold-stored peach fruit.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1972-1978. https://doi.org/10.11869/j.issn.100-8551.2017.10.1972In order to investigate the inhibitory effects of SIME (squid ink melanin extracts) on cancer cells, in vitro test is applies with the anti-proliferative activity of SIME in human colon carcinoma HCT-116 cells, cervical cancer Hela cells, hepatoma HepG2 cells, breast cancer MCF-7 cells and prostate cancer PC-3 cells being assessed using the MTT (methylthiazolyl tetrazolium) assay. The effects of SIME on the cell migration were measured by the scratch assay. The results showed that the cells morphology was changed by the treatment of SIME. The proliferation rates of the cells were all negatively related to the SIME concentration. SIME had inhibitory effects on the non directional migration of cancer cells. SIME showed a better inhibitory effect against PC-3 and HCT-116 cells with IC50 (concentration of inhibitor required for 50% inhibition) values of 0.144 and 0.485 mg·mL-1. The results suggested that SIME have strong anti-tumor activities, which provides a theoretical basis for the utilization of squid ink.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1979-1985. https://doi.org/10.11869/j.issn.100-8551.2017.10.1979The optimum submerged culture medium for the Sparassis crispa and fermentaiton condition for its polysaccharides production were investigated using single-factor experimental design and orthogonal experimental design, with the mycelia dry weight and exopolysaccharides (EPS) as indexes. The results showed that the optimum processing conditions were as follows: the optimum carbon source of glucose, the optimum nitrogen sources of peptone, the optimum inorganic salt of magnesium sulfate, the optimum C/N of 20/1, initial pH value of 5.5, fermentation temperature of 27℃. Under the optimum processing conditions, the mycelia dry weight was 1.5 g·L-1 and the content of EPS was 2.87 mg·L-1. The results of this study can provide a theoretical basis for further research.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1986-1992. https://doi.org/10.11869/j.issn.100-8551.2017.10.1986In order to screen out the optimal Bacillus natto for clam fermentation to obtain ACE inhibitory peptides, six strains with high protease activity were separated from seven kinds of Japanese natto foods. With ACE inhibitory rate in vitro and peptides concentration as evaluation indicators, three strains of Bacillus natto (named GL-5, GL-12 and GL-25, respectively) were selected. The clam fermentation product with the strains above presented 71.55%,78.31% and 75.08% respectively for ACE inhibitory rate, and 8.12 mg·mL-1, 9.62 mg·mL-1 and 8.79 mg·mL-1for the peptides concentration, respectively. Thus, the clam fermentation product with GL-12 could still keep 68.31% ACE inhibitory rate after degradation by intestinal enzymes, which implicated its strong anti-digestive ability. The research results provided a certain scientific basis for the high-valued utilization of clams to produce functional foods which assist blood pressure reduction.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1993-1997. https://doi.org/10.11869/j.issn.100-8551.2017.10.1993Amaranthus spinosus L. is a kind of invasive plants,thorn amaranth pollen has become an important allergen in south China, and the Amaranthus spinosus L. pollen allergen easily with other cross-reactive allergens. To investigate the hypersensitivity, Amaranthus spinosus L. Pollen, allergen, the BALB /c mice were intraperitoneally injected with,sensitive nose drops stimulate the establishment of BALB /c mice allergy evaluation model. Through the on the nasal symptoms were observed and score, nasal secretion smear staining were observed and serum histamine and IgE content determination, and the anatomy of mouse lung were observed by HE staining to identify mouse induced by sensitizing dose. The results revealed that the content of IgE increased linearly with the increase of injection quantity,the content of IgE reached a maximum when the injection dose is 75 μg,the content of histamine also increased linearly with the increase of injection of low doses,and after the injection of doses reached 38 μg,the content of histamine changed slowly,75 μg injection doses can cause the serious anaphylactic reaction and inflammatory to lung infection.Amaranthus spinosus L. pollen allergy evaluation study provides a supplement to a comprehensive health risk assessment of invasive plants.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 1998-2006. https://doi.org/10.11869/j.issn.100-8551.2017.10.1998To explore whether the rice paddy culture could increase the yield and improve the quality of the rice by modifying the plant structure, by introducing a field contrast experiment, this paper studied part of the rice plant structure at the stage of tillering, booting, and full heading. The result showed that compared with the rice direct sowing treatment, the coupling of rice-duck-loach showed the following benefits: firstly, it promote the growth of the rice root length, plant height and increase the root shoot ratio as well as reduce fuitle tillering with steady tillering at the later growth period. Secondly, the coupling of rice-duck-loach improved the plant structure. The stem basal width decreased while the canopy width increased, giving plants more looseness. The opening angle and drooping degree of the third leaf and fourth leaf decreased and that of the flag leaf and second leaf increased. The upper part of the plants had larger leaf area and more chlorophyll, conducing to the accumulation of the shoot dry matter. Thirdly, the rice-duck-loach coupling increased the base leaf height and reduced the number of withered and aging leaves, and extened the function period of the leaves. The above results provide a theoretical basis for yield improvement of rice.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 2007-2015. https://doi.org/10.11869/j.issn.100-8551.2017.10.2007The objective of this study was to explore effect of nitrogen (N) applied rate and planting density on yield formation and rice quality of hybrid rice under different ecological conditions. Hybrid rice, Jingyou127, was grown under two N rates (medium nitrogen rate, MN, 120 kg·hm-2; high nitrogen rate, HN, 180 kg·hm-2) and three planting densities (12.0 hills·m-2, D1; 16.5 hills·m-2, D2; 22.5 hills·m-2, D3) in Deyang and Luzhou in Sichuan Province. Grain yield, yield components, biomass production and rice quality were measured for each treatment in each location. The result showed that the soil total N and available N contents in Deyang were higher than that in Luzhou. The mean solar radiation, maximum and minimum temperature from sowing (SO) to heading (HD) in Deyang were higher than that in Luzhou, while the mean solar radiation, maximum and minimum temperature from HD to maturity (MA) in Deyang were lower than that in Luzhou. The yield, brown rice percentage and milled rice percentage of the rice in Deyang were 14.3% to 24.3%, 0.9% to 1.9% and 0.7% to 5.3% higher than that in Luzhou, which was mainly due to the contribution of higher panicle number, spikelets per panicle, biomass and harvest index. In Deyang, rice yield decreased with N rate increasing, and increased with planted density increasing, the highest grain yield (10.87 to 11.72 t·ha-1) was recorded in the combination of medium nitrogen rate with high planted density. Similarly, hybrid rice had relatively high milling efficiency, appearance and cooking and eating characteristics under the combination of medium nitrogen rate with high planted density. In Luzhou, rice yield increased with nitrogen rate and planted density increasing. Under the combination of high nitrogen rate with high planted density, hybrid rice produced the highest grain yield (9.25 to 9.85 t·ha-1), and had relatively high milling efficiency and cooking and eating characteristics. Our results indicated that grain yield and rice quality of hybrid rice could be simultaneously improved by the optimal combination of N rate and planting density, but which varied with rice production region. For rice production in Deyang, the optimum combination is N 120 kg·ha-1 plus density of 22.5 hills·m-2, and N 180 kg·ha-1 plus density of 22.5 hills·m-2 in Luzhou. This study provides a theoretical basis for the optimum fertilizer management and planted density in different rice production region.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 2016-2022. https://doi.org/10.11869/j.issn.100-8551.2017.10.2016In order to explore the effects of microbial fertilizer on functional diversity of rhizosphere microorganisms in fertilizer-saving levels, the Biolog-ECO technology was adopted to study the effect of two microbial fertilizers(Jinnong No.1 and Degenbei) on carbon metabolism characteristics of rhizosphere microbe functional diversity in 4 fertilizer-saving levels(0%, 10%, 20% and 30%). The results showed that: the utilization ability of 4 carbon sources were decreased as the amount of chemical fertilizer reduction in groups treated with microbial fertilizer. The principal component analysis showed that there were difference between 2 kinds of microbial fertilizers on utilization of the four carbon sources. The preference of Jinnong No.1 were intermedia and secondary metabolites, while the preference of Degenbei were glucides, fatty acids and lipids. The richness index, dominance index and evenness index of groups treated with microbial fertilizer were significantly higher than those of CK in 4 fertilizer-saving levels (P<0.05). The fertilizer-saving proportion of two microbial fertilizers should be less than 20%, and the comprehensive effect of Degenbei was better than Jinnong No.1 on two aspects of rhizosphere microbial carbon source utilization ability, and metabolic diversity. The results provide a theoretical basis for the selection of microbial fertilizers and fertilizer-saving proportion in tobacco production.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 2023-2031. https://doi.org/10.11869/j.issn.100-8551.2017.10.2023To explore the effects of topping-control technology on nicotine content in upper leaves of flue-cured tobacco and its physiological indexes, improve the industrial availability of upper leaves, the dynamic changes of nitrogen, potassium and nicotine content and physiological indexes such as synthetase activity and endogenous hormone in upper leaves and root system in box plot by topping-regulation were studied in this paper. The results showed that dry matter accumulation in upper leaves and root follow the order of topping > keeping stem unremoved > keeping flower unremoved, and tobacco by topping and keeping stem unremoved were higher than that of keeping flower unremoved by 32.55% and 5.99% at 40 d. The contents of Nitrogen and potassium in upper leaves by keeping flower unremoved were the highest, but the accumulation of nitrogen and potassium in upper leaves by topping was the highest. Nitrogen and potassium accumulation in upper leaves by topping were higher than that by keeping flower unremoved by 39.73% and 40.35% at 40d. The nicotine content and accumulation in upper leaves and roots followed the order of topping > keeping stem unremoved > keeping flower unremoved. Nicotine accumulation of keeping flower and stem unremoved were decreased by 53.72% and 35.82% compared with the topping at 40d. The increase degree of root volume of keeping flower unremoved was low, root activity, ornithine decarboxylase (ODC), putrescine-N methyltransferase (PMT) and N-methyl putrescine oxidase (MPO) activity remained unchanged overall, and the content of auxin (IAA) changed a little; while root volume, root activity, ODC, PMT, MPO activity and IAA content of topping and keeping stem unremoved treatments significantly enhanced than those of keeping flower unremoved. Root activity, ODC and IAA content of topping were increased by 36.68%, 119.61% and 74.19%, respectively, compared with keeping flower unremoved at 10d. Root nicotine synthesis and root activity, the content of IAA and the activity of nicotine synthetase were positively correlated. Therefore, the technique of keeping topping and threshing affected the uptake of nitrogen and potassium and nicotine content in the upper leaves by adjusting the activity of nicotine synthetase, IAA content in the root, and weaken the capacity of root second growth and nicotine synthesis. The research lay in the improvement of the internal quality of upper leaves of flue-cured tobacco and improved its industrial availability.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 2032-2038. https://doi.org/10.11869/j.issn.100-8551.2017.10.2032In order to explore the response of the flue-cured tobacco growth and development characters (G & Ds), yield and quality to the fertilization technology,a comparative study of the response difference of the flue-cured tobacco G & Ds, yield and quality on three fertilizer application types of bio-organic fertilizer, green fertilizer and chemical fertilizer was carried. The result was showed that the treatment of bio-organic and green fertilizer combined with chemical fertilizer increased root system volume, improved photosynthetic leaves areas and net photosynthetic rate (Pn),accelerated flue-cure tobacco G & Ds, reduced soil-borne diseases,increased the ratio of first-class tobacco leaves, improved flue-cure tobacco leaves quality, and increased yield and out-put value. The indexes such as economic character index (ECI),chemical components usability index (CCUI),the ratio of the first-class tobacco leaves,yield and out-put value of the treatment with bio-organic manure were 88.7,71.0,72.1,43.68%,2 436.5 kg·hm-2 and 64 079.9 yuan·hm-2 respectively, higher than the other two kinds of treatment. Next was the treatment of green fertilizer combined with chemical fertilizer, followed by that of pure chemical fertilizer. The yield and out-put value of the treatment with combined application of bio-organic fertilizer was significantly higher than that of the other treatments. Consequently, the response effect of bio-organic fertilizer on the flue-cured tobacco growth and development characters,yield and quality to the fertilization technology is the best, and then comes the response effect of the treatment of green fertilizer combined with chemical fertilizer and that of the pure chemical fertilizer comes last. The above results provide effective measures for organic fertilizer and green fertilizer utilization and a theoretical basis for promoting the flue-cured tobacco quality.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 2039-2046. https://doi.org/10.11869/j.issn.100-8551.2017.10.2039In order to study the interaction of drought tolerance of Sophora viciifolia in Karst Mountain Area and exogenous calcium, and the drought-resistance mechanism, the seedlings of Sophora viciifolia were used in this study. PEG were induced to simulate the drought condition. One half concentration of hoagland nutrient solution without PEG was defined as control. The effect of calcium on the growth, physiological responses under drought stress induced by PEG were studied. The results showed that with the increase of drought stress induced by PEG, the root dry weight, root-shoot ratio, the content of MDA and the activities of CAT in Sophora viciifolia leaves increased gradually, which significantly higher than the control when the stress intensity of PEG was 10%. The content of soluble protein, the activities of SOD and POD in Sophora viciifolia leaves increased firstly and then decreased, which (except for POD) were significantly higher than the control and reached the maximum value when exposed to 10% of PEG. The above-ground biomass, net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr) in Sophora viciifolia leaves decreased. The above-ground biomass and Pn decreased significantly when the stress intensity of PEG was 10%. Gs and Tr decreased significantly when the stress intensity of PEG was 15%. The seedling of Sophora viciifolia took the strategy that increase the content of osmotic adjustment matter, the activities of protective enzyme, and the root-shoot ratio to adapt to the drought environment induced by PEG-6000. Under drought stress induced by PEG with the addition of Ca2+, the above-ground biomass, the scale of decrease of net photosynthetic rate(Pn), stomatal conductance(Gs), transpiration rate(Tr) and the degree of increase of the content of MDA were significantly reduced. The root dry weight, the increasing extent of soluble protein content, activities of SOD, POD and CAT were significantly increased. Therefore, Sophora viciifolia seedling increased the root dry weight, the content of osmotic adjustment matter and the activities of protective enzymes, decreased the transpiration rate, and protected the photosynthetic system under the drought stress induced by PEG with the addition of Ca2+. According to the results of subordinate function value analysis, 50 mmol·L-1 exogenous calcium application is the best choice to alleviate the impact of drought stress on Sophora viciifolia. The results provide the theory evidence for adequately and reasonably using the Sophora viciifolia.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 2047-2054. https://doi.org/10.11869/j.issn.100-8551.2017.10.2047In order to understand the photosynthetic characteristics of N. tangutorum Bobr. and N. sibirica Pall. adapting to salt stress, pot experiments were carried out under NaCl mass concentration of 8‰ for 40 days with the the control of no salt stress. The key parameters such as photosynthetic pigments, photosynthetic parameters, the activivity of Rubisco and PEPC, and the changes of δ13C of the leaves were measured. The results showed that the contents of photosynthetic pigments trended to decrease in two species under high salt stress. The Chl a, total chlorophyll content and Car content in the leaves of N. tangutorum Bobr. leaves decreased by 5.6%、2.1%and 11.3%,Chl b increased by 8.9%. And the contents of Cha, Chlb, total chlorophyll and Car of N. sibirica Pall. declined by 14.2%、15.4%,14.5% and 10.7%, respectively. But all the photosynthetic pigments decreasment were not significant (P> 0.05) from the control. The Pn of N. tangutorum Bobr. was 15.4% lower and N. sibirica Pall. was 10.0% higher than that of the control when the effective light radiation reached about 1000 μmol · m-2· s-1. But they were not significantly different (P>0.05) from the control. The activities of Rubisco, PEPC, Ci and Gs decreased by 9.9%, 8.3%,0.9% and 26.4% in the leaves of N. tangutorum Bobr leaves, respectively, while Ls was increased. These results indicated that the decrease of net photosynthetic rate was under the influences of stomatal and non-stomatal limitation in N. tangutorum Bobr.. The PEPC activity of N. sibirica Pall. leaves decreased significantly by 56.2%. Rubisco activity, Ci and Gs increased by 41.4%, 5.8% and 35.1%, respectively, and Ls decreased. The δ13C value increased by 1.9% and 1.4% for N. tangutorum Bobr and N. sibirica Pall., which was mainly due to the effects of salt on its physiological activities. Salt stress also led to the decrease of LCP and Rd by 30.5%, 38.6% for N. tangutorum Bobr and 15.9%, 27.1% for N. sibirica Pall.. Meanwhile, significant increase of CCP were 61.6% and 26.8% in the N. tangutorum Bobr. and N. sibirica Pall., respectively. The results suggested that salt stress reduced the metobolic activity of two species of Nitraria, but was not significantly decreased the Pn, indicating that these two species of Nitraria have high salt tolerance. The higher carboxylation efficiency of Rubiso was the reason why the NaCl salt tolerate ability of N. sibirica Pall. was stronger than that of N. tangutorum Bobr.. This study will provide physiological and ecological basis for using Nitraria to improve the saline land.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 2055-2062. https://doi.org/10.11869/j.issn.100-8551.2017.10.2055In order to investigate the mitigative effect of exogenous 5-aminolevulinic acid (ALA) on plant growth under salt stress, Prunella vulgaris seedlings were exposed to different concentrations of ALA (an exogenous nitric oxide donor)from 1.25 to 10.0 mg·L-1. The antioxidant capacities in the leaves and roots, the chlorophyll content and photosynthetic characteristics in the leaves of P. vulgaris seedlings were studied under salt stress of 70 mmol·L-1. The results showed that 1.25~5.00 mg·L-1ALA could increase the activities of peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), the content of soluble sugar, chlorophyll a(Chla), chlorophyll b(Chlb), total chlorophyll(Chl a+b), carotenoid, the net photosynthetic rate (Pn), stomatal conductance (Gs) and transpiration rate (Tr), meanwhile reduce intercellular CO2 concentration (Ci) at different extents. Exogenous ALA could significantly alleviate the damages of salt stress on P. vulgaris seedlings and promote the salt resistance by improving the antioxidant enzyme activities, the content of osmotic adjustment substances and the photosynthetic capacities; furthermore, 5.00 mg·L-1 ALA was considered to be the optimal concentration. This study provided a theoretical basis for the application of ALA in reducing the toxicity of salt stress to P. vulgaris seedlings.
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 2063-2071. https://doi.org/10.11869/j.issn.100-8551.2017.10.2063In order to clarify the influences of heritable variation degree,variation pattern and geographical factors of germplasm and grain of Tibet highland hullessbarley on grain phenotypic characters, define the critical characters determining the grain phenotype and provide a fundamental model of grain phenotype for the breeding of Tibet highland hullessbarley, this study employed 527 material form Local cultivar and wild relatives of hullessbarley, precisely measured seven phenotypic characters including grain length, grain width, grain length-to-width ratio, grain area, grain roundness, density index and thousand seed weight(TKW) of 527 germplasm resources of cultivated and wild sibling Tibet highland hullessbarley by means of digital image analysis accoroling to the grain phenotypic character changes and relevent geographical factors of germplasm resources of Tibet highland hullessbarely. Typical correlation analysis, clustering analysis, principal component analysis were conducted using SPSS20 and R language software. Results showed that grain phenotype of Tibet highland hullessbarley had wide variation types, with the variable coefficient of TKW being the biggest and that of the grain length being the smallest. Geographical factors such as elevation, longitude and latitude had significant correlation with seven grain phenotypic characters by canonical correlation analysis(α=0.05)。 The increase of elevation increased the grain size, grain length-width ratio and grain roundness while decreasing the grain length. The increase of longitude and latitude showed positive correlation with the grain length and certain relation with the TKW. According to the clustering analysis of seven phenotypic characters, these 527 highland hullessbarley materials could be classified into 3 groups, with each in a certain geographical zone.The principal component analysis indicated that the TKW, grain area, grain width and grain density of highland hullessbarley can represent the seven phenotypic characters in terms of variation,and grain width, thousand seed weight and grain area mainly to indicate grain sizes and the other group of length-width ratio, grain length and roundness mainly to indicate grain shapes.This research showed that germplasm resources of Tibet highland hullessbarley have rich grain phenotypic variation which has significant correlation with changeable geographical factors.The phenotypic characters of highland hullessbarley can be divided into one group of with contribution rates of 60.3% and 33.8% respectively, and showed independent hereditary characters. The indicators of grain sizes should be emphasized firstly before considering those of grain shapes during the future breeding of highland hullessbarley.This study provides a theoretical basis for the breeding of high yield cultivation of hullessbarley in Tibet
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Journal of Nuclear Agricultural Sciences. 2017, 31(10): 2072-2079. https://doi.org/10.11869/j.issn.100-8551.2017.10.2072In order to explore effect of different concentrations of selenium(Se) on plant growth, chemical index and mineral nutrients, the growth, chemical index and contents of mineral nutrition (N, P, K, Ca, Mg, Mn, Zn, and Cu) in roots, stems and leaves were determined in Yunyan 87 by pot culture. The results showed that the contents of mineral nutrition (N, P, K, Ca, Mg, Mn, Zn, Cu) in roots, stems and leaves of flue-cured tobacco reached the maximum value at 4.4 mg·kg-1 of Se treatment, and the contents of Nicotine, reducing sugar and protein in leaves of flue-cured tobacco were within the optimum range. Selenium at low levels (Se≤4.4 mg·kg-1) stimulated the growth of flue-cured tobacco by enhancing the uptake of mineral nutrition, especially for N, K, Ca, Mg and Mn, and ultimately promoted the growth of flue-cured tobacco as well as the chemical composition was more harmonious. However, high Se levels (Se≥11.1 mg·kg-1) depressed the absorption of mineral nutrition, especially for N, P and K, and ultimately inhibited the growth of flue-cured tobacco. Therefore, different Se concentration in soil affected the growth and chemical index of flue-cured tobacco by regulating the absorption of mineral elements in plants. This research provides a theoretical basis for the guidance of Se-rich agricultural production.
