10 December 2019, Volume 33 Issue 12
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2311-2318. https://doi.org/10.11869/j.issn.100-8551.2019.12.2311In order to create excellent planting materials for maize germplasm innovation and variety improvement, dry maize seeds of inbred line LY8405 were irradiated by12C6+heavy ion beams under different doses of 0 (control), 30, 60, 90, 120 Gy and the biological effects of progeny plants after irradiation were compared and analyzed in detail. The analysis results showed that with the increase of irradiation dose, the germination rate, plant height, ear position height and pollen vitality of LY8405 in M1 generation were significantly decreased compared to the control. The physiological damage detection index of M2 offspring irradiated with the same dose was some recovered, but was still significantly lower than that of the control. The germination rate, plant height and ear position height of M1 and M2 irradiated by 90 Gy and 120 Gy showed extremely significant differences from that of the control. When the radiation dose was 30 Gy, a variety of agronomic phenotype mutants were screened in M2 and M3, indicating that the biological effects by 30 Gy was the most obvious for inbred line LY8405, followed by 60 Gy. At the same time, 60 Gy was the threshod of semi-lethal dose. The mutation types of M2 and M3 including dwarf, lower ear position height, wrinkled leaf blade, yellowish leaf, white and mottled leaves, larger and longer spike, red cob instead of white, wine red grain color from yellow, and grain shape changing from dent corn to flint corn. Biological studies showed that 30-40 Gy is the suitable irradiation dosage for breeding maize inbred LY8405 with 12C6+ heavy ion irradiation within the scope of 0-120 Gy. This study will provide a method and dose reference for the creation of new germplasm resources of different maize inbred lines, and more important, it also provide some stable genetic materials for the selection and breed of new maize varieties.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2319-2327. https://doi.org/10.11869/j.issn.100-8551.2019.12.2319To establish an efficient and stable regeneration system for Dendrocalamus asper, different concentrations and combinations of plant hormone and organic additives, as well as low light treatment were conducted by using shoot tips in proliferation buds from embryo as explants. The results showed that MS medium supplemented with (0.5~1) mg·L-1 NAA and 3 mg·L-1 2,4-D was the optimum medium for callus induction, with the frequency of granular and compact callus to 61.7%. The suitable medium for shoot differentiation was MS medium supplemented with 1 mg·L-1 6-BA, 1 mg·L-1 KT, and 1 mg·L-1 NAA, with low light (10 μmol·m-2·s-1) treatment for 6 days, with which the highest differentiation rate reached up to 46.67%. The most suitable rooting medium was 1/2 MS medium supplemented with 3 mg·L-1 IBA with the rooting rate of 55%. The resulting roots were sturdy coupled with lateral roots developed partly. Rooted plantlets were transferred to artificial mixture with the survival rate up to 83.33%. The regeneration system of the shoot tips in proliferation buds from embryo of D. asper was established, providing guidelines for the research and application of the genetic transformation system of Dendrocalamus asper.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2328-2337. https://doi.org/10.11869/j.issn.100-8551.2019.12.2328To detect peanut genes associated with stress resistance. A novel mitogen-activated protein kinase kinase gene, named AhMKK4, was isolated from the leaf of peanut (Arachis hypogaea L. cultivar Huayu 20) using PACR-PCR. The full-length cDNA of AhMKK4 is 1 434 bp, including a 966 bp ORF, a 317 bp 5'UTR and a 151 bp 3' UTR. The ORF encodes 322 amino acid protein with the predicted molecular weight of 36.74 kDa, which belongs to the group D MAPKKs in plants. Further, subcellular localization analysis showed that AhMKK4 was located in the nucleus and cytoplasm in plant cells. The analysis of RT-qPCR showed that the highest expression of AhMKK4 was in roots, revealing that AhMKK4 was tissue specific expression gene. The expressions of AhMKK4 were induced by JA and IAA, and were not induced by SA and ABA. These results suggested that AhMKK4 may be involved in JA and IAA mediated signal pathway of peanut. The expression of AhMKK4 was induced distinctly under salt stress, suggesting that AhMKK4 may participate in the salt stress regulation of peanut. This will provide genetic resource for peanut resistance breeding.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2338-2346. https://doi.org/10.11869/j.issn.100?8551.2019.12.2338To explore the mechanism of phytoene synthase gene (PSY) and phytoene desaturase gene (PDS) in leaf coloration?emerging of Acer palmatum. Sequence of PSY and PDS gene was cloned by RT?PCR using the leaf of Acer palmatum cultivar Goldenstemmed, their bioinformatics were analyzed and the gene expression in leaves of different leaf color varieties and at different growth periods were detected. The results showed that the length of ApPSY cDNA sequence was 1 497 bp, with a full open reading frame of 1 257 bp, encoding 418 amino acids. The length of ApPDS cDNA sequence was 1 974 bp, with a complete open reading frame of 1 692 bp, which encode 563 amino acids. Bioinformatics analysis showed that ApPSY and ApPDS protein were hydrophilic protein, with no signal peptide and transmembrane structure. The phylogenetic tree analysis showed that the ApPSY and ApPDS protein of Goldenstemmed had close relation ship with Citrus maxima, Citrus x paradisi and Citrus sinensis. qPCR results indicated that the relative expression of ApPSY gene was the highest in coloration?leaf stage and yellow cultivars Goldstemmed, while ApPDS gene was the highest in formed?leaf stage and orange cultivars Orange Dream. The results provided a theoretical basis for further elucidating the biological functions of ApPSY and ApPDS genes in Acer palmatum.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2347-2353. https://doi.org/10.11869/j.issn.100-8551.2019.12.2347In order to explore the antifungal effect of endophytic fungi from allelopathic rice on plant pathogenic fungi and its influence on physiological characteristics of rice, totally twelve strains of endophytic fungi were isolated from an allelopathic rice accession 6173. Using Thanatephorus cucmeris,Magnaporthe oryzae and Fusarium moniliforme Sheld as indicative fungi strains, antibacterial activities of the isolated endophytic fungi were studied with the plate confrontation method, then the antifungal activities of fermentation products from the antagonistic strains were further screened by the Oxford cup diffusion method. Moreover, heat stabilities of fermentation products from the selected antagonistic strains and their effects on activities of enzymes related to protection in non allelopathic rice 93067 were studied. The results showed that the endophytic fungi REF-04 exhibited the strongest inhibition effect against pathogenic fungi, inhibition rate to Thanatephorus cucmeris reached 50.63%. Ethyl acetate extract of fermentation product from the REF-04 had the best inhibition effect on Thanatephorus cucmeris, and its inhibitory zone diameter reached 18.6 mm. Ethyl acetate extract of the REF-04 fermentation product also showed high heat stability compared to other endophytic fungi, and its fermented liquid could significantly improve the activities of AL,SOD and POD in rice seedlings. The present results indicate that fermentation products from the endophytic fungi REF-04 has a good bacteriostatic activity and can improve activities of the protective enzyme of rice, which may have certain application and prospect for the development of biological pesticide.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2354-2361. https://doi.org/10.11869/j.issn.100-8551.2019.12.2354To determine the dominant pathogenic fungi of postharvest water bamboo shoot, the pathogenic strains were isolated from decayed samples at room temperature by tissue separation method and identified by morphological identification and rDNA-ITS sequence and TEF-1α gene sequences analysis. The biological characteristics were further investigated. The results showed that three pathogenic fungi were isolated and one of them could cause spoilage in pathogenicity tests, which was identified as Fusarium graminearum. For mycelial growth and sporulation of F. graminearum, the suitable culture temperature ranged from 20℃ to 30℃, and the optimum temperature was 25℃. Lethal temperature was 55℃ for 10 min. The strain grew well in medium or alkaline medium. The strain could produce spores when pH ranged from 4 to 11 and the optimal pH value for sporulation was 6. For mycelial growth, the optimal carbon source was mannitol and the optimal nitrogen source was yeast extract. For sporulation, the optimal carbon source was D-fructose and the optimal nitrogen source was ammonium sulfate. This study would set up a theoretical reference and targeted technical guidance for the preservation and prolongation of the shelf-life of water bamboo shoot.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2362-2375. https://doi.org/10.11869/j.issn.100-8551.2019.12.2362Starch is the predominant reserves in rice seed. Rice yield and eating quality are influenced by starch content, structure and its physicochemical properties. With the continuous developments of molecular biology, more and more rice genes related to starch biosynthesis are being cloned, and the mechanism of starch biosynthesis is gradually clarified through the study of rice starch mutants. This review summarized current understanding of starch structure and biosynthesis through the starch mutants including waxy, amylose-extender, chalkiness, floury, dull, sugary and shrunken mutants. It will provide useful references for studies on biosynthetic pathway and breeding of good quality cultivars in rice.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2376-2383. https://doi.org/10.11869/j.issn.100-8551.2019.12.2376In order to improve the storage quality of Coral dealbatus, it was used as a test material in this paper, and the effects of different concentrations of cinnamon essential oil on postharvest storage quality of Coral dealbatus at 4℃ was studied. The results showed that proper cinnamon essential oil concentration could effectively maintain the color and alleviate weight loss, yellowing rate and decay rate of Coral dealbatus, and retard decline of contents of Vc, chlorophyll, total phenols, flavonoids and oleanolic acid. Moreover, cinnamon oil could inhibit the activity changes of POD, SOD and CAT during storage, and delay the senescence process of Coral dealbatus. Coral dealbatus treated by 6 μL·L-1 cinnamon essential oil fumigation, presented the best color and the highest contents of Vc and chlorophyll; The Coral dealbatus with cinnamon of 8 μL·L-1 cinnamon essential oil had the lowest rot rate, and the highest contents of total phenols, total flavonoids and oleanolic acid, as well as the smallest activity changes of the activities of POD, SOD, CAT. Altogether, suitable cinnamon essential oil concentration could effectively preserve the postharvest quality, and extend the shelf life of Coral dealbatus, which provided technical support for reducing post-harvest losses of Coral dealbatus.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2384-2391. https://doi.org/10.11869/j.issn.100-8551.2019.12.2384To identify the pathagen of black spot rot in postharvest blueberry in Taian, Shandong province, traditional morphological identification method in combination with rDNA-ITS analysis and phylogenetic tree were conducted on the pathogenic fungal strain isolated from rotten blueberry. The results showed that the strain was identified as Alternaria alternate. Antifungal effects toward A. alternata of five kinds of essential oils including cinnamon, thyme, clove, lemongrass and palmarosa were tested in vitro in order to select the optimum oil specie and concentration. The results showed that all the essential oils exhibited different degree of antifungal activity cinnamon bark oil exhibited the most obvious antifungal effect on Alternaria alternate, and the MIC and MFC were 0.03 μL·mL-1 and 0.06 μL·mL-1, respectively. With the concentration of 0.03 μL·mL-1, cinnamon bark oil could effectively reduce rot incidence after artificial inoculation in vivo. In addition, compared to the control group, the configuration of mycelium treated with cinnamon oil was destroyed with some deformation such as shrinkage and rough appearance through scanning electron microscope (SEM). The results can provide reference for prevention and green control of black spot rot during storage of blueberry in Shandong province.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2392-2404. https://doi.org/10.11869/j.issn.100-8551.2019.12.2392The study aimed to investigate the differences of soft-boiled chicken made from 3 different types of raw chicken and discuss the possibility of using chilled or frozen chicken, instead of hot fresh chicken for making soft-boiled chicken. Xueshan chickens subjected to different treatments (hot fresh, 15 ℃; chilling, 4 ℃; freezing,-18 ℃) were used as raw materials. The soft-boiled chicken was made by adopting a traditional cooking method, the soft-boiled chicken was made. The pH value, contents of organic acids, nucleotides, free amino acids and volatile compounds of soft-boiled chicken were measured. Results showed that there were no significant differences in IMP and total free amino acids contents among chickens from 4 chilled treatment groups and those from two hot fresh treatment groups (2 h and 4 h). However, the chicken from 4 chilled treatment groups had higher volatile compound values and succinic acid contents than those from hot fresh treatment groups (2 h and 4 h). Moreover, the contents of IMP in chicken from hot fresh 1 h treatment group was significant higher than those from chilled treatment groups (P<0.05), but it had lower volatile compound values. The content of hexanal in chickens from frozen treatment groups (60 d and 90 d) were significant higher than those from hot fresh or chilled treatments groups, while other indexes values and total free amino acids were lower. No significant differences in most volatile and taste compounds were found among chickens from frozen treatment groups (7 d and 30 d) and those from hot fresh or chilled treatments groups. The results indicate that it is feasible to use chilled or short-period frozen chicken to make soft-boiled chicken, which could provide theoretic support for the commercialized production of soft-boiled chicken.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2405-2413. https://doi.org/10.11869/j.issn.100-8551.2019.12.2405In order to seek nitrite substitutes for meat products, the effect of different colorants (Test group 1∶0.5% beet powder + 50 mg·kg-1 sodium nitrite, Test group 2∶0.1% beet powder + 0.06% modified hemoglobin, Test group 3: 100 mg·kg-1 sodium nitrite) on the sensory evaluation, nutrients and volatile flavor compounds of Chinese sausage was investigated. The results showed that the difference of appearance, color and taste among three test groups was not significant, but were significantly different from those of the control group (P<0.05). The total content of amino acids in Test group 1 was significantly higher than other groups (P<0.05). The content of fatty acids in Test group 2 was relatively high, and the content of C18:2 was significantly higher than other groups (P<0.05). Compared to Test group 3, more volatile flavor compounds were detected in Test group 1 and 2. The contents of aldehydes and esters in Test group 2 were higher than Test group 1, indicating of better flavor. This study provids a technical guidance for substituting nitrite during the sausage process, which can improve the quality of Chinese sausage.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2414-2420. https://doi.org/10.11869/j.issn.100-8551.2019.12.2414The aim of this study was to prepare B-group aflatoxins(BGAFs) antibody with strong specificity and goodeurytopicity. According to the molecular structure and active site of aflatoxin B1 (AFB1), the BGAFs artificial antigen AFB1-BSA was prepared by 6 methods including oxime active ester(OAE),methylation of ammonia(MOA),mixed anhydride(MA),semi acetal(SA),epoxide(EP) and enol ether derivative(EED) and identified by UV and SDS-PAGE. Polyclonal antibodies against AFB1(AFB1 pAb) were prepared by immunizing New Zealand rabbits with AFB1-BSA, and the titers of AFB1 pAb was detected by indirect ELISA, the sensitivity of AFB1 pAb was analyzed by indirect competitive ELISA(icELISA) and the specificity and eurytopicity of AFB1 pAb was analyzed by cross-reactivity(CR) test. The results showed that AFB1-BSA was synthesized successfully and the best one was OAE method among the six synthesis methods of BGAFs artificial antigen and its conjugation ratio of AFB1 to BSA was 8.46∶1. The immune efficacy of OAE method was the best, that its AFB1 pAb had the highest titers of 1∶1.28×104 by indirect ELISA, a good sensitivity with the 50% inhibition concentration(IC50) of 10.32 μg·L-1 to AFB1 by icELISA and showed a high CR to AFB2 of 75.21%, AFG1 of 44.13%, AFG2 of 14.72%, AFM1 of 16.36% and AFM2of 1.44%, respectively. In this study, AFB1 pAbs with high titer, sensitivity, specificity and eurytopicity were prepared, proving a technical support for the establishment of BGAFs immunoassay.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2421-2429. https://doi.org/10.11869/j.issn.100-8551.2019.12.2421In order to explore nitrogen (N) utilization characteristics for different peanut varieties, changes in some related indexes of N accumulation and utilization of 19 peanut varieties and their relationship with yield were investigated by using15N tracer technique. Results showed that: Significant differences were observed in the indexes of the N content and accumulation, N pod production efficiency, N bio-efficiency, N fertilizer utilization rate, N fertilizer partial productivity among these 19 peanut varieties. The coefficient variations (CV) for different varieties ranged from 6.2% to 32.0%; N accumulation significantly positively correlated with dry matter accumulation in different organs of peanut, and the correlation coefficient varied from 0.801 1 to 0.9208, whereas no significant correlation was found with N content. The high harvest index was beneficial to increase the N pod production efficiency, while the increases of vegetative and total biological yield were beneficial to enhance N bio-efficiency. Total biomass and its allocation rate to the reproductive body exerted large impacts on N use efficiency and N fertilizer partial productivity. Soil N and nodule fixation were the main N sources of peanut, while the average N supplying proportions from soil and nodule fixation were 46.4% and 40.7%, respectively. Therefore, more attentions should be paid in exploiting N supply potential from soil and nodule fixation in agricultural production. For high-yield peanut plants, the sufficient total biomass and N accumulation were necessary, and also the high allocation rate to the reproductive body. It was possible to select and breed the peanut varieties with both high yield and high N element (or fertilizer) efficiency. This study provides theoretical basis for peanut variety selection and breeding of high N efficiency, and N-saving cultivation technology.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2430-2438. https://doi.org/10.11869/j.issn.100-8551.2019.12.2430In order to explore effect of different winter planting patterns on soil structure and quality of paddy fields, five winter planting modes were set in the experiment, including winter fallow, winter Chinese vetch, and winter rape, winter garlic and winter rotation (potato, Chinese vetch and rape). The water stability and distribution of aggregates in paddy fields were analyzed by measuring the composition of soil aggregates and the organic carbon content of aggregates in different layers of paddy fields. The results showed that the soil aggregate content(> 2mm) was dominant (the highest), followed by <0.053mm, while the soil aggregate content of 1~2mm, 0.5~1mm, 0.25~0.05mm, 0.053~0.25 mm was similar; the mean weight diameter (MWD) and geometric mean diameter (GMD) of water-stable aggregates in paddy fields were increased by all winter cultivation treatments. The MWD of winter rape treatment, winter potato, Chinese milk vetch and rape rotation treatment and winter Chinese milk vetch treatment were increased by 21.50%, 21.16% and 16.32% respectively (P<0.05). GMD of potato, Chinese milk vetch and rape in winter rotation treatment increased by 44.74% and 62.50%, respectively, compared with that in winter fallow treatment (P<0.05); in addition, the fractal dimension values of soil water-stable aggregates were significantly reduced by different winter planting patterns (P<0.05), which was beneficial to the stability of soil structure; the organic carbon content of soil aggregates increased with different winter planting patterns. Therefore, different winter planting patterns are beneficial to enhance the paddy soil aggregate stability and the accumulation of organic carbon with different particle fraction of soil water-stable aggregates. The winter crop rotation with potato milk vetch and rape showed the best result. The findings provide a theoretical basis for the selection of the optimal pattern of winter fallow fields in southern China.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2439-2450. https://doi.org/10.11869/j.issn.100-8551.2019.12.2439In order to reveal effects of saline-alkali soil improved by desulfurized gypsum on chlorophyll fluorescence characteristics in rice, a rice variety Jite605 was used as material, four combinations of integrated technology were designed, and no soil ameliorants application was used as control. Simultaneously, soil EC and pH, chlorophyll fluorescence parameters and chlorophyll content in rice leaves were measured in two consecutive years at rice seedling, tillering, booting and grain filling stages, and the modified effects of four integrated modes were analyzed. The results showed that with the extension of treatment time, compared with the control, the soil EC and pH values were significantly decreased under different modified combinations. The chlorophyll fluorescence parameters Y, ETR, Fmand Fv/m of rice leaves increased significantly (P<0.05) and Fo showed a decreased trend. Except for the original fluorescence (Fo), photochemical quenching coefficient (qP), there were significant positive correlations between SPAD, leaf chlorophyll content (LCC) and other chlorophyll fluorescence parameters (P<0.01), among which the correlation coefficient between NPQ and LCC was the largest, which was 0.771.The two-year average value of qP in each technology integrated modes had no significant difference in these four growth stages (P>0.05). The two-year average value of SPAD in mode D and E were significantly higher than A(CK) and LCC in mode E, and was also significantly higher than A(CK). At different growth stages, the chlorophyll fluorescence induction curves of each integrated modes showed the same trend, but the time of each characteristic point in the curve appeared differently and the peak value was different. As the improved modes optimized, the slope and the relative variable fluorescence intensity values of each feature point increased gradually. Through principal component analysis, two principal components were extracted at the seedling, tillering, booting and grain filling stages, and the cumulative contribution rates were 96.285%, 93.491%, 91.285% and 95.104%, respectively. An objective comprehensive evaluation value (D value) of the comprehensive evaluation improvement effect was obtained using membership function with index weight method. The ranking followed the order of E>D>C>B>A(CK), indicated that the mode E had the best effect to improve saline-alkali soil. On this basis, combining with reasonable irrigation and drainage measures can effectively alleviate the damage of saline-alkaline soil to rice seedlings, significantly improve the chlorophyll content and photosynthetic electron transport efficiency of rice leaves, and reduce the damage of PSII during rice growth under saline-alkali stress. The results provide a theoretical basis and technical guarantee for planting rice using the desulfurized gypsum to improve saline-alkaline soil.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2451-2459. https://doi.org/10.11869/j.issn.100-8551.2019.12.2451The traditional rice farming technology such as rice straw incineration, high-nitrogen and low-density and others will be transformed to the direction of resource-saving and environment-friendly. Therefore, 4 kinds of double machine-transplanted cultivation modes consisted of T1 with nitrogen- regular and density-regular,T2 with nitrogen-regular and density- increase,T3 with nitrogen-reduction and density-regular, T4 with nitrogen-reduction and density-increase were set to study the biological characteristics and annual yield of double machine- transplanted rice under nitrogen-reduction and density-increase measures with rice straw returning. The results showed that compared with T1 under the condition of rice straw returning,T4 with that of basal fertilizers was reduced by 20% of total nitrogen and density was increased by 27.3% in the early and late rice, which significantly (P<0.05) increased the spike rate, effective panicle and seed-setting rate, dry matter weight of the population decreased by 3.3% and 1.3% respectively, thus the yield of early rice increased by 1.6% and only decreased by 0.5% in late rice, and finally the annual yield increased by 0.4%. The growth period of T4 in early rice and late rice were both shortened by 2 days, which was favorable for guaranteeing a suitable seedling age of the late rice under the condition of machine-transplanted. The individual SPAD and the Pn of early rice and late rice were reduced with the decrease of nitrogen application rate or density, however, the population export rate, attenuation rate of population leaf area, attenuation rate of SPAD and Pn show a opposite law, which led to the lowest value in T4 than that of others. In summary, although the nitrogen-reduction and density-increase under rice straw returning inhibited the growth of individuals in double rice,high yield was also obtained by increasing the yield capacity through improving the production and transport capacity of photosynthetic substances of population from full heading to maturity, thereby, a certain theoretical basis for the development and transformation of machine- transplanted cultivation techniques was provided for double rice area.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2460-2471. https://doi.org/10.11869/j.issn.100-8551.2019.12.2460To explore the feasibility of reducing N application and maintaining high grain yield through rice genetic improvement, 20 rice varieties, including Jingliangyouhuazhan, Shengtaiyou 722, Fengtianyou 553, Wuyou 308, Yuejingsimiao 2, 4HD005, Chuanyousimiao, Hengfengyou 701, Guoyou 9113, Yundan 4, 9311A/R672, Quanxiangyou 6, Huarun 2, Wushansimiao, Tianyouhuazhan, Shenyou 513, Liangyou 336, Chunliangyouyouzhan, Shengtaiyou 018 and Juliangyou 751, were evaluated at a reduced N rate (120 kg·hm-2, 1/3 lower than the local high-yield and high-efficiency practice) in 2015 and 2016. Grain yield, yield components, tillers number, biomass accumulation and allocation, sink-source characters and N uptake and utilization were measured. Significant differences in grain yield were found among the tested varieties, ranging from 4.99 to 7.18 t·hm-2 in 2015 and from 6.22 to 7.73 t·hm-2 in 2016. Compared with the control, Yuejingsimiao 2, the varieties with 10% higher yield in 2015 were Jingliangyouhuazhan, Shengtai you 722, Fengtianyou 553, Wuyou 308, Hengfengyou 7011, Guoyou 9113, 9311A/R672 and Quxiangyou 6, the varieties with 10% higher yield in 2016 were Jingliangyouhuazhan, Shentaiyou 722, Fengtianyou 553, Tianyouhuazhan, Shenyou513 and Juliangyou 751. Among them, Jingliangyouhuazhan (two years), Guoyou 9113, Quxiangyou 6, Shenyou 513 and Juliangyou 751 were greater than 7.00 t·hm-2, which were at least 20% higher than the control variety. Under reduced N input, grain yield were significantly correlated with total biomass and sink size. While no significant correlations were found between grain yield and yield components, tiller number and biomass accumulation at specific growth stages. Varieties with high yield under reduced N input had comparable total N uptake, but higher N use efficiency for grain production (NUEg). These results showed that it is feasible to maintain high yield under reduced N input through genetic improvement. Greater biomass, larger sink size, and higher NUEg are important characteristics for the varieties with high-yield under reduced N input. The findings provide reference for the breeding of varieties with high-yield under reduced N input.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2472-2481. https://doi.org/10.11869/j.issn.100-8551.2019.12.2472In order to study the effect of dual mulching of furrow and ridge patterns in dry farming area on soil moisture, soil water consumption characteristics in different stages, potato yield and water use efficiency in dry farming areas, six kinds of dual-mulching of furrow-and-ridge patterns were conducted in the mountainous area of southern Ningxia in 2016. Ridges were mulched with plastic film, while furrows were covered with common mulching film (DD), straw mulching (DJ), biodegradable film (DS), liquid mulching film (DY), hemp fiber mulching film (DM) and furrow without mulching (DB), and traditional flat (CK) was used as control. The results showed that, the DJ treatment had the highest soil water storage capacity during the whole growth period of potato, and the soil water status during the growing period of potato was obviously improved. During the whole growth period of potato, the soil water content with DJ treatment in the 0-200 cm layer was the highest, especially for the soil moisture content in 0-40 cm layer. The water consumption, water consumption intensity and water consumption mold coefficient under the dual-mulching of furrow-and-ridge patterns were different during the growing stage of potato. The overall trend in the water consumption, water consumption intensity and water consumption mold coefficient was lower in early growth stage and increase in middle of stage but decreasing in the late stage. In the sowing~seedling and tuber formation~ expansion stage, the water consumption, water consumption intensity and water consumption modulus of potato with DS treatment reached the maximum, and the DJ treatment was the lowest. In seedling~budding stage, the DD treatment had the largest water consumption, water consumption intensity and water consumption modulus, followed by DM treatment, and the DS treatment was the lowest. In budding~tuber forming stage, water consumption, water consumption intensity and water consumption modulus with DY treatment were the highest, followed by DJ treatment, and the DM treatment was the lowest. The dual-mulching of furrow-and-ridge patterns could increase potato yield and water use efficiency, the DJ and DD treatments were the most significant in increasing production. Compared with CK, the yields of potato under DJ and DD were increased by 47.77% and 44.84%, respectively. The DJ treatment had the highest water use efficiency (68.2 kg·hm-2·mm-1), which was 58.97% higher than CK. It can be seen that the plastic film mulched ridges and maize straw mulched furrows can significantly improve the soil water status at 0-200 cm layer in the middle and late stages of potato, with less water consumption in the early stage and more water consumption in the middle and late stages, and significantly improve the yield and water use efficiency. This study provides scientific evidence for the high-yield mulching cultivation technology of dry-farming potato in southern Ningxia.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2482-2491. https://doi.org/10.11869/j.issn.100-8551.2019.12.2482In order to find out the response mechanism of starch accumulation and key enzyme activities to black plastic film mulching in potato tubers in semi-arid rain-red agriculture area of southern Ningxia. In 2016 and 2017, the main plant variety Qingshu No.9 in the mountainous area of Ningnan was used as experimental material. Two-year field experiment was conducted to study effects of black film(BF),white film(WF) and no-film on the accumulation of starch and its components and the activity of key enzymes of starch synthesis in potato tuber. Results showed that compared with WF and NF, BF treated amylose, amylopectin and total starch content increased by 11.37-35.68%, 8.56-27.05%, 8.33-27.60%, respectively, and starch accumulation rate increased by 13.80-37.90%. Under the condition of BF, WF and NF, the activity of tuber ADPG pyrophos phorylase(AGPase), UDPG pyrophos phorylase(UGPase), starch branching enzyme(SBE), soluble starch synthase(SSS), and granule-bound starch synthetase(GBSS), showed a single peak curve. The key enzyme activity of starch synthesis in BF was significantly higher than that in WF and NF. Compared with WF and NF, under BF treatment, AGPase activity was increased by 12.81% and 40.24% with UGPase activity increased by 15.34% and 36.52%, SBE activity increased by 16.64% and 44.17%, SSS activity increased by 13.69% and 34.76%, and GBSS activity increased by 15.75% and 45.44%, respectively. The yield of BF increased by 14.54% and 57.23% compared with WF and NF. Correlation analysis showed that amylose, amylopectin and total starch content in potato tubers were positively correlated with AGPase, UGPase, SBE, SSS and GBSS activities in most of the periods (P<0.01). Therefore, the use of black plastic film mulching cultivation in arid and semi-arid areas affects the starch and its components in potato tubers by affecting starch-related enzymes, which ultimately affects potato yield.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2492-2498. https://doi.org/10.11869/j.issn.100-8551.2019.12.2492To reveal the physiological mechanism of light shading on seed yield and quality improving, and to determine the optimum shading time, the following physiological indexes of P. ostii Feng Dan were investigated such as the dynamic changes of net photosynthetic rate (Pn), maximum net photosynthetic rate (Pmax), chlorophyll content (Chl), the content of malondialdehyde (MDA), hydrogen peroxide (H2O2), and proline (Pro), the activity of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD), as well as the content of auxin (IAA), gibberellic acid (GA3), abscisic acid (ABA). The results showed that under light shading environment, Pn was significantly lower than the control before 70 DAP(days after pollination), but significantly higher after 70 DAP. The average Pn increased by 16.7% than the control. Pmax decreased by 6.5% only at 56 DAP, and the average increased by 78.1%. Chl content was higher than control during the process, and the average increased by 63.1%. The accumulation of H2O2, MDA and Pro content were significantly lower than control, and the average decreased by 25.2%, 22.9% and 19.0%, respectively. During seed filling period, the average of CAT, POD and SOD activities increased by 11.4%, 19.5% and 12.5%, respectively; the contents of IAA and GA3 increased by 25.1% and 6.0%, and the ABA decreased by 9.6%, respectively. In moderate shading, Pn was higher than the control only at the maturity stage. In severe shading treatment, the accumulation of Pro was always higher than that of control. This indicated that improved photosynthetic performance and delayed senescence of leaves during slow growth and maturity period were the physiological basis for light shading improving the seed yield and quality. The findings provided a theoretical reference for selection of optimum shading time of oilseed peony.
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Journal of Nuclear Agricultural Sciences. 2019, 33(12): 2499-2508. https://doi.org/10.11869/j.issn.100-8551.2019.12.2499In order to investigate autotoxic effects of the aqueous extracts of leaf litter of Toona ciliata var. pubescens, the effects of leaf aqueous extracts on seed germination and seedling growth of the same species were investigated using biological test. Meanwhile, the autotoxic compounds in three different polar extracts of ether, ethyl acetate and n-butanol extracted from leaf aqueous extracts were analyzed by gas chromatography mass spectrometry (GC-MS). The results showed that the aqueous extract of T. ciliata var. pubescens has inhibitory effects on its seed germination, seedling growth and seedling survive rate. It was also found the higher concentration will result in a stronger inhibition. In addition, the inhibition effect of the medium concentration (100 g·L-1) solution on seed germination and shoot length was significant, and the inhibition rates of seed germination rate, potential and index were 18%, 31%, 31% and 17%, respectively. Meanwhile, it was also found the extract with low concentration (10 g·L-1) had significant inhibitory effect on root length, and the inhibition rate reached 25%. Finally, 22 compounds were identified from three different polar extracts of aqueous extracts of leaf litter, which may mainly contain amides, long chain fatty acids, phenols, benzoic acid derivatives, alkanes, nitriles, xylene, terpinene, sterols and other substances. Amongst these compounds, amides, long chain fatty acids, phenols, benzoic acid derivatives were regarded as the possible autotoxic substances of T. ciliata var. pubescens. In conclusion, the findings help to explore the endangered mechanism of the plant and provide reference for the promotion of seedling regeneration of T. ciliata var. pubescens.
