09 September 2019, Volume 33 Issue 9
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1667-1676. https://doi.org/10.11869/j.issn.100-8551.2019.09.1667To explore the mutagenic effects of 60Co-γ irradiation, stem cutting of two cassava varieties, xinxuan 048 and SC205, were irradiated with 0, 5, 10, 20 and 40 Gy of60Co-γ, respectively. The growth of tissue culture seedlings with different radiation treatment and the growth of plants after transplanting were observed and compared. The results showed that the rooting rate and germination rate of two varieties were decreased significantly with the increment of the irradiation dose. The median lethal dose (LD50) for two varieties was defined as 15.3 Gy, 17.2 Gy, respectively. With the increasement of the irradiation dose, the damage severity of tissue culture seedlings was reinforced, the seedling height, rooting rate and transplanting survival rate were decreased significantly. There were different vadiation sensitivity between varieties, xinxuan 048 are more radiation susception than SC205. After irradiation, different morphological variations such as petiole color, leaf shape, etiolated seedling and dwarf seeding were observed in both of two tissue culture seedlings. The variation rate of xinxuan048 and SC 205 was 4.4% and 6.6%, respectively. Three pairs of microsatellite (simple sequence repeat, SSR) primers were found to be polymorphism between genomic of SC205 wide type and mutants plants, five SSR primers were shown to be polymorphism between Xinxuan 048 wide type and it’s corresponding mutants. The results laid a foundation for creating a new cassava germplasms by60Co-gamma rays radiation and opening a new method for cassava breeding.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1677-1685. https://doi.org/10.11869/j.issn.100-8551.2019.09.1677
In order to reveal the function of UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) in regulating anthocyanin biosynthesis in spine grape (Vitis davidii Foëx.) callus at the cellular level, the gene encoding VdUFGT was isolated from spine grape callus by using RT-PCR with RACE technology. Its sequence was analyzed by bioinformatics and the expression profiles were investigated by real-time quantitative PCR (RT-qPCR). The results showed that the open reading frame (ORF) of cDNA and DNA of VdUFGT are 1 371 bp and 1 448 bp in length, respectively. It contains two exons and one intron, encoding 456 amino acid residues. The VdUFGT protein, an unstable and hydrophilic protein with negative charges, is a member of the UDPGT superfamily, including a UDPGT domain and a UDP: flavonoid glycosyltransferase YjiC feature regions. Six Vitis plants are clustered into the same group according to the phylogenetic tree, which constructed by proteins encoded from UFGT homologous genes. RT-qPCR analysis showed that the VdUFGT transcription level of red callus of spine grape was significantly higher than that of white callus, which was above 79 times when they were cultured for 25 days. During the continuous culture of spine grape callus, the VdUFGT expression level changed greatly in red callus, two peaks occurred at the middle stage of rapid-growth and the beginning of senescence, respectively. While the expression level of VdUFGT in white callus of spine grape changed not as wells as in red callus, it always maintained at a very low level. These results suggested that VdUFGT is the major gene involved in the regulation of anthocyanin biosynthesis in cell cultures of spine grape callus, and its regulatory role was mainly worked at the middle stage of rapid-growth and the beginning of senescence. This result would lay a foundation for further studying of the regulatory mechanism of anthocyanin biosynthesis in spine grape cells.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1686-1697. https://doi.org/10.11869/j.issn.100-8551.2019.09.1686In order to establish an efficient regeneration and transformation system, and provide the basis for gene function verification, leaf disk from ground-cover chrysanthemum Yuhualuoying was used as explant in this study, and the effects of the ratio of hormones and the age of the tissue culture seedlings on regeneration efficiency were studied. What’s more, we screened the concentration of hygromycin and carbenicillin, explored the influence of several conditions such as preculture and delayed culture on transformation efficiency. The results showed that the best regeneration system contains the medium MS+6-BA 1.5 mg·L-1+NAA 0.8 mg·L-1, with the seedling age was 30 days, with which the regeneration rate was up to 91.11%, and the average number of buds is as high as 5.90. The optimal genetic transformation was supposed to be: pre-cultured for 2 days, infected for 5 minutes, co-cultured for 2 days, postponed antibiotics selecting for 5 days and then followed by selective culture. During the whole process, the optimum concentration of carbenicillin in the postponed culture medium was 400 mg·L-1. As for hygromycin, the optimal selection pressure for leaf disk was 8-10 mg·L-1, while the best concentration for rooting screening was 11 mg·L-1. What’s more, studies have shown that 6-KT can effectively increase the regeneration rate of resistant shoots. And vitrified seedlings can be transformed into normal seedlings successfully by changing 6-BA to 1.0 mg·L-1 sucrose to 40 g·L-1. Finally, we obtained transgenic 15 resistant lines among which there were 10 positive seedlings. The CmERF12 genes of 9 lines were significantly inhibited compared with WT. So the positive rate as 67%. In general, the efficient regeneration and transformation system of ground-cover chrysanthemum Yuhualuoying has been established, which may lay a foundation for further studies on gene functions and genetic improvements.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1698-1706. https://doi.org/10.11869/j.issn.100-8551.2019.09.1698In order to study the mechanism of AP2 transcription factor of Lonicera japonica Thunb. responding to low temperature. With online bioinformatics, the physicochemical properties the physicochemical, subcellular localization, phosphorylation sites, protein motifs and evolution of AP2 transcription factor of L. japonica Thunb. were identified analyzed based on the transcriptome sequencing data of L. japonica Thunb. at low temperature. The expression of three DREB genes and one RAV gene under low temperature stress was detected by quantitative real-time PCR. Results showed that 34 AP2 transcription factors were screened in L. japonica Thunb., their physical and chemical properties were different, indicating that they may play different functions in the different micro-environment. Subcellular localization results showed that only two AP2 were localized to chloroplasts, the others were localized to the nucleus, conformed with the properties of transcription factors to regulate downstream genes expression; all AP2 phosphorylation sites were Ser>Thr>Ttry. According to the domain number of AP2 contained in the sequence 34 AP2 were grouped into 4 major categories, 20 AP2 belong to ERF subfamily, 3 AP2 belong to DREB subfamily, one is RAV subfamily, and the left 10 AP2 belong to AP2 subfamily. The results of quantitative real-time PCR showed that DREB and RAV genes were responded to low temperature stress, and the expression was varying in tissue and treatment time. This experiment provides a theoretical basis for further exploring the mechanism of AP2 transcription factor response to low temperature in L. japonica Thunb..
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1707-1716. https://doi.org/10.11869/j.issn.100-8551.2019.09.1707In order to screen the appropriate reference genes for real-time quantitative polymerase chain reaction (RT-qPCR) analysis of the main pigments synthesis related genes in the blue/white flower buds of Iris bulleyana, in this study, 6 traditional reference genes (ɑ-TUB、β-TUB、AQP、ACT、GAPDH、UBQ) were selected based on RNA-seq data of I. bulleyana Dykes and its white form-I. bulleyana Dykes f. alba Y. T. Zhao. lily 18S was used as the control reference gene. The expression of all 7 candidate reference genes were examined by reverse transcriptional PCR (RT-PCR) and RT-qPCR, and the stability were analyzed by geNorm, NormFinder and BestKeeper programs. The RT-PCR results showed that the primers of the 7 candidate reference genes were all specifically amplified, and no significant difference was detected on the gene expression level among the 6 different samples. The RT-qPCR analysis showed a significant difference among the expression level of 7 reference genes, which displayed the highest level for 18S and the lowest level for UBQ. The analyses of geNorm, NormFinder and BestKeeper showed that Actin was the most stable reference gene and β-TUB displayed the lowest stability, indicating Actin was suitable for reference gene. The RNA-seq data was exactly consistent with the RT-qPCR analyses of the partial relative genes in the two biosynthetic pathways of flavonoid/anthocyanin and carotenoid which using Actin as reference gene. This research gives an example of the reference gene screen for the relative genes expression analysis in the flavonoid/anthocyanin and carotenoid biosynthetic pathway of Iris, and provides a theoretical basis for plant resource utilization and flower color breeding.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1717-1723. https://doi.org/10.11869/j.issn.100-8551.2019.09.1717To research the expression of heat shock protein Hsp70 in early embryonic development of mice in vitro,and to explore the effect and mechanism of Hsp70 in embryonic development.The ovaries of SPF mice aged 8-12 weeks were collected in this study,then oocytes were collected under the microscope and cultivated to maturity,we placed COCs into the SrCl2+CB solution for parthenogenetic activation for 5 hours (37℃)after digesting it with 0.1% hyaluronidase,then we transferred it into G1 culture fluid for cultivating.We extracted the total RNA from the mouse embryos that had been cultivated to 2 cell embryo,4-8 cell embryo,9-16 cell embryo,morula and blastocyst,then we detected the expression of Hsp70 in each period by real-time Q-PCR,and the expression and location of Hsp70 at various stages of mouse embryos by immunofluorescence staining. The result of the real-time Q-PCR shows that Hsp70 expressed in the 2 cell embryo, 4-8 cell embryo, 9-16 cell embryo, morula and blastocyst in early extracorporeal embryo of mice,but the expression of Hsp70 is higher in the 2 cell embryo and 4-8 cell embryo,and lower in the 9-16 cell embryo,morula and blastocyst.The result of immunofluorescence staining shows that Hsp70 locates in the nucleus and cytoplasm of mouse embryos at various stages,but Hsp70 mainly locates in the nucleus after the 9-16 cell embryo.In summary,Hsp70 has the potential regulatory effects in early embryonic development of mice in vitro,and this study provides a theoretical basis for further clarifying the role and mechanism of heat shock protein Hsp70 in embryo heat stress resistance.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1724-1733. https://doi.org/10.11869/j.issn.100-8551.2019.09.1724In order to screen tea germplasms with high contents of amino acid and theanine and explore the relationship between the contents of amino acid and theanine, in present research, we detected the amino acid contents of steamed one bud and two leaves from spring shoots of 218 tea germplasms by nihydrin colorimetry combining with microplate assay, and the theanine contents by HPLC. The results showed that, the contents of amino acid ranged 1.50%~8.98%, among which 55 samples had high amino acid contents (≥5%); the contents of theanine varied from 0 to 4.03%, among which 13 samples had high level (≥3%) of theanine and four samples had no theanine; the ratio of theanine content to total amino acid content distributed was 0 to 0.78, mainly ranging from 0.2 to 0.5. In addition, the correlation coefficient between them reached to 0.752, indicating a significant positive correlation. In summary, a batch of specific tea germplasms with extreme amino acid contents had been screened in this study, which provides the foundation for selecting new tea plant varieties with high amino acid and high theanine contents and studying the molecular mechanism of accumulating amino acid.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1734-1741. https://doi.org/10.11869/j.issn.100-8551.2019.09.1734To demonstrate the effects of nitrogen on secondary metabolic accumulation and regulation of microalgae. The effect of different nitrogen concentrations on the growth, fucoxanthin, lipid and chlorophyll a of Phaeodactylum tricornutum was studied. The expression of fucoxanthin-chlorophyll protein complex gene (FCPb) and acyl-ACP desaturase gene (FAB2) were examined by real-time quantitive PCR (RT-qPCR). The results showed that nitrogen limitation reduced the growth of P. tricornutum cells and inhibited the synthesis of fucoxanthin in P. tricornutum, while it promoted the synthesis of lipid. When the nitrogen concentration was reached to 112 μmol·L-1, the fucoxanthin content was the lowest (only 0.084 mg·g-1DW-1), while the lipid content was the highest and it was 1.37 times higher than that of the control group. The chlorophyll a content was consistent with the change rhythm of fucoxanthin content. Correlation analysis showed that under nitrogen limitation, the fucoxanthin content of P. tricornutum was significantly correlated with the relative content of lipid (R2=0.998 8). Nitrogen limitation inhibited the expression of FCPb in P. tricornutum, and promoted the expression of FAB2 in P. tricornutum. These findings indicate that nitrogen limitation affects fucoxanthin and total lipid accumulation by regulating the expression of fucoxanthin and lipid biosynthesis pathway-related genes in P. tricornutum. The results provide a theoretical reference for further exploring the correlation between fucoxanthin and lipid metabolism and synthesis.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1742-1748. https://doi.org/10.11869/j.issn.100-8551.2019.09.1742As the major component of rice endosperm, starch possesses important biological functions and economic values. Amyloplast is one sort of specialized plastid for starch synthesis and storage in grain endosperm. During filling periods, grain endosperm accumulates a great amount of starch to fill the intracellular space of amyloplast for further formation of crystal starch granules. Thus, starch biosynthesis and structures in endosperm have great effects on the yields and the formation of eating and cooking qualities (ECQs). Here, we reviewed the molecular pathway of starch biosynthesis in rice endosperm, and proposed some strategies for improvement on yields and ECQs, which would provide theoretical basis for rice breeding.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1749-1754. https://doi.org/10.11869/j.issn.100-8551.2019.09.1749In order to improve the performance of corn starch, corn starch was irradiated by 60Co-γ rays under oxygen, air and nitrogen conditions. The adopted irradiation doses were 1, 3, 5, 7 and 10 kGy, respectively. The variation of viscosity and carboxyl content of corn starch were investigated. The morphology and crystalline structure changes were analyzed using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The results showed that the viscosity of corn starch decreased gradually while the content of carboxyl group increased gradually with the increase of irradiation dose. The viscosity decreased rapidly as much as 70% when the irradiation dose in the range of 1~5 kGy. The viscosity decreased much slower in the range of 5~10 kGy. Irradiation under different atmospheric conditions also had a significant effect on the viscosity and the carboxyl content of corn starch, and the influence of atmosphere was increased in the order of nitrogen, air and oxygen. With irradiation at 5 kGy under oxygen, the viscosity was 12.0% lower than that under nitrogen; meanwhile, the carboxyl content of relative increase ratio was 107.7% higher. As compared with the original starch, there were no visible changes in respects of the molecular structure and surface morphology among the three different atmospheres (irradiation dose = 5/10 kGy), but the quantitative index, which characterizes the order of corn starch structure via the FTIR peak ratio of 1 047 cm-1/1 022 cm-1,was generally decreased. The change of starch molecular structure caused by irradiation mainly occurred within the amorphous region, which can be promoted by the oxygen environment. The increase of oxygen content may enhance the cracking and oxidation of starch macromolecules in the amorphous region via radiation. By optimizing the radiation dose and the atmospheric conditions, it would save the irradiation processing cost and show higher yield of the modified starch. This study will provide technique support for the further practical application of irradiation.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1755-1764. https://doi.org/10.11869/j.issn.100-8551.2019.09.1755In order to develop and utilize flavonoids in Sonchus oleraceus, total flavonoids from Sonchus oleraceus were extracted by ultrasonic-assisted method. The extaction conditions of ultrasonic-assisted extraction of total flavonoids from Sonchus oleraceus were optimized by response surface methodology and the antioxidant capacity of the total flavonoids under the optimal extraction conditions was analyzed. The results showed that the optimal extraction parameters were as follows, ethanol concentration 49%, extraction temperature 69℃, extraction time 162 min, and solid-liquid ratio 1∶62(m/v). Under these conditions, the yield of total flavonoids were 3.73%±0.03%, and the IC50 of scavenging DPPH free radical, hydroxyl free radical and superoxide anion free radical were 0.005 9, 0.153, 0.024 8 mg·mL-1, respectively, implying such material had a strong antioxidant activity in vitro. This research would provide the theoretical basis for the development and application of flavonoids from Sonchus oleraceus.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1765-1773. https://doi.org/10.11869/j.issn.100-8551.2019.09.1765Increasing the trace element contents of wheat grains, such as Fe and Zn, is one of the important ways to solve the nutritional deficiencies for Chinese. Three wheat genotypes (Zhoumai 16, Heng 5229 and Han 6172) were grown in Huixian County (Henan Province), Yangling District (Shaanxi Province) and Zhao County (Hebei Province) from 2012 to 2015. Field trials were carried out in 3 plots with an area of 10 m2 for each district, and the wheat varieties were grown according to the local wheat management experience. 36 wheat samples were collected and then they were milled to obtain the whole-wheat flour, flour, bran and fine bran were obtained by milling. The Fe and Zn contents within whole-wheat flour and milling products (coarse bran, fine bran and flour) were determined using inductively coupled plasma mass spectrometry(ICP-MS). Single factor analysis of variance and Duncan multiple comparisons were applied to analyze the differences of Fe and Zn contents among different wheat flour products of wheat from different regions, different genotypes and different years. Genotype had the most significant influence on the Fe content for the whole wheat flour in this study. Region was the most important factor affecting the Zn content for the whole wheat flour. The Fe and Zn contents in different wheat flour milling components were in the trend of Bran> Fine bran> Flour. Fe content of each component was most affected by genotype. Zn content of whole-wheat flour and bran was mostly affected by the region, and Zn content of the fine bran was the most affected by the harvest year. Year×regional interaction, the genotype and year showed the highest influence on the Zn content of in wheat flour (P<0.01). The Fe and Zn contents were higher in whole-wheat flour than in flour, and it is feasible to increase their contents by selecting certain genotypes or choosing suitable areas for cultivation. This study can provide a theoretical reference for wheat planting and processing with a purpose of increasing the iron and zinc content in the staple food.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1774-1782. https://doi.org/10.11869/j.issn.100-8551.2019.09.1774In order to optimize the extraction technique of polyphenols from maize bran by enzymatic extraction, and to investigate the antioxidant properties of the products, the effect of ultrasonic time, extraction temperature, liquid to solid ratio and enzyme dosage were investigated and the extraction amount of polyphenol from maize bran was used as the response value. Based on the single factor experimental analysis, Central Composite Design of response surface analysis was applied to optimize the extraction process. The results showed that the optimal extraction conditions were ultrasonic time 6.5 min, enzymolysis temperature of 55℃, liquid to material ratio of 41 mL·g-1and the addition of xylanase 2.10%. Under these conditions, the highest yield of polyphenols was 7.26 ± 0.15 mg·g-1, which was similar to the predicted value of 7.17 mg·g-1. The antioxidant tests by DPPH· and ABTS+·scavenging methods showed that polyphenols of maize bran had strong antioxidant capacity, and can be used as potential natural antioxidants in the food industry. These results provided theoretical basis for the comprehensive application of maize bran.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1783-1788. https://doi.org/10.11869/j.issn.100-8551.2019.09.1783In order to prepare hydrolysate peptides from soybean meal with low bitterness and high biological activity, seven different enzyme combinations were selected to prepare the hydrolyzed peptides with comprehensively considering their enzymatic cleavage sites. Protein conversion rate, degree of hydrolysis, molecular weight distribution and intelligent sensory evaluation were meausred as the evaluation indexs of the hydrolyzed peptides. The result showed that the optimum combination was alkaline protease + neutral protease + debittering enzymolysis, the pH value of enzymolysis solution was 8.5, 7.5, and 7.5, and the reaction time was 3 h, 2 h, and 2 h, and the reaction temperature was kept at 55℃. After hydrolysis, the products showed degree of hydrolysis of 16%, and the distribution range of small-peptide molecular weight (≤ 1 000 Da) was up to 89.8%. The hydrolyzed peptides had better physical properties and textures. The results of this study provide a good foundation for the utilization of soybean protein and further application of functional peptides.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1789-1799. https://doi.org/10.11869/j.issn.100-8551.2019.09.1789The effects of the five extraction methods, including enzymatic hydrolysis, dilute alkali hydrolysis, organic solvent extraction, ultrasonic-assisted organic solvent extraction, and water-boiling extraction on the quality of turtle oil were studied. The turtle fat was chosen as raw material, and the turtle oils extracted by different methods were compared in terms of physicochemical characteristics, sensory properties, fatty acid composition, and volatile compounds based on gas chromatography (GC) and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). As a result, the performance of turtle oils obtained with the five methods showed significant difference (P value < 0.05, n=3). Among them, the extraction yield of ultrasound-assisted solvent method was the higest(78.51%), in which acid value (0.97 mg KOH·g-1) and peroxide value (2.16 m Eq·kg-1) were better than those from other methods. Furthermore, it was also rich in the health beneficial fatty acids including oleic acid, EPA, and DHA. The relative contents of the key characteristic flavor compounds, such as nonanal, hexanal, 2-nonanone, 2-undecone and 1-penten-3-ol, were lower, which endowed the turtle oil with light fishy taste and translucent color. The results indicated that the quality of turtle oil extracted by the ultrasonic-assisted solvent was superior to the other four extraction methods and could provide a theoretical basis for industrial processing of turtle oil in the future.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1800-1805. https://doi.org/10.11869/j.issn.100-8551.2019.09.1800For elucidating the mechanism of moisture migration in the process of hot air drying of dried meat, this study used low-field nuclear magnetic resonance to investigate the moisture migration and protein-water interaction of dried meat during hot air drying under lower temperature (temperature: 35℃, relative humidity: 60%, wind speed: 3 m/s). It is found the immobilized water (intra-myofibrillar) was the main form of water in dried meat. During air drying, the immobilized water migrated to the extra-myofibril, and the content was decreased. The relaxation times of all water populations including free water, immobilized water, and bound water of external part of dried meat decreased with drying, indicating that the water-protein interactions changed (P < 0.05). However, in the inner part of the dried meat, the relaxation times of free water and bound water did not decrease, implying that the water-protein interaction in inner part was different with the one in the external part of dried meat. This might be due to the higher temperature and lower water content in the external part of the dried meat. In conclusion, the faster water migration and higher temperature in the external part of dried meat caused the differences of water-protein interaction between inner and external part of dried meat. In conclusion, the faster water migration and higher temperature in the external part of dried meat caused the differences of water-protein interaction between the inner and external part of dried meat.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1806-1817. https://doi.org/10.11869/j.issn.100-8551.2019.09.1806In order to clarify the influence of different condition on the quality of Brassica chinensis L. and accurately predict its shelf life, the weight loss rate, Vc content, yellowing rate and a*value、b*value、ΔE value of boxed and bagged Brassica chinensis L. were measured during holding period at 3, 10 and 20℃. Multiple analysis methods of dynamic, principal component and correlation analyses were applied in this study to establish a comprehensive prediction model based on the change of color and Vc content. The results showed that the yellowing rate and a*value、b*value、ΔE value of Brassica chinensis L.were in accordance with the zero-order reaction under the condition of 3, 10 and 20℃, while the Vc degradation was consistent with the first-order kinetics reaction. The shelf life prediction model based on above single factor showed relative good fitting with separate practical test (R2>0.9) and the correlation between measured and predicted value was highly correlated (>0.93). After principal component and dynamics analyses, a more accurate mixed model with relative error less than 10% was established, which is suitable for predicting the shelf life of Brassica chinensis L.during the holding and delivery period. These results provide theoretical basis and technical support for the cold chain delivery of Brassica chinensis L..
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1818-1823. https://doi.org/10.11869/j.issn.100-8551.2019.09.1818In order to explore the distribution and dynamic changes of calcium in various organs of Feicheng peach, the 11-year-old Feicheng Peach was used as the test material and 41Ca isotope was injected into the trunk and calcium fertilizer (0.5% amino acid calcium and 0.5% calcium nitrate solution, with fresh-water as the control) was applied to detect 41 Ca abundance and total calcium content in each organ. The results showed that calcium content had significantiy increased in shoots and leaves during the early growth stage, which increased by 40%~68% and 13%~28%, respectively; the calcium content in the fruit reached its maximum value in the young fruit period and then gradually decreased; the calcium content of perennial branches decreased first and then increased. The competitiveness against 41Ca was far more powerful in leaves than in other tissues. The distribution of 41Ca during the mature period showed as follow: the trunk (67.78%), followed by the leaves and branches, next is the peel and flesh and the lowest in the trunk and sticks skin. In summary, spraying different forms of calcium fertilizer at various stages of fruit development in Feicheng peach can effectively increase the calcium content of young organs such as fruits, shoots and leaves. With the help of 41Ca tracer accelerator-based mass spectroscopic(AMS) technology, the movement distribution law of calcium in plants can be accurately studied. The results of this study provide a theoretical basis for calcium supplementation of Feicheng Peach.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1824-1832. https://doi.org/10.11869/j.issn.100-8551.2019.09.1824
In order to explore the physiological response of Brassica napus at seedling stage under aluminum stress, in this study, two oilseed rape varieties with significant difference in aluminum toxicity tolerance of R178 (Al-resistant) and S169 (Al-sensitive) as experimental materials were cultured in the nutrient solution to measure morphological and physiological indexes after 4 weeks with treatments of 0, 50, 100, 150, 200 and 300 μmol·L-1 aluminum (pH 4.5). The results showed that the main root length, total root length, total root surface area, root average diameter and total root volume of R178 had no significant difference in 50 μmol·L-1 aluminum , while compared with the control group, the root-related morphological indexes of S169 had significant difference. In addition, the total number of root tips increased first and then decreased with the increase of aluminum treatment concentration, and other morphology parameters decreased continually with the increase of aluminumconcentration; Under the treatment of 300 μmol·L-1 aluminum , the relative elongation of the main root decreased 65.7% and 79.7%, respectively, in the two varieties than the control group. The content of soluble protein and proline in the seedlings roots of the two varieties increased first and then decreased with the increase of aluminum concentration, with the content of soluble protein decreased and proline increased in leaves with the increase of aluminum concentration, respectively. Under aluminum stress, the plasma membrane permeability of decrease both roots and leaves at seedling stage of two varieties increased significantly, under the treatment of 300 μmol·L-1 aluminum concentration, the relative electrolyte exosmosis rate in roots of R178 and S169 increased by 54% and 59%, and in leaves increased by 82% and 90%, respectively. Under the same treatment, the electrolyte exosmosis rate of R178 roots and leaves was lower than that of S169. The activities of superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) in the roots of two varieties first increased and then decreased with the increase of aluminum concentration. SOD activity in R178 leaves increased with the increase of aluminum concentration, SOD activity in leaves of S169 first increased and then decreased and when the aluminum concentration is 200 μmol·L-1, it reached the maximum value. The activities of POD, CAT and APX in the leaves of two varieties showed the same trend that increased first and then decreased with the increase of aluminum concentration. The results showed that aluminum stress inhibited root growth significantly and damaged the integrity of cytoplasmic membrane of rapeseed. Rape seedlings resist aluminum stress by accumulating the protein and proline content and increasing protective enzyme activity. These results provide a theoretical basis for the selection of resources and breeding of new cultivars of aluminum-tolerant rapeseed.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1833-1840. https://doi.org/10.11869/j.issn.100-8551.2019.09.1833Twelve cauliflower materials were used to evaluate their drought tolerance by examining their relative germination percentage (RGP), relative germination rate (RGR), relative germination index (RGI), relative vigor index (RVI), relative seedling height (RSH) and relative root length (RRL) under different PEG concentrations including 0(CK), 100, 150 and 200 g·L-1 by method of subordinate function. The results showed that, 100 g·L-1PEG stress presented lower effect on seed germinating, while 150~200 g·L-1PEG stress significantly inhibited seed germinating. The 100~150 g·L-1PEG stress had a promoting effect on RRL, while 150~200 g·L-1PEG stress presented significant inhibition on RSH. Therefore, 150~200 g·L-1 PEG was most suitable for screening drought resistance of cauliflower at germination stage. According to comprehensive evaluation of subordinate function method based on RGP, RGR, RGI, RVI, RSH and RRL, the drought resistance of the 12 cauliflower materials followed the order of P3>P6>A1>P8>P7>P2>P1>P4>P5>A2>A3>P9. These results provide theoretical evidence for breeding of drought resistance in cauliflower.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1841-1855. https://doi.org/10.11869/j.issn.100-8551.2019.09.184138 grain sorghum cultivars were assessed and screened under 150 mmol·L-1 NaCl in order to get salt tolerant cultivars which would be grown in saline and alkaline soil. The result showed that germination potential, germination rate, root length and shoot length of 38 grain sorghums were differently inhibited by saline expect root shoot ratio; Variation coefficients of relative root shoot ratio (CV=62.84%) and relative root length (CV=44.55%) were higher than other relative values of all the traits, while variation coefficients of salt injury rate of germination potential (CV=39.86%) was the highest in salt injury rates of all traits. Relative germination potential and relative germination rate had significant positive correlation (R=0.341), while they had no correlation with relative root length (R=0.214;R=-0.041) and relative shoot length (R=0.041;R=0.205). Two principal components were ascertained by principal component analysis, which reflected root growth and germination situation, respectively; Relative ratio of root versus shoot, relative germination potential and relative germination rate were ascertained as salt tolerance identification index by loading matrix of each component. There was significant positive correlation between principal component score and membership values, which indicated that comprehensive score for both would be adapted in evaluation and classification for salt tolerance of sorghum. The research also screened strong salt tolerant cultivars, such as Tongza141, Jinliangbai2, Jiza137, Longmiliang1, Jiza148 and so on. The findings supplied theoretical basis and identification method for salt tolerant screening of sorghum at germination stage.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1856-1864. https://doi.org/10.11869/j.issn.100-8551.2019.09.1856In order to investigate effects of straw returning and nitrogen application on dry matter accumulation and yield of indica hybrid rice in karst region of Guizhou province. The dry matter production characteristics of indica hybrid rice Nei5You5399 were studied as under different straw treatments and nitrogen application rates. The results showed that the yield and total biomass of rice first increased and subsequently decreased slowly with the increase of nitrogen application. Meanwhile, plant height, maximum tiller number, leaf area index, dry matter accumulation at key growth stages, dry matter accumulation at main growth stages, post-panicle ratio and total grain number per panicle increased with the increase of nitrogen application. In contrast, panicle rate and 1000-grain weight showed the opposite trends. Compared with straw leaving treatment at late growth stage, the dry matter accumulation and total grains per panicle of straw returning treatment increased by 10.9% and 2.4%, respectively, while the dry matter output rate, dry matter conversion rate, apparent dry matter output and seed setting rate of straw leaving treatment increased by 45.3%, 60.3%, 41% and 1.4%, respectively. In summary, under the experimental conditions, the optimum combination of rice straw treatment and nitrogen application rate in this area was straw returning and N 150 kg·hm-2 application. The maximum actual yield could reach 9 758.02 kg·hm-2, which increased by 18.9% compared with the combination of straw leaving the field and no N application. This study provid technical support for the sustainable development of indica hybrid rice in the karst region of Guizhou Province.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1865-1872. https://doi.org/10.11869/j.issn.100-8551.2019.09.1865A plot experiment was carried out to explore the effects of different soil types on Si isotope composition and fractionation of rice. Rice (Oryza sativa L. cv. Jia 58) was grown in red soil, black soil and cinnamon soil, respectively. Soil chemical properties, rice dry weight, rice Si content, rice Si isotope composition were determined. The results indicated that different types of soil had a remarkable impact on the rice Si-isotopic fractionation. The Si isotope fractionation factors (αPre-Dsi) of rice grown in red soil, black soil and cinnamon soil were 0.998 8, 0.997 8 and 0.997 5, respectively, illustrating that the extent of Si isotope fractionation of rice planted in cinnamon soil was the strongest, followed by rice in black soil and rice in red soil. Correlation analysis showed that the δ30Si values of rice (bulk and leaves) were significant correlated with the contents of organic matter, available Si, free Fe oxide, free Al oxide and pH values of soils (P<0.01), indicating that rice Si-isotopic signature might be primarily affected by pH values, organic matter content, available Si content of soils and the extent of soil weathering since the contents of free Fe oxide and free Al oxide increase with weathering. The results provide a theoretical basis for using Si isotope tracing technology to explore the model of Si cycle in nature.
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Journal of Nuclear Agricultural Sciences. 2019, 33(9): 1873-1881. https://doi.org/10.11869/j.issn.100-8551.2019.09.1873In order to explore the difference of intrinsic water use efficiency (IWUE) between different crop types and its environmental impact factors, Kehe28 for maize and Dingxixin24 for wheat were used as experimental materials, through the barrel and plot test, the two set enough moisture and drought stress treatment, observation of corn, wheat in different water content and photosynthetic physiological processes under different meteorological conditions and literature information collection, analysis and comparison between C3 and C4 plants, under different environmental conditions and characteristics of the same crop IWUE of slope and stomatal conductance model. The results showed that C4 corn had higher IWUE than C3 wheat. Under favorable environmental conditions, the IWUE of wheat was lower, while under unfavorable environmental conditions, wheat tended to increase the IWUE. Meanwhile, C3 crop growing in humid climate had lower IWUE than that growing in semi-arid climate. The slope of stomatal conductance model of maize was higher than wheat. Additionally, under stressed conditions and semi-arid climate, crops tend to reduce the slope of stomatal conductance model. In conclusion, this research indicates that stomatal conductance of crop could regulate its aperture to maximize water use. Crops tend to conserve water use under stressed conditions, whereas it consumes little water as much as possible under optimal condition to maximize assimilation. The results could provide a basis for crop variety selection and allocation in a research area.
