Acta Agriculturae Zhejiangensis

Contents

2022, 34(1): 0-0.

Abstract ( 325 )

PDF (9781KB) ( 848 )

Related Articles | Metrics

Difference analysis on seed yield and root cap characteristics for spring maize under water fertilizer and high yield optimization of shallow burying drip irrigation

GAO Xin, YANG Hengshan, ZHANG Ruifu, ZHANG Yuqin, LI Rui, ZHANG Mingwei

2022, 34(1): 1-9. DOI: 10.3969/j.issn.1004-1524.2022.01.01

Abstract ( 746 )

HTML ( 166069 )

PDF (1084KB) ( 1165 )

To investigate the effect of field practice of shallow burying drip irrigation on seed yield and root cap characteristics, differences in yield characters, root and shoot dry matter quality and morphological characteristics under two cultivation modes: shallow burying drip irrigation and fertilizer optimized high yield mode (HY) and farmer production mode (CK) were studied by using two maize cultivars, Xianyu1483 and Dika159. The results showed that number of panicles and grains per unit area, yield and nitrogen fertilizer under HY mode were increased significantly compared with those under CK mode. HY practice mode also enhanced dry matter accumulation from silking to maturity stage, increased the leaf area per plant and leaf area index, kept leaf activity at a high level; In addition, dry matter mass of root system in soil depth of 0-20 cm was significantly reduced, and both the number of roots in depth of 20-40 cm and root activity improved under HY mode compared with those under CK mode. Therefore, it was concluded that HY mode weakened the adverse effects caused by dense planting, made root cap form an excellent structure and maintained a strong individual material production capacity for plants, and thereby increased seed yield.

Figures and Tables | References | Related Articles | Metrics

Expression of ERβ in hypothalamic-pituitary-ovarian axis of Ganjia Tibetan sheep in estrus cycle

BAO Yingying, CHEN Weigang, GE Wenbo, HE Yuqin, YANG Zhijie, ZHOU Kairen, YANG Dapeng, YANG Yawen, LIU Lili

2022, 34(1): 10-16. DOI: 10.3969/j.issn.1004-1524.2022.01.02

Abstract ( 638 )

HTML ( 73 )

PDF (2743KB) ( 873 )

To evaluate the expression and distribution of estrogen receptor β (ERβ) in the hypothalamus-pituitary-ovarian (HPO) axis of Ganjia Tibetan sheep in estrum cycle, thirty-two sheep with healthy and non-pregnant Ganjia Tibetan sheep during the estrus cycle were collected from the Tibetan sheep farm. Real-time fluorescent quantitative polymerase, Western blot and immunohistochemical staining were used to detect the expression and distribution of ERβ mRNA and its protein in HPO axis of Ganjia Tibetan sheep at different stages of the estrus cycle. The results showed that ERβ mRNA and its protein were expressed and distributed in hypothalamus, pituitary and ovary during the whole estrus cycle (proestrus, estrus, metestrus and diestrus) of Ganjia Tibetan sheep. ERβ mRNA and its protein were significantly higher in the proestrus as compared with the other three stages (P<0.05) in hypothalamus. It was found that ERβ mRNA and protein in proestrus was significantly higher than the other three stages (P<0.05) in pituitary, and the highest expression was found in ovarian tissue in diestrus and significantly higher than the other three stages(P<0.05). The immunohistochemical results reported that the positive expression of ERβ was mainly distributed in large neuronal cytoplasm and axons. The stronger expression was observed in the eosinophilic cytoplasm in distal and intermediate parts of the pituitary, but weaker expression was found in nucleus. In ovary, ERβ positive reaction was distributed in cytoplasm of growth follicular granulosa cells and nuclei, follicular endometrium cells and luteal cells. The different expression of ERβ in the HPO axis in the estrus cycle of Ganjia Tibetan sheep suggests that ERβ has important significance for reproductive physiological activities such as the estrus cycle of Tibetan sheep.

Figures and Tables | References | Related Articles | Metrics

Polymorphism and bioinformatics analysis of pig CAST gene

XU Jingen, JIN Erhui, WANG Chonglong, GU Youfang, LI Qinggang

2022, 34(1): 17-23. DOI: 10.3969/j.issn.1004-1524.2022.01.03

Abstract ( 642 )

HTML ( 39 )

PDF (1061KB) ( 1193 )

The aim of this study was to detect the CAST gene polymorphism of Berkshire pig, Huoshou black pig and their hybrid F₁ generation, and to analyze the effect of base variation on the mRNA secondary structure and CAST type Ⅲ protein by bioinformatics. The results showed that there were AA, AC and CC genotypes in Berkshire pig, Huoshou black pig and Berkshire × Huoshou black pig, and the frequency of allele A was higher than that of allele C. The mutation was in Hardy-Weinberg equilibrium in all three pig populations (P>0.05), and with moderate polymorphism (0.25<PIC<0.5). Bioinformatics prediction showed that c. 1980A>C slightly changed the secondary structure of porcine CAST gene mRNA sequence, and increased the minimum free energy. The p. Arg660Ser mutation resulted in a slight change in some physicochemical properties of the porcine CAST type Ⅲ protein, including molecular formula, molecular weight, isoelectric point, instability index, grand average of hydropathicity, positively charged residues (Arg and Lys) number. The secondary structure of porcine CAST type Ⅲ protein was not changed by the missense mutation, and the proportion of random coil and α-helix were higher before and after mutation. The p. Arg660Ser mutation was not located in the conserved domain of the porcine CAST type Ⅲ protein, but could lead to a decrease in the number of protein kinases that catalyzed the phosphorylation of adjacent p. 663Ser. In summary, the c.1980A>C mutation might have a certain impact on the transcription efficiency and function of the pig CAST gene.

Figures and Tables | References | Related Articles | Metrics

Identification and synergistic susceptibility of pathogenic Providencia rettgeri isolated from diseased Procambarus clarkii

DONG Jing, ZHANG Lushan, ZAHNG Guodong, LIU Yongtao, LIU Shaochun, YANG Yibin, AI Xiaohui

2022, 34(1): 24-32. DOI: 10.3969/j.issn.1004-1524.2022.01.04

Abstract ( 489 )

HTML ( 59 )

PDF (982KB) ( 913 )

To clarify the cause of death of Procambarus clarkii (P. clarkii) during May to June and bring out treatment protocols, a bacterial pathogen (L20190509) was isolated from P. clarkia with typical symptom. The isolated pathogen was characterized by physiological and biochemical assay, 16S rRNA sequencing and phylogenetic analysis. Then the sensitivity of the isolated pathogen was tested by agar diffusion method, the synergistic effect of antibiotics and natural compounds were determined by checkerboard assays. The results showed that the 50% lethal concentration of the isolate to healthy P. clarkii was 9.27×10⁴ CFU·mL^-1, which exhibited similar physiological and biochemical characteristics to Providencia rettgeri (P. rettgeri) and shared over 99% homologies with P. rettgeri. Thus, the isolate was determined to be a P. rettgeri strain. The sensitivity study showed that the isolate was susceptible to imipenem, cefotaxime and enrofloxacin; intermediate to florfenicol and doxycycline; resistant to other tested antibiotics. Moreover, florfenicol combined with magnolol had synergistic effect against L20190509. Taken together, L20190509 is a bacterial pathogen of farmed P. clarkii which exhibited multi-resistance to antibiotics, these findings help to further acknowledge the pathogens of P. clarkii in May and formulate scientific and effective treatments.

Figures and Tables | References | Related Articles | Metrics

Effect of cryptochlorogenic acid on immunomodulatory and antioxidant in mice of lung injury induced by H9N2-AIV

ZHANG Xin, ZHANG Ming, HE Hongxuan, HU Yanchun

2022, 34(1): 33-40. DOI: 10.3969/j.issn.1004-1524.2022.01.05

Abstract ( 587 )

HTML ( 61 )

PDF (2615KB) ( 964 )

To investigate the effect of cryptochlorogenic acid(4-CQA)on lung injury and recovery in mice infected with avian influenza H9N2 virus, ninety SPF KM mice(6-8 weeks old)were randomly divided into H9N2 group,H9N2+4-CQA group, control group and 4-CQA group. Then H9N2-AIV was used to induce lung injury and received 4-CQA intragastric administration respectively in mice. The lung histopathlogy changes, the lung index and spleen index, and the contents of malondialdehyde (MDA),total superoxide dismutase (T-SOD) and myeloperoxidase (MPO) in the lung tissue homogenate, and the ratio of T cell subgroups (CD4⁺、CD8⁺、CD4⁺/CD8⁺) were observed. The results showed that the group of H9N2 presented depression and shortness of breath; lung index increased and spleen index decreased; histopathological manifestations of lung were alveolar atrophy, alveolar septal thickening and local lung consolidation; CD4⁺/CD8⁺ ratio of T lymphocyte subsets decreased significantly (P<0.05), activity of T-SOD decreased significantly, content of MDA increased significantly, and activity of MPO increased significantly (P<0.05). After 4-CQA treatment, lung index decreased and spleen index increased; lung histopathological damage was alleviated; CD4⁺/CD8⁺ ratio of T cell subgroups was significantly increased (P<0.05); T-SOD and MPO activity in lung were significantly increased and the content of MDA was significantly decreased (P<0.05). It was concluded that 4-CQA can alleviate the lung injury induced by avian influenza H9N2 virus by maintaining immune balance and reducing oxidative damage.

Figures and Tables | References | Related Articles | Metrics

Effects of dietary oregano essential oil on growth performance, slaughter performance, organ indexes and intestinal morphology of Luhua chickens

JIANG Xiaofan, WU Tao, WEI Yuming, YANG Farong, CHEN Guoshun, JIAO Ting, CAI Yuan, ZHAO Shengguo

2022, 34(1): 41-49. DOI: 10.3969/j.issn.1004-1524.2022.01.06

Abstract ( 618 )

HTML ( 44 )

PDF (836KB) ( 1145 )

To investigate the effects of dietary supplementation with oregano essential oil on growth performance, slaughter performance, organ indexes and intestinal morphology of Luhua chickens.A total of 120 49-day-old female Luhua chickens [body weight was (1 478.75±85.81) g] were randomly divided into 4 groups with 3 replicates per group and 10 chickens per replicate. Each group was fed diets supplemented with 0 (Q8 group), 50 (QO50 group), 100 (QO100 group) and 150 mg·kg^-1(QO150 group) oregano essential oil, respectively. The experiment lasted for 75 days.The results showed as follows: compared with Q8 group, addition of oregano essential oil had no significant effect on growth performance of Luhua chickens(P>0.05);Half-eviscerated weight, slaughter percentage, eviscerated percentage and bectoral muscle percentage of QO50 group and QO100 group were significantly increased (P<0.05),and there were linear and quadratic relationships between slaughter percentage, eviscerated percentage and oregano essential oil supplemental level(P<0.05) of QO100 group, half-eviscerated weight and pectoral muscle percentage showed a quadratic curve with the increase of oregano essential oil supplemental level; Glandular stomach index in QO50, QO100 and QO150 groups were increased by 21.05%, 21.05% and 26.32%, respectively (P<0.05),and had linear and quadratic relationship with oregano essential oil supplemental level (P<0.05);Ileal crypt depth in QO50 and QO100 groups was decreased by 6.07% and 6.43% (P<0.05), respectively; Jejunal crypt depth in QO100 and QO150 groups was decreased by 5.11% and 4.45% (P<0.05), respectively; Duodenal villus height in QO150 group was increased by 14.00% (P<0.05), and there were linear and quadratic relationships between jejunar crypt depth, duodena villus height and oregano essential oil supplemental level(P<0.05).In conclusion, adding 50 mg·kg^-1 oregano essential oil to dietary could significantly improve the slaughter performance,glandular stomach index and crypt depth in jejunum and ileum of Luhua chickens.

Figures and Tables | References | Related Articles | Metrics

Growth curve fitting and correlation analysis of body weight and body measurements in Angus cattle

FENG Xiaofang, JIANG Qiufei, FENG Yuan, WANG Yu, CHEN Yafei, MU Tong, LI Ming, ZHOU Zihang, CAI Zhengyun, ZHANG Juan, GU Yaling

2022, 34(1): 50-59. DOI: 10.3969/j.issn.1004-1524.2022.01.07

Abstract ( 801 )

HTML ( 66 )

PDF (1066KB) ( 1156 )

The research was performed on Angus cattle to understand their growth and development patterns, and make relevant predictions to guide feeding management and improve breed selection. Logistic, Gompertz, and Von Bertalanffy models were used to fit the growth curves for weight and body size traits in Angus cattle from 0 to 18 months of age, and to choose the best growth curve model. The model was then applied to calculate relative growth (R) and absolute growth (G) of weight and body size, and simple correlation analysis was performed for each trait. The results showed that Von Bertalanffy model was the best fit for weight and body size traits, and the model estimated the inflection point of weight growth as (8.33 months of age, 245.13 kg). Growth pattern of each trait was analyzed, and it was found that the growing intensity of weight and body size traits decreased gradually with the increase of monthly age, and growth rate of weight reached the maximum from 0 to 10 months of age then decreased gradually. The correlation analysis among the traits showed a strong positive correlation between body weight and body size traits (P<0.01), indicating a positive selection relationship between body weight and body size traits. The above results demonstrated the advantages of early maturity and high early growth intensity and weight gain rate of Angus cattle.

Figures and Tables | References | Related Articles | Metrics

Primary culture of fibroblast from embryonic liver of Chinese soft-shelled turtle (Pelodiscus sinensis) and establishment of polyinosinic acid cytidylic acid (Poly I:C) stimulation cell model

WANG Shuitao, HE Shengsheng, JIANG Lingli, GAO Youling

2022, 34(1): 60-69. DOI: 10.3969/j.issn.1004-1524.2022.01.08

Abstract ( 583 )

HTML ( 23 )

PDF (6429KB) ( 1012 )

The aims of the present study were to establish an in vitro isolation and culture system for the embryonic liver fibroblast of Chinese soft-shelled turtle(Pelodiscus sinensis), and to study the effect of polyinosinic acid cytidylic acid (Poly I:C) stimulation on the key factors of the cellular interferon production pathway, finally, to establish the activation model of interferon production pathway based on the fibroblast. The embryo developed to stage 23 was used to obtain the liver fibroblast by trypsin digesting. After that, the cell was identified by PCR method. Its biological characteristics including cell morphology and growth pattern were analyzed. Besides, the gene and protein expression levels of the factors related to the interferon production signal pathway were detected at 24 h after cell transfection with Poly I:C. The results showed that the obtained embryonic liver fibroblasts were in good growth condition and had been successfully passed to the 20^th generation. The growth curve of the cell was S-shaped, which conformed to the cell proliferation law. Fibroblast marker genes VIM and ACTA2 were confirmed. Before and after cryopreservation, the cell survival rates were 90.51% and 82.95%, respectively. After Poly I:C stimulation, the protein expressions of RIG-Ⅰ and MAVS were up-regulated, the gene expression of RIG-Ⅰ was up-regulated. Whereas, the gene expressions of m⁶A and YTHDF2 were down-regulated. In addition, the change of cell morphology was recorded. In conclusion, the study successfully established an in vitro isolation and culture system for embryonic liver fibroblasts and constructed an activation model of interferon production pathway based on embryonic liver fibroblasts of Chinese soft-shelled turtle.

Figures and Tables | References | Related Articles | Metrics

Bioinformatics analysis and function prediction of miR172 gene family in Eucommia ulmoides

YE Jing, YANG Yuanling, SHI Qingqiu, WU Longfei, SONG Guotao

2022, 34(1): 70-78. DOI: 10.3969/j.issn.1004-1524.2022.01.09

Abstract ( 666 )

HTML ( 57 )

PDF (2124KB) ( 922 )

To understand the evolutionary characteristics of the miR172 family members and their role in the growth and development of Eucommia ulmoides, the precursor and mature sequences of miR172 family were collected from the high-throughput sequencing results (accession number:SRP216820) and published literature related to E. ulmoides. In addition, sequence alignment, WebLogo conservation analysis, phylogenetic tree construction, precursor stem-loop structure prediction, promoter structure analysis, target gene prediction and functional prediction were performed. The E. ulmoides miR172 family contains 8 precursor sequences and 8 mature sequences, and all precursor sequences can form a stable stem-loop structure. Sequence alignment and WebLogo analysis showed that 7 mature sequences (except eu-miR172d-5p) were highly conservative, however the precursor sequences were less conservative. Evolutionary analysis showed that the mature sequences of this family were highly conservative, but the precursor sequences were less conservative. Promoter analysis showed that the E. ulmoides miR172 family promoters contained abundant photoreaction components and hormone response elements and stress response elements, indicating that they may regulate the process of flower organ formation and stress response. Target gene prediction showed that there were many target genes for miR172 family of E. ulmoides, and they were involved in E. ulmoides growth and development and adversity stress, but the miR172 family members mainly regulated the expression of AP2 genes. The E. ulmoides miR172 family members were both conservative and differentiated during evolution, and they play an important regulatory roles in the growth and development of E. ulmoides by regulating AP2 expression.

Figures and Tables | References | Related Articles | Metrics

Effects of alkaline salt stress on growth and ion allocation of Sinocalycanthus chinensis

ZHOU Beining, MAO Lian, HUA Zhuangzhuang, LU Jianguo

2022, 34(1): 79-88. DOI: 10.3969/j.issn.1004-1524.2022.01.10

Abstract ( 1541 )

HTML ( 117 )

PDF (951KB) ( 1069 )

In this study, the three years old Sinocalycanthus chinensis seedlings were treated with different concentrations of alkaline salts (NaHCO₃) solutions, and the response mechanism of Sinocalycanthus chinensis to alkaline salt stress was analyzed from the morphological growth and ion transport routes, so as to provide theoretical guidance for the rational development and utilization of Sinocalycanthus chinensis. The results showed that the seedling height, relative growth of ground diameter, biomass and root-shoot ratio decreased with the increase of saline-alkali stress. With the increase of saline-alkali concentration, the Na⁺ content in each organ were significantly higher than that in the control group, the sequence was as follows: root>leaf>stem. Under low concentration alkaline salt stress, the K⁺ content sequence was as follows: stem>root>leaf, while under high concentration stress, the K⁺ content sequence was as follows: leaf>stem>root. The Ca²⁺ content sequence was as follows: leaf>root>stem. The K⁺/Na⁺ ratio in the stems and leaves of Sinocalycanthus chinensis was much higher than that in the roots and the Ca²⁺/Na⁺ ratio in the leaves was much higher than that in the stems and roots. The sequence of root-stem selective transport capacity of K⁺ and Ca²⁺: K⁺>Ca²⁺, stem-leaf: Ca²⁺>K⁺, while the root-leaf selective transport capacity was basically the same.In conclusion,under alkaline salt stress, the stems and leaves of Sinocalycanthus chinensis prevented the entry of Na⁺ by absorbing K⁺ and Ca²⁺, separated the Na⁺ storage area in the roots to reduce the damage of salt ions to the aboveground part, and the leaves maintained ion balance by increasing the absorption of mineral elements.

Figures and Tables | References | Related Articles | Metrics

Effects of different light-emitting diode (LED) light quality on growth, development and photosynthetic characteristics of Jinqiu Shatangju seedlings

YANG Chao, LIU Minzhu, LI Qiang, HAN Tao, PENG Liangzhi, LING Lili, FU Xingzheng, CHUN Changpin, CAO Li, HE Yizhong

2022, 34(1): 89-97. DOI: 10.3969/j.issn.1004-1524.2022.01.11

Abstract ( 1636 )

HTML ( 74 )

PDF (845KB) ( 1190 )

In order to clarify the influence of different light-emitting diode (LED) light quality on growth, development and photosynthetic characteristics of Jinqiu Shatangju, Jinqiu shatangju container seedlings with trifoliate orange as the rootstock were used as the experimental materials, six light quality treatments [red light (R), blue light (B), red and blue composite light (RB11, RB21, RB41, RB81)] were set up in this study with white light (W) as the control. Phenotypic index, biomass, photosynthetic pigment content and photosynthetic characteristic parameters of the newly grown stems and leaves were measured after two months treatment, and the principal component analysis was performed on the relevant indicators. The results showed that red light significantly promoted elongation of new shoots, increased the number of leaves, leaf area and biomass, and inhibited thickening of stems and leaves, while effect of blue light was opposite to that of red light. Low proportion of red light also significantly promoted the elongation of new shoots, made stem thicker, increased number of leaves, leaf area and biomass, however, as the proportion of red light increased, growth trend was significantly reduced. Stem length, stem thickness, number of leaves and leaf area of compound light RB11 were 1.97 times (P<0.05), 1.14 times (P>0.05), 2.05 times (P<0.05), 1.84 times (P<0.05) of the control, respectively. Fresh weight and dry weight of new shoots were 1.68 times (P<0.05), 1.88 times (P<0.05) of the control. Fresh weight of leaves and stems, dry weight of leaves and stems were 1.46 times (P>0.05), 3.00 times (P<0.05), 1.68 times (P<0.05), 3.06 times (P<0.05) of the control. Red light and blue light all lead to a significant decrease in photosynthetic pigment content and net photosynthetic rate (P_n), while red-blue composite light promoted increase of chlorophyll b (chlb), carotenoid (car) content and P_n. In addition, increasing the proportion of red light, content of chlorophyll and car, as well as chla/chlb and P_n showed significant decreasing trend. All treatment light led to a decreasing trend in stomatal conductance (G_s) (except RB41 treatment) and transpiration rate (T_r) (except RB21 and RB41 treatments). Through principal component analysis, it could be found that the red-blue 1:1 compound light (RB11) was more conducive to growth and development, material accumulation and photosynthesis of new shoots of Jinqiu Shatangju. This study provided a theoretical basis for establishment of LED light supplement technology for rapid propagation of Jinqiu Shatangju seedlings.

Figures and Tables | References | Related Articles | Metrics

Visual detection method of Colletotrichum scovilleiin fruit and vegetable based on LAMP

LUO Yue, WU Xiaomao, LIU Ali, YAO Xiaolong, LI Rongyu, GENG Guangdong

2022, 34(1): 98-103. DOI: 10.3969/j.issn.1004-1524.2022.01.12

Abstract ( 427 )

HTML ( 40 )

PDF (2080KB) ( 918 )

To provide an efficient, convenient, specific and visual detection method for the detection of Colletotrichum scovillei of fruit and vegetable, taking the ITS sequence of the internal transcription spacer of C.scovillei of fruit and vegetable as the target gene, 4 LAMP primers and 1 loop primer were designed. By choice the primer ratio, reaction time, reaction system and other conditions, a LAMP detection method with specific amplification for C. scovillei was established. The results of the specificity test show that the established LAMP reaction system was amplified for 60 min at the optimal reaction temperature of 65 ℃. The reaction system using C. scovillei DNA as a template was used as the indicator calcein and hydroxynaphthol. Under the action of blue, green and blue appear, respectively. The reaction result was positive, and the amplified product was detected as a ladder band by 2% agarose gel electrophoresis. The reaction system and blank control using the DNA of other 8 control strains as templates,they were orange and purple respectively, and both were negative reactions, and no amplified bands appeared, indicating that the LAMP detection method is highly specific to C.scovillei of fruit and vegetable.

Figures and Tables | References | Related Articles | Metrics

Epidemic dynamic and prediction model of cucumber powdery mildew under protected cultivation

WU Yanjun, HONG Wenying, ZHANG Zhongmei, WU Yao, MIAO Qiang

2022, 34(1): 104-111. DOI: 10.3969/j.issn.1004-1524.2022.01.13

Abstract ( 1004 )

HTML ( 30 )

PDF (793KB) ( 957 )

To determine the occurrence rule and prediction model, the field dynamic of cucumber powdery mildew under protected cultivation in Hangzhou during the years from 2007 to 2019 was investigated. The results showed that the peak period of the disease occurrence was very similar among different years. The powdery mildew severity in spring cucumber reached the highest peak in the middle ten days of June, while the occurrence of the disease would reach the peak in early October for autumn cucumber. There were significant differences in the peak duration and quantity of cucumber powdery mildew among years. The disease of spring and autumn cucumber led to peak quantities in 2019 and 2009, respectively. It was an unusual year in 2013 that the disease was found to be serious both in spring and autumn but short in the peak duration. In addition, it was found that the field dynamic of cucumber powdery mildew was closely related to the climate condition. For example, the disease would break out if the air temperature or environmental humidity exchanged frequently. Based on the monitoring data including the disease index of powdery mildew and climate factors from March to October every year, the prediction mathematical models of occurrence quantity for the disease in spring and autumn cucumber were established using the method of stepwise regression. Testing of the prediction accuracy of these models showed that the predicted values were consistent with the measured values and the scores representing prediction accuracy were over 75. Thus, these models could accurately predict the degree of occurrence for cucurbit powdery mildew.

Figures and Tables | References | Related Articles | Metrics

Heterologous expression and physicochemical characterization of Brassica napus Kunitz protease inhibitor

FENG Wei, LI Pengpeng, SONG Peng

2022, 34(1): 112-119. DOI: 10.3969/j.issn.1004-1524.2022.01.14

Abstract ( 687 )

HTML ( 18 )

PDF (999KB) ( 876 )

A Kunitz inhibitor gene (RTI;rti)from rapeseed was cloned and expressed in Pichia pastoris expression system for the first time. Its physicochemical characteristics were investigated after separation and purification. The results showed that the expression level of recombinant RTI reached 628 mg·L^-1 and its inhibitory activity reached 69.6 TIU·mg^-1 in shaking flask fermentation. The recombinant RTI maintained over 70% inhibitory activity between 30-90 ℃ and retained over 80% inhibitory activity between pH 2.0-11.0. The metal ions Cu²⁺ and Co²⁺, the organic reagents methanol, ethanol, acetone or chloroform inhibited the activity of RTI. The recombinant RTI reacted with trypsin in a non-competitive manner, and demonstrated a strong and specific inhibitory effect on trypsin. These results indicated that RTI was a typical plant Kunitz trypsin inhibitor. Combined with good physicochemical properties, RTI has the potential to be developed as insect resistant protein.

Figures and Tables | References | Related Articles | Metrics

Preliminary research on wing dimorphism of pear psylla (Cacopsylla chinensis) and its influence factor

ZHAO Longlong, WEI Jie, XIE Yingping, LI Jie

2022, 34(1): 120-127. DOI: 10.3969/j.issn.1004-1524.2022.01.15

Abstract ( 356 )

HTML ( 18 )

PDF (2456KB) ( 857 )

The wing dimorphism of pear psylla (Cacopsylla chinensis) under different months and different photoperiods were studied in this paper. It was shown that there were two distinctive wing morph which changed with months. The short-wing pear psylla occurred from May to September, while the long-wing pear psylla occurred from October to the next April. Under constant temperature of 20 ℃, short photoperiod conditions (9 h light/15 h dark, 8 h light/16 h dark) induced long-wing pear psylla; while long photoperiod conditions (12 h light/12 h dark, 10 h light/14 h dark) induced short-wing pear psylla. Due to the longer body length of long-wing pear psylla induced under short photoperiod conditions, its relative wing length turned shorter. Based on the analysis of the distance between the wing vein cross landmarks under different months and different photoperiods, which exhibited the same variation characteristics in the wing dimorphism, it was deduced that the photoperiod was a major inducing factor of the pear psylla wing dimorphism.

Figures and Tables | References | Related Articles | Metrics

Application of rpoB, gyrA and cheA genes in identifying Bacillus genus

YAN Jingting, QIAO Kai, CAI Yanfei

2022, 34(1): 128-140. DOI: 10.3969/j.issn.1004-1524.2022.01.16

Abstract ( 1435 )

HTML ( 49338 )

PDF (1546KB) ( 1401 )

To determine the discriminatory power of rpoB, gyrA and cheA genes in Bacillus identification,comparative sequence analysis of rpoB, gyrA and cheA genes were conducted through Blast-N algorithm. Based on this, a rapid and accurate identification method for Bacillus genus was proposed.The genomic DNA of a purified strain was extracted and amplified by using specific primers which were selected by the original taxonomy stated on the packaging. Then, the final bacterial taxonomy was determined by sequence identities and phylogenetic analysis. A total of 19 Bacillus isolates were adopted in the present study to verify the feasibility of this proposed method. It was shown that sequence identities of rpoB, gyrA and cheA genes within B. licheniformis and B. subtilis group (including Bacillus subtilis subsp. subtilis,Bacillus subtilis subsp. inaquosorum,Bacillus subtilis subsp. spizizenii), and operational group B. amyloliquefaciens(including Bacillus amyloliquefaciens,Bacillus velezensis) were 84.93%-86.57%,less than 78.21%, and 78.25%-78.58%, respectively.Sequence identities of gyrA and cheA genes within B. subtilis group and operational group B. amyloliquefaciens were 81.01%-95.82% and 94.50%-95.83%, respectively. B.cereus was 94.54% identical to B. thuringiensis by gyrA gene, while B. megaterium was 94.55% identical to B. aryabhattai by cheA gene. It was summarized that B. licheniformis, B. subtilis group and operational group B. amyloliquefaciens could be distinguished by rpoB, gyrA and cheA gene. The subspecies within B. subtilis group and operational group B. amyloliquefaciens could be identified by gyrA and cheA genes. Moreover, gyrA gene was sufficient to distinguish B. cereus from B. thuringiensis, and cheA gene could differentiate B. megaterium from B. aryabhattai.By using the proposed method, 19 Bacillus isolates were identified as Brevibacillus reuszeri,Bacillus mesonae, Bacillus wudalianchiensis,Bacillus massiliogorillae, Bacillus subtilis subsp.subtilis, Bacillus cereus, Bacillus aryabhattai and Bacillus velezensis.

Figures and Tables | References | Related Articles | Metrics

Land suitability evaluation of citrus cultivation based on fuzzy mathematics

XI Wenyong, FU Peihong

2022, 34(1): 141-152. DOI: 10.3969/j.issn.1004-1524.2022.01.17

Abstract ( 1016 )

HTML ( 152 )

PDF (19722KB) ( 964 )

This study introduces fuzzy mathematics theory into the land suitability evaluation for citrus planting.By taking Tongshan County in Hubei Province as an example, 207 soil sample points were collected from local agricultural land, and climate, soil and topographic data were converted into fuzzy membership data.Then, the analytic hierarchy process and fuzzy mathematics method in the ArcGIS software environment were combined, and a suitability evaluation model of citrus planting land containing 15 indicators was established. The results showed that 26.94% (652.37 km²), 32.85% (795.51 km²), 23.14% (560.42 km²) and 17.07% (413.40 km²) of the land in this area were highly suitable, moderately suitable, marginally suitable and not suitable for citrus production, respectively. The research results were consistent with the actual production, indicating that the established research methods were feasible and could provide references for improving land utilization efficiency and better guiding citrus production.

Figures and Tables | References | Related Articles | Metrics

Optimization of formulation of reconstituted liquid egg by response surface methodology

YANG Yeshuang, ZHANG Yingping, CHEN Yifan, ZHANG Jin, LI Huanhuan, CHEN Lihong, TANG Honggang, GAO Bin

2022, 34(1): 153-162. DOI: 10.3969/j.issn.1004-1524.2022.01.18

Abstract ( 663 )

HTML ( 370 )

PDF (3065KB) ( 1044 )

In order to investigate effects of the proportion of yolk, gellan gum and NaCl on gelling properties of reconstituted liquid egg, texture characteristics (hardness, elasticity, chewiness), color and water holding capacity of the gel were evaluated by single factor experiment. To obtain the optimal formulation, the Box-Behnken response surface methodology was used to establish a regression equation with chewiness as evaluation index. The results showed that the order of influence factors on chewiness of reconstituted liquid egg gel was as follows: egg yolk ratio>gellan gum additive amount>sodium chloride additive amount. The optimal formulation was 64% egg yolk and 36% egg albumin, added 0.14% gellan gum and 1.5% NaCl, and the theoretical value of chewiness of the reconsititued liquid egg gel was 978.063, while the verification test value was 910.494. In conclusion, gel performance of liquid egg was improved effectively by formulation optimization with response surface methodology. The research results could provide technical support for preparation of high quality leisure egg products with reconstituted liquid egg.

Figures and Tables | References | Related Articles | Metrics

Optimization of carrot vacuum pulsating steam blanching process under combined drying method

YUAN Yuejin, HONG Chen, XU Yingying, WANG Dong, ZHANG Man, JING Xuesong

2022, 34(1): 163-172. DOI: 10.3969/j.issn.1004-1524.2022.01.19

Abstract ( 617 )

HTML ( 326 )

PDF (3583KB) ( 969 )

In order to improve the drying rate and the quality of dried products, a new pretreatment process of fruits and vegetables before drying was explored. The new pretreatment process of vacuum pulsating steam blanching was applied on carrot slices under the hot-air vacuum combined drying method. Single factor experiments and regression orthogonal test were carried out.The relationship among blanching vacuum degree, blanching temperature, blanching time and cycle times with vitamin C (V_C) content, rehydration ratio and color difference of carrot was analyzed by response surface methodology,corresponding mathematical models were established, and the parameters for vacuum pulsating steam blanching were optimized.The results showed that the increase of blanching intensity would damage V_C to some extent, but it was beneficial for the rehydration ratio of dried carrot products.The optimized parameters for carrot vacuum pulsating steam blanching were as follows: blanching temperature of 110 ℃, blanching vacuum degree of 0.08 MPa, blanching time of 3 min, and cycle times of 2 times.The research results could provide reference for the application of vacuum pulsating steam blanching as pretreatment technology in fruit and vegetable drying.

Figures and Tables | References | Related Articles | Metrics

Does feminization of agriculture promote outsourcing of agricultural machinery services?

XU Hui, TONG Junhao, CHEN Guangyan, ZHUANG Tianhui

2022, 34(1): 173-183. DOI: 10.3969/j.issn.1004-1524.2022.01.20

Abstract ( 568 )

HTML ( 12496 )

PDF (1226KB) ( 987 )

Based on the relevant theoretical analysis, the impact of feminization of agriculture on the outsourcing of agricultural machinery service, and its mechanism were analyzed by using China Labor-force Dynamics Survey (CLDS) 2016 data via ordinary least square (OLS), two stage least square (2SLS), generalized method of moments (GMM). It was shown that the deepening of feminization of agriculture would promote farmers to choose outsourcing of agricultural machinery service. When the household was youth or middle-aged, and the village was in the western or central region, with education level of primary school or below, feminization of agriculture had more significant impact on the outsourcing of agricultural machinery services. Feminization of agriculture affected farmers’ choice on outsourcing of agricultural machinery services by expanding agricultural labor constraints and increasing the opportunity cost of agricultural labor. Thus, it was suggested to strengthen the investment in skills capital of female agricultural labor, promote the development of agricultural machinery cooperatives, to alleviate agricultural labor constraints, and convert opportunity costs into development dividends.

Figures and Tables | References | Related Articles | Metrics

Scale effects of trade-offs and synergies of multifunction of cultivated land: evidence from Wuhan Metropolitan Area

YANG Fengyanzi, HU Weiyan, LIU Tian, ZHANG Siyu

2022, 34(1): 184-195. DOI: 10.3969/j.issn.1004-1524.2022.01.21

Abstract ( 581 )

HTML ( 941 )

PDF (4639KB) ( 970 )

It is of significance to explore the scale effect of trade-offs and synergies of multifunction of cultivated land for the effective protection and sustainable utilization of cultivated land. Thus, Wuhan Metropolitan Area, China, was selected as the study area to explore the trade-offs and synergies of multifunction of cultivated land at multiple scales based on the establishment of evaluation system of multifunction of cultivated land and Spearman’s rank correlation. It was shown that the single function index and multi-function index of cultivated land had obvious spatial difference. The trade-offs and synergies within cultivated land functions had scale effect, which would change with the changing scale.These findings might provide basis for policy-makers to implement appropriate measures for the protectection of multifunction of cultivated land at the right spatial scale, and to promote higher-level synergies of multifunction of cultivated land to realize sustainable utilization.

Figures and Tables | References | Related Articles | Metrics

Research progress of effects of muscle fiber type composition on muscle quality and energy metabolism in pigs

OU Xiuqiong, LI Rui, ZHANG Xiaochun, ZHONG Zhengze, LI Xing, JING Shaohong, GUO Zongyi, LI Xinggui

2022, 34(1): 196-203. DOI: 10.3969/j.issn.1004-1524.2022.01.22

Abstract ( 958 )

HTML ( 17519 )

PDF (840KB) ( 1151 )

Muscle fiber was the basic structural unit of muscle tissue. Improving muscle quality by changing the composition of muscle fiber types had recently been a hot topic for researchers. According to the polymorphism expression of myosin heavy chain (MyHC) gene, skeletal muscle fiber types in adult mammals could be divided into four types: I, 2a, 2x and 2b, and type I and 2a muscle fibers were partial to oxidation metabolism, type 2x and 2b muscle fibers were partial to glycolysis metabolism. Before birth of mammals, MyHC isoform was generally expressed as embryonic type, fetal type, I and 2a. After birth of mammals, the number of muscle fibers did not increase, and development of muscle fibers was mainly showed the increase in volume and type transformation, proportion of oxidation metabolism muscle fiber in muscle showed a decreasing trend, while that of glycolysis metabolism muscle fiber showed an increasing trend. Transformation of muscle fiber type followed the rule of I↔2a↔2x↔2b. The composition of muscle fiber types was closely related to the muscle quality formation of pigs after slaughter. High content of oxidation metabolism muscle fiber leaded to better muscle quality, and high content of glycolysis metabolism muscle fiber leaded to poor muscle quality. This paper expounded the effects of muscle fiber type composition on muscle quality formation and its energy metabolism mechanism in pigs, which provided a theoretical basis for improving pig muscle quality by changing muscle fiber type composition.

References | Related Articles | Metrics

Archive