2021 Vol. 36, No. 12
Display Method:
2021, 36(12): 1387-1394.
doi: 10.19303/j.issn.1008-0384.2021.12.001
Abstract:
Objective The egg-laying of Chahua chickens was analyzed, and applicable prediction models evaluated. Methods The indicators of egg-laying performance, including the age and body weight of chicken at start of egg-laying and the individual weight and number of eggs of 30- and 43-week-old chickens, were recorded for a Pearson correlation analysis. Various nonlinear models for curve fitting on egg production rate and cumulative egg production of 20- to 45-week-old chickens were compared. Results The coefficients of variation on the initial egg-laying age and the egg weight of 30- and 43-week-old chickens were below 10%. But those on the body weight at start of egg-laying and the numbers of eggs laid at 30- and 43-week were higher than 10%. There were significant correlations among 10 characteristics of the egg-laying performance (P＜0.05). For instance, a significant inverse correlation was observed between the chicken body weight and age at first egg-laying, between the age at start of egg-laying and the egg number of 30- and 43-week-olds, and between the egg weight of 30-week-olds and the numbers of eggs laid by the 30- and 43-week-old chickens. Whereas significant positive correlations were found between the body weight of chickens at time of initial egg-laying and the egg weights of 30- and 43-week-olds and between that and the egg weight of 30-week-olds. Significant correlations were also shown between the egg weight of 30-week-old chickens and that of 43-week-olds, and between the number of eggs laid by the 30-week-olds and that by 43-week-olds. Among the tested models, Yang-Ning had the highest R2 of 0.990 on curve fitting for the egg yield. For the cumulative egg yield, all 3 models yielded R2 above 0.991 with Von Bertalanffy being the highest at 0.999. Conclusion There appeared rooms for performance improvements on the body weight of the birds that started laying eggs and the weights of individual egg laid by the 30- and 43-week-old Chahua chickens, but less so on the starting age of egg-laying and the weights of egg of the 30- and 43-week-olds. Since the egg weight negatively correlated to the number of eggs laid by the chickens, in addition to the starting age of egg-laying, those factors would need be put into consideration in breeding selection. Yang-Ning model seemed adequate for the rate prediction and evaluation, while Von Bertalanffy for the cumulative egg production estimation on Chahua chickens.
2021, 36(12): 1395-1405.
doi: 10.19303/j.issn.1008-0384.2021.12.002
Abstract:
Objective Effects of addition of allicin and/or Bacillus natto in feed on the production performance, antioxidant enzymes, intestinal morphology, and cecal microbiota of Fujian white rabbits were studied for forage supplement as an antibiotic replacement. Method Forty-eight healthy 40-day-old Fujian white rabbits with similar body weight were randomly divided into 4 groups of 12 rabbits each, half male and half female, for a 50 d feeding trial. The rabbits in the control group were fed a basal diet (Group A), while those in the treatment groups the basal diet supplemented with 200 mg·kg−1 allicin (Group B), 0.5% B. natto (Group C), and 200 mg·kg−1 allicin+0.5% B. natto (Group D). Growth of the rabbits was monitored during the trial, and at the end, the animals were slaughtered to determine the meat production, serum antioxidant enzymes, intestinal morphology, and cecum microbiota. Results (1) The rates of diarrhea occurrence and mortality of the rabbits in Group B, C, and D were lower than those of Group A. The average daily weight gain of Group D was significantly higher than that of Group A and B at P＜0.01 and Group C at P＜0.05. Group D had the lowest F/G among all, and significantly higher half-eviscerated weight than that of Group A or Group B (P＜0.01). No significant differences were observed in the eviscerated and half-eviscerated rates among the groups. (2) On serum GSH-Px, Group A was significantly lower than Group B, C and D. The difference between group A and Group B was significant (P＜0.05), while those between Group A and Group C and between Group A and Group D extremely significant (P＜0.01). (3) The ileal crypt depth of Group B was significantly higher than Group C(P ＜0.05). Group A had a lower depth of jejunum crypt than the treatment groups and significantly different from Group B (P＜0.01) and Group D (P＜0.05). (4) The unclassified_o__Clostridiales significantly differed at both family and genus levels among the groups (P＜0.05) with Group A being significantly higher than Group D. Whereas, at genus level, Ruminococcaceae_UCG-010 significantly differed among the groups (P＜0.05), but Group A was significantly higher than Group C. Conclusion The combined use of allicin and B. natto in feed significantly increased the average daily weight gain and half-eviscerated weight, decreased the F/G, increased the depth of jejunum crypt, reduced the harmful bacteria population, balanced the cecum microbiota, mitigated diarrhea and deaths, promoted the growth and development of Fujian white rabbits.
2021, 36(12): 1406-1413.
doi: 10.19303/j.issn.1008-0384.2021.12.003
Abstract:
Objective Effects of plant-spacing and water-supply on the biomass, yield, and water use efficiency of sweet corn plants were studied for better irrigation management. Method A field experiment including varied plant-spacing (i.e., 20, 30, and 40 cm) and amount of water supplied for the irrigation (i.e., 215, 265, and 365 m3·hm−2) for sweet corn cultivation was conducted to determine their effects on the biomass, yield, and water use efficiency of the plants. Result The spacing between individual plants significantly affected the biomass accumulation of each plant; the water-supply for the irrigation significantly altered the biomass allocation on a plant; and the interactions between the plant-spacing and irrigation significantly modified the allocation as well as the distribution of biomass on a plant. (1) As the spacing increased, the biomass increased significantly to reach a maximum at 40 cm separation between two plants. When that was combined with water-supply, both quantity and proportion of stem biomass on a plant significantly increased; and the weight of fresh ears became the largest and the principal component comprehensive score greatest on a plant at the irrigation that provided 365 m3·hm−2 of water. (2) The allometric constants of leaf and stem/aboveground biomass rose as the spacing and water-supply decreased and followed by an increase, while that of ear/aboveground biomass being the opposite. Those of ear/aboveground biomass peaked at the combined 30 cm for the spacing and 265 m3·hm−2 for the water-supply. Meanwhile, the constants of leaf and stem/aboveground biomass lowered but that of ear/aboveground biomass maxed. (3) Increasing spacing significantly decreased the sweet corn population yield. However, the irrigation did not exert significant effect on either yield or water use efficiency as they were the highest at the 265 m3·hm−2×20 cm combination. Conclusion The biomass of a sweet corn plant peaked with the combined treatments of 365 m3·hm−2 on water-supply and 40 cm on plant-spacing. But the greatest population yield and water use efficiency were observed under the combination of 265 m3·hm−2×20 cm. The information would lead to an improved irrigation operation for a high yield and high efficiency sweet corn production in arid hot valley and similar areas.
2021, 36(12): 1414-1421.
doi: 10.19303/j.issn.1008-0384.2021.12.004
Abstract:
Objective Contents and interrelations of 4 important secondary metabolites in parts of a Portulaca oleracea L. plant were studied. Method Metabolomics of P. oleracea root, stem, and leaf were analyzed using high performance liquid chromatography combined with tandem mass spectrometry (HPLC-MS/MS). Result There were 3 categories of 43 alkaloids, 7 categories of 34 flavonoids, 2 categories of 16 lignans and coumarins, and 3 categories of 5 terpenoids identified in the metabolites. A heatmap analysis showed the relative contents of the 4 important secondary metabolites to be similar in the stems and leaves but different from what in the roots. The alkaloids content was higher in the roots and leaves, while the flavonoids in the stems. Whereas the contents of terpenoids, lignans, and coumarins were increasingly more abundant from the roots to the stems and the leaves. Conclusion Same in kind, but significantly different in quantity, on the alkaloids, flavonoids, terpenoids, lignans, and coumarins were found in the roots, stems, and leaves of a P. oleracea plant.
2021, 36(12): 1422-1430.
doi: 10.19303/j.issn.1008-0384.2021.12.005
Abstract:
Objective To utilize spent of Chinese herbal medicine materials after extraction, feasibility of the application as a soilless substrate for watermelon cultivation in a greenhouse was studied. Methods The herbal residues were fully fermented and decomposed prior to mixing with cow dung, mushroom discards, and other waste materials in varied proportions for the experiment. Effects of the substrates on the plant growth and yield and quality of watermelon in a greenhouse were analyzed. Results Increasing amount of the spent material raised the porosity, aeration pores, ratio of pore sizes as well as the pH and EC, but lowered the bulk density and water holding pores of the substrates. As the plants grew, the SPAD and net photosynthetic rate (Pn) of the leaves rose at first to peak in the flowering and fruit setting stages and declined afterward. Meanwhile, the intercellular CO2 concentration (Ci) continuously increased to reach a maximum at maturity. For the various formulations, Chinese medicine residue V ∶ cow dung V ∶ mushroom residue V=3 ∶ 4 ∶ 3 produced plants with 33.15% increase on the dried weight of aboveground parts, 34.29% on the fresh weight of aboveground parts, 35.36% on the dried weight of underground parts, 30.26% on the fresh weight of underground parts, and 37.33% on the main root length over control. During flowering and fruit setting, the leaf SPAD, Pn, stomatal conductance (Gs), and transpiration rate (Tr) were significantly higher than those of control by 12.24%, 8.47%, 93.94%, and 9.85%, respectively, but Ci significantly lower by 8.65%. The leaf water use efficiency (WUE) of the plants grown on Chinese medicine residue V ∶ cow dung V ∶ mushroom residue V=3 ∶ 3 ∶ 4 was significantly greater than that of control by 70.25%. On fruit yield, the plants under Chinese medicine residue V ∶ cow dung V ∶ mushroom residue V= 3 ∶ 4 ∶ 3 were the highest with a significant increase over control by 21.23%. In contrast, Chinese medicine residue V ∶ cow dung V ∶ mushroom residue V =3 ∶ 3 ∶ 4 and Chinese medicine residue V ∶ cow dung V ∶ mushroom residue V =3 ∶ 1 ∶ 1 cultivations resulted in significantly reduced yields by 12.49% and 36.47%, respectively, while the other formulations exerted no significant differences in comparison to control (P＜0.05). The melons harvested from Chinese medicine residue V ∶ cow dung V ∶ mushroom residue V =4 ∶ 3 ∶ 3 and Chinese medicine residue V ∶ cow dung V ∶ mushroom residue V =3 ∶ 4 ∶ 3 treatments had significantly higher soluble solid contents than control, but those from Chinese medicine residue V ∶ cow dung V ∶ mushroom residue V =3 ∶ 3 ∶ 4 and Chinese medicine residue V ∶ cow dung V ∶ mushroom residue V =3 ∶ 1 ∶ 1 significantly lower by 8.63% and 12.66%, respectively. No significant effects by other treatments were observed. Conclusion It seemed feasible to use the traditional Chinese medicine spent for watermelon cultivation. An inclusion of the material with cow dung and mushroom discards in the ratio of 3 ∶ 4 ∶ 3 in the soilless substrate was considered optimal for melon cultivation, and at the same time, for effective cost reduction on production and waste disposal.
2021, 36(12): 1431-1438.
doi: 10.19303/j.issn.1008-0384.2021.12.006
Abstract:
Objective Genetic diversity and structure of the tea germplasms in Yunxiao were studied to facilitate the collection and utilization of the natural resource. Method SNP molecular marker was used to analyze the genetic relationship and diversity of 61 varieties of Camellia sinensis in Yunxiao, Fujian. Result The mean polymorphism information index, observed and expected heterozygosity, fixed index, and minor allele frequency of the SNP marker were determined to be 0.415, 0.309, 0.260, −0.072, and 0.197, respectively. Sixty-six high quality loci that could effectively and accurately identify the genetic relationship of tea plants were obtained. The genetic distance of 6 populations ranged from 0.150 to 0.926. The DNA fingerprints of the germplasms were constructed. The principal coordinates analyses and cluster analyses showed the component distribution to be relatively close within a population and the exchanges among the groups evident. Of the varieties, Xiaomaoshan was the richest in genetic diversity. Conclusion The genetic diversity of tea germplasms in Yunxiao was vast with populations of high geographic differentiation and in-between group exchanges. The SNP molecular marker-based technology was proven applicable for identifying the germplasms benefitting the utilization of local tea resource for selection and breeding.
2021, 36(12): 1439-1446.
doi: 10.19303/j.issn.1008-0384.2021.12.007
Abstract:
Objective A method to verify authenticity of an Oncidium hybrid progeny was developed based on the EST-SSR and SRAP molecular markers for cultivar selection at early stage. Method In this study, Wil. ‘Rich Yellow’, Onc. ‘Million Dollar’ and their 46 hybrid progenies were used as test materials. The effective primers with patermal characteristic bands, while the bands were clear and stable, were screened from 21 pairs of EST-SSR primers and 176 pairs of SRAP primer combinations. Then, the selected effective primers were used to amplify the test materials. According to the amplification results, the authenticity identification, cluster analysis and genetic similarity coefficient analysis of the hybrid progenies were carried out. Result Six pairs of EST-SSR primers and 10 pairs of SRAP primer combinations were chosen for the verification on 46 hybrid progenies. From the EST-SSR primers 34 polymorphic bands were obtained with 87.18% polymorphic loci, while the SRAP primer combinations rendered 81 polymorphic bands with 81.82% polymorphic loci. From the clustering results, we can see that all the hybrid progeny strains were closely related to the female parent. The average genetic similarity coefficient between hybrid progenies and female was higher than that of the male parent, indicating that the hybrid progenies are closer to female parent in heredity, which was consistent with the results of clustering analysis. Conclusion EST-SSR and SRAP molecular markers can be effectively used in the study of authenticity identification of hybrid progenies of Oncidium hybridum.
2021, 36(12): 1447-1456.
doi: 10.19303/j.issn.1008-0384.2021.12.008
Abstract:
Objective A hyperspectral estimation model for the chlorophyll content in the leaves of honey pomelo was developed using spectral measurements on the characteristic parameters for the establishment of a rapid, noninvasive, accurate determination method. Method Characteristic bands of spectrum of the leaves were obtained. The first-order differential spectrum and spectral characteristic variables were used to analyze the correlation between the hyperspectral bands and the relative chlorophyll content (SPAD) of pomelo leaves. Univariate estimation and multiple regression models were constructed and compared to arrive at the best prediction model. Result At the wavelengths between 350 nm and 1 050 nm, the reflectance spectra on the pomelo leaves of varied SPADs decreased significantly with increasing chlorophyll content. SPAD significantly correlated with either the original or the first-order differential spectrum at several wavelengths in the visible light range. The sensitive wavelengths for the original spectral curve were 576 nm and 701 nm, and 691 nm and 748 nm for the first order differential spectrum. Based on the precision of fitting, the one that based on the hyperspectral Conclusion The multiple regression model based on hyperspectral indices NDVI′691,748, GRVI550,770, R′691 and DVI′691,748 could be adequately applied for estimating chlorophyll content of honey pomelo leaves.
2021, 36(12): 1457-1463.
doi: 10.19303/j.issn.1008-0384.2021.12.009
Abstract:
Objective To isolate and identify and determine the biological characteristics of the pathogen that caused the stem rot disease on Dendrobium officinale. Method Typical diseased plants were collected from 3 farms in Zhaoan and Songxi for pathogen isolation. Morphological and molecular identification methods including gene sequencing of ITS, EF1-α, ACT, RPB2, and LSU were performed on the isolates. Biological characteristics of the pathogen in response to temperature, pH, light condition, carbon source, and nitrogen source were determined. Result The pathogen was identified as Fusarium oxysporum, which grew optimally at 30 ℃ and pH 7 under light on a medium using starch for carbon and peptone for nitrogen sources. Conclusion F. oxysporum was identified to be the pathogen that caused the stem rot disease on D. officinale in Fujian, and the optimal mycelial growth conditions determined.
2021, 36(12): 1464-1470.
doi: 10.19303/j.issn.1008-0384.2021.12.010
Abstract:
Objective Biological properties of Curvularia coicis Castellani, which causes coix leaf spot (CLS) on Chinese pearl barley, and the control efficacy of 3 fungicides on the disease were studied. Method Effects of temperature, pH, light, and carbon and nitrogen sources on the mycelial growth of the pathogen as well as the toxicity of mefentrifluconazole, pyraclostrobin, fludioxonil, and their binary compounds toward the pathogen were determined. Result The optimum conditions for the mycelial growth of C. coicis were found to be 25 ℃, pH 8, starch for carbon, and peptone for nitrogen with no specific preference for light exposure. All 3 tested fungicides exhibited inhibitory effects on the pathogenic growth as indicated by the toxicity indices of mefentrifluconazole at 234.83-fold, pyraclostrobin at 97.84-fold, and fludioxonil at 84.97-fold of that of carbendazim. In combination of the agents, only mefentrifluconazole and pyraclostrobin were shown synergistic in the antifungal efficacy with the best mixing ratio of 5∶5 with a toxicity index of 221.85. Conclusion Temperature, pH, and carbon and nitrogen sources significantly affected C. coicis growth. Mefentrifluconazole, pyraclostrobin, and fludioxonil were strongly antifungal against the pathogen. But application of combinations of these agents require further evaluation.
2021, 36(12): 1471-1477.
doi: 10.19303/j.issn.1008-0384.2021.12.011
Abstract:
Objective Identification of the leaf spot pathogen on Plectranthus scutellarioides in Fujian and screening fungicides for effective disease prevention and control were conducted. Method A causative pathogen was isolated from the diseased tissues, and the species verified by Koch’s rule, morphological observations under a microscope, and molecular ITS and LSU sequence analyses. An in vitro toxicity test on 6 commercially available fungicides was performed on the pathogen to determine their efficacy. Result The coleus leaves inoculated with the conidia of the isolated ZZCYC1706 produced same symptoms as those observed on the diseased plants in the field. The ITS and LSU sequences of ZZCYC1706 suggested it be Alternaria alternata. The toxicity test showed, among the 6 fungicides, 96% pyrisoxazole to be most effective in inhibiting the pathogenic growth with the lowest EC50 of 0.621 μg·mL−1. It was followed by 98% iprodione with an EC50 at 1.155 μg·mL−1 , 95% pyrimethanil at 5.258 μg·mL−1, and 96.4% captan, which was the least effective, at 89.010 μg·mL−1. Conclusion The pathogen of the leaf spot disease on P. scutellarioides in Fujian province was identified as A. alternata, which was the first reported in China. The fungicides, pyrisoxazole, iprodione, and pyrimethanil, were shown in the laboratory effective in inhibiting the growth of A. alternata. And, being of different types, these fungicides could potentially be applicable for the coleus leaf spot disease control with a reduced concern of the development of drug resistance by the pathogen.
2021, 36(12): 1478-1483.
doi: 10.19303/j.issn.1008-0384.2021.12.012
Abstract:
Objective Inhibitory effect of lipopeptides secreted by Bacillus FJAT-2349 on the pathogen of anthracnose was investigated. Method Agar plate diffusion and pin-prick inoculation were used to determine the inhibition effect of the lipopeptides on the pathogen. The fungal morphology was observed under a scanning and a transmission electron microscope. Result The lipopeptide-producing B. amyloliquefaciens FJAT-2349 could effectively inhibit the growth of Colletotrichum acutatum with an inhibition rate of 87.8%. The lipopeptides were composed of mainly fengycin, but also iturin and surfactin. The diameter of inhibition zone on the agar plate by the lipopeptide against C. acutatum was up to 22 mm. The effect was dose-dependent. Under the electron microscopes, the fungal hyphae appeared deformed and cell walls damaged by the lipopeptides. Inoculation of FJAT-2349 on harvested loquats could delay the onset of anthracnose by one day. The in vivo tests showed that on the 4th day after inoculation the relative biocontrol efficacy on a curative-treatment group was 29.2% and 72.7% on a preventive-treatment group; and the average lesion diameter on the treatment groups was 4.67-5.00 mm, as opposed to the larger 6.89-7.25 mm of control. Conclusion The lipopeptides secreted by B. amyloliquefaciens FJAT-2349 could effectively inhibit the growth of Colletotrichum acutatum.
2021, 36(12): 1484-1490.
doi: 10.19303/j.issn.1008-0384.2021.12.013
Abstract:
Objective An artificial intelligence-based identification method to effectively differentiate bok choy seedlings from weeds was proposed to facilitate vegetable farm weeding operation. Methods Bok choy seedlings were recognized by the neural network models to exclude the green pixels from other vegetations considered as weeds by color differentiation. Effectiveness of the convolutional neural networks (CNN) and the emerging transformer models in correctly separating the seedlings and weeds was evaluated. Result Although both performed acceptable, the YOLOX model delivered a higher average accuracy of 98.1% and a faster speed at 44.8 fps than Deformable DETR in the recognition operation. Conclusion By defining the green pixels of bok choy seedlings as target color, weeds could be rejected by the AI recognition program providing a robust separation for efficient weeding in the field of the random-planting vegetables such as bok choy.
2021, 36(12): 1491-1498.
doi: 10.19303/j.issn.1008-0384.2021.12.014
Abstract:
Objective Biological functions of the regulatory protein ompR in the two component EnvZ/OmpR system, including prodigiosin-producing ability and other biological characteristics, of Serratia marcescens FZSF02 were studied. Methods Homologous recombination was used to construct ompR-knockout S. marcescens FZSF02. Effect of OmpR on the prodigiosin-producing ability was examined by LB agar plate incubation and qPCR. Methods of crystal violet staining, agar plate incubation, and others were applied to determine the biofilm-forming, mobility, and stress adaptation abilities of the transcription factor protein under various environmental stresses. Results OmpR was a protein with high conserved amino acid sequences. An ompR- deleted strain, FZSF02 ∆ompR, was successfully obtained by homologous recombination and confirmed by PCR. As a result, FZSF02 ∆ompR lost prodigiosin-producing ability that possessed by the wild strain. The transcriptional levels of pigA, pigF, and pigN of the prodigiosin biosynthesis gene cluster in FZSF02 ∆ompR were respectively 3.8%, 2.0% and 2.1% of the wild type strain. The biofilm formation of FZSF02 ∆ompR declined 37.5% (at 37 ℃) and 15.1% (at 27 ℃) from its wild counterpart. On the other hand, OmpR exhibited no significant effect on the growth, mobility, or response to the environmental stress. Conclusion OmpR was a newly reported gene that specifically regulated the prodigiosin biosynthesis in S. marcescens. It also significantly affected the biofilm formation but not on the growth, mobility, or stress response.
2021, 36(12): 1499-1505.
doi: 10.19303/j.issn.1008-0384.2021.12.015
Abstract:
Objective Effects of drying methods on rehydration property of bacterial cellulose (BC) were investigated. Method BC samples dried by means of hot air, microwave under vacuum, and freeze-drying were compared on the swelling and reconstitution rates upon rehydration. A scanning electron microscope (SEM) was used to observe and characterize the BC microstructure. Result The varied dehydration processes affected the microstructure and rehydration of the dried BC. Among the untreated control and treated samples, the freeze-dried BC displayed the highest rehydration rate of 44.79%. It was followed by the hot air and the microwave-vacuum dried specimens. The SEM images showed the freeze-drying rendered BC with a loose but well-defined fibrous network, while the other two methods produced a tight structure with clusters. Insofar as hygroscopic property is concerned, freeze-drying BC at −80 ℃ was superior to all other methods. The dynamics of the water adsorption and swelling of BC followed the Fickian diffusion law. A better maintained 3D structure would have greater diffusion coefficient, and therefore, more efficient water absorption for the dried BC when water was added. Conclusion The freeze-dried BC could be rehydrated most desirably among all tested samples. The processing technology was recommended for the dehydration.
2021, 36(12): 1506-1514.
doi: 10.19303/j.issn.1008-0384.2021.12.016
Abstract:
In response to heavy metal stress plants alter the root exudate secretion in ways depending on the plant species and type of heavy metals, among other factors. This article reviews the published literature on the organic acids, amino acids, and soluble sugars in root exudates and their roles in the chemistry and physiology of the plants under varieties of heavy metal stresses. The referred material and documents concerning the tolerance and adaptability of plants to heavy metals as well as the response mechanisms involving the key chemicals would provide a concise and update information for the scientists interested in the field of study.
In response to heavy metal stress plants alter the root exudate secretion in ways depending on the plant species and type of heavy metals, among other factors. This article reviews the published literature on the organic acids, amino acids, and soluble sugars in root exudates and their roles in the chemistry and physiology of the plants under varieties of heavy metal stresses. The referred material and documents concerning the tolerance and adaptability of plants to heavy metals as well as the response mechanisms involving the key chemicals would provide a concise and update information for the scientists interested in the field of study.
