Scientia Agricultura Sinica

Genome-Wide Association Study of Yield Component Traits in Upland Cotton (Gossypium hirsutum L.)

WANG Juan, MA XiaoMei, ZHOU XiaoFeng, WANG Xin, TIAN Qin, LI ChengQi, DONG ChengGuang

Scientia Agricultura Sinica. 2022, 55(12): 2265-2277. doi:10.3864/j.issn.0578-1752.2022.12.001

Abstract ( 507 )

HTML ( 121 )

PDF (6687KB) ( 268 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】The loci, elite alleles and candidate genes associated with yield component traits, such as boll weight, lint percentage, number of bolls per plant and seed index, were explored using a genome-wide association analysis (GWAS), which provided a theoretical reference for the molecular breeding of cotton yield.【Method】The GWAS based on a mixed linear model was performed on 408 upland cotton accessions grown in six different environments using the Cotton SNP 80K chip for the four yield component traits, and the significant SNP loci (SNPs) and elite allele were also detected. Finally, on the basis of the gene expression levels of the transcriptome, candidate genes related to the target traits were mined within a 1 Mb genome range of the flanking sequences of the significant SNPs. 【Result】The four yield component traits showed wide phenotypic variations in different environments, with the maximum coefficient of variation for number of bolls per plant being 16.67%-22.66%. The heritability of each trait was between 48.4% and 92.2%. The correlations among traits were significant or highly significant, except between boll weight and lint percentage. A total of 23 significant SNPs distributed in seven different genomic regions associated with the four traits were identified across the 408 cotton accessions in the BLUP. The numbers of loci associated with boll weight, lint percentage, number of bolls per plant and seed index were 5, 1, 9 and 8, respectively, and three loci (TM21094, TM21102, and TM57382) were associated with multiple target traits simultaneously. Seven elite allele types, TM21099(TT), TM57382(GG), TM78920(CC), TM53448(TT), TM59015(AA), TM43412(GG) and TM69770(AA), were identified. A total of 158 candidate genes potentially related to yield formation were selected through an analysis of gene expression patterns in RNA-Seq data. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses indicated that the functions and metabolic pathways of most genes were varied.【Conclusion】In this study, 23 significant SNPs associated with four yield component traits were identified across 408 cotton accessions, and 158 candidate genes were predicted using RNA-Seq.

Comprehensive Evaluation of Potato Tuber Texture

LI WenLi, YUAN JianLong, DUAN HuiMin, JIANG TongHui, LIU LingLing, ZHANG Feng

Scientia Agricultura Sinica. 2022, 55(12): 2278-2293. doi:10.3864/j.issn.0578-1752.2022.12.002

Abstract ( 398 )

HTML ( 74 )

PDF (3410KB) ( 178 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 The comprehensive evaluation of texture qualities of potato tubers not only are beneficial to the subdivision of processing quality traits and accurately locate purpose of potato, but also assist breeders screening new varieties, and accelerate the development of potato products.【Method】Potato cultivated varieties were selected as the research samples. Puncture, TPA compression and shear methods were chosen to analyze the texture parameters. These included puncture distance, puncture initial force, puncture speed, compression deformation, compression speed, compression interval time, compression initial force, shear initial force and speed. The texture indexes of eight varieties were measured under the optimal texture analyzer parameters setting, then the correlation among the texture parameters and the evaluation of optimal texture parameters were analyzed. 【Result】 Optimal parameters of fresh tuber puncture: Cylindrical metal probe (TMS 2 mm Steel), 2 mm puncture distance and, 2.5 N initial force, 50 mm·min^-1 detection speed. The optimal test factors of TPA compression (fresh/steamed): The cylinder sample for fresh and steamed tubers both ranged in the diameter and height from 10 mm to 15 mm, no significant difference was examined among three probe selection in the fresh tubers. Cylindrical aluminum probe (TMS 36.0 mm Aluminum Cylinder) was the optimal type for steamed tubers probe. The optimal parameters (fresh/steamed): 50% and 60% deformation, 60 mm·min^-1 and 80 mm·min^-1 detection speed, 6 s and 10 s interval time, both 0.7 N initial force. The optimal shear parameters (fresh/steamed): The length, width and height of the cuboid sample were 30 mm, 15 mm, and 10 mm, respectively. The probe type was light single knife probe (TMS Perspex Knife Edge), with both 60 mm·min^-1 detection speed, and 1 N and 0.5 N initial force. They’re existed significant correlation between springiness and the peel crispness, no significant correlation among the other texture parameters of TPA compression and shear. They’re existed significant positive correlation among puncture, TPA compression and shear texture parameters (0.410-0.959) in fresh tubers. There also existed significant positive correlation between TPA compression and shear texture parameters (0.441-0.952) in steamed tubers. 【Conclusion】 Puncture, TPA compression and shear methods were suitable for the samples evaluation of the quality of fresh tubers. The indexes of peel hardness, peel brittleness, TPA hardness, cohesiveness, chewiness, shear hardness can be chosen as important parameters to compare differences of texture. TPA compression and shear methods were suitable for the sample’s evaluation of the quality of steamed tubers. The indexes of TPA hardness, adhesiveness, cohesiveness, springiness, chewiness, shear hardness can be chosen as important parameters to compare differences of texture.

Effects of Intercropping with Different Maturity Varieties on Grain Filling, Dehydration Characteristics and Yield of Spring Maize

XIAO ShanShan, ZHANG YiFei, YANG KeJun, MING LiWei, DU JiaRui, XU RongQiong, SUN YiShan, LI WeiQing, LI GuiBin, LI ZeSong, LI JiaYu

Scientia Agricultura Sinica. 2022, 55(12): 2294-2310. doi:10.3864/j.issn.0578-1752.2022.12.003

Abstract ( 305 )

HTML ( 48 )

PDF (1414KB) ( 173 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】In view of the high grain moisture content during the maize harvest period in high latitude and cold areas of China, it restricts the efficient promotion and application of mechanical grain harvesting technology. In this study, the maize varieties with different maturities were intercropped according to a certain proportion under field conditions, in order to clarify the regulating effects of intercropping at different maturity on grain filling, dehydration characteristics and yield of spring maize.【Method】Maize varieties of Zhengdan 958 (ZD958), Xianyu 335 (XY335) and Yinongyu 10 (YNY10) with different maturities were used as experimental materials, two-factor randomized block design was applied to set up the intercropping between varieties with longer growth period (LGPV) and varieties with shorter growth period (SGPV), that is, ZD958 and YNY10 intercropping (Z‖Y), and XY335 and YNY10 intercropping (X‖Y). Based on the above main treatment, six kinds of intercropping width (line number) ratios, namely 6﹕6, 4﹕4, 2﹕2, 1﹕1, 0﹕1 and 1﹕0, were designed to compare and analyze the changes of maize grain filling, dehydration characteristics and yield under different treatment combinations.【Result】For LGPV, with the decrease of the intercropping ratio, the moisture content of grains in the physiological maturity and harvest phases decreased. The average dehydration rate and total dehydration rate of grains before and after physiological maturity showed a trend of acceleration, and the average filling rate (G_mean), the maximum grain filling rate (G_max), and the grain weight at which the filling rate reached the maximum (W_max) gradually increased; The number of days required for the maximum filling rate (T_max) and the active grain-filling period (D) gradually shortened, and grain yield and 100-kernel weight increased significantly (P<0.05). In response to the decline of intercropping ratios, it was showed that SGPV increased in grain moisture content and decreased in dehydration rate during the physiological maturity period and harvest period, while G_mean, G_max, and W_max continued to decreased, and T_max and D were slightly extended. Although yield and 100-kernel weight showed a downward trend for SGPV, but the variation did not reach a significant level. At the same time, the average grain moisture content of the intercropping compound population at the harvest period was significantly lower than that of the LGPV monocropping. The percentage of grain moisture content decline were 6.44%-7.29% for Z‖Y-(6﹕6-1﹕1) and 4.30%-4.75% for X‖Y-(6﹕6-1﹕1) on 2-year means. In terms of average grain yield to intercropping compound population, the grain yield increased with the decrease of intercropping ratios. Moreover, compared with the SGPV YNY10 monocropping, the average grain yield for Z‖Y-(6﹕6-1﹕1) and X‖Y-(6﹕6-1﹕1) increased by 5.12%-6.49% and 1.87%-2.96% on 2-year means, respectively and the increase was obvious under Z‖Y treatment.While the average grain yield of Z‖Y and X‖Y treatments was not significantly different from that of longer growth period (LGPV) monocropping.【Conclusion】Under dense planting conditions, the intercropping with different maturity maize varieties significantly promoted the increase of maximum grain filling rate and grain weight with shortening of active grain filling period and accelerating total grain dehydration rate of LGPV, effectively reduced the average grain moisture content of field composite population at harvest time, and realized the coordinated development of high and stable yield, and efficient dehydration of maize grains.

Research on Senescence Process and Suitable Indicators of Maize Ear Leaves

LÜ ZhiWei,DU Kang,ZHOU ZhiGuo,ZHAO WenQing,HU Wei,ZHAO JianMing,ZHU SuQin,WANG YouHua

Scientia Agricultura Sinica. 2022, 55(12): 2311-2323. doi:10.3864/j.issn.0578-1752.2022.12.004

Abstract ( 315 )

HTML ( 36 )

PDF (833KB) ( 122 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】The main objectives of this study were to find more optimized methods and suitable indicators to accurately indicate the senescence process of maize ear leaves, and to clarify the senescence process of maize ear leaves, so as to provide the theoretical reference for accurate and efficient cultivation measures of maize. 【Method】In the spring and summer of 2020, the field trial was carried out at Dafeng Research Station (33°12′ N, 120°28′ E) in Jiangsu province. By using hybrid cultivar Suyu 29 (SY29) as the testing material, six maize populations (N1-N6) with different leaf nitrogen concentration under different nitrogen application rates (0, 67.5, 136.5, 205.5, 274.5, and 343.5 kg N·hm^-2) were constructed. The dynamic changes of 12 morphological and physiological indicators after silking were fitted by the Logistic model and the accuracy of indicating the senescence process by these indicators were compared. 【Result】The fitting trend and degree of the Logistic formula y=(a-d)/(1+(x/c)^b)+d were better than the predecessor commonly used Logistic formula y=a/(1+e^-b(x-c)). It was showed by a multi-indicator analysis that the ear leaves of spring maize and summer maize initiated senescence process at 18.8-29.1 ($\bar{x}$=25.8) days and 17.5-28.2 ($\bar{x}$=23.9) days after silking, rapid senescence occurred at 30.5-37.9 ($\bar{x}$=34.4) days and 28.0-35.7 ($\bar{x}$=31.8) days after silking, and terminated senescence process at 40.6-54.1 ($\bar{x}$=45.9) days and 38.3-47.0 ($\bar{x}$=42.1) days after silking, respectively. The effective accumulated temperature of spring and summer maize at 25.8 days and 23.9 days from silking to the initiation of senescence process was 392.9 ºC and 477.6 ºC, respectively. The effective accumulated temperature of spring and summer maize at 20.1 days and 18.2 days from the initiation to termination of senescence process was 360.0 ºC and 284.0 ºC, respectively. It was showed by an indicator classification analysis that the σ-value under normal distribution of the senescence characteristic time indicated by physiological indicators was greater than that indicated by morphological indicators within the same senescence stage, which was the case in both spring maize and summer maize. The coefficient of variation (CV) of senescence characteristic time indicated by the content of malondialdehyde (MDA), total chlorophyll, chlorophyll a, fructose, glucose and transpiration rate (T_r) were all less than 5%. The root mean square error (RMSE) between the mean time of each stage and the senescence characteristic time indicated by the content of MDA, total chlorophyll, fructose, glucose and net photosynthetic rate (P_n) were all less than 2. 【Conclusion】The Logistic formula y=(a-d)/(1+(x/c)^b)+d could serve as a mathematical tool to accurately fit the dynamic changes of senescence related indicators of maize ear leaves. Based on this evaluation method, the ear leaves of spring maize and summer maize initiated senescence at 26 days and 24 days after silking, their senescence rate reached the maximum at 34 days and 32 days after silking, and substantially enter the functional death stage at 46 days and 42 days after silking, respectively. Effective accumulated temperature was an important factor to affect the senescence process of maize ear leaves. The content of MDA, total chlorophyll, fructose, and glucose were excellent indicators to characterize the senescence process of maize ear leaves.

Study on Optimal Time and Construct a Prediction Model of Mechanical Grain Harvest of Maize in Ningxia

LI HongYan,XUE Jun,WANG YongHong,WANG KeRu,ZHAO RuLang,MING Bo,ZHANG ZhenTao,ZHANG WenJie,LI ShaoKun

Scientia Agricultura Sinica. 2022, 55(12): 2324-2337. doi:10.3864/j.issn.0578-1752.2022.12.005

Abstract ( 279 )

HTML ( 34 )

PDF (7907KB) ( 104 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 In this study, the date when the kernel moisture content of different types of maize variety dehydrates to a suitable level for mechanical grain harvesting was predicted for different sowing dates in the Ningxia Hui Autonomous Region of China, in order to provide a basis for the variety selection at the regional scale, the determination of a suitable harvest period, and the development of the mechanical harvesting of maize varieties with a low moisture content. 【Method】Using the average kernel moisture content at physiological maturity (30.1%) and the average accumulated temperature (3 274.3 °C·d) required for sowing to physiological maturity ≥0 ℃·d as indicators, 38 common maize varieties were classified into four types by the two-way average method: type I varieties were characterized by late maturity and slow dehydration; Type II were characterized by early maturity and slow dehydration; type III varieties were characterized by early maturity and fast dehydration; type IV varieties were characterized by late maturity and fast dehydration. According to the production practice in Ningxia, the varieties with medium kernel moisture content and accumulated temperature requirement at physiological maturity stage were selected as the representative variety of each type. Then, the Logistic Power nonlinear growth model was used to predict the dehydration of the 38 maize varieties base on 10 years of recent meteorological data (2008-2017). Based on these data, the kernel moisture characteristics of each type of variety were predicted for various regions of Ningxia with different heat resources for three different sowing dates (initial sowing, peak sowing, and initial sowing). 【Result】The results showed that, initial sowing could obtain an accumulated temperature of 162.2-229.8 °C·d in crop growth more than that of final sowing. The accumulated temperatures required for kernel dehydration to a moisture content of 25% from sowing for Type I, Type II, Type III, and Type IV cultivars were 3 615.2, 3 290.6, 3 138.0, and 3 426.6 °C·d, respectively. In northern and central Ningxia, all types of varieties could meet the requirement that the kernel moisture content be reduced to 25%, while in the southern regions, Type III varieties could meet the requirement that the kernel moisture content be reduced to 25% for sowing at the initial and peak sowing times. The predicted accumulated temperatures from sowing to dehydration required for kernel dehydration to a moisture content of 16% for Type I, Type II, Type III, and Type IV cultivars were 4 320.6, 3 816.4, 3 632.9, and 4 023.6 °C·d, respectively. For the Type III varieties, in northern Ningxia on the initial sowing date and final sowing date, the kernel moisture content of both could be reduced to 16%; in the central region on the initial sowing date and peak sowing date, the accumulated temperature required for dehydration to 16% could be satisfied. 【Conclusion】 The heat resources of Ningxia could be used rationally through the selection of maize varieties with appropriate dehydration characteristics and early planting, thereby help to achieve high-quality mechanical maize kernel harvesting in this region. In northern and central Ningxia, it was recommended to select early-maturing, fast-dehydrating (Type III) varieties in order to achieve the mechanical harvesting of maize with a low kernel moisture content and thus convert regional heat resources into economic benefits.

Cloning and Function Analysis of a Serine Protease Inhibitor Gene Nlserpin2 in Nilaparvata lugens

WU Wei,XU HuiLi,WANG ZhengLiang,YU XiaoPing

Scientia Agricultura Sinica. 2022, 55(12): 2338-2346. doi:10.3864/j.issn.0578-1752.2022.12.006

Abstract ( 256 )

HTML ( 67 )

PDF (1668KB) ( 109 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】The objective of this study is to clone a serine protease inhibitor gene Nlserpin2 and clarify its expression patterns and biological functions in the brown planthopper (BPH), Nilaparvata lugens.【Method】Based on the transcriptome data of N. lugens, the full-length cDNA of Nlserpin2 was cloned by PCR, and its nucleotide and protein sequences were subsequently characterized using bioinformatics tools. The expression patterns of Nlserpin2 across different developmental stages (egg, 1st-5th instar nymphs, female and male adults), in different tissues (fat body, gut and ovary) of the newly emerged female adults, and in the 5th instar nymphs at different times post infection of an entomopathogenic fungus Metarhizium anisopliae were determined by qRT-PCR. The effects of Nlserpin2 knockdown on the survival rate and the resistance to M. anisopliae infection of the N. lugens nymphs at 5th instar were evaluated based on RNAi technique.【Result】The Nlserpin2 (GenBank accession number: KC355239) was successfully cloned from N. lugens. The open reading frame (ORF) is 1 209 bp in length, encoding 402 amino acids with a conserved serpin domain and a reactive center loop (RCL) that typically existed in the members of the serpin superfamily. A signal peptide consisting of 27 amino acid residues was also predicted at the N-terminus. The phylogenetic analysis showed that Nlserpin2 is clustered together with other hemipteran serpin, and has the highest homology with Sogatella furcifera serpin. The qRT-PCR results showed that the expression of Nlserpin2 had obvious spatio-temporal characteristics. The expression level of Nlsperpin2 in adults was significant higher than that in other developmental stages, and the highest expression level was observed in male adult. Significant higher expression level was detected in the high-instar nymphs (4th-5th instar) when compared to that in the eggs and the low-instar nymphs (1st-3rd instar), and the lowest expression level was observed in the 3rd instar nymph. Nlserpin2 was expressed in the gut, fat body and ovary of the female adults, and its expression level in the gut was significantly higher than that in the fat body and ovary. The expression of Nlserpin2 was significantly upregulated at 2 and 3 days post infection with M. anisopliae, but gradually stabilized with the increase of infection time. RNAi results showed that the expression level of Nlserpin2 could be significantly inhibited by microinjection of dsNlserpin2. Inhibition of Nlserpin2 expression caused significant decrease in the survival rate and the capability to resist M. anisopliae infection of the 5th instar nymphs of N. lugens. Compared with the control group, the corrected survival rates of Nlserpin2-interfered N. lugens nymphs were significantly decreased by 28.4% and 31.0% at 5 and 8 days post infection with M. anisopliae, respectively.【Conclusion】Nlserpin2 plays important roles in the pathogen defense of N. lugens, which can be used as a potential target for RNAi-mediated control of N. lugens and provides the gene of interest for genetic improvement of entomopathogenic fungi with a hypervirulent to N. lugens.

Light Energy Utilization and Response of Chlorophyll Synthesis Under Different Light Intensities in Mikania micrantha

JIN MengJiao,LIU Bo,WANG KangKang,ZHANG GuangZhong,QIAN WanQiang,WAN FangHao

Scientia Agricultura Sinica. 2022, 55(12): 2347-2359. doi:10.3864/j.issn.0578-1752.2022.12.007

Abstract ( 316 )

HTML ( 36 )

PDF (1217KB) ( 103 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】Light is one of the important ecological factors for photosynthesis of plants. The capture and utilization of light by photosynthetic pigments affects the growth and development of plants, and then affects their survival and fitness in natural ecosystems. The objective of this study is to clarify the photosynthetic physiological characteristics and response of gene expression of chlorophyll biosynthesis pathway to different light intensities in Mikania micrantha, as well as the relationship between photosynthetic energy and chlorophyll transformation, and to provide physiological and ecological evidences for explaining the “rapid growth” of M. micrantha.【Method】The photosynthetic pigment content of M. micrantha was determined by ethanol extraction under different light intensities (0, 20%, 40% and 100%). The variation pattern of chlorophyll a and b ratio (Chl a/b) was analyzed. The photosynthetic characteristics of M. micrantha were compared with the representative plants of different photosynthetic pathways (C3, C4 and CAM). The contents of ATP and starch in M. micrantha leaves under the above light intensities were determined by micro-method and anthrone colorimetric method. The cDNA library of M. micrantha under different light intensities was established and sequenced. Bioinformatics software including OrthoFinder, Blastp, HISAT2, StringTie, R package were used to analyze the expression pattern of genes involved in chlorophyll synthesis and light-harvesting complex (LHC) in M. micrantha under different light intensities. The expression patterns of genes related to chlorophyll synthesis pathway were identified.【Result】At 100% light intensity, the Chl b and carotenoid contents and Chl a/b in M. micrantha leaves were similar to those in C4 plant (maize). The Chl a/b in M. micrantha and maize leaves was significantly higher than that in C3 (rice and tomato) and CAM (aloe) plants. The contents of Chl a, Chl b and carotenoid in M. micrantha leaves under different light intensities did not change significantly, but Chl a/b significantly increased with increasing light intensity. Between the 40% and 100% light intensity, ATP content in M. micrantha leaves changed slightly, while starch content in M. micrantha leaves increased significantly in 100% light intensity. When the light intensity was 0, starch content decreased sharply and ATP content increased. The gene expression levels of HEMA, CHLH, CRD1 and CAO gene families involved in chlorophyll biosynthesis in M. micrantha were regulated by light induction, and the expression levels of light-harvesting complex (LHC) genes were higher under high light intensity.【Conclusion】Under different light conditions, M. micrantha may regulate the synthesis of Chl a and Chl b, and the mutual transformation of starch and ATP, which lay the foundation for the higher photosynthetic rate and light adaptability of M. micrantha.

Effects of Fertilization Methods on Ammonia Volatilization of Spring Maize in Dry Farming on the Loess Plateau

XU FangLei,ZHANG Jie,LI Yang,ZHANG WeiWei,BO QiFei,LI ShiQing,YUE ShanChao

Scientia Agricultura Sinica. 2022, 55(12): 2360-2371. doi:10.3864/j.issn.0578-1752.2022.12.008

Abstract ( 311 )

HTML ( 47 )

PDF (1319KB) ( 112 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 A two-year on-farm experiment was conducted to evaluate the effects of different fertilization application methods and nitrogen application rates on soil ammonia volatilization of spring maize in dry farming on the Loess Plateau. 【Method】The split zone test design was adopted in the experiment, the main factor included three nitrogen application rates of 0, 180 and 300 kg·hm^-2 (namely N0, N180 and N300, respectively), and the sub-factors included three fertilization methods of solid granular urea one-time basal fertilization (UR), solid granular urea basal and top-dress fertilization (URT, 40% as basal fertilizer and 60% as top-dressing at 10 leaf stage), and common urea and controlled-release urea mixed in one-time basal application (CRU). Sponge absorption ventilation method was used for in-situ determination. 【Result】 (1) As for the ammonia volatilization after basal fertilizer, the three fertilization methods all showed the peak value of ammonia volatilization, and the peak value of ammonia volatilization under UR treatment was higher than that of the other two fertilization methods, especially under the condition of high nitrogen application rate. For the ammonia volatilization after topdressing, only the URT treatment showed the peak value, which was higher than that after basal fertilizer. (2) The accumulation of ammonia volatilization increased with the increase of nitrogen application rate. Under the same nitrogen application rate, the accumulation of ammonia volatilization under URT treatment was the highest (2.88-36.84 kg·hm^-2), which was mainly concentrated in the top dressing period (72.24%-90.4% of the whole growth period). The second was UR treatment (1.08-10.07 kg·hm^-2), while the cumulative ammonia volatilization under CRU treatment was the lowest (0.96-5.69 kg·hm^-2). 3. The interaction between nitrogen application rate and fertilization method on ammonia volatilization was very significant. The annual difference of ammonia volatilization emission was mainly influenced by rainfall after fertilization. 【Conclusion】For spring maize covered with film in dry farming in northwest China, CRU could reduce both the artificial input of topdressing and the loss of ammonia volatilization, which could be used as a green fertilization method worthy of promotion in this area.

Soil Available Sulfur Content in Jilin Province and Its Correlation with Soil Organic Matter and Soil Total Nitrogen

CUI Shuai,LIU ShuoRan,WANG Yin,XIA ChenZhen,YAN Li,FENG GuoZhong,GAO Qiang

Scientia Agricultura Sinica. 2022, 55(12): 2372-2383. doi:10.3864/j.issn.0578-1752.2022.12.009

Abstract ( 291 )

HTML ( 41 )

PDF (4439KB) ( 130 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 The aim of this study was to clarify the status of effective sulfur content of dryland soils in Jilin province and its distribution differences, so as to provide a basis for reasonable sulfur application to regional crops.【Method】232 surface (0-20 cm) soil samples were collected from 8 major soil types in different ecological zones of Jilin province, and the spatial distribution characteristics of effective sulfur content were analyzed by geostatistical methods to compare the differences in effective sulfur content of different types of soils and to establish the correlation between effective sulfur, organic matter and total nitrogen in soils.【Result】 The distribution of effective sulfur content in dryland soils of Jilin Province ranged from 5.8 to 40.7 mg·kg^-1, with a mean value of 18.06 mg·kg^-1. The proportions of sulfur deficiency and potential sulfur deficiency in all samples were 27.2% and 20.7%, respectively. The spatial distribution showed that the overall trend of effective soil sulfur content gradually decreased from east to west, and the corresponding incidence of sulfur deficiency gradually increased from east to west. The mean values of soil effective sulfur content (incidence of sulfur deficiency or potential sulfur deficiency) in the three major ecological zones of east, central and west were 22.3 mg·kg^-1 (24.2%), 18.1 mg·kg^-1 (40.0%) and 14.3 mg·kg^-1 (75.6%), respectively. The mean values of effective sulfur content of albic soil and dark brown loam, which were mainly distributed in Eastern humid mountainous area, were 22.1 and 22.0 mg·kg^-1, respectively, and 15.2% and 28.3% of the samples were sulfur deficient or potentially sulfur deficient, respectively; the mean values of effective sulfur content of black soil, alluvial soil and meadow soil in the central semi-humid plain area were 18.8, 17.1 and 16.2 mg·kg^-1, respectively. The mean values of effective sulfur content of chernozem, aeolian sandy soil and saline-alkali soil in the western semi-arid plain area were 11.9, 14.0 and 13.9 mg·kg^-1, respectively, with higher risk of sulfur deficiency or potential sulfur deficiency, accounting for 73.6%, 73.3% and 75.5% of the samples, respectively. The regression analysis results showed that the effective sulfur in dryland soils of Jilin province was significantly logarithmically correlated with soil total nitrogen and soil organic matter, and the effective sulfur content of soil increased with the increase of soil organic matter and soil total nitrogen content. 【Conclusion】 The effective sulfur content of dryland soils in Jilin province varied significantly among regions and soil types, and the sulfur deficiency was more common, especially in aeolian sandy soil, saline-alkali soil and chernozem in the central and western regions, where the risk of sulfur deficiency was higher, so the sulfur supplementation should be emphasized in soil fertilization and crop management.

Effects of Long-Term Intercropping of Maize with Hairy Vetch Root Returning to Field on Crop Yield and Nitrogen Use Efficiency Under Nitrogen Fertilizer Reduction

LU BingLin,CHE ZongXian,ZHANG JiuDong,BAO XingGuo,WU KeSheng,YANG RuiJu

Scientia Agricultura Sinica. 2022, 55(12): 2384-2397. doi:10.3864/j.issn.0578-1752.2022.12.010

Abstract ( 289 )

HTML ( 36 )

PDF (567KB) ( 123 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】Effects of long-term intercropping hairy vetch and its stubble returning on maize yield and nitrogen fertilizer contribution rate under nitrogen fertilizer reduction were studied, in order to provide a scientific basis for nitrogen fertilizer substitution and nitrogen resource efficient management in maize/hairy vetch intercropping system.【Method】The field experiment was carried out from 2014 to 2019 at scientific observing and experimental station of arable land conservation and agriculture environment of Gansu Province, Ministry of Agriculture of Rural Affairs. The monocropping maize treatment was set under the levels of no fertilization and conventional nitrogen fertilization, the intercropping system of maize with hairy vetch were set under 90%, 80%, 70%, 60% and 0% of conventional nitrogen application levels, and there were 7 treatments with 3 replicates in a field experiment by using a randomized block design. The changes of crop yield, economic benefits, partial productivity of nitrogen fertilizer, nitrogen agronomic efficiency and nitrogen fertilizer contribution rate were studied in long-term intercropping of maize with hairy vetch under different nitrogen fertilizer reductions.【Result】The long-term intercropping system of maize with hairy vetch and hairy vetch stubble returning had the obvious advantage for increasing maize yield, the yield increase advantage increased with the lengthening of intercropping years. Compared with conventional nitrogen fertilization, the hay yield of hairy vetch could be increased by 2 273.2 kg·hm^-2under the condition of ensuring stable maize grain yield, the total profit was 29 686 yuan/hm²and increased by 0.9%, and the partial productivity of nitrogen fertilizer and nitrogen agronomic efficiency were significantly increased by 20.7% and 14.7%, respectively, in the long-term intercropping system of maize with hairy vetch and hairy vetch stubble returning under the condition of reduced 20% nitrogen fertilizer. Compared with conventional nitrogen fertilization, although the maize grain yield was significantly reduced by 7.7%, the hay yield of hairy vetch could be increased by 2 319.34 kg·hm^-2, and the total profit was 28 652 yuan/hm², which was equivalent to that of conventional nitrogen fertilization, while the partial productivity of nitrogen fertilizer and nitrogen agronomic efficiency were significantly increased by 31.8% and 16.3%, respectively, in the long-term intercropping system of maize with hairy vetch and hairy vetch stubble returning under the condition of reduced 30% nitrogen fertilizer. Compared with conventional nitrogen fertilization, although the hay yield of hairy vetch could be increased by 2 303.09 kg·hm^-2, the partial productivity of nitrogen fertilizer and nitrogen agronomic efficiency were significantly increased by 48.8% and 23.8%, respectively; however, the maize grain yield was significantly decreased by 10.7%, and the total profit was only 27 929 yuan/hm², which was significantly lower than that of conventional nitrogen fertilization in the long-term intercropping system of maize with hairy vetch and hairy vetch stubble returning under the condition of reduced 40% nitrogen fertilizer.【Conclusion】If only maize grain yield was considered, 20% chemical nitrogen fertilizer could be substituted, and if total output value of maize and hairy vetch was considered, 30% chemical nitrogen fertilizer could be substituted, in maize/hairy vetch intercropping and hairy vetch stubble returning for 9 years under nitrogen fertilizer reduction in the production process of maize in Hexi oasis irrigation area of Gansu Province.

Development and Evaluation of a Coating Substitute for Individual Polyethylene Film Packaging of Citrus Fruit

ZOU YunQian,LIN ZiZhen,XU RangWei,CHENG YunJiang

Scientia Agricultura Sinica. 2022, 55(12): 2398-2412. doi:10.3864/j.issn.0578-1752.2022.12.011

Abstract ( 212 )

HTML ( 34 )

PDF (2898KB) ( 72 )

Save

Figures and Tables | References | Related Articles | Metrics

【Background】 Individual polyethylene film packaging is the most popular way to maintain citrus quality during storage in China. This method has been applied nationwidely since the 1970s. In recent years, the environmental pollution problems caused by the use of polyethylene films aroused caused concerns of the public. Besides, the conflict between labor-intensive property of individual polyethylene film treatment and the shrinking workforce as well as increasing labor costs in China makes it urgent to develop a substitute of polyethylene film to achieve mechanization in citrus postharvest preservation industry. 【Objective】 A new formula of coating called “BC” (Beeswax-Candelilla Wax Coating) based on beeswax and candelilla wax was developed, and its potential to replace polyethylene film and the effects on the improvement of postharvest quality and the extension of shelf life of satsuma mandarin were evaluated. 【Method】 The optimal formulas among different groups were selected to treat satsuma mandarin fruit. Satsuma mandarin fruit were used as experimental material for the packaging (TD) or coating treatment. The indicators were tested at different time points during storage, including the rate of weight loss, firmness, color index, TSS (Total soluble solid)/TA (Titratable acid), total phenol and flavonoid contents in the peels, respiration rate, internal CO₂ concentration of fruits and the content of off-flavor substances. The primary metabolits contents in the peel were tested by GC-MS (Gas chromatography mass spectrometry). The microstructure of fruit surface was examined by SEM (Scanning Electronic Microscopy). Besides, the glossiness, off-flavor, flavor, juiciness, sweetness, acidity and overall satisfaction of satsuma mandarin were assessed by sensory evaluation. 【Result】 The weight loss of “BC” coated fruit sharply dropped from 22.62% to 3.83% after one month of storage at 23-25℃. “BC” coating delayed changes in firmness, color deterioration, TSS and TA loss, and increase in TPC, TFC and primary metabolites contents. The increased internal CO₂ levels led to a striking decrease in respiration intensity from 43.36 mL·kg^-1·h^-1to 16.75 mL·kg^-1·h^-1. “BC” coating also significantly improved the sensory quality compared with the control treatment, with the score increasing from 3.09 to 3.69. No differences (P<0.05) were found between TD and “BC” groups except for the content of off-flavor substances and respiration rate. The ethanol concentration of “BC” coating group (777.9 mg·L^-1) was significantly lower than human perception threshold (1 500 mg·L^-1) and that of commercial wax treatment (2 021.2 mg·L^-1). 【Conclusion】 The optimal formula of “BC” coating could enhance water retention capacity of satsuma mandarins. No significant differences were found in internal quality, appearance and other biochemical indicators between the polyethylene film packaged fruit and those from “BC” coating treatment. The advantages such as high productivity, low cost and less environmental pollution in modern postharvest handling of fruits and vegetables made “BC” coating a promising alternative to polyethylene films.

Effects of Trichoderma on Root and Leaf Ionic Homeostasis and Photosystem II in Chinese Wolfberry Under Salt Stress

BIAN LanXing,LIANG LiKun,YAN Kun,SU HongYan,LI LiXia,DONG XiaoYan,MEI HuiMin

Scientia Agricultura Sinica. 2022, 55(12): 2413-2424. doi:10.3864/j.issn.0578-1752.2022.12.012

Abstract ( 275 )

HTML ( 25 )

PDF (648KB) ( 75 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】This research aimed to investigate the effect of Trichoderma on salt tolerant ability of Chinese wolfberry (Lycium chinense), and to reveal the salt tolerant mechanisms in terms of in ion homeostasis, oxidative stress and photosystem II (PSII) performance.【Method】Chinese wolfberry was used as the experimental material, and Trichoderma agent was applied around roots. Salt treatment was carried out by irrigation with NaCl solution (300 mmol·L^-1), so as to compare the differences of biomass, K⁺/Na⁺, K⁺ and Na⁺ absorption and transport in roots, leaf oxidative damage and PSII performance in plants applied with and without Trichoderma agents under salt stress.【Result】Under salt stress, the biomass decreased less in plants applied with Trichoderma agents, indicating that Trichoderma could improve salt tolerance in Chinese wolfberry and alleviate the inhibition on growth. Under salt stress, Trichoderma alleviated the decline of photosynthetic rate and actual photochemical efficiency of PSII, inhibited the elevation of PSII excitation pressure, and aided in defending PSII photoinhibition. The decrease in Fv/Fm and the loss of PSII reaction center protein were relatively less in plants applied with Trichoderma agents under salt stress, confirming that Trichoderma alleviated PSII photoinhibition and protected PSII reaction center. Consistent with the result of photoinhibition, the oxidative damage was slighter in plants applied with Trichoderma agents according to lower leaf lipid peroxidation extent and H₂O₂ content. Under salt stress, the lower decrease in the efficiency that an electron moved beyond Q_Awas noted in plants with Trichoderma agents application, while J step of chlorophyll a fluorescence transient (OJIP) did not obviously rise, indicating that Trichoderma protected the electron transporters at PSII acceptor side. Trichoderma also protected oxygen-evolving complex at PSII donor side of PSII, because the application of Trichoderma agent prevented a significant increase in variable fluorescence intensity at K step and an emergence of K step in OJIP curve under salt stress. Therefore, Trichoderma played a protective role for all PSII components, alleviated the decline of PSII performance index under salt stress, and improved PSII integral stability. Under salt stress, the lower Na⁺ content and higher K⁺ content were noted in roots and leaves in plants applied Trichoderma agents, indicating that Trichoderma inhibited the decline of K⁺/Na⁺ for maintaining ion homeostasis by reducing Na⁺accumulation and K⁺ loss in roots and leaves. As the key mechanism for maintaining ion homeostasis, Trichoderma enhanced root Na⁺ efflux, improved root K⁺ uptake and promoted K⁺transport to shoot in Chinese wolfberry under salt stress.【Conclusion】Trichoderma regulated the uptake and transport of Na⁺ and K⁺ in roots under salt stress, maintained ion homeostasis, reduced oxidative stress on PSII, and enhanced salt tolerant capacity in Chinese wolfberry and alleviate the inhibition on its growth.

Effects of Thermal Sterilization on Aroma Quality of Flat Peach Juice Based on Sensory Evaluation and GC-MS Combined with OPLS-DA

TAN FengLing,ZHAN Ping,WANG Peng,TIAN HongLei

Scientia Agricultura Sinica. 2022, 55(12): 2425-2435. doi:10.3864/j.issn.0578-1752.2022.12.013

Abstract ( 323 )

HTML ( 34 )

PDF (2551KB) ( 124 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】In order to provide a theoretical basis for the quality control of flat peach juice products, the aroma quality changes and the main deterioration factors of flat peach juice after thermal sterilization were investigated.【Method】 Flat peach juice samples were prepared by using four flat peach varieties from Xinjiang province (Zaolupan, ZLP; Zaopan, ZP; Ruipan1, RP1; Ruipan18, RP18) as raw materials and treated at 85℃ for 30 min. Then, the changes of sensory characteristics and aroma composition were investigated by using E-nose, descriptive sensory evaluation (DSA), and GC-MS. Furthermore, OPLS-DA model was applied to screen the marker compounds which caused the quality changes in thermally sterilized juice.【Result】Descriptive sensory analysis and E-nose results indicated that differences existed among four fresh juices, but all of the fresh samples showed high scores in green, peach-like, floral, and fruity attributes. Whereas, the aroma quality of flat peach juice changed greatly after thermal sterilization, as reflected by the decrease of green attribute and the increase of sweet, off-flavor, and cooked flavor. Seven categories of volatile compounds were identified by GC-MS, including esters, lactones, aldehydes, alcohols, ketones, terpenes, and furan compounds. The concentration of aldehydes (hexanal, (E)-2-hexenal), esters (ethyl acetate, hexyl acetate) and terpenes (limonene) decreased significantly after thermal sterilization, while some compounds with off-flavor attribute (pentanal, α-terpineol, β-damascenone) increased significantly. Ten compounds, including three categories compounds (aldehydes, esters, and terpenes) and (E)-2-hexenal, hexanal, ethyl acetate, benzaldehyde, limonene, hexyl acetate and (Z)-3-hexenyl acetate were screened as markers that could distinguish the fresh juice and thermally sterilized juice according to S-Plot and VIP value of OPLS-DA model, so this result verified the accuracy of sensory evaluation and GC-MS analysis.【Conclusion】 The green attribute significantly decreased, meanwhile off-flavor and cooked flavor attributes emerged after thermal sterilization. The decrease of (E)-2-hexenal, hexanal, ethyl acetate, benzaldehyde, limonene, hexyl acetate and (Z)-3-hexenyl acetate and the formation of pentanal and β-damascenone were the main factors for leading to the loss of green attribute and formation of off-flavor and cooked flavor. GC-MS and sensory evaluation coupled with multivariate statistical analysis method (PCA/ OPLS-DA) could be used to accurately evaluate the effect of thermal sterilization on the aroma profile of flat peach juice, and further to trace the key factors of flavor quality deterioration of thermally sterilized juice, which provided a reference for further exploring the degeneration mechanism of thermally processed juice.

Identification of Cashmere Dermal Papilla Cells Based on Single- Cell RNA Sequencing Technology

ZHANG WeiDong,ZHENG YuJie,GE Wei,ZHANG YueLang,LI Fang,WANG Xin

Scientia Agricultura Sinica. 2022, 55(12): 2436-2446. doi:10.3864/j.issn.0578-1752.2022.12.014

Abstract ( 243 )

HTML ( 39 )

PDF (3368KB) ( 84 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】 Based on single-cell RNA sequencing, this article aims to explore the marker genes of cashmere dermal papilla cells, and to optimize the methods to identify dermal papilla cells in vitro, thereby laying a cell model for future pertinent research in cashmere hair follicle development. 【Methods】 The single-cell transcriptional data from the skin tissues of Shanbei white cashmere embryonic stage (E60, E90 and E120) were analyzed with Seurat package. After quality control, filter and normalization of raw data, the dimension reduction analysis and cell cluster identification were performed by uniform manifold approximation and projection (UMAP). Moreover, depending on cluster-specific expressed gene expression, the principal cell lineage information was identified. The type-specific marker genes of the dermal papilla were obtained after gene expression analysis. The immunofluorescence staining was used to validate the expression position of marker protein to identify the dermal papilla specific protein in goat skin. Whole hair follicles were isolated mechanically under stereoscope, and combined with enzyme detach, cashmere dermal papilla region was isolated and cultured in vitro until cell separation. The dermal papilla cells were purified by different-speed adherence methods. When the cells were highly pure, the expression of candidate marker protein was verified by immunofluorescence assay. 【Result】 In current study, the key transcription information of goat hair follicle cells was analyzed at single cell level. Information of 17 subsets of cells in cashmere goat skin structure was obtained successfully including dermal cell lineage, epidermal cell lineage, dermal papilla cell, hair stem cell and inner root sheath cell, as well as other functional cell groups such as pericyte cell, macrophage and muscle cell. 427 specific markers of dermal papilla cells including SOX2, FGF7, APOD, BMP3, HHIP, HEY2 and SPON1 were screened. By comparison, the expression of these marker genes in cashmere dermal papilla cells was much higher than that in other cell types, which could be confirmed as the specific genes of hair papilla cells. Immunofluorescence result further proved that SOX2, FGF7 and APOD were specifically expressed in the dermal papilla region, and could be used to trace the dermal papilla cells in vivo. In addition, in current study, the single cashmere goat secondary hair follicle was separated successfully, and the adherent culture of dermal papilla was realized. A large number of cells were observed migrating from the hair papilla area. Immunofluorescence assay showed that SOX2, FGF7 and APOD were all expressed in goat dermal papilla cells, and about 76% of cells were SOX2 positive, while more than 98% of cells were FGF7 and APOD positive. Combined with the immunofluorescence results, SOX2, FGF7 and APOD genes factually could be used to identify the cultured goat dermal papilla cells in vitro. 【Conclusion】 In this study, single cell RNA sequencing technology was used to describe the main transcriptome information of cells in cashmere goat skin, and the specific marker genes of dermal papilla cells were sifted out successfully. And it proved that single-cell sequencing based method was simple and efficient to identify marker genes further identified by immunofluorescence. The discovering of SOX2, FGF7 and APOD not only provided the markers for the localization of hair papilla cells in vivo, but also provided the possibility for the identification of dermal papilla cells with multiple markers, which laid the foundation for further study of the gene functions in regulating hair follicle development.

DUS Traits Variation Analysis and Application of Standard Varieties of Lolium multiflorum Introduced from Japan

FENG JunJie,ZHAO WenDa,ZHANG XinQuan,LIU YingJie,YUAN Shuai,DONG ZhiXiao,XIONG Yi,XIONG YanLi,LING Yao,MA Xiao

Scientia Agricultura Sinica. 2022, 55(12): 2447-2460. doi:10.3864/j.issn.0578-1752.2022.12.015

Abstract ( 228 )

HTML ( 24 )

PDF (2382KB) ( 67 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】This study aimed to determine the consistency and specificity of DUS test traits of Lolium multiflorum (annual ryegrass) standard varieties introduced from Japan, and to optimize the DUS test system of L. multiflorum in China, thus identify new varieties (lines) more quickly and accurately. 【Method】In this study, seven standard varieties of annual ryegrass introduced from Japan were planted in Chengdu Plain, China. Fifteen individuals with the similar growth status were selected from each standard variety. Cluster analysis of the standard varieties was conducted based on their DUS test data to identify the DUS trait expression of the standard varieties in Chengdu Plain. In order to screen out the characters with the high intra-population consistency and obvious inter-population specificity, the coefficient of variation and variance values of 18 tested DUS characters were calculated, and the nested variance analysis of the studied characters was also conducted. Furthermore, the probability classification was conducted based on the selected characters, which was used to clustering analysis and identification of the tested national approved varieties and new lines, and to evaluate the correlation coefficients of test traits. 【Result】According to the values of 18 DUS test traits of standard varieties, the standard varieties could be clearly clustered into 7 groups. The DUS traits were fully expressed and could be clearly distinguished from each other, which were suitable for subsequent correlation analysis. The results of intraspecific consistency analysis showed that, six traits, including leaf color degree, growth habit after vernalization, plant width at booting stage, flag leaf width at booting stage, flag leaf length-width ratio at booting stage, and spikelet length, possessed the poor intra-population consistency for multiple varieties. When conducting the inter-population specificity analysis of varieties, however, the poor specificity among the tested varieties was found in plant height at booting stage, ratio of flag leaf length to width at booting stage and spikelet density among cultivars, among which the variance component between populations of flag leaf length-width ratio at booting stage was 54.83%, and the variance component between individuals within populations was 45.17%. The selected ten quantitative traits were conducted the K-S test and χ² test analysis, however, only the basal spikelet length conformed to χ² test. Afterwards, the ten quantitative traits were divided into five grades. On the basis of these traits grading criterion, the identification of national approved varieties and new lines of L. multiflorum. The results showed that the tested varieties and new lines of annual ryegrass could be clustered into eight groups according to its classification results and corresponding to varieties origin, which revealed the reliability of traits grading criterion built in this study on variety identification. The heat map drawn based on the trait values of the tested varieties showed that the leaf length of ‘Tetragold’ was significantly different from that of other tested varieties in the vegetative growth period, which was manifested as shorter leaf length; the variety ‘Chuannong No. 2’ showed higher plant height after vernalization; the internode length under spike of ‘Diamond T×changjiang No. 2’ was significantly shorter than that of other varieties; the poor intra-population consistency of ‘Double Barrel’, ‘Chuannong No. 1’ and ‘Chuannong No. 2’ showed good intra-population consistency. The low correction and strong independence were existed within the selected ten traits, indicating that these traits were very well suited for DUS test. 【Conclusion】The character classification system for DUS test based on Japanese standard varieties could be applied to the identification and distinguish of L. multiflorum varieties released in China. This study could provide the important technical and theoretical reference for the optimization of DUS test method system of annual ryegrass varieties.

Molecular Cloning and Expression Pattern Analysis of NPC2 Gene Family of Apis cerana cerana

ZHANG Li,ZHANG Nan,JIANG HuQiang,WU Fan,LI HongLiang

Scientia Agricultura Sinica. 2022, 55(12): 2461-2471. doi:10.3864/j.issn.0578-1752.2022.12.016

Abstract ( 336 )

HTML ( 35 )

PDF (1275KB) ( 110 )

Save

Figures and Tables | References | Related Articles | Metrics

【Background】As an important native resource insect, the Chinese honeybee (Apis cerana cerana) plays important ecological roles in pollinating the plants that bloom at low temperatures in early winter in China, and the pollination behavior of A. c. cerana is closely related to its olfactory system. According to the analysis of antenna transcriptome data collected from foragers treated at high and low temperatures, it was found that the Niemann-Pick type C2 protein (NPC2) gene family related to insect olfaction was up-regulated expression at low temperatures.【Objective】Therefore, this study aims on the A. c. cerana NPC2 family genes, including cloning and analysis of their structural characteristics and expression profiles. Moreover, the NPC2 family gene expression under high and low temperatures was also studied. It will provide an evidence of the AcNPC2 gene family in the low-temperature adaptation involved in the chemosensory and olfactory function of A. c. cerana.【Method】Based on the results of high and low temperatures transcriptome sequencing of A. c. cerana, the ORF sequence of AcNPC2 genes was cloned by RT-PCR, and phylogenetic tree analysis and three-dimensional structure prediction were performed. Then, the spatio-temporal expression profile of AcNPC2 genes in different developmental stages and different tissues, as well as the amount of expression at high and low temperatures of A. c. cerana were analyzed by qRT-PCR.【Result】The full length ORFs of four NPC2 genes of A. c. cerana (AcNPC2a, AcNPC2b, AcNPC2c, and AcNPC2d) were obtained as 447, 480, 459, and 465 bp, respectively, encoding 148, 159, 152, and 154 amino acids. The predicted protein molecular weight is 16.12-18.53 kD, and the isoelectric points are 7.98, 7.57, 6.56, and 6.34, respectively. Phylogenetic tree analysis showed that AcNPC2 sequences were most close to the NPC2 homologous sequence of Apis mellifera ligustica. qRT-PCR results showed that the expression level of AcNPC2a was the highest in the abdomen of the newborns, followed by the abdomen of the nurses and the larval stage. The expression of AcNPC2b was the highest in the thorax of the newborn bees, followed by the head, thorax and metapodium of the foragers. AcNPC2c was notably expressed in high abundance in the antennae of the nurses and the foragers. AcNPC2d had the highest expression in the head of the foragers. After low temperature treatment, the expression levels of all AcNPC2 genes in the forager antennae increased, but there was no significant difference.【Conclusion】AcNPC2 has the conserved structure of NPC2 protein family, and its members show diversity in the spatio-temporal expression profile of A. c. cerana. Among them, AcNPC2c is highly expressed in the antennae, indicating that it is closely related to the olfactory function of A. c. cerana. The expression of the whole AcNPC2 family genes increased in the antennae of the foragers at lower temperature, indicating that these genes might be involved in the low-temperature adaptability of A. c. cerana and pollination behavior in early winter.

Effects of Flooding on Soil Chemical Properties and Microbial Community Composition on Farmland of Continuous Cropped Pepper

GONG XiaoYa,SHI JiBo,FANG Ling,FANG YaPeng,WU FengZhi

Scientia Agricultura Sinica. 2022, 55(12): 2472-2484. doi:10.3864/j.issn.0578-1752.2022.12.017

Abstract ( 375 )

HTML ( 42 )

PDF (1496KB) ( 169 )

Save

Figures and Tables | References | Related Articles | Metrics

【Objective】This paper aimed to clarify the effect of farmland flooding on the soil environment of continuous pepper cropping, and to provide the technical basis for reducing the soil sickness caused by continuous pepper cropping. 【Method】In this experiment, the flooded and non-flooded soil of continuous cropped pepper in Hexian County of Anhui Province were analyzed, with non-flooded soil as control. The determination of chemical property and microbial community structure in soil with flowing analyser, qPCRand Illumina MiSeq sequencing explored the effect of flooding on the soil. Besides, the pepper was used as plant material to explore the effects of flooded and non-flooded soil on seed germination and seedling growth by the Petri dish method. 【Result】Soil flooding significantly decreased the soil EC value, organic matter, nitrate N, ammonium N, available K, and Olsen P. Quantitative PCR analysis showed that soil flooding significantly increased the bacterial community abundance (P<0.05), however decreased that of the fungal communities. Illumina MiSeq sequencing showed that the soil flooding significantly increased the relative abundances of Actinobacteria and Myxococcota, which decreased the Firmicutes and Mortierellomycota at phylum level. The soil flooding decreased the relative abundance of potential pathogenic fungi, such as Fusarium spp., positive correlation with nitrate N. The soil flooding increased potential Azotobacter, including Azoarcus, Gemmatimonas, Sideroxydans, Candidatus_Solibacter, Bryobacter, Sideroxydans spp. and plant-beneficial potential such as Aspergillus and Acremonium spp., which were negatively correlated with nitrate N. The soil microbial community structure and composition was significantly affected by soil nitrate N. In petri dish, the seed germination rate, seeding fresh weight and root length of peppers planted in flooded soil were significantly higher than those in non-flooded soil. 【Conclusion】Soil flooding significantly reduced the EC value and abundance of potentially pathogenic microbial community and increased the abundance of potentially beneficial bacterial, but significantly reduced the content of available nutrients. At the same time, Soil flooding was conducive to the seed germination and seedling growth and alleviated the pepper continuous cropping obstacles.

Table of Content