Sponsor(s): Chinese Academy of Agricultural Sciences；Chinese Association of Agricultural Science Societies
24 issues per year
Current Issue: Issue 24, 2017
Scientia Agricultura Sinica, the 1st in Comprehensive Agricultural Science, is supervised by Ministry of Agriculture of PRC, and sponsored by Chinese Academy of Agricultural Sciences; Chinese Association of Agricultural Science Societies. Scientia Agricultura Sinica, launched in 1960, is a leading peer-reviewed and mufti-disciplinary journal and published semi-monthly in Chinese with English title, abstract, figures, tables and references. It aims to publish those papers that are influential and will significantly advance scientific understanding in agriculture fields worldwide. The scope covers Crop Genetics, Breeding, Germplasm Resources; Physiology, Biochemistry, Cultivation, Tillage Plant Protection; Soil & Fertilization, Agro-Ecology & Environment, Bio-energy; Animal Science, Veterinary Science, Agricultural Information Science; Food Science; Agricultural Economics and Management; Agricultural Sustainability. The journal is included in JST, CA and CSCD.
Editor-in-Chief Wan Jianmin Associate Editor-in-Chief Zou Ruicang Tang HuaJun Wu Kongming Guo YuYuan Geng Xu Sun Tan Executive Editor Lu Wenru
Effect of Fertilizer Being Bag-Controlled Released on Root Growth, Nitrogen Absorption and Utilization, Fruit Yield and Quality of Peach Trees
Scientia Agricultura Sinica,2017,Vol 50,No. 24
[Objective] In order to provide reference for scientific fertilization in peach orchard, the effect of fertilizer being bag-controlled released and fertilizer furrow application treatments on dynamic changes of available nutrients in soil, root growth and horizontal distribution, N utilization rate and fruit yield and quality was studied. [Method] Late-maturing peach Ruipan 21 was used as the experimental material. Field experiment was conducted from 2012 to 2016 with three fertilization modes: fertilizer being bag-controlled released (BCRF), furrow application of equal-amount fertilizer in one time (FSA Ⅰ) and furrow application of high-amount fertilizer in two times (HFSA Ⅱ). The content of soil available nutrients was determined in April, July and October every year, and the fruit yield and quality were investigated from 2014 to 2016. The nitrogen absorption and distribution in peach plants were studied by using 15N tracer technique, and the root growth and distribution were investigated in 2016. [Result] The soil available nutrients, including available phosphorus, available potassium and alkali-hydrolyzable nitrogen of BCRF treatment were steady during the five years, but the soil available nutrients of FSA Ⅰ and HFSA Ⅱ treatments were higher at the early stage and then showed a declining trend. The roots in BCRF treatment were horizontally distributed in the range of 100 cm from the trunk and those in FSA Ⅰ and HFSA Ⅱ treatments could grow to the range of 140 cm and 160 cm. Moreover, the proportion of fine roots in BCRF treatment was high and they accounted for 83.95% of the total roots’ length, while those in the FSA Ⅰ and HFSA Ⅱ treatments only accounted for 75.16% and 70.63%, respectively. In addition, the BCRF treatment could maintain the biomass stability of the root system. The plant N utilization rate for BCRF treatment was 1.39 times and 1.81 times that of FSA Ⅰ and HFSA Ⅱ treatments, respectively. The yield of BCRF treatment was increased by about 20% as compared with that of FSA Ⅰ and had no significant difference with that of HFSA Ⅱ treatment, but the fruit quality of BCRF treatment was significantly improved as compared with that of the HFSA Ⅱ treatment. [Conclusion] Under the BCRF treatment for 5 years, the soil nutrient levels were stable and the number of fine roots was increased, resulting in concentrated root distribution, compact roots, and long root longevity, and finally increasing the N utilization rate of peach plant and improving the fruit yield and quality.
The Effects of Soil Water Content on N 2O Emissions and Isotope Signature of Nitrification and Denitrification
Scientia Agricultura Sinica,2017,Vol 50,No. 24
[Objective] The objective of this paper is to understand the contribution of microbial processes to N 2O production and its changing rules under different water content treatments, aiming at providing a theoretical basis for reducing agricultural N 2O emissions. [Method] A microcosm experiment was carried out to investigate the effects of different water-filled pore space on N 2O emissions and isotopic signatures (δ 15N bulk, δ 18O and nitrogen isotopomer site preference of N 2O) of soil in Shunyi District, Beijing. The study combined stable isotope technique and gas inhibitor method to analyze N 2O flux and its isotope signatures that emitted from soil. Three different water content levels were set in this study, which were 67%, 80% and 95% WFPS, and three inhibitor levels (without C 2H 2, with 0.1% (V/V) C 2H 2 and with 10% (V/V) C 2H 2) were designed. After two hours of incubation, the soil samples were collected to determine the concentrations of NH 4+-N and NO 3−-N. The gas samples were collected to determine the isotope signatures, and the two end-member mixing model was applied to quantify the respective contribution of microbial processes to N 2O production. [Result] According to the incubation of the soil, the weighted average N 2O fluxes of 95%, 80% and 67% WFPS were 1.17, 0.27 and 0.08 mgN·kg −1·d −1, respectively. The N 2O emissions of 95% WFPS were significantly higher than those of 80% and 67% WFPS and the N 2O emissions of 80% WFPS were significantly higher than those of 67% WFPS. The cumulative emissions of (N 2O + N 2) in 95%, 80% and 67% WFPS were 18.05%, 5.27%, and 1.24% of initial mineral nitrogen, respectively, during the entire incubation period. The cumulative emissions of (N 2O + N 2) were 19.61, 5.72 and 1.35 mgN·kg −1, respectively; the initial contents of NH 4+-N + NO 3−-N was 108.62 mg N·kg −1. Compared with 67% WFPS, the cumulative (N 2O+N 2) emissions of 95% and 80% WFPS increased by 13.53 and 3.24 times, respectively. The cumulative emissions of (N 2O+N 2) in 95% WFPS were 2.43 times greater than that of 80% WFPS. The values of reduced NH 4+-N + NO 3−-N as gaseous nitrogen increased with the increase of the water content. The weighted average δ 15N bulk values varied from −42.93‰ to −4.07‰, and the higher level of soil water content showed significantly higher N 2O emissions. The 10% (V/V) C 2H 2 would inhibit the reduction of N 2O to N 2. The δ 18O value with 10% (V/V) C 2H 2 was significantly smaller than that of with 0.1% (V/V) C 2H 2 in three water content treatments. The ratio of N 2O/(N 2O+N 2) reduced with the increase of soil water content. Multiple N 2O processes occurred simultaneously in all treatments. The values of SP increased during the initial four days and then decreased gradually with incubation time. The SP values of 67%WFPS treatment during the first two days ranged from 6.74‰ to 12.04‰, and the contribution of denitrification to N 2O production was from 56.36% to 66.15%, suggesting that denitrification was the dominant microbial process. Then, the contribution of nitrification (55.78%–100%) to N 2O production became greater. The weighted average SP value was 10.26‰ in 80% WFPS treatment, indicating denitrification (40.90%–74.04%) was the major N 2O production process. There were larger SP values in 95% WFPS treatment with 10% (V/V) C 2H 2 in the first seven incubation days, ranging from 7.61‰ to 21.11‰. Compared with 0.1% (V/V) C 2H 2, the weighted average SP values of N 2O under 95%, 80% and 67% WFPS treatments with 10% (V/V) C 2H 2 produced from soil reduced by 0.10, 0.33 and 0.06 times, respectively. [Conclusion] The increase of soil water content promoted N 2O emission, and the 95% WFPS treatment showed the highest N 2O emissions. In the 67% WFPS treatment, the initial stage of N 2O emission was dominated by denitrification, followed by nitrification. Denitrification was the dominant process in 80% WFPS treatment and nitrification was the dominate process in 95% WFPS treatment.
Scientia Agricultura Sinica,2017,Vol 50,No. 24
[Objective] The objective of this study is to screen genomic-specific SNPs, considering the SNP with single loci and the reference genomic sequence information of upland cotton TM-1. [Method] Based on 719 natural germplasm resources with plentiful genetic backgrounds, using the CottonSNP63K array developed by Illumina, quality control of the original genotyping data obtained from chip scanning was performed by Genome Studio software, the genotyping data of the SNP locus of the tested samples were obtained. According to the two published Gossypium hirsutum TM-1 genome versions, including the G. hirsutum (AD1) genome BGI v1.0 of Cotton Research Institute of Chinese Academy of Agricultural Sciences and the G. hirsutum (AD1) genome NBI v1.1 of Nanjing Agricultural University, genome-wide BLAST analysis was performed on the flanking sequences of each SNP with CottonSNP63K (63 058 SNPs) array to screen specific SNP loci with single copy, and these SNPs were used for the construction of fingerprints. [Result] SNP genotyping of 719 materials using CottonSNP63K was classified into SNP locus without detectable signal, SNP locus without polymorphism and the polymorphism SNP loci. The polymorphism SNP loci could be divided into double-site SNP, multiple-site SNP and single-site SNP (genomic-specific SNP). The results of the Blast analysis with the two upland cotton TM-1 reference genome sequences showed that there were 5 474 specific SNP markers in the BGI v1.0 version, while NBI v1.1 TM-1 version only 1 850, and the common specific SNPs of both were 1 594. Further considering the three evaluation indexes including the genotyping effect, call rate and polymorphism, the SNPs with scores≥0.7, call frequency≥0.95 and MAF≥0.2 were screened, and 471 specific SNPs with high call rate and high polymorphism were obtained. Among these SNP loci, 430 were on chromosomes and 41 were on scaffolds. Taking into account of the degree of linkage between the markers, finally 393 core SNP loci were obtained after removing 37 linkage markers, and the DNA fingerprints of 719 resource materials were constructed by using 393 core SNPs. The results showed that 97% of the materials could be accurately and effectively identified except for some accessions with similar genetic background. [Conclusion] A total of 393 genomic-specific SNPs were screened out, and these core SNPs were used to construct the DNA fingerprints of 719 resource materials. This study will provide a reference for application of SNP molecular markers in genetic improvement of important cotton traits.
Scientia Agricultura Sinica,2017,Vol 50,No. 24
[Objective] The relationship of different plots, nitrogen application rate, SPAD value derivative index, and yield was studied to construct linear model of nitrogen application rate based on SPAD value in rice, so as to easily, quickly, perfectly recommend nitrogen application rate. [Method] The experiment was conducted by using Qyou6 as the materials with four nitrogen levels (0, 75, 150, and 225 kg·hm −2) in 2015 and 2016. We compared the relationship between yield and apparent nitrogen supply of field, and between SPAD value derivative index and apparent nitrogen supply of field in this experiment. The effect of variable nitrogen application based on leaf value model was also studied. [Result] The results showed that, the curve relationship between yield and apparent nitrogen supply of field at heading stage was extremely significant positive, and the R2 of two years was 0.552 3 and 0.714 8, respectively. In this fitting relationship, the maximum yield of each year was 9 264.93 kg·hm −2 and 11 167.97 kg·hm −2, respectively. The difference of maximum yield was 1 903.14 kg·hm −2 in two years, and yield in 2016 was 20.54% higher than that in 2015. However, the apparent total nitrogen uptakes of the highest yield in different years were close, which were 575.27 kg·hm −2, 546.71 kg·hm −2, respectively. The difference of apparent total nitrogen uptake was only 28.56 kg·hm −2, and the apparent total nitrogen uptake was −4.96% higher than that in 2015. The linear relationships between SPAD L3 (SPAD value of third leaf from the top), SPAD L4 (SPAD value of fourth leaf from the top), SPAD mean (average SPAD value of the top four leaves), SPAD L3×L4/mean (product of SPAD value of third leaf from the top and SPAD value of fourth leaf from the top divided by average SPAD value of the top four leaves) and apparent nitrogen supply of field were significant or extremely significant under different growth periods and years. On single leaf, the change of slope of linear relationship between SPAD L3 and apparent nitrogen supply was smaller at jointing stage in years, and the value of slope was 0.015 6 in 2015 and 0.015 4 in 2016, respectively. At heading stage, the slopes of linear relationship between SPAD L1 and apparent nitrogen supply of field in 2015 and 2016 were 0.017 2 and 0.017 3, respectively. At joining and heading stages of different years, the slope and intercept of linear relationship between SPAD L3×L4/mean and apparent nitrogen supply of field of 2016 were increased by −28.70% and 17.41%, and −15.34%, and 56.11% compared with those of 2015, respectively. A new rice nitrogen model based on SPAD value was constructed, which was called the leaf value model. The total nitrogen application rates of leaf value model were different between apparent total nitrogen uptake and apparent nitrogen supply of soil, and it could estimate the apparent nitrogen supply of soil by the measured value of SPAD value derivative index. The R2 of linear fitting between SPAD value derivative index and apparent nitrogen supply of field at heading stage was higher than that at jointing stage. At joining stage, the total nitrogen rate which was estimated by SPAD L4 or SPAD L3×L4/mean was close to that estimated by SPAD L3 or SPAD mean, and the former was 50% higher than the later. The effect of variable nitrogen application based on leaf value model showed that the yield of variable area was 820.68 kg·hm −2 higher than that of control area, and the nitrogen partial productivity and nitrogen agronomic efficiency of variable area were 13.74% and 103.45% higher than those of control area, respectively. A general expression for leaf value model was N w = N z − [(Y s − b)/ k − N g], where N w, N z, Y s, and N g mean total nitrogen application rate (kg·hm −2), apparent total nitrogen uptake (kg·hm −2), SPAD value derivative index, base-tiller fertilizer amount (kg·hm −2), respectively, and k and b are slope and intercept of linear relationship betweent apparent nitrogen supply of field (N x) and SPAD value derivative index (Y s). N x is the sum of nitrogen content of soil (kg·hm −2) and already manure amount. [Conclusion] Variable nitrogen application based on leaf value model could reduce yield difference and increase yield, nitrogen agronomic efficiency, nitrogen partial productivity and nitrogen contribution rate.
Scientia Agricultura Sinica,2017,Vol 50,No. 24
[Objective] The objective of this study is to identify Telosma mosaic virus (TeMV) on passion fruit in an orchard of Fujian, to develop a molecular method for specific and rapid identification of TeMV, and to provide a reference for prevention and control of the virus. [Method] The Fujian passion fruit samples were detected by serological method, electron microscopic observation, RT-PCR with universal degenerate primers, and RT-PCR with specific primers. The PCR products of the positive sample were cloned and sequenced. A set of specific primes amplified the total length of coat protein (CP) gene was designed according to the reported sequences of TeMV and the sequence obtained this study, and then RT-PCR with specific primers was established after the optimization of reaction conditions. The sequence determination results were analyzed with BLAST program and DNAMAN software, and Bayesian inference (BI) method implemented in MrBayes was used to construct the phylogenetic tree based on the CP gene sequences obtained in this study. [Result] The serological test results showed that one passion fruit sample exhibiting mosaic and crinkle symptom reacted with Potyvirus antiserum. The positive sample was found to have about 750 nm × 12 nm linear virions by electron microscopic observation. The expected fragment was amplified from the positive sample by universal degenerate primers RT-PCR, and then cloned and sequenced. The sequence analysis showed that the obtained sequence from the positive sample was identical with the expected size (680 bp), and shared the highest nucleotide sequence identity (98.2%) with the reported TeMV gene sequence. The full-length sequence of CP gene obtained by RT-PCR with specific primers was 816 bp (named BXGFJ-13 isolate), and the nucleotide and amino acid sequences of BXGFJ-13 respectively showed the identities of 86.2%–98.4% and 88.2%–97.8% with the reported TeMV isolates. The results of phylogenetic analysis showed that the 13 TeMV isolates could be divided into three groups, and the same area or host derived isolates preferentially clustered together, suggesting these isolates had a strong geographical and host specificity. The BXGFJ-13 isolate obtained in this study and Guangxi isolate of China (KJ789129) clustered into a branch with high posterior probability, and then clustered together with two Thailand isolates (AM409188, AM409187) into the 2nd group (Group II), showing that BXGFJ-13 and Guangxi isolate had the closest phylogenetic relationship. The RT-PCR with specific primers showed good specificity, which only amplified the expected fragment from TeMV-infected passion fruit sample, and no expected fragment was obtained from Cucumber mosaic virus (CMV), Beet mosaic virus (BtMV), Soybean mosaic virus (SMV), Ornithogalum mosaic virus (OrMV), Onion yellow dwarf virus (OYDV), East Asian Passiflora virus (EAPV) and healthy control. The sensitivity results showed that the target fragment could be amplified from 10 2 time-diluted RNA sample. [Conclusion] According to the species demarcation criteria for Potyvirus given by International Committee on Taxonomy (ICTV) and the results of serological test and electron microscopic observation, the TeMV on the passion fruit sample exhibiting mosaic and crinkle symptom in the Fujian orchard was confirmed. The established assay of specific RT-PCR could be used for the rapid detection of TeMV.