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Does nature-based solution sustain grassland quality? Evidence from rotational grazing practice in China

LI Dong-qing, ZHANG Ming-xue, LÜ Xin-xin, HOU Ling-ling

2023, 22 (8): 2567-2576. DOI: 10.1016/j.jia.2023.07.001

Abstract （229） PDF in ScienceDirect

Rotational grazing is considered as one of the nature-based solutions (NbS) to grassland protection by natural scientists. However, its effects on improving grassland quality are still unclear when it is adopted by herders. Using a household-level panel data from field survey in two main pastoral provinces of China, empirical results from fixed-effect model and instrumental approach show that rotational grazing practices have insignificant short-term effects on grassland quality, but have positive long-term effects. In addition, rotational grazing practices can improve grassland quality when villages invest public infrastructure or herders have private supporting measures for more efficiency livestock production. Further analysis shows that herders adopting rotational grazing have higher grazing intensity, higher supplementary intensity and more livestock-house-feeding days, which indicate herders can utilize more efficient livestock management without increasing pressure on natural grassland. We also find that herders with pastoral income are more likely to adopt rotational grazing practice. These insightful findings offer policy implications on promoting grassroot NbS for ecosystem protection and resource utilization in developing pastoral countries.

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Use of transcriptome sequencing to explore the effect of CSRP3 on chicken myoblasts

SHAN Yan-ju, JI Gai-ge, ZHANG Ming, LIU Yi-fan, TU Yun-jie, JU Xiao-jun, SHU Jing-ting, ZOU Jian-min

2023, 22 (4): 1159-1171. DOI: 10.1016/j.jia.2022.08.067

Abstract （343） PDF in ScienceDirect

The mechanisms that regulate the specificity and maintenance of chicken muscle fiber types remain largely unknown. In mammals, CSRP3 has been shown to play a vital role in the maintenance of typical muscle structure and function. This study investigated the role that CSRP3 plays in chicken skeletal muscle. First, the antibody against chicken CSRP3 protein was prepared, and the expression levels of the mRNA and protein of the CSRP3 gene in four chicken skeletal muscles with different myofiber compositions were compared. Then the effects of CSRP3 silencing on the expression profile of chicken myoblast transcriptomes were analyzed. The results showed that the expression levels of the mRNA and protein of the CSRP3 gene were both associated with the composition of fiber types in chicken skeletal muscles. A total of 650 genes with at least 1.5-fold differences (Q<0.05) were identified, of which 255 genes were upregulated and 395 genes were downregulated by CSRP3 silencing. Functional enrichment showed that several pathways, including adrenergic signaling in cardiomyocytes, adipocytokine signaling pathway and apelin signaling pathway, were significantly (P<0.05) enriched both in differentially expressed genes and all expressed genes. The co-expressed gene network suggested that CSRP3 silencing caused a compensatory upregulation (Q<0.05) of genes related to the assembly of myofibrils, muscle differentiation, and contraction. Meanwhile, two fast myosin heavy chain genes (MyH1B and MyH1E) were upregulated (Q<0.05) upon CSRP3 silencing. These results suggested that CSRP3 plays a crucial role in chicken myofiber composition, and affects the distribution of chicken myofiber types, probably by regulating the expression of MyH1B and MyH1E.

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Breeding against mycorrhizal symbiosis: Modern cotton (Gossypium hirsutum L.) varieties perform more poorly than older varieties except at very high phosphorus supply levels

WANG Xin-xin, ZHANG Min, SHENG Jian-dong, FENG Gu, Thomas W. KUYPER

2023, 22 (3): 701-715. DOI: 10.1016/j.jia.2022.08.004

Abstract （276） PDF in ScienceDirect

Cotton (Gossypium hirsutum L.) is an important fiber cash crop, but its root traits related to phosphorus (P) acquisition, including mycorrhizal root traits, are poorly understood. Eight cotton varieties bred in northwestern China that were released between 1950 and 2013 were grown in pots with or without one arbuscular mycorrhizal fungal (AMF) species (Funneliformis mosseae) at three P supply levels (0, 50 and 300 mg P as KH₂PO₄ kg^–1). Eleven root traits were measured and calculated after 7 wk of growth. The more recent accessions had smaller root diameters, acquired less P and produced less biomass, indicating an (inadvertent) varietal selection for thinner roots that provided less cortical space for AMF, which then increased the need for a high P fertilizer level. At the two lower P levels, the mycorrhizal plants acquired more P and produced more biomass than non-mycorrhizal plants (3.2 vs. 0.9 mg P per plant;1.8 vs. 0.9 g biomass per plantat P₀; 14.5 vs. 1.7 mg P per plant; and 4.7 vs. 1.6 g biomass per plant at P₅₀). At the highest P level, the mycorrhizal plants acquired more P than non-mycorrhizal plants (18.8 vs. 13.4 mg per P plant), but there was no difference in biomass (6.2 vs. 6.3 g per plant). At the intermediate P level, root diameter was significantly positively correlated with shoot biomass, P concentration and the P content of mycorrhizal plants. The results of our study support the importance of the outsourcing model of P acquisition in the root economics space framework. Inadvertent varietal selection in the last decades, resulting in thinner roots and a lower benefit from AMF, has led to a lower productivity of cotton varieties at moderate P supply (i.e., when mycorrhizal, the average biomass of older varieties 5.0 g per plant vs. biomass of newer varieties 4.4 g per plant), indicating the need to rethink cotton breeding efforts in order to achieve high yields without very high P input. One feasible way to solve the problem of inadvertent varietal selection for cotton is to be aware of the trade-offs between the root do-it-yourself strategy and the outsourcing towards AMF strategy, and to consider both morphological and mycorrhizal root traits when breeding cotton varieties.

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Interactions between phosphorus availability and microbes in a wheat–maize double cropping system: a reduced fertilization scheme

YU Xiao-jing, CHEN Qi, SHI Wen-cong, GAO Zheng, SUN Xiao, DONG Jing-jing, LI Juan, WANG Heng-tao, GAO Jian-guo, LIU Zhi-guang, ZHANG Min

2022, 21 (3): 840-854. DOI: 10.1016/S2095-3119(20)63599-7

Abstract （197） PDF in ScienceDirect

Mechanisms controlling phosphorus (P) availability and the roles of microorganisms in the efficient utilization of soil P in the wheat–maize double cropping system are poorly understood. In the present study, we conducted a pot experiment for four consecutive wheat–maize seasons (2016–2018) using calcareous soils with high (30.36 mg kg^–1) and low (9.78 mg kg^–1) initial Olsen-P content to evaluate the effects of conventional P fertilizer application to both wheat and maize (Pwm) along with a reduced P fertilizer application only to wheat (Pw). The microbial community structure along with soil P availability parameters and crop yield were determined. The results showed that the Pw treatment reduces the annual P input by 33.3% without affecting the total yield for at least two consecutive years as compared with the Pwm treatment in the high Olsen-P soil. Soil water-soluble P concentrations in the Pw treatment were similar to those in the Pwm treatment at the 12-leaf collar stage when maize requires the most P. Furthermore, the soil P content significantly affected soil microbial communities, especially fungal communities. Meanwhile, the relative abundances of Proteobacteria and alkaline phosphatase (ALP) activity of Pw were significantly higher (by 11.4 and 13.3%) than those of Pwm in soil with high Olsen-P. The microfloral contribution to yield was greater than that of soil P content in soil with high Olsen-P. Relative abundances of Bacillus and Rhizobium were enriched in the Pw treatment compared with the Pwm treatment. Bacillus showed a significant positive correlation with acid phosphatase (ACP) activity, and Rhizobium displayed significant positive correlations with ACP and ALP in soil with high Olsen-P, which may enhance P availability. Our findings suggested that the application of P fertilization only to wheat is practical in high P soils to ensure optimal production in the wheat and maize double cropping system and that the soil P availability and microbial community may collaborate to maintain optimal yield in a wheat–maize double cropping system.

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Evidence of silk growth hampering in maize at high planting density using phenotypic and transcriptional analysis

ZHANG Min, XING Li-juan, REN Xiao-tian, ZOU Jun-jie, SONG Fu-peng, WANG Lei, XU Miao-yun

2022, 21 (11): 3148-3157. DOI: 10.1016/j.jia.2022.08.083

Abstract （350） PDF in ScienceDirect

Increasing the planting density is an effective way to increase the yield of maize (Zea mays L.), although it can also aggravate ovary apical abortion-induced bald tips of the ears, which might, in turn, reduce the yield. While the mechanism underlying the regulation of drought-related abortion in maize is well established, high planting density-related abortion in maize remains poorly understood. Therefore, the present study was designed to investigate the mechanism underlying the ovary apical abortion response to high density. This was achieved by evaluating the effects of four different plant densities (60 000 plants ha^–1 (60 k), 90 k, 120 k, and 150 k) on plant traits related to plant architecture, the plant ear, flowering time, and silk development in two inbred lines (Zheng58 and PH4CV) and two hybrid lines (Zhengdan958 and Xianyu335). The phenotypes of both inbred and hybrid plants were observed under different planting density treatments, and the high planting density was found to increase the phenotypic performance values of the evaluated traits. The anthesis–silking interval (ASI) was extended, and the amount of the silk extruded from husks was reduced upon increasing the planting density. Delayed silk emergence resulted in asynchronous flowering and ear bald tips. Observations of the silk cells revealed that the silk cells became smaller as planting density increased. The changes in transcript abundances in the silks involved the genes associated with expansive growth rather than carbon metabolism. These findings further our understanding of silk growth regulation under high planting density and provide a theoretical basis for further research on improving high planting density breeding in maize.

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Improving maize grain yield by formulating plant growth regulator strategies in North China

GONG Li-sha, QU Shu-jie, HUANG Guan-min, GUO Yu-ling, ZHANG Ming-cai, LI Zhao-hu, ZHOU Yu-yi, DUAN Liu-sheng

2021, 20 (2): 622-632. DOI: 10.1016/S2095-3119(20)63453-0

Abstract （105） PDF in ScienceDirect

Plant growth regulators (PGRs) are artificially synthesized compounds that have become an important technical guarantee for agricultural production. EDAH (containing 27% ethephon and 3% DA-6) has been proven to inhibit stalk elongation, promote stalk bold and increase mechanical strength and number of vascular bundles. DA-6 could enhance plant photosynthetic capacity and promote cell division and growth. In our study, experiments were performed at summer maize growing season during 2018–2019. The result showed that plant height, ear height and center of gravity height of maize with EDAH+DA-6 treatment were decreased by 10.18, 16.77 and 13.21%, respectively; leaf area and leaf area index also significantly (P<0.001) decreased by 24.11 and 60.15%, respectively; the value of mean tilt angle significantly (P<0.001) increased by 16.72% compared with the control plants, which meant that EDAH+DA-6 could shape more compact plant type. Therefore, lodging rate of maize with EDAH+DA-6 treatment decreased by 6.95% compared with control plants, and the grain yield was increased by 15.51%. In addition, EDAH+DA-6 treatment significantly improved the quality of maize base stalks, such as improving mechanical properties, which increased maize base stalk crushing strength by 22.23%; increased the hemicellulose, cellulose and lignin contents by 6.93, 3.87 and 30.21%, respectively. In conclusion, EDAH+DA-6 treatment could improve summer maize yield by shaping plant morphological characteristics and group photosynthesis.

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Optimizing the application of a novel harvest aid to improve the quality of mechanically harvested cotton in the North China Plain

MENG Lu, ZHANG Li-zhen, QI Hai-kun, DU Ming-wei, ZUO Yan-li, ZHANG Ming-cai, TIAN Xiao-li, LI Zhao-hu

2021, 20 (11): 2892-2899. DOI: 10.1016/S2095-3119(20)63280-4

Abstract （147） PDF in ScienceDirect

Defoliation is an indispensable step in cotton production with mechanical harvesting, especially in the North China Plain (NCP) where mechanical harvesting is limited by a large proportion of green leaves and unopened bolls at harvest time due to insufficient thermal resources. It is essential to quantify the optimal use of defoliation products while minimizing yield and quality loss in China. The objective of this study was to test the effect of a new defoliant Xinsaili (XSL, a compound of 10% thidiazuron and 40% ethephon) on the spatial distribution of cotton leaves and bolls, yield and quality in the NCP. There were four treatments: XSL 1 800 mL ha^–1 , XSL 2 700 mL ha^–1, XSL splitted into two equal applications (1 350 mL ha^–1 for each), and XSL-free (water) control. Field experiments were conducted in Hebei, China in 2016–2017. All the defoliant treatments did not significantly affect cotton yield and fiber quality compared with the water control. At harvest time, the rate of open bolls under XSL 2 700 mL ha^–1 was 13.5% higher than that under XSL-free control, while the other two treatments showed no significant difference, across the two years. Defoliation percentage of the three XSL treatments showed no difference, but they were on average 42.2% higher than that of XSL-free control. The year-round effect of the defoliant XSL was significant, indicating that climate factors would affect its application. It was concluded that the optimal dose of XSL in the NCP was 2 700 mL ha^–1, and it was unnecessary to split it into two applications. These results would promote cotton mechanical harvesting and reduce the labor cost of cotton production in China.

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Egg tanning improves the efficiency of CRISPR/Cas9-mediated mutant locust production by enhancing defense ability after microinjection

ZHANG Ting-ting, WEN Ting-mei, YUE Yang, YAN Qiang, DU Er-xia, FAN San-hong, Siegfried ROTH, LI Sheng, ZHANG Jian-zhen, ZHANG Xue-yao, ZHANG Min

2021, 20 (10): 2716-2726. DOI: 10.1016/S2095-3119(21)63736-X

Abstract （135） PDF in ScienceDirect

The mutant efficiency and hatching ratio are two key factors that significantly affect the construction of genome-modified mutant insects. In the construction of CRISPR/Cas9-mediated dsLmRNase2^–/–mutant locusts, we found that the tanned eggs which experienced a 20-min contact with the oocyst exhibited a higher success rate compared to fresh newly-laid eggs that were less tanned. However, the heritable efficiency of the dsLmRNase2 deletion to the next generation G₁ progeny was similar between adults derived from the tanned or less tanned engineered eggs. Further, the similar effective mutant ratios in the normally developed eggs and G₀ adults of tanned and less tanned eggs also indicated that tanning did not reduce the absolute mutation efficiency induced by CRISPR/Cas9. Moreover, we found that the syncytial division period, which was longer than the time for tanning, conferred a window period for microinjection treatment with efficient mutation in both tanned and less tanned eggs. We further found that tanned eggs exhibited a higher hatching rate due to a reduced infection rate following microinjection. Both the anti-pressure and ultrastructure analyses indicated that the tanned eggs contained compressed eggshells to withstand increased external pressure. In summary, tanned eggs possess stronger defense responses and higher efficiency of genome editing, providing an improved model for developing Cas9-mediated gene editing procedures in locusts.

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PGC-1α differentially regulates the mRNA expression profiles of genes related to myofiber type specificity in chicken

SHAN Yan-ju, JI Gai-ge, ZOU Jian-min, ZHANG Ming, TU Yun-jie, LIU Yi-fan, JU Xiao-jun, SHU Jing-ting

2020, 19 (8): 2083-2094. DOI: 10.1016/S2095-3119(20)63177-X

Abstract （122） PDF in ScienceDirect

Previous studies on mammals showed that peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) played a prominent role in regulating muscle fiber type transition and composition. However, the role of PGC-1α in chicken muscle has seldom been explored. To investigate the effect of PGC-1α on chicken skeletal muscles in this study, the PGC-1α gene was overexpressed or silenced in chicken primary myoblasts by using lentivirus, and then the effects of the PGC-1α gene overexpression and knockdown on the mRNA expression profile of genes related to myofiber type specificity were examined during fiber formation. The results showed that overexpression of PGC-1α from proliferation to differentiation was accompanied by the up-regulated expression of Pax7, MyoD, and CnAα, which was significantly (P<0.01) increased after one day of transfection (1I). The enhancement of MyoG, MEF2c, and MyHC SM expression lagged, which was improved significantly (P<0.01) after four days of transfection (1I3D). Overexpression of PGC-1α decreased (P<0.01) the MyHC FWM expression after four days of transfection (1I3D), and it had no significant impact (P>0.05) on the expression of CnB1, NFATc3, and MyHC FRM during myofiber formation. The effective silence (P<0.01) of PGC-1α by lentivirus mediating short hairpin RNA (shRNA) was detected after four days of transfection (1I3D) in cultures, and the lack of its function in chicken primary myoblasts significantly (P<0.01) down-regulated the expression of Pax7, MyoD, CnAα, MyoG, MEF2c, and MyHC SM, significantly (P<0.01) up-regulated the expression of MyHC FWM, and had no significant impact (P>0.05) on the expression of CnB1, NFATc3, and MyHC FRM. These results indicated that the role of PGC-1α in regulating the fiber type specificity of chicken skeletal muscles might be similar to that in mammals, which interplayed with key genes related to myocyte differentiation and calcineurin signaling pathway.

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Pearprocess: A new phenotypic tool for stone cell trait evaluation in pear fruit

XUE Yong-song, XU Shao-zhuo, XUE Cheng, WANG Run-ze, ZHANG Ming-yue, LI Jia-ming, ZHANG Shao-ling, WU Jun

2020, 19 (6): 1625-1634. DOI: 10.1016/S2095-3119(20)63193-8

Abstract （111） PDF in ScienceDirect

The content of stone cells is an important factor for pear breeding as a high content indicates severely reduced fruit quality in terms of fruit taste. Although the frozen-HCl method is currently a common method used to evaluate stone cell content in pears, it is limited in incomplete separation of stone cell and pulp and is time consuming and complicated. Computer-aided research is a promising strategy in modern scientific research for phenotypic data collection and is increasingly used in studying crops. Thus far, we lack a quantitative tool that can effectively determine stone cell content in pear fruit. We developed a program, Pearprocess, based on an imaging protocol using computer vision and image processing algorithms applied to digital images. Using photos of hand-cut sections of pear fruit stained with phloroglucin-HCl (Wiesner’s reagent), Pearprocess can extract and analyze image-based data to quantify the stone cell-related traits measured in this study: number, size, area and density of stone cell. We quantified these traits for 395 pear accessions by Pearprocess and revealed large variation in different pear varieties and species. The number of stone cells varied greatly from value of 138 to 2 866, the density of stone cells ranged from 0.0019 to 0.0632 cm² cm^–2, the distribution of stone cell area ranged from 0.06 to 2.02 cm², and the stone cell size was between 2e-4 and 1e-3 cm². Moreover, trait data were correlated with fruit taste data. We found that stone cell density is likely the most important factor affecting the taste of pear fruit. In summary, Pearprocess is a new cost-effective web-application for semi-automated quantification of two-dimensional phenotypic traits from digital imagery using an easy imaging protocol. This simpler, feasible and accurate method to evaluate stone cell traits of fruit is a promising new tool for use in evaluating future germplasms for crop breeding programs.

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Biotic and abiotic stress-responsive genes are stimulated to resist drought stress in purple wheat

LI Xiao-lan, Lü Xiang, WANG Xiao-hong, PENG Qin, ZHANG Ming-sheng, REN Ming-jian

2020, 19 (1): 33-50. DOI: 10.1016/S2095-3119(19)62659-6

Abstract （131） PDF in ScienceDirect

Triticum aestivum L. cv. Guizi 1 (GZ1) is a drought-tolerant local purple wheat cultivar. It is not clear how purple wheat resists drought stress, but it could be related to anthocyanin biosynthesis. In this study, transcriptome data from drought-treated samples and controls were compared. Drought slightly reduced the anthocyanin, protein and starch contents of GZ1 grains and significantly reduced the grain weight. Under drought stress, 16 682 transcripts were reduced, 27 766 differentially expressed genes (DEGs) were identified, and 379 DEGs, including DREBs, were related to defense response. The defense-response genes included response to water deprivation, reactive oxygen, bacteria, fungi, etc. Most of the structural and regulatory genes in anthocyanin biosynthesis were downregulated, with only TaDFR, TaOMT, Ta5,3GT, and TaMYB-4B1 being upregulated. TaCHS, TaF3H, TaCHI, Ta4CL, and TaF3’H are involved in responses to UV, hormones, and stimulus. TaCHS-2D1, TaDFR-2D2, TaDFR-7D, TaOMT-5A, Ta5,3GT-1B1, Ta5,3GT-3A, and Ta5,3GT-7B1 connect anthocyanin biosynthesis with other pathways, and their interacting proteins are involved in primary metabolism, genetic regulation, growth and development, and defense responses. There is further speculation about the defense-responsive network in purple wheat. The results indicated that biotic and abiotic stress-responsive genes were stimulated to resist drought stress in purple wheat GZ1, and anthocyanin biosynthesis also participated in the drought defense response through several structural genes.

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Effect of relative humidity at chronic temperature on growth performance, glucose consumption, and mitochondrial ATP production of broilers

ZHOU ying, ZHANG Min-hong, FENG Jing-hai, DIAO Hua-jie

2019, 18 (6): 1321-1328. DOI: 10.1016/S2095-3119(19)62584-0

Abstract （205） PDF in ScienceDirect

An experiment was conducted to investigate the effect of relative humidity (RH) at chronic temperature on growth performance, glucose consumption, and mitochondrial adenosine triphosphate (ATP) production of broilers. A total of 180 28-day-old Arbor Acres broilers (half males and half females) were randomly allocated to three treatments, each containing six replicates of 10 birds per treatment, using a completely randomized design. Birds were reared at 35, 60 or 85% RH at 32°C for 15 days (temperature increased by 3°C every 3 days from 20 to 32°C within 15 days: 20–23–26–29–32°C). RH affected (P<0.05) average daily feed intake (ADFI), average daily gain (ADG), average daily water consumption (ADWC), blood glucose concentrations, muscle glycogen levels, avian uncoupling protein (av UCP) mRNA expression, and cytochrome c oxidase (CCO) activity in liver of broilers at 42 days of age. The 85% RH decreased (P<0.05) ADFI, ADG and ADWC; 35% RH decreased (P<0.02) ADG. Both 85 and 35% RH increased (P<0.01) blood glucose and decreased (P<0.05) muscle glycogen. Both 85 and 35% RH increased (P<0.05) av UCP mRNA expression. 35% RH decreased (P<0.05) CCO activity. In conclusion, both high and low RH inceased glucose consumption and reduced mitochondrial ATP poduction, leading to a decline in growth rate.

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Effect of relative humidity at either acute or chronic moderate temperature on growth performance and droppings’ corticosterone metabolites of broilers

ZHOU ying, LI Xiu-mei, ZHANG Min-hong, FENG Jing-hai

2019, 18 (1): 152-159. DOI: 10.1016/S2095-3119(18)62049-0

Abstract （284） PDF in ScienceDirect

The present study aimed to investigate the effect of relative humidity (RH) at either acute or chronic moderate ambient temperature (Ta) on growth performance and droppings’ corticosterone metabolites of broilers. Two experiments were conducted: effect of RH (35, 60 or 85%) on average daily feed intake (ADFI) and droppings’ corticosterone metabolites at acute (1 d: 20–26 or 31–20°C, 26 or 31°C for 6 h d^–1 at 10:00–16:00) moderate Ta (experiment 1) and effect of RH (35, 60 or 85%) on growth performance and droppings’ corticosterone metabolites at chronic (step-wisely increasing temperature by 3°C every 3 d from 20 to 32°C within 15 d: 20–23–26–29–32°C) moderate Ta (experiment 2). Droppings were collected at the 2, 4, 6, 8, and 22 h after Ta-RH controlled in experiment 1 and at the 2, 4, 6, and 22 h after Ta controlled to 32°C in experiment 2. The results showed that: 1) In experiment 1, 85% RH increased (P<0.05) the droppings’ corticosterone metabolites at the 2, 6, 8, and 22 h and 35% RH increased (P<0.05) it at the 2 and 22 h compared to the 60% RH. Moreover, 85% RH further increased (P<0.05) it compared to the 35% RH, however, no difference (P>0.05) was found in ADFI among the three RH groups at acute moderate 26°C; 35 and 85% RH increased (P<0.05) droppings’ corticosterone metabolites at the 2, 6, 8 and 22 h and decreased (P<0.05) ADFI compared to the 60% RH, moreover, 85% RH further increased (P<0.05) droppings’ corticosterone metabolites and further decreased (P<0.05) ADFI compared to the 35% RH at acute moderate 31°C; and the average of droppings’ corticosterone metabolites in the whole period had a negative correlation (P<0.02) with the ADFI. 2) In experiment 2, 85% RH increased (P<0.01) droppings’ corticosterone metabolites only at the 2 h and decreased (P<0.02) ADFI and average daily gain (ADG) compared to the 60% RH, no difference (P>0.05) in droppings’ corticosterone metabolites was found between the 35 and 60% RH, however, 35% RH decreased (P<0.01) ADG compared to the 60% RH, and the average of droppings’ corticosterone metabolites in the whole period also had a negative correlation (P<0.02) with ADFI and ADG. In conclusion, droppings’ corticosterone metabolites could be used as a RH stress index and low and high RH, especially high RH, reduced growth performance possibly through inducing RH stress at moderate temperature.

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How plant density affects maize spike differentiation, kernel set, and grain yield formation in Northeast China?

ZHANG Ming, CHEN Tao, Hojatollah Latifmanesh, FENG Xiao-min, CAO Tie-hua, QIAN Chun-rong, DENG Ai-xing, SONG Zhen-wei, ZHANG Wei-jian

2018, 17 (08): 1745-1757. DOI: 10.1016/S2095-3119(17)61877-X

Abstract （508） PDF in ScienceDirect

A two-year field experiment was conducted to evaluate the effects of plant density on tassel and ear differentiation, anthesis-silking interval (ASI), and grain yield formation of two types of modern maize hybrids (Zhongdan 909 (ZD909) as tolerant hybrid to crowding stress, Jidan 209 (JD209) and Neidan 4 (ND4) as intolerant hybrids to crowding stress) in Northeast China. Plant densities of 4.50×10⁴ (D1), 6.75×104 (D2), 9.00×10⁴ (D3), 11.25×10⁴ (D4), and 13.50×10⁴ (D5) plants ha^–1 had no significant effects on initial time of tassel and ear differentiation of maize. Instead, higher plant density delayed the tassel and ear development during floret differentiation and sexual organ formation stage, subsequently resulting in ASI increments at the rate of 1.2–2.9 days on average for ZD909 in 2013–2014, 0.7–4.2 days for JD209 in 2013, and 0.5–3.7 days for ND4 in 2014, respectively, under the treatments of D2, D3, D4, and D5 compared to that under the D1 treatment. Total florets, silking florets, and silking rates of ear showed slightly decrease trends with the plant density increasing, whereas the normal kernels seriously decreased at the rate of 11.0–44.9% on average for ZD909 in 2013–2014, 2.0–32.6% for JD209 in 2013, and 9.7–28.3% for ND4 in 2014 with the plant density increased compared to that under the D1 treatment due to increased florets abortive rates. It was also observed that 100-kernel weight of ZD909 showed less decrease trend compared that of JD209 and ND4 along with the plant densities increase. As a consequence, ZD909 gained its highest grain yield by 13.7 t ha^–1 on average at the plant density of 9.00×104 plants ha^–1, whereas JD209 and ND4 reached their highest grain yields by 11.7 and 10.2 t ha^–1 at the plant density of 6.75×104 plants ha^–1, respectively. Our experiment demonstrated that hybrids with lower ASI, higher kernel number potential per ear, and relative constant 100-kernel weight (e.g., ZD909) could achieve higher yield under dense planting in high latitude area (e.g., Northeast China).

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Yield and water use responses of winter wheat to irrigation and nitrogen application in the North China Plain

ZHANG Ming-ming, DONG Bao-di, QIAO Yun-zhou, SHI Chang-hai, YANG Hong, WANG Ya-kai, LIU Meng-yu

2018, 17 (05): 1194-1206. DOI: 10.1016/S2095-3119(17)61883-5

Abstract （569） PDF in ScienceDirect

With increasing water shortage resources and extravagant nitrogen application, there is an urgent need to optimize irrigation regimes and nitrogen management for winter wheat (Triticum aestivum L.) in the North China Plain (NCP). A 4-year field experiment was conducted to evaluate the effect of three irrigation levels (W1, irrigation once at jointing stage; W2, irrigation once at jointing and once at heading stage; W3, irrigation once at jointing, once at heading, and once at filling stage; 60 mm each irrigation) and four N fertilizer rates (N0, 0; N1, 100 kg N ha⁻¹; N2, 200 kg N ha⁻¹; N3, 300 kg N ha⁻¹) on wheat yield, water use efficiency, fertilizer agronomic efficiency, and economic benefits. The results showed that wheat yield under W2 condition was similar to that under W3, and greater than that under W1 at the same nitrogen level. Yield with the N1 treatment was higher than that with the N0 treatment, but not significantly different from that obtained with the N2 and N3 treatments. The W2N1 treatment resulted in the highest water use and fertilizer agronomic efficiencies. Compared with local traditional practice (W3N3), the net income and output-input ratio of W2N1 were greater by 12.3 and 19.5%, respectively. These findings suggest that two irrigation events of 60 mm each coupled with application of 100 kg N ha⁻¹ is sufficient to provide a high wheat yield during drought growing seasons in the NCP.

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The damage risk evaluation of Aphis gossypii on wheat by host shift and fitness comparison in wheat and cotton

FAN Yin-jun, LI Fen, Abd Allah A. H. Mohammed, YI Xiao-qin, ZHANG Min, Nicolas Desneux, GAO Xi-wu

2018, 17 (03): 631-639. DOI: 10.1016/S2095-3119(17)61784-2

Abstract （698） PDF in ScienceDirect

Aphids are considered as one of the key pests for wheat production worldwide. Major aphid species that infest wheat in China include Sitobion avenae, Rhopalosiphum padi, Schizaphis graminum and Metopolophium dirhodum. However, during our wheat field survey in Wenshang County of Shangdong Province, China, we observed that Aphis gossypii can feed on wheat. The damage risk of A. gossypii on wheat was assessed using host shift method. A population of A. gossypii collected from a wheat field in 2015 and another population reared on cotton under laboratory conditions for a decade without exposure to insecticides were used in the study. The results of host shift demonstrated that the A. gossypii colony from wheat has not yet developed wheat specialization. Moreover, the assessment of A. gossypii fitness on wheat and cotton showed that fecundity and net reproductive rate of A. gossypii population fed on wheat was significantly higher comparing to the population fed on cotton, whether the initial host of A. gossypii population was wheat or cotton. This study raises a warning that the cotton aphid has potential to establish well on wheat and it may cause significant effects under specific circumstances. Therefore, future studies are required to evaluate the effects of A. gossypii on wheat production.

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Drought-induced responses of organic osmolytes and proline metabolism during pre-flowering stage in leaves of peanut (Arachis hypogaea L.)

ZHANG Ming, WANG Li-feng, ZHANG Kun, LIU Feng-zhen, WAN Yong-shan

2017, 16 (10): 2197-2205. DOI: 10.1016/S2095-3119(16)61515-0

Abstract （754） PDF in ScienceDirect

Peanut (Arachis hypogaea L.), an improtant oil crop, usually encounters drought stress in the process of growth and development, especially at pre-flowering stage. In order to gain insight into the drought tolerance potentials based on osmolyte accumulation and metabolism of proline aspects of peanut, pot experiments were conducted with a split-plot design in Tai’an, Shangdong Province, China in 2013 and 2014. Pre-flowering drought (PFD) stress and optinum irrigation (control, CK) were served as the main plots and the two peanut cultivars Shanhua 11 and Hua 17 served as sub-plots. Shanhua 11 was drought-tolerant cultivar and Hua 17 was drought-sensitive. The content of soluble sugars, soluble protein, free proline and other free amino acids, the activities of enzymes involved in proline metabolism, and malondialdehyde (MDA) content and ion leakage were all investigated in the two cultivars at pre-flowering stage. Results showed that PFD stress significantly increased the levels of soluble protein, free proline and free amino acid, and increased Δ¹-pyrroline-5-carboxylate synthetase (P-5-CS, EC 2.7.2.11) activity in the leaves of drought-tolerant and drought-sensitive cultivars. The activity of proline dehydrogenase (proDH) (EC 1.5.99.8) decreased under PFD stress in both cultivars. The leaves of the tolerant cultivar maintained higher increments of osmolyte levels, lower increments of MDA content and ion leakage, as well as a higher increased proportion of P-5-CS activity and higher inhibited proportion of proDH activity under water stress compared with the drought-sensitive cultivar. The study suggests that proline accumulation in peanut leaves under PFD can be explained by the higher enhanced activities of P-5-CS and higher inhibition of proDH. The results will provide useful information for genetic improvement of peanut under drought tolerance.

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Assessment of the cropland classifications in four global land cover datasets: A case study of Shaanxi Province, China

CHEN Xiao-yu, LIN Ya, ZHANG Min, YU Le, LI Hao-chuan, BAI Yu-qi

2017, 16 (02): 298-311. DOI: 10.1016/S2095-3119(16)61442-9

Abstract （1088） PDF in ScienceDirect

Accurate and reliable cropland surface information is of vital importance for agricultural planning and food security monitoring. As several global land cover datasets have been independently released, an inter-comparison of these data products on the classification of cropland is highly needed. This paper presents an assessment of cropland classifications in four global land cover datasets, i.e., moderate resolution imaging spectrometer (MODIS) land cover product, global land cover map of 2009 (GlobCover2009), finer resolution observation and monitoring of global cropland (FROM-GC) and 30-m global land cover dataset (GlobeLand30). The temporal coverage of these four datasets are circa 2010. One of the typical agricultural regions of China, Shaanxi Province, was selected as the study area. The assessment proceeded from three aspects: accuracy, spatial agreement and absolute area. In accuracy assessment, 506 validation samples, which consist of 168 cropland samples and 338 non-cropland ones, were automatically and systematically selected, and manually interpreted by referencing high-resolution images dated from 2009 to 2011 on Google Earth. The results show that the overall accuracy (OA) of four datasets ranges from 61.26 to 80.63%. GlobeLand30 dataset, with the highest accuracy, is the most accurate dataset for cropland classification. The cropland spatial agreement (mainly located in the plain ecotope of Shaanxi) and the non-cropland spatial agreement (sparsely distributed in the south and middle of Shaanxi) of the four datasets only makes up 33.96% of the whole province. FROM-GC and GlobeLand30, obtaining the highest spatial agreement index of 62.40%, have the highest degree of spatial consistency. In terms of the absolute area, MODIS underestimates the cropland area, while GlobCover2009 significantly overestimates it. These findings are of value in revealing to which extent and on which aspect that these global land cover datasets may agree with each other at small scale on each ecotope region. The approaches taken in this study could be used to derive a fused cropland classification dataset.

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Development and detection application of monoclonal antibodies against Zucchini yellow mosaic virus

CHEN Zhe, ZHANG Ming-hao, ZHOU Xue-ping, WU Jian-xiang

2017, 16 (01): 115-124. DOI: 10.1016/S2095-3119(16)61416-8

Abstract （998） PDF in ScienceDirect

Aphid-borne Zucchini yellow mosaic virus (ZYMV) is one of the most economically important viruses of cucurbitaceous plants. To survey and control this virus, it is necessary to develop an efficient detection technique. Using purified ZYMV virion and the conventional hybridoma technology, three hybridoma cell lines (16A11, 5A7 and 3B8) secreting monoclonal antibodies (MAbs) against ZYMV Zhejiang isolate were obtained. The working titers of the ascitic fluids secreted by the three hybridoma cell lines were up to 10^–7 by indirect enzyme-linked immunosorbent assay (ELISA). All MAbs were isotyped as IgG1, kappa light chain. Western blot analysis indicated that the MAb 3B8 could specifically react with the coat protein of ZYMV while MAbs 5A7 and 16A11 reacted strongly with a protein of approximately 51 kDa from the ZYMV-infected leaf tissues. According to this molecular weight, we consider this reactive protein is likely to be the HC-Pro protein. Using these three MAbs, we have now developed five detection assays, i.e., antigen-coated-plate ELISA (ACP-ELISA), dot-ELISA, tissue blot-ELISA, double-antibody sandwich ELISA (DAS-ELISA), and immunocapture-RT-PCR (IC-RT-PCR), for the sensitive, specific, and easy detection of ZYMV. The sensitivity test revealed that ZYMV could be readily detected respectively by ACP-ELISA, dot-ELISA, DAS-ELISA and IC-RT-PCR in 1:163 840, 1:2 560, 1:327 680 and 1:1 310 720 (w/v, g mL^–1) diluted crude extracts from the ZYMV-infected plants. We demonstrated in this study that the dot-ELISA could also be used to detect ZYMV in individual viruliferous aphids. A total of 275 cucurbitaceous plant samples collected from the Zhejiang, Jiangsu, Shandong and Hainan provinces, China, were screened for the presence of ZYMV with the described assays. Our results showed that 163 of the 275 samples (59%) were infected with ZYMV. This finding indicates that ZYMV is now widely present in cucurbitaceous crops in China. RT-PCR followed by DNA sequencing and sequence analyses confirmed the accuracy of the five assays. We consider that these detection assays can significantly benefit the control of ZYMV in China.

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Effects of high ambient temperature on lipid metabolism in finishing pigs

WU Xin, LI Ze-yang, JIA An-feng, SU Hong-guang, HU Chun-hong, ZHANG Min-hong, FENG Jing-hai

2016, 15 (2): 391-396. DOI: 10.1016/S2095-3119(15)61061-9

Abstract （1801） PDF in ScienceDirect

In this study, we investigated the effects of high ambient temperature on lipid metabolism in finishing pigs. Sixteen pigs ((79.6±1.2) kg) were randomly assigned to two groups: (1) ambient temperature of 30°C with ad libitum access to feed (HT; n=8) and (2) ambient temperature of 22°C and fed the average amount consumed by eight pigs in HT group on the previous day (PF; n=8). After 21 days of constant exposure to different environmental conditions, all the pigs were euthanized, and blood and tissue samples were obtained. High ambient temperature increased the proportion of backfat (P=0.04, +21.6%) and flare fat (P<0.01, +43.3%). Compared with pair-fed pigs, the activities of fatty acid synthase (FAS) and malic enzyme in backfat and flare fat were lower (P<0.05) in heat-stressed pigs, as were the amounts of acetyl-CoA-carboxylase and FAS in the longissimus muscle (LM), the amount of FAS in backfat (P<0.01), and FAS activity in the liver (P<0.01). Ambient temperature did not affect the amount of hormone-sensitive lipase in different tissues. The amount of lipoprotein lipase in flare fat tended to be higher (P=0.09, +28.3%), and the activities of β-hydroxyacyl coenzyme A dehydrogenase in front and back of LM were lower (P<0.01, –48.3 and –49.8%, respectively) at 30°C than at 22°C. The plasma concentration of high-density lipoprotein tended to be lower (P=0.08), but the plasma concentrations of very low-density lipoprotein (VLDL) (P=0.09, +50.0%) and nonestesterified fatty acid (NEFA) (P=0.04, +44.2%) were higher in heat-stressed pigs. We concluded that high ambient temperature depressed de novo fatty acid synthesis in both adipose tissues and the liver. However, β-oxidation of fatty acid in skeletal muscles was also inhibited in the high-temperature environment. As a result, more plasma NEFAs were used to synthesize VLDLs in the liver and were absorbed by adipose tissues. This may be one reason that high ambient temperature enhances the accumulation of backfat and flare fat in finishing pigs.

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Effects of sustained cold and heat stress on energy intake, growth and mitochondrial function of broiler chickens

ZHANG Shao-shuai, SU Hong-guang, ZHOU Ying, LI Xiu-mei, FENG Jing-hai, ZHANG Min-hong

2016, 15 (10): 2336-2342. DOI: 10.1016/S2095-3119(15)61314-4

Abstract （1637） PDF in ScienceDirect

To study the correlation of broiler chickens with energy intake, growth and mitochondrial function which exposed to sustained cold and heat stress and to find out the comfortable temperature, 288 broiler chickens (21-day with (748±26) g, 144 males and 144 females) were divided randomly into six temperature-controlled chambers. Each chamber contained six cages including eight AA broilers per cage, each cage as a repeat. After acclimation for one week (temperature, 21°C; relative humidity, 60%), the temperature of each chamber was adjusted (finished within 1 h) respectively to 10, 14, 18, 22, 26, or 30°C (RH, 60%) for a 14-day experimental period. After treatment, gross energy intake (GEI), metabolizable energy intake (MEI), the ratio of MEI/BW, metabolizability, average daily gain (ADG), the concentration of liver mitochondria protein and cytochrome c oxidase (CCO) were measured respectively. Our results confirmed that when the temperature over 26°C for 14 days, GEI, MEI and CCO activities were decreased significantly (P<0.05), but the concentration of liver mitochondria protein was increased and metabolizability of broilers was not influenced (P>0.05). Compared with treatment for 14 days, the ratio of MEI/body weight (BW) were also decreased when the temperature over 26°C after temperature stress for 7 days (P<0.05), meanwhile mitochondrial protein concentration was increased at 10°C and CCO activity was not affected (P>0.05). Additionally at 22°C, the ADG reached the maximal value. When kept in uncomfortable temperatures for a long time, the ADG and CCO activities of broiler were reduced, which was accompanied by mitochondrial hyperplasia. In summary, our study focused on the performance of broilers during sustained cold and heat environmental temperatures ranging from 10 to 30°C. From the point of view of energy utilization, moreover, 22 to 26°C is comfortable for 28–42 days broilers. And these could provide the theoretical basis on the high efficient production.

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Effect of feeding transgenic cry1Ab/cry1Ac rice on indices of immune function in broilers

LIU Ran-ran, ZHAO Gui-ping, ZHENG Mai-qing, LIU Jie, ZHANG Jing-jing, LI Peng, LI Qing-he, FENG Jing-hai, ZHANG Min-hong, WEN Jie

2016, 15 (06): 1355-1363. DOI: 10.1016/S2095-3119(15)61281-3

Abstract （1869） PDF in ScienceDirect

The safety of feeding transgenic cry1Ab/cry1Ac rice (a genetically modified (GM) rice variety) to broilers was examined from an immunological perspective. Hatchling Arbor Acres chickens (240) were assigned to two dietary treatments (diets containing GM or non-GM rice) with 12 replicates per group and 10 birds per replicate. Traits were measured on one randomly selected bird from each replicate at d 21 and 42. The 42-d feeding trial revealed that cry1Ab/cry1Ac rice had no significant effect relative to non-GM rice on body weight and the immune organ indices. No significant pathological lesion in the spleen and bursa of Fabricius was found in the GM rice group. There were no significant differences in serum concentrations of immunoglobulin Y (IgY), IgM, interleukin 4 (IL-4) and IL-6 between the two groups at d 21 or 42, except for IL-6 being higher (P<0.05) in the GM-fed chickens at d 42. There were no differences in the T and B lymphocyte transformation rate and CD4+/CD8+ ratio between the two groups at d 42. Additionally, there was no significant difference between the two diets in expression of relevant genes viz. the major histocompatibility complex class II beta chain (BLB2), interferon beta 1 (IFNβ), tumour necrosis factor alpha-like (TNFα) and toll-like receptor 4 (TLR4) in the spleen and bursa of Fabricius. All the data demonstrated that transgenic cry1Ab/cry1Ac rice had no adverse effect on these aspects of immune function of broilers during 42-d feeding trial. Transgenic rice was therefore indistinguishable from non-GM rice in terms of short-term feeding in chickens.

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Differentiation of expression profiles of two calcineurin subunit genes in chicken skeletal muscles during early postnatal growth depending on anatomical location of muscles and breed

SHAN Yan-ju, XU Wen-juan, SHU Jing-ting, ZHANG Ming, SONG Wei-tao, TAO Zhi-yun, ZHU Chunhong, LI Hui-fang

2016, 15 (05): 1085-1094. DOI: 10.1016/S2095-3119(15)61162-5

Abstract （1780） PDF in ScienceDirect

Calcineurin (Cn or CaN) is implicated in the control of skeletal muscle fiber phenotype and hypertrophy. However, little information is available concerning the expression of Cn in chickens. In the present study, the expression of two Cn subunit genes (CnAα and CnB1) was quantified by qPCR in the lateral gastrocnemius (LG, mainly composing of red fast-twitch myofibers), the soleus (mainly composing of red slow-twitch myofibers) and the extensor digitorum longus (EDL, mainly composing of white fast-twitch myofibers) from Qingyuan partridge chickens (QY, slow-growing chicken breed) and Recessive White chickens (RW, fast-growing chicken breed) on different days (1, 8, 22, 36, 50 and 64 days post-hatching). Although CnAα and CnB1 gene expressions were variable with different trends in different skeletal muscles in the two chicken breeds during postnatal growth, it is highly muscle phenotype and breed specific. In general, the levels of CnAα and CnB1 gene expressions of the soleus were lower than those of EDL and LG in both chicken breeds at the same stages. Compared between the two chicken breeds, the levels of CnAα gene expression of the three skeletal muscles in QY chickens were higher than those in RW chickens on days 1 and 22. However, on day 64, the levels of both CnAα and CnB1 gene expressions of the three skeletal muscles were lower in QY chickens than those in RW chickens. Correlation analysis of the levels of CnAα and CnB1 gene expressions of the same skeletal muscle showed that there were positive correlations for all three skeletal muscle tissues in two chicken breeds. These results provide some valuable clues to understand the role of Cn in the development of chicken skeletal muscles, with a function that may be related to meat quality.

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A possible mechanism of mineral responses to elevated atmospheric CO2 in rice grains

GUO Jia, ZHANG Ming-qian, WANG Xiao-wen, ZHANG Wei-jian

2015, 14 (1): 50-57. DOI: 10.1016/S2095-3119(14)60846-7

Abstract （1711） PDF in ScienceDirect

Increasing attentions have been paid to mineral concentration decrease in milled rice grains caused by CO2 enrichment, but the mechanisms still remain unclear. Therefore, mineral (Ca, Mg, Fe, Zn and Mn) translocation in plant-soil system with a FACE (Free-air CO2 enrichment) experiment were investigated in Eastern China after 4-yr operation. Results mainly showed that: (1) elevated CO2 significantly increased the biomass of stem and panicle by 21.9 and 24.0%, respectively, but did not affect the leaf biomass. (2) Elevated CO2 significantly increased the contents of Ca, Mg, Fe, Zn, and Mn in panicle by 61.2, 28.9, 87.0, 36.7, and 66.0%, respectively, and in stem by 13.2, 21.3, 47.2, 91.8, and 25.2%, respectively, but did not affect them in leaf. (3) Elevated CO2 had positive effects on the weight ratio of mineral/biomass in stem and panicle. Our results suggest that elevated CO2 can favor the translocation of Ca, Mg, Fe, Zn, and Mn from soil to stem and panicle. The CO2-led mineral decline in milled rice grains may mainly attribute to the CO2-led unbalanced stimulations on the translocations of minerals and carbohydrates from vegetative parts (e.g., leaf, stem, branch and husk) to the grains.

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Timing of N Application Affects Net Primary Production of Soybean with Different Planting Densities

ZHANG Ming-cong, SUN Wen-xiang, LIU Yuan-ying, LUO Sheng-guo, ZHAO Jing, WU Qiong, WU Zhen-yu , JIANG Yi

2014, 13 (12): 2778-2787. DOI: 10.1016/S2095-3119(13)60535-3

Abstract （1085） PDF in ScienceDirect

Understanding the relationship between the timing of N fertilizer applications and crop primary production is crucial for achieving high yield and N use efficiency in agriculture. This study investigated the effects of starting-N plus topdressing N applications (as compared to the common practice of all basal application) on soybean photosynthetic capacity under different planting densities. A field experiment was conducted in two growing seasons (2011 and 2012), and the soybean (Glycine max L. Merrill) cultivar was Dongnong 52, three planting densities (20, 25 and 30 plants m-2), and four N fertilizer application patterns (all N fertilizer of 6 g N m-2 as basal fertilizer, all N fertilizer as topdressing at beginning pod stage (R3), 1.8 g N m-2 as basal fertilizer and 4.2 g N m-2 as topdressing at stage R3 and full pod stage (R4), respectively). The results indicated that under the same planting density, compared to applying all N as basal fertilizer, the application of starter-N plus topdressing N substantially reduced the rate of pod abscission, and enhanced leaf area index (LAI) significantly at beginning seed stage (R5) (P<0.05), net assimilation rate (NAR) during stages R4-full seed stage (R6) (P<0.05), contribution rate of post-seed filling assimilate to seed (CPA) (P<0.05), and yield (P<0.05). Applying topdressing N at stage R4 resulted in higher net primary production and yield than applying topdressing N at stage R3. When applying starter-N plus topdressing N at planting density of 25 plants m-2, LAI after stage R5 and NAR after stage R4 were increased by 5.92-16.3% (P<0.05) and 13.7-26.6% (P<0.05) with the planting density of 20 plants m-2, respectively, and yield was 8.46-14.0% (P<0.05) higher than that under 20 plants m-2. When planting density increased to 30 plants m-2, only LAI during stages R4-R5 and NAR during stages R4-R5 increased by applying starter-N plus topdressing N, while the other indexes declined. Overall, results of this study demonstrated that applying starter-N plus topdressing N could significantly enhance soybean photosynthetic capacity after stage R5 at planting density of 25 plants m-2.

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Quantitative Evaluation of Sustainable Development and Eco- Environmental Carrying Capacity in Water-Deficient Regions: A Case Study in the Haihe River Basin, China

WANG Zhong-gen, LUO Yu-zhou, ZHANG Ming-hua , XIA Jun

2014, 13 (1): 195-206. DOI: 10.1016/S2095-3119(13)60423-2

Abstract （1763） PDF in ScienceDirect

Quantitative assessment of development sustainability could be a challenge to regional management and planning, especially for areas facing great risks of water shortage. Surface-water decline and groundwater over-pumping have caused serious environmental problems and limited economic development in many regions all around the world. In this paper, a framework for quantitatively evaluating development sustainability was established with water-related eco-environmental carrying capacity (EECC) as the core measure. As a case study, the developed approach was applied to data of the Haihe River Basin, China, during 1998 through 2007. The overall sustainable development degree (SDD) is determined to be 0.39, suggesting that this rate of development is not sustainable. Results of scenario analysis revealed that overshoot, or resource over- exploitation, of the Basin’s EECC is about 20% for both population and economy. Based on conditions in the study area in 2007, in order to achieve sustainable development, i.e., SDD>0.70 in this study, the EECC could support a population of 108 million and gross domestic product (GDP) of 2.72 trillion CNY. The newly developed approach in quantifying eco- environmental carrying capacity is anticipated to facilitate sustainable development oriented resource management in water- deficient areas.

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Evaluation of Harvest Aid Chemicals for the Cotton-Winter Wheat Double Cropping System

DU Ming-wei, REN Xiao-ming, TIAN Xiao-li, DUAN Liu-sheng, ZHANG Ming-cai, TAN Wei-ming , LI Zhao-hu

2013, 12 (2): 273-282. DOI: 10.1016/S2095-3119(13)60226-9

Abstract （1506） PDF in ScienceDirect

Timing of harvest is critical for mechanical picking in cotton production, especially in those regions with double cropping system. Appropriate and safe harvest aids will improve timing and facilitate harvest of cotton in the double cropping system. Three defoliants (dimethipin, thidiazuron, and thidiazuron-diuron) and one boll opener (ethephon) were included in this research. They were evaluated for their effects on defoliation, boll opening, seedcotton yield, seed quality, and fiber quality of field grown cotton when used alone or as a mixture in 2009 and 2010. Defoliation and/or boll opening were increased by all three defoliants and ethephon, especially by mixtures of a defoliant and ethephon. First harvest of seedcotton was significantly increased with defoliant-ethephon mixtures. No significant adverse effects were observed on boll weight, lint percentage, seed quality, and fiber properties. It was estimated that tank mixes of ethephon and one of the three defoliants can improve the adjusted gross revenue. Boll opening can be used as an alternative indicator for the adjusted gross revenue, because, it was linearly and positively correlated with the relative adjusted gross revenue and convenient in measurements. Wheat seedling growth was not affected by thidiazuron, whereas its seedling emergence, root dry weight, relative water content, and electrolyte leakage were adversely affected by dimethipin and thidiazurondiuron when concentration was above 340 and 100 g (a.i.) ha-1, respectively. 90% defoliation and 80% boll opening were observed with the high rate of thidiazuron-ethephon mixture, but no adverse effects on winter wheat. The results suggested that tank mixes of ethephon with thidiazuron can be used effectively and safely in the cotton-winter wheat double cropping system to improve yield without adverse effects on seed quality and fiber quality.

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Mechanical Harvesting Effects on Seed Yield Loss, Quality Traits and Profitability of Winter Oilseed Rape (Brassica napus L.)

MA Ni, ZHANG Chun-lei, LI Jun, ZHANG Ming-hai, CHENG Yu-gui, LI Guang-ming, ZHANG Shujie

2012, 12 (8): 1297-1304. DOI: 10.1016/S1671-2927(00)8658

Abstract （1547） PDF in ScienceDirect

China is one of the most important rapeseed producing countries in the world. Effective mechanical harvesting time for decreasing harvesting loss of winter oilseed rape has been becoming a critical factor. An elite cultivar Zhongshuang 11 (Brassica napus L.) was employed in two rounds of field experiments from 2009 to 2011. Seeds were sown with machine, three combine harvesting times namely combine harvesting A, B, and C (CHA, CHB, and CHC) were designed and manual harvesting (MH) as control was performed at maturity. The harvesting treatments were determined according to color of pod and seed in the field. Seed yield loss and quality in different treatments were evaluated. Results showed that both seed yields and harvesting losses in 2009-2010 were higher than that in 2010-2011, whereas seed oil contents in 2010-2011 were higher than that in 2009-2010. The highest yield appeared in CHB, which was significantly higher than that in MH. Furthermore, harvesting loss in CHB were 50% that in MH. Seed oil content and chlorophyll exhibited no obvious difference between CHB and MH. Economic profit analysis demonstrated that mechanical sowing/combine harvesting (MS/CH) showed an input/output ratio of 1:1.6, and it was 1:1.2 in mechanical sowing/manual harvesting (MS/MH). Labor-cost accounted for more than 70% of the total cost in MS/MH, which led to low profitability to a great extent. Our results suggested that CHB was the optimum harvesting time for winter oilseed rape along the Yangtze River.

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Development of High Performance Liquid Chromatography-Tandem Mass Spectrometry Method for the Detection of Tulathromycin in Swine Plasma

HUANG Xian-hui, LIANG Zi-sen, ZENG Zhen-ling, ZHANG Min, FANG Bing-hu

2012, 12 (3): 465-473. DOI: 10.1016/S1671-2927(00)8565

Abstract （2665） PDF in ScienceDirect

An accurate and precise method for the determination of tulathromycin in swine plasma was developed and validated. Plasma samples were analyzed by high-performance liquid chromatography with tandem mass spectrometry detection (HPLC-MS/MS) using electrospray ionization (ESI). Tulathromycin was extracted from plasma by precipitation with acetonitrile and separated using a Phenomenex Luna 5 μm C18 column (150 mm×2.0 mm) at a flow rate of 0.25 mL min-1. Solvent A consisted of 0.002 mol L-1 ammonium acetate and formic acid (999:1, v/v), and solvent B was acetonitrile. The mass spectrometer was operated in the selected-ion mode with atmospheric pressure chemical ionization to monitor the respective MH+ ions, namely, m/z 577.3 for tulathromycin and m/z 679.3 for the internal standard roxithromycin. The calibration curves were linear in a dynamic range of 2.0-500 ng mL-1 on the column. The accuracy was ranged from 95.25 to 109.75%, and the precision was ranged from 2.81 to 7.72%. The recoveries measured at 3 concentration levels (20, 250, and 500 ng mL-1) were higher than 98%. The method described above is efficient, and has the required accuracy and precision for rapid determination of tulathromycin in plasma. The method was applied to study the pharmacokinetics of tulathromycin in swine, and tulathromycin demonstrated a rapid absorption, wide distribution, and slow elimination after intramuscular administration.

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