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.

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.

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.

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. 

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.

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.  

  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.

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.

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.

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.

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.

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.