Scientia Agricultura Sinica

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Driving Mechanism and Regional Differentiation of Cultivated Land Non-Agricultural-Transformation

ZHANG Guang-hong, CUI Xu-feng

Scientia Agricultura Sinica 2015, 48 (8): 1632-1640. DOI: 10.3864/j.issn.0578-1752.2015.08.18

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【Objective】 The purpose of this study is to reveal the cultivated land non-agricultural-transformation and its regional differentiation. 【Method】 Firstly, the cultivated land non-agricultural-transformation in China was analyzed based on the method of fixed-effect panel data model and by using Chinese cultivated land non-agricultural-transformation, growth of town populations, investment in fixed assets, level of economic development, cultivated land resource endowment panel data in 2001-2008. In order to compare the difference of different areas, test the models using eastern region data, midland data, and western region data, respectively, the differences among the three regions in cultivated land non-agricultural-transformation were comparative analyzed. 【Result】 Model test results show that the economic development level and its quadratic term, cultivated land resource endowment show a significant state based on the control of urban population growth and fixed asset investment. There are differences among eastern, central and western regions. Investment in fixed assets and cultivated land resource endowment show a extreme significance in eastern, central, and western regions respectively. Elastic coefficient of investment in fixed assets in central regions is bigger than western regions.【Conclusion】 The cultivated land non-agricultural-transformation and economic development show a significant reverse diagram "U" rule of Environmental Kuznets Curve. The cultivated land non-agricultural-transformation in China is significantly influenced by the urbanization growth and investment in fixed assets. Urban population increase (or decrease) of each 1%, the quantity of cultivated land conversion will increase (or decrease) of 0.1 percentage, investment in fixed assets increase (or decrease) of each 1%, the quantity of cultivated land conversion will increase (or decrease) of 0.7 percentage. Cultivated land non-agricultural-transformation driving factors have significant difference among eastern, central and western regions. Cultivated land resource endowment is a significant affecting factor of non-agricultural-transformation in eastern China, cultivated land resource rich regions tend to higher speed of cultivated land non-agricultural-transformation. Investment in fixed assets is a significant affecting factor of non-agricultural-transformation in central and western China, driving effect of investment in fixed assets in central regions is greater than western regions.

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Cited: Baidu(6)

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Spatial Evolution, Mechanism, Effect and Policies of Vegetable Production Agglomeration in China

WU Jian-zhai, SHEN Chen, WANG Sheng-wei, ZHANG Jian-hua, KONG Fan-tao

Scientia Agricultura Sinica 2015, 48 (8): 1641-1649. DOI: 10.3864/j.issn.0578-1752.2015.08.19

Abstract （403）

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【Objective】 In recent years, vegetable supply and demand pattern characterized by “large market, great circulation” has been basically formed in China. And the change of the spatial agglomeration in vegetable industry is remarkable. In this paper, the characteristics, effects, and mechanism of the spatial agglomeration evolution in China’s vegetable production from 1995 to 2012 were systematically discussed by taking 31 provinces (cities) as research units, and the policy suggestions were also proposed. This research will provide a support for optimizing production arrangement and ensuring effective supply. 【Method】 The share of n largest provinces (cities) in total production was calculated based on the index of concentration ratio. In order to reveal the characteristics of spatial agglomeration in vegetable production industry from 1995 to 2012, the spatial concentration on provincial level was measured by using Gini coefficient model. To show the effect of production agglomeration on vegetable industry development, the model based on modified Cobb-Douglas production function was built to analyze the significance of the inputs such as vegetable production agglomeration level, vegetable price, labor per unit, and investment per unit. 【Result】 The characteristic of China’s vegetable production spatial distribution clustered in Southwest, mainly in eastern China, and less in western China at the beginning of the study period was significantly changed in the research period. During 1995 to 2012, the ratio of output in western China increased 6%. The gap gradient in output between eastern and western China diminished obviously. In the vertical direction, the ratio of output in northern China increased 5% which indicated that the gravity of output had moved towards the north. During 1995 to 2012, CR₄ and CR₈, the two indexes of concentration ratio, were increased slightly with constant fluctuation at first, and were decreased a little to steady state at the later stage, lingering between 0.4 and 0.6. The peaks of the two indexes were hit in 2001 and 2004, and the bottoms were reached in 1995 and 1997, respectively. The Gini coefficient increased at first and decreased later then. It reached its highest level of 0.5045 in 2004 and gradually decreased after that. The spatial agglomeration of vegetable production was affected by a variety of factors such as nature, society, and economy, which could lead a space reconstruction and was also a process of industrial optimization. It was more dependent on light, temperature, water, soil, and other natural factors at the beginning, and then the economic and policy factors played more important roles in the evolution process. The modified effect evaluation equation passed F-test which meant that it had a relatively high capacity in interpretation. Gini coefficient at 10% level of significance passed t-test. The result of model showed that per unit vegetable production would increase by 2.48% when Gini coefficient increased by 1%. 【Conclusion】 From 1995 to 2012, the gap gradient of China’s vegetable production between eastern and western area diminished notably. The gravity of production moved towards the north and the characteristics of spatial distribution changed obviously, especially the volatility showed at the beginning. The impact to vegetable production due to the spatial agglomeration is significant, and strengthening the agglomeration could effectively promote the production of vegetable. In view of optimizing the spatial pattern of vegetable production, strengthening the construction of the main production areas, promoting large-scale and specialized production, and focusing on the commencement of industrial nodes collaboration should be carried out in the future to promote healthy development of vegetable industry.

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Cited: Baidu(3)

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Vacuolar Protein Sorting AtVPS25 Regulates Auxin Responses in Arabidopsis thaliana

GUO Meng-meng;CHEN Ming; LIU Rong-bang; MA You-zhi; LI Lian-cheng; XU Zhao-shi; ZHANG Xiao-hong;

Scientia Agricultura Sinica 2014, 47 (17): 3501-3512. DOI: 10.3864/j.issn.0578-1752.2014.17.018

Abstract （425）

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【Objective】The objective of this study is to identify the phenotype of homozygous mutant vps25 under auxin stress conditions, get the interacting protein of Arabidopsis vacuolar protein sorting AtVPS25, and analyze the function and molecular mechanisms of their interaction in the process of auxin response.【Method】The "three primer method" was adopted to identify the mutants. The function of the VPS like protein, AtVPS25, was analyzed by identification of the responses of AtVPS25 mutants to exogenous auxin. AtVPS25 protein was used as a bait to screen its interacting proteins by the split-ubiqutin system in Arabidopsis. The interaction between AtVPS25 and AtAIR12 (for Auxin - Induced Root in cultures) was confirmed by the yeast interaction experiment and the bimolecular fluorescence complementation test (BiFC). The subcellular locations of AtVPS25 and AtAIR12 protein was analyzed by the confocal scanning. The expression patterns of auxin transport-related genes in AtVPS25 mutants were identified by real-time PCR. The subcellular locations of AtVPS25 and AtAIR12 protein were analyzed in plants cells; The expression of part of auxin transport related genes in vps25 mutant under auxin treatment condition were identified by real-time PCR. 【Result】Real-time PCR results showed that under 10 μmol?L-1 IAA treatment conditions, in wild-type Arabidopsis thaliana (WT), the AtVPS25 expression level was increased with the stress time, and reached the highest at 12 h , about 40 times the size of 0 h, which proved that AtVPS25 was induced by auxin treatment. The AtVPS25 protein was used as a bait to screen the interacting protein from Arabidopsis by using the split-ubiqutin system and get the interacting protein AtAIR12. Two-hybrid interaction tests of AtVPS25 and AtAIR12 protein full-length sequence proved that AtVPS25 interacted with AtAIR12. Subcellular localization test proved that AtVPS25 is located on the cell membrane and cytoplasm, AtAIR12 is located on the cell membrane and chloroplast membrane. BiFC (bimolecular fluorescence complementation) test results showed that AtVPS25 is interacted with AtAIR12, and the interaction sites were on the cell membrane and cytoplasm. Molecular identification showed that homozygous mutant vps25 was obtained. When vps25 growth in conditions of 0.1 mg?L-1 IAA, the elongation of primary root was inhibited, and the difference in primary root was relatively significant (P＜0.01) compared with WT in the same condition, while no significant difference in the number of lateral roots, which have been reported the similar phenotype of the mutant air12-1 under the stress conditions of auxin. When treated with 10 μmol•L-1 IAA, under WT background conditions, the expression level of AtAIR12 responsed obviously for IAA, and increased with the stress time, reached a maximum at 12 h, about 80 times as 0 h, which proved that AtAIR12 and AtVPS25 have the exactly same change trend in WT under conditions of 10 μmol•L-1 IAA treatment. Under the background of vps25 mutant, the expression of AtAIR12 was restrained relative to the WT, the expression level had no obvious change from 0 to 24 h. Additionally, the expression level of auxin efflux carrier gene (AtPIN2) was reduced, while the auxin input vector gene was increased in mutant vps25.【Conclusion】 IAA had the effects of inducing the expression of vacuolar sorting protein gene AtVPS25 in Arabidopsis and AtVPS25 regulated the development of plant primary root. AtVPS25, which interacted with AtAIR12 at cell membrane and cytoplasm, regulated the expression of some IAA associated genes. Results indicated that AtVPS25 had influence on the response of IAA in plant root through regulating expression level of downstream genes above-mentioned. Further research is required to clarify the regulatory mechanism between AtVPS25 and AtAIR12 in plants.

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Design of Products for Rice Agro-Meteorological Index Insurance: A Case in Zhejiang Province

WU Li-hong,LOU Wei-ping ,YAO Yi-ping,MAO Yu-ding,SU Gao-Li

Scientia Agricultura Sinica 2010, 43 (23): 4942-4950. DOI: 10.3864/j.issn.0578-1752.2010.23.021

Abstract （865）

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【Objective】 Products for agro-meteorological index of rice crop insurance were designed to provide technical support for sustainable development of policy-guided agricultural insurance. 【Method】 By means of the correlations between the reduction of rice production and weather factors as well as atmosphere circulation index, a model of reduction of rice output was established. Using meteorological data, the probability of risk in rice reduction at different levels was calculated through beta, and the rates and premiums of insurance were determined. Synthesizing the advantages of products and weather index insurance, the insurance products would be designed. 【Result】 Calculating the risk rates of rice yield reduction, the deducible amount was 7.5% in the 18 coastal counties of Taizhou, Zhoushan and Ningbo, 5.0% in 16 counties such as Lanxi and 2.5% in 34 counties in Jiaxing. According to the calculus of probability and the model of rice yield loss, the plan and the contracts of rice agro-meteorological index insurance products were designed. 【Conclusion】 Agro-meteorological index crop insurance is an innovation meeting the requirements of insurance operations in China. Using the techniques of rice production forecast, determining the damages by means of real meteorological data, the shortages such as low efficiency, high costs and low accuracy would be cut greatly in agricultural insurance operations. It is good to reduce the anti-selection and promote the constant development of agriculture insurance.

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