Perinereis aibuhitensis(Grube, 1878) lives in marine sediments of estuary or shoal areas, where substrate has some crucial environmental factors affecting its burrowing and distribution. In order to provide basic data...Perinereis aibuhitensis(Grube, 1878) lives in marine sediments of estuary or shoal areas, where substrate has some crucial environmental factors affecting its burrowing and distribution. In order to provide basic data for the habitat selection and suitability evaluations of the artificial aquaculture of P. aibuhitensis, this paper conducted a quantified analysis of its burrowing ability and explored its behavioral preferences in different substrates,including mud(<75 μm), fine sand(125–250 μm), medium sand(250–500 μm), coarse sand(500–2 000 μm), gravel(2 000–4 000 μm) and ceramsite(4 000–8 000 μm). The research results revealed that substrate grain size significantly affected the burrowing time, burrowing rate, burrowing depth and distribution rate(P<0.01).Moreover, P. aibuhitensis demonstrated preferential selections relating to substrate grain sizes, had higher burrowing ability in ceramsite, mud and fine sand compared with other substrates. The strongest burrowing ability and the highest distribution rate were observed in ceramsite. The study indicated that P. aibuhitensis was sensitive to substrate grain size, which also had an impact on its burrowing process and population distribution.In the natural sea, substrates mainly composed of mud and fine sand are fit for aquaculture and stock enhancement. Based on behavioral preferences and ecological rehabilitation function of P. aibuhitensis, this paper proposes a symbiotic system of marine animals and halophytes, and constructs an ecosystem model of"Marine fish-Halophytes-Perinereis aibuhitensis" with P. aibuhitensis as the link.展开更多
Studies were conducted with rice varieties developed in recent years in Liaoning Province of China as test materials. Results showed that the varieties tested could be divided into three types： （1） the high-yieldi...Studies were conducted with rice varieties developed in recent years in Liaoning Province of China as test materials. Results showed that the varieties tested could be divided into three types： （1） the high-yielding （HYV）, （2） the mediumyielding （MYV）, and （3） the low-yielding （LYV）. The panicle population was in the order of HYV〈 MYV 〈 LYV, while the grain number per panicle and seed-setting rate were just opposite. There was no significant difference in the 1 000-grain weight. Biomass was higher in HYV than in MYV and LYV, while the harvest index was higher in HYV and MYV than in LYV. Yield was inversely correlated with panicle population, but positively correlated with the grain number per panicle, seed-setting rate, the number of primary and secondary branch grains, seed density and harvest index. Yield was most closely linked with the grain number per panicle which was determined chiefly by the number of secondary branch grains and to a lesser degree by seed density and the number of primary branch grains. The seed-setting rate of the secondary branches was positively correlated with that of the whole panicle and yield. The peak value of primary branches for HYV, MYV and LYV was 12-14, 10-13 and 8-12, respectively. LYV had fewer secondary branch grains, while MYV and HYV had more. Such grains distributed mainly in the middle and lower parts of panicle axis for LYV and in the middle and upper parts for MYV and HYV.展开更多
Nitrogen(N)fertilization is critical for spike and floret development,which affects the number of fertile florets per spike(NFFs).However,the physiological regulation of the floret development process by N fertilizati...Nitrogen(N)fertilization is critical for spike and floret development,which affects the number of fertile florets per spike(NFFs).However,the physiological regulation of the floret development process by N fertilization is largely unknown.A high temporal-resolution investigation of floret primordia number and morphology,dry matter,and N availability was conducted under three N fertilization levels:0(N0),120(N1)and 240(N2)kg ha^(−1).Interestingly,fertile florets at anthesis stage were determined by those floret primordia with meiotic ability at booting stage:meiotic ability was a threshold that predicted whether a floret primordium became fertile or abortive florets.Because the developmental rate of the 4th floret primordium in the central spikelet was accelerated and then they acquired meiotic ability,the NFFs increased gradually as N application increased,but the increase range decreased under N2.There were no differences in spike N concentration among treatments,but leaf N concentration was increased in the N1 and N2 treatments.Correspondingly,dry matter accumulation and N content of the leaf and spike in the N1 and N2 treatments was increased as compared to N0.Clearly,optimal N fertilization increased leaf N availability and transport of assimilates to spikes,and allowed more floret primordia to acquire meiotic ability and become fertile florets,finally increasing NFFs.There was no difference in leaf N concentration between N1 and N2 treatment,whereas soil N concentration at 0–60 cm soil layers was higher in N2 than in N1 treatment,implying that there was still some N fertilization that remained unused.Therefore,improving the leaf’s ability to further use N fertilizer is vital for greater NFFs.展开更多
From the point of view of industrial market structure,we analyze the influence of market structure on grain production,circulation,and processing,and on the grain pricing power of entities along China's grain indu...From the point of view of industrial market structure,we analyze the influence of market structure on grain production,circulation,and processing,and on the grain pricing power of entities along China's grain industrial chain.Through analysis,it is indicated that different features of market structure play a significant role in pricing power of such microeconomic entities as farmers and grain enterprises in grain production and transaction.And the market structure determines welfare distribution model of consumers' surplus and producers' surplus at the market.展开更多
基金The Weifang Sci-tech Development Project under contract No.2015ZJ1042the Research on New Model of Marine Ecological Farming and Intelligent Monitoring System under contract No.H2016-02
文摘Perinereis aibuhitensis(Grube, 1878) lives in marine sediments of estuary or shoal areas, where substrate has some crucial environmental factors affecting its burrowing and distribution. In order to provide basic data for the habitat selection and suitability evaluations of the artificial aquaculture of P. aibuhitensis, this paper conducted a quantified analysis of its burrowing ability and explored its behavioral preferences in different substrates,including mud(<75 μm), fine sand(125–250 μm), medium sand(250–500 μm), coarse sand(500–2 000 μm), gravel(2 000–4 000 μm) and ceramsite(4 000–8 000 μm). The research results revealed that substrate grain size significantly affected the burrowing time, burrowing rate, burrowing depth and distribution rate(P<0.01).Moreover, P. aibuhitensis demonstrated preferential selections relating to substrate grain sizes, had higher burrowing ability in ceramsite, mud and fine sand compared with other substrates. The strongest burrowing ability and the highest distribution rate were observed in ceramsite. The study indicated that P. aibuhitensis was sensitive to substrate grain size, which also had an impact on its burrowing process and population distribution.In the natural sea, substrates mainly composed of mud and fine sand are fit for aquaculture and stock enhancement. Based on behavioral preferences and ecological rehabilitation function of P. aibuhitensis, this paper proposes a symbiotic system of marine animals and halophytes, and constructs an ecosystem model of"Marine fish-Halophytes-Perinereis aibuhitensis" with P. aibuhitensis as the link.
基金This work was supported by the National Natural Science Foundation of China （30370866）the National 863 Program of China.
文摘Studies were conducted with rice varieties developed in recent years in Liaoning Province of China as test materials. Results showed that the varieties tested could be divided into three types： （1） the high-yielding （HYV）, （2） the mediumyielding （MYV）, and （3） the low-yielding （LYV）. The panicle population was in the order of HYV〈 MYV 〈 LYV, while the grain number per panicle and seed-setting rate were just opposite. There was no significant difference in the 1 000-grain weight. Biomass was higher in HYV than in MYV and LYV, while the harvest index was higher in HYV and MYV than in LYV. Yield was inversely correlated with panicle population, but positively correlated with the grain number per panicle, seed-setting rate, the number of primary and secondary branch grains, seed density and harvest index. Yield was most closely linked with the grain number per panicle which was determined chiefly by the number of secondary branch grains and to a lesser degree by seed density and the number of primary branch grains. The seed-setting rate of the secondary branches was positively correlated with that of the whole panicle and yield. The peak value of primary branches for HYV, MYV and LYV was 12-14, 10-13 and 8-12, respectively. LYV had fewer secondary branch grains, while MYV and HYV had more. Such grains distributed mainly in the middle and lower parts of panicle axis for LYV and in the middle and upper parts for MYV and HYV.
基金This study was supported by the National Key Research and Development Program of China(2022YFD1900703,2022YFD2300802)the Earmarked Fund for CARS(CARS-3)+1 种基金the National Natural Science Foundation of China(31871563)China Postdoctoral Science Foundation(2022M723437).
文摘Nitrogen(N)fertilization is critical for spike and floret development,which affects the number of fertile florets per spike(NFFs).However,the physiological regulation of the floret development process by N fertilization is largely unknown.A high temporal-resolution investigation of floret primordia number and morphology,dry matter,and N availability was conducted under three N fertilization levels:0(N0),120(N1)and 240(N2)kg ha^(−1).Interestingly,fertile florets at anthesis stage were determined by those floret primordia with meiotic ability at booting stage:meiotic ability was a threshold that predicted whether a floret primordium became fertile or abortive florets.Because the developmental rate of the 4th floret primordium in the central spikelet was accelerated and then they acquired meiotic ability,the NFFs increased gradually as N application increased,but the increase range decreased under N2.There were no differences in spike N concentration among treatments,but leaf N concentration was increased in the N1 and N2 treatments.Correspondingly,dry matter accumulation and N content of the leaf and spike in the N1 and N2 treatments was increased as compared to N0.Clearly,optimal N fertilization increased leaf N availability and transport of assimilates to spikes,and allowed more floret primordia to acquire meiotic ability and become fertile florets,finally increasing NFFs.There was no difference in leaf N concentration between N1 and N2 treatment,whereas soil N concentration at 0–60 cm soil layers was higher in N2 than in N1 treatment,implying that there was still some N fertilization that remained unused.Therefore,improving the leaf’s ability to further use N fertilizer is vital for greater NFFs.
基金Supported by Humanities and Social Sciences Planning Fund of Ministry of Education (09YJA790140)
文摘From the point of view of industrial market structure,we analyze the influence of market structure on grain production,circulation,and processing,and on the grain pricing power of entities along China's grain industrial chain.Through analysis,it is indicated that different features of market structure play a significant role in pricing power of such microeconomic entities as farmers and grain enterprises in grain production and transaction.And the market structure determines welfare distribution model of consumers' surplus and producers' surplus at the market.
