Field experiments were conducted in farmers’rice fields in 2001 and 2002 to study the effects of nitrogen(N)man-agement strategies on N use efficiency in recovery(RE),agronomy(AE)and physiology(PE)and redistribution ...Field experiments were conducted in farmers’rice fields in 2001 and 2002 to study the effects of nitrogen(N)man-agement strategies on N use efficiency in recovery(RE),agronomy(AE)and physiology(PE)and redistribution of dry matter accumulation(DMA)and nitrogen accumulation(NA)in two typical rice cultivars in Jinhua,Zhejiang Province.This study aimed mainly at identifying the possible causes of poor fertilizer N use efficiency(NUE)of rice in Zhejiang by comparing farmers’fertilizer practice(FFP)with advanced site-specific nutrient management(SSNM)and real-time N management(RTNM).The results showed that compared to FFP,SSNM and RTNM reduced DMA and NA before panicle initiation and increased DMA and NA at post-flowering.There is no significant difference between SSNM and FFP in post-flowering dry matter redistribution(post-DMR)and post-flowering nitrogen redistribution(post-NR).These results suggest that high input rate of fertilizer N and improper fertilizer N timing are the main factors causing low NUE of irrigated rice in the farmer’s routine practice of Zhejiang.With SSNM,about 15%of the current total N input in direct-seeding early rice and 45%in single rice could be reduced without yield loss in Zhejiang,China.展开更多
financed by the Special Program of Super Rice of Ministry of Agriculture, China （02318802013231）;the National Public Services Sectors （Agricultural） Research Projects, Ministry of Agriculture, China （201303102）;...financed by the Special Program of Super Rice of Ministry of Agriculture, China （02318802013231）;the National Public Services Sectors （Agricultural） Research Projects, Ministry of Agriculture, China （201303102）;the Great Technology Project of Ningbo, China （2013C11001）展开更多
The search for pattern in the ecology and evolutionary biology of insect-plant associations has fascinated biologists for centuries. High levels of tropical （tow-latitude） plant and insect diversity relative to pole...The search for pattern in the ecology and evolutionary biology of insect-plant associations has fascinated biologists for centuries. High levels of tropical （tow-latitude） plant and insect diversity relative to poleward latitudes and the disproportionate abundance of host-specialized insect herbivores have been noted. This review addresses several aspects of local insect specialization, host use abilities （and loss of these abilities with specialization）, host-associated evolutionary divergence, and ecological （including ＂hybrid＂） speciation, with special reference to the generation of biodiversity and the geographic and taxonomic identification of ＂species borders＂ for swallowtail butterflies （Papilionidae）. From ancient phytochemically defined angiosperm affiliations that trace back millions of years to recent and very local specialized populations, the Papilionidae （swallowtail butterflies） have provided a model for enhanced tmderstanding of localized ecological patterns and genetically based evolutionary processes. They have served as a useful group for evaluating the feeding specialization/physiological efficiency hypothesis. They have shown how the abiotic （thermal） environment interacts with host nutritional suitability to generate ＂voltinisrn/suitability＂ gradients in specialization or preference latitudinally, and geographical mosaics locally. Several studies reviewed here suggest strongly that the oscillation hypothesis for speciation does have considerable merit, but at the same time, some species-level host specializations may lead to evolutionary dead-ends, especially with rapid environmental/habitat changes involving their host plants. Latitudinal gradients in species richness and degree of herbivore feeding specialization have been impacted by recent developments in ecological genetics and evolutionary ecology. Localized insect- plant associations that span the biospectrum from polyphenisms, polymorphisms, biotypes, demes, host races, to cryptic species, remain academically contentious, with simple definitions still debated. However, molecular analyses combined with ecological, ethological and physiological studies, have already begun to unveil some answers for many important ecological/evolutionary questions.展开更多
Increasing the efficiency of water use by crops continues to escalate as a topic of concem because drought is a restrictive environmental factor for crop productivity woridwide .Greater yield per unit rainfall is one ...Increasing the efficiency of water use by crops continues to escalate as a topic of concem because drought is a restrictive environmental factor for crop productivity woridwide .Greater yield per unit rainfall is one of the most important challenges in water-saving agriculture Besides water-saving by irrigation engineering and conservation tillage, a good understanding of factors limiting and/or regulating yleld now provides us with an opportunity to identify and then precisely seiect for physiciogical and breeding traits that increase the efficiency of water use and drought tolerance under water-limited conditions, biological water-saving is one means of achieving this goal, A definition of bilogical water-saving measures is proposed which embraces improvements in water use efficiency （WUE） and drought tolerance, by genetic improvement and physiological regulation. The preponderance of bilogical water-saving measures is discussed and strategies identified for working within natural resource constraints. The technology and future perspectives of bilogical water saving could provide not only new water-saving techniques but also a scientific base for application of water-saving irrigation and conservation tillage.展开更多
基金Project supported by the International Rice Research Institute(IRRI)Swiss Agency for Development and Cooperation(SDC)+3 种基金the Potash&Phosphate Institute and the Potash&Phosphate Institute of Canada(PPI-PPIC)the International Fertilizer Industry Association(IFA)the International Potash Institute(IPI)948 Project of the Ministry of Agriculture of China(No.2003-Z53)
文摘Field experiments were conducted in farmers’rice fields in 2001 and 2002 to study the effects of nitrogen(N)man-agement strategies on N use efficiency in recovery(RE),agronomy(AE)and physiology(PE)and redistribution of dry matter accumulation(DMA)and nitrogen accumulation(NA)in two typical rice cultivars in Jinhua,Zhejiang Province.This study aimed mainly at identifying the possible causes of poor fertilizer N use efficiency(NUE)of rice in Zhejiang by comparing farmers’fertilizer practice(FFP)with advanced site-specific nutrient management(SSNM)and real-time N management(RTNM).The results showed that compared to FFP,SSNM and RTNM reduced DMA and NA before panicle initiation and increased DMA and NA at post-flowering.There is no significant difference between SSNM and FFP in post-flowering dry matter redistribution(post-DMR)and post-flowering nitrogen redistribution(post-NR).These results suggest that high input rate of fertilizer N and improper fertilizer N timing are the main factors causing low NUE of irrigated rice in the farmer’s routine practice of Zhejiang.With SSNM,about 15%of the current total N input in direct-seeding early rice and 45%in single rice could be reduced without yield loss in Zhejiang,China.
基金financed by the Special Program of Super Rice of Ministry of Agriculture, China (02318802013231)the National Public Services Sectors (Agricultural) Research Projects, Ministry of Agriculture, China (201303102)the Great Technology Project of Ningbo, China (2013C11001)
文摘financed by the Special Program of Super Rice of Ministry of Agriculture, China （02318802013231）;the National Public Services Sectors （Agricultural） Research Projects, Ministry of Agriculture, China （201303102）;the Great Technology Project of Ningbo, China （2013C11001）
基金Acknowledgments This review reflects decades of personally treasured friendships and assistance from colleagues in the insectplant interactions field of study. The Papilionidae research from our lab was supported in part by the National Science Foundation （DEB-9201122 DEB-9510044+1 种基金 DEB 0716683 DEB 0918879） and the Michigan Agricultural Experiment Station （Project # 01644）. I wish to thank all lab members and friends for their enthusiasm and assistance over the years, and most recently, Matthew Aardema, Rodrigo Mereader and Gabe Ording.
文摘The search for pattern in the ecology and evolutionary biology of insect-plant associations has fascinated biologists for centuries. High levels of tropical （tow-latitude） plant and insect diversity relative to poleward latitudes and the disproportionate abundance of host-specialized insect herbivores have been noted. This review addresses several aspects of local insect specialization, host use abilities （and loss of these abilities with specialization）, host-associated evolutionary divergence, and ecological （including ＂hybrid＂） speciation, with special reference to the generation of biodiversity and the geographic and taxonomic identification of ＂species borders＂ for swallowtail butterflies （Papilionidae）. From ancient phytochemically defined angiosperm affiliations that trace back millions of years to recent and very local specialized populations, the Papilionidae （swallowtail butterflies） have provided a model for enhanced tmderstanding of localized ecological patterns and genetically based evolutionary processes. They have served as a useful group for evaluating the feeding specialization/physiological efficiency hypothesis. They have shown how the abiotic （thermal） environment interacts with host nutritional suitability to generate ＂voltinisrn/suitability＂ gradients in specialization or preference latitudinally, and geographical mosaics locally. Several studies reviewed here suggest strongly that the oscillation hypothesis for speciation does have considerable merit, but at the same time, some species-level host specializations may lead to evolutionary dead-ends, especially with rapid environmental/habitat changes involving their host plants. Latitudinal gradients in species richness and degree of herbivore feeding specialization have been impacted by recent developments in ecological genetics and evolutionary ecology. Localized insect- plant associations that span the biospectrum from polyphenisms, polymorphisms, biotypes, demes, host races, to cryptic species, remain academically contentious, with simple definitions still debated. However, molecular analyses combined with ecological, ethological and physiological studies, have already begun to unveil some answers for many important ecological/evolutionary questions.
文摘Increasing the efficiency of water use by crops continues to escalate as a topic of concem because drought is a restrictive environmental factor for crop productivity woridwide .Greater yield per unit rainfall is one of the most important challenges in water-saving agriculture Besides water-saving by irrigation engineering and conservation tillage, a good understanding of factors limiting and/or regulating yleld now provides us with an opportunity to identify and then precisely seiect for physiciogical and breeding traits that increase the efficiency of water use and drought tolerance under water-limited conditions, biological water-saving is one means of achieving this goal, A definition of bilogical water-saving measures is proposed which embraces improvements in water use efficiency （WUE） and drought tolerance, by genetic improvement and physiological regulation. The preponderance of bilogical water-saving measures is discussed and strategies identified for working within natural resource constraints. The technology and future perspectives of bilogical water saving could provide not only new water-saving techniques but also a scientific base for application of water-saving irrigation and conservation tillage.
