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1.
Through the efforts of the International Rice Genome Sequencing Project, the whole genome sequence office has been decoded (International Rice Genome Sequencing Project, 2005). This sequence information has provided new tools for genetics and has created a new paradigm of plant breeding. Many phenotypic traits of economic interest are controlled by multiple genes and often show complex and quantitative inheritance: Recent progress in rice genomics has had a great impact in the genetic dissection of such traits into single genetic factors. Such genetic factors can subsequently be identified at the molecular level by map-based strategies (Yano, 2001). So far, we have identified several genes involved in heading date (Yano et al., 2001), field resistance to rice blast, cool temperature tolerance (Takeuchi et al., 2001) and pre-harvest sprouting (Takeuchi et al., 2003), and genetic dissection of root morphology and yield-related traits is progressing. Working from the current status of genetic dissection, we have begun marker-assisted introgression of particular genes of interest into elite rice cultivars in Japan. Exploitation of economically important genes in natural variants will be essential to enhance the potential of new breeding strategies.  相似文献   

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Each city includes memory elements. As a precious resource, the city memory exists, changes and continues in reality through visual material objects and cultural sub-consciousness. It is the basic context clue for urban people to apperceive, to experience themselves and their existent environment with the lapse and change of time. Beginning with the concept of memory, this article analyzed the relationship of time, space, human being and environment. It tried to use interdisciplinary research methods and rethink about the essence of city and architecture in the perspective of psychology and sociology, so as to explore the dee Pissues of ideology and value conception in urban design and urban conservation of history and culture.  相似文献   

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Natural variation is at the core of plant breeding. Genetic or linkage mapping is the traditional method for identifying loci/genes responsible for variati on in complex traits. More recently, association mapping or linkage disequilibrium (LD) mapping, which establishes marker-trait association in populations of unrelated individuals, is becoming an alternative approach for gene discovery (Borevitz and Nordborg, 2003; Yu and Buckler, 2006). We have developed tools and methods for positional cloning as well as genome-wide association analysis in maize, thus enabling the molecular dissection of traits of agronomic interest.  相似文献   

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In this paper, the management philosophy of 'governance without unwanted action' of Taoism, 'to keep balance in each aspect' of Confucianism and 'governance with laws' of legalism are firstly discussed in detail. Then, the connotations of management philosophy and management and the relationship between them are discussed. The model of the modern cubic management is briefly introduced. Finally, the application and practice of the management philosophy of Taoism, Confucianism and Legalism in the establishment of the modern management model are studied and it is suggested that the idea of variation is necessary in the application of the management philosophy of Taoism, Confucianism and Legalism.  相似文献   

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From the viewpoint of nonlinear dynamics, this review outlines the recent advances as well as some open problems in the study of neural networks with time delays, an important class of delayed systems in various neural network models. The survey includes three aspects as fellows: the dynamic features, available approaches and advances in research on most attractive problems. The evolution of a delayed neural network depends not only on the current state of the systems but also on previous ones. Hence, a delayed neural network should be modeled by a functional differential equation, the solution space of which is of infinite dimensions. Therefore, the dynamical behavior of delayed neural networks is very complex.  相似文献   

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City is not a concretionary but a dynamic matter. It should keep close touch with the animated tradition, and we should look forward to its future too. Thus we will be facing with the problem of inheritance and development of the tradition. Because the tradition is a potential for good as wdll as for evil, it can promote the development of a thing, and also may hinder its progress, so there should be correct attitudes to the traditional inheritance. This paper studies the modem application of the traditional street, lane and courtyard, which brings new vitality to the tradition and imparts fresh life to the modem city.  相似文献   

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Tipburn is a calcium related and environmentally induced physiological disorder causing economic damage in all lettuce (Lactuca sativa L.) production regions. The objectives of this research were to determine (1) the genetic variation for tipburn incidence, (2) the genotype (G) × environment (E) interaction (GE) for tipburn incidence, and (3) the efficiency of field selection for tipburn resistance. Tipburn incidence was recorded over 2 years in Salinas, CA, and Yuma, AZ, for 55 romaine, crisphead, green leaf, and red leaf type cultivars, and over 3 years in Quebec for 15 romaine cultivars. Analysis revealed that G, E, and GE affected tipburn incidence, including crossover interactions that were not repeatable over years. This indicates that cultivar/breeding line evaluations should be based on mean performance and stability over multiple environments. Among lettuce types, only crisphead had significant genetic variability for tipburn resistance, reflecting the greater breeding effort applied to this type compared romaine, green and red leaf types. Analysis of a dataset with five romaine cultivars in eight environments in California, Arizona, and Quebec for 2 years revealed that Yuma in 2006 and Saint-Blaise in 2005 were highly correlated (r = 0.923, P < 0.05), and were the most discriminating and most representative environments for tipburn evaluation. Single plant selection for tipburn resistance in three F2 romaine populations was ineffective. Further, the degree of head closure was significantly associated with tipburn incidence. Identification and selection of morphological characters associated with resistance in conjunction with direct selection against tipburn may be an effective method for genetic improvement of tipburn resistance.  相似文献   

8.
Intercrops of pea (Pisum arvense L.), a popular legume used in intercropping systems with winter cereals for forage and silage production, with wheat (Triticum aestivum L.), rye (Secale cereale L.), and triticale (× Triticosecale Wittmack) in two seeding ratios (60:40 and 80:20) were compared with monocrops of pea and cereals for two growing seasons. Growth rate, dry matter yield, and N uptake were determined in each intercropping system. Furthermore, several indices were used to evaluate the intercropping systems and analyze the competition and the interrelationships between mixture components. Growth rate of cereals was lower in the mixtures than in the monocrops. Dry matter yield was higher in triticale monocrop, followed by its two intercrops, and the pea–wheat 80:20 intercrop. Moreover, triticale monocrop, pea–triticale intercrops, and pea–wheat 80:20 intercrop showed the highest crude protein yield and N uptake. The land equivalent ratio (LER), relative crowding coefficient (K), actual yield loss (AYL), and system productivity index (SPI) values were greater for the pea–triticale mixtures and the pea–wheat and pea–rye mixtures (80:20), indicating an advantage of intercropping. In most intercrops, the values of partial K, AYL, aggressivity, and competitive ratio (CR) indicated that the cereal was more competitive than pea. The highest values of monetary advantage index (MAI) and intercropping advantage (IA) were recorded for the pea–triticale and the pea–wheat mixtures (80:20). Overall, pea–triticale and pea–wheat mixtures (80:20) were more productive and produced better forage quality than the other mixtures and thus could be adopted by the farmers as alternative options for forage production.  相似文献   

9.
Differing from the standpoint of classical finance theory, investors is non-rational in security market in China. They have obvious non-rational characteristics, such as overconfidence, herd behavior, disposition effect and policy dependence. Because non-rational investors have intensification effect and risk-dispersed effect, under some market condition, they may lead to stock spillover or discount when their forecast error on stock expected return is less than certain bound, but when their forecast error goes beyond the certain bound, they will impulse undulation of stock price.  相似文献   

10.
Summary Parent-offspring regression was used to estimate heritability for three traits (-glucan content, groat percentage, and resistance to crown rust (Puccinia coronata Cda. f. sp. avenae Eriks.) in oat (Avena sativa L.). The populations used were derived from two crosses, Nova x Marion QC and Sylva x Marion QC. Marion QC was used as a parent because other research had shown that it is relatively high in -glucan, a trait for which heritability had not previously been estimated. Nova and Sylva are similar in adaptation to Marion QC, and Sylva may be a source of general resistance to crown rust. Random F5 plants were grown in a greenhouse, and their F6 and F7 progeny were grown in replicated field trials. Heritability estimates for the two grain quality traits were based on regression of F6 values on F5 values, F7 values on F6 values, and F7 values on F5 values. Heritability estimates for -glucan content were between 0.27 and 0.45. The highest estimate was the one based on the F6 and F7 generations of Sylva x Marion QC: 0.45, compared to estimates of 0.32 or less for earlier generations of the same cross, and to estimates of 0.35 or less for all generations of Nova x Marion QC. Heritability estimates for groat percentage were all between 0.23 and 0.32. The F6 and F7 generations were evaluated for resistance to crown rust resistance. The Sylva x Marion QC cross seemed to segregate for heritable resistance (h 2=0.31) but the Nova x Marion QC cross did not (h 2=0.07). Several lines from the Sylva x Marion QC cross had low symptoms in both the F6 and F7 generations. There were no strong genetic correlations among the traits.  相似文献   

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主要阐述了日本北海道优质稻米生产、加工及贮藏技术。包括低直链淀粉及蛋白质含量材料的早期筛选,低蛋白米栽培,分品质收购,稻谷精选, 糙米色选, 超低温贮藏技术等  相似文献   

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In this article, we compare four fishing‐based areas in Thailand and the Philippines to examine if and how small‐scale fishing communities are able to escape marginalisation. Three questions guide our inquiry: (i) How have fishing communities been affected by overfishing, climate change and other pressures? (ii) What adaptive strategies have these communities employed to mitigate socio‐economic and environmental challenges? (iii) What has been the impact of these strategies on (escaping) marginalisation? Through a survey of 393 fishing‐based households and semi‐structured interviews with 59 key informants we find an uneven mixture of drivers, strategies and impacts. Respondents varyingly attribute declining fish catch to illegal fishing, overfishing, population increase, climate change and pollution. The case studies illustrate various degrees of adaptive successes that result from integration of top‐down and bottom‐up initiatives, and availability and access to livelihood strategies. However, the impact of adaptive strategies on overcoming marginalisation remains meagre and constrained by, among others, the power of illegal and commercial fishing and the absence of integrated spatial planning. We call for policy interventions and further research that takes into account the integration of top‐down and bottom‐up institutions, and the multiple dimensions and spaces of the drivers that shape fisherfolk marginalisation.  相似文献   

16.
Two genetic linkage maps based on doubled haploid (DH) and recombinant inbred lines (RILs) populations, derived from the same indica-japonica cross ‘Samgang × Nagdong’, were constructed to analyze the quantitative trait loci (QTLs) affecting agronomic traits in rice. The segregations of agronomic traits in RILs population showed larger variations than those in DH population. A total of 10 and 12 QTLs were identified on six chromosomes using DH population and seven chromosomes using RILs population, respectively. Three stable QTLs including pl9.1, ph1.1, and gwp11.1 were detected through different years. The percentages of phenotypic variation explained by individual QTLs ranged from 8 to 18% in the DH population and 9 to 33% in the RILs population. Twenty-three epistatic QTLs were identified in the DH population, while 21 epistatic QTLs were detected in the RILs population. Epistatic interactions played an important role in controlling the agronomic traits genetically. Four significant main-effect QTLs were involved in the digenic interactions. Significant interactions between QTLs and environments (QE) were identified in two populations. The QTLs affecting grain weight per panicle (GWP) were more sensitive to the environmental changes. The comparison and QTLs analysis between two populations across different years should help rice breeders to comprehend the genetic mechanisms of quantitative traits and improve breeding programs in marker-assisted selection (MAS).  相似文献   

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Rockburst Hazard and Its Forcast and Treatments in Underground Engineering   总被引:1,自引:0,他引:1  
Rockburst is a serious damage geologic hazard. According to the rockburst phenomenon in Erlangshan tunnel and the Jinping 2nd hydropower station and a large of rockburst data,this paper proposes that rockburst is a result that many factors synthesize. These factors include teconics ,epigenetic and superficial structure, wall-rock intensity, attitude of rocks, wall-rock state of stress, wall-rock deformation and underground engineering arrangement, etc. It is given that the mechanism of rockburst is a tension fracture damage under press.  相似文献   

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