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Cereal grains contain many phytochemicals, some of which significantly influence the grain colour. Anthocyanins are accumulated in the aleurone or pericarp layer and give blue, purple or combination of these colours. Flavonoids, such as yellow C-glycosides of flavones, flavonols, flavanonols, proanthocyanidins and reddish-coloured phlobaphenes are mainly present in the outer layer of grains while carotenoids that are responsible for yellow grain are in the endosperm. Therefore, accumulation of these pigments in the grain can represent an important target in breeding programmes aimed at increasing the concentrations of bioactive components in grain and products. This review therefore summarises our current knowledge of anthocyanin and carotenoid pigments, their genetic control and variation in levels in different wheat lines. 相似文献
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《Field Crops Research》1996,47(1):65-75
The average maize grain yield of Jilin Province increased from 2835 kg/ha in 1974 to 6329 kg/ha in 1993, an average increase of 6.2% per year. Comparative analysis and regression of historical statistical data revealed that genetic improvement of cultivars, application of chemical fertilisers and adoption of improved cultural practices contributed 62.0, 50.9 and 37.0%, respectively, to total yield gain over these 20 years. Decreased application of organic manure, incidence of diseases and pests, and continuous cropping reduced yield by 27.1%, while unidentified factors accounted for a further loss of 22.8%. 相似文献
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This review provides an overview on the most common rice weed species of the world. It shows that a few generalists have established in rice independent from sites, crop management systems, and local climatic conditions. Cosmopolitan weeds are even constant elements where rice cultivation started just a century ago. Local differences may be explained by cultivation methods, growing seasons, or special weed management. Some general changes in weed spectra have been observed globally in recent years. Weedy rice (Oryza sativa L.) and herbicide resistance have become general global problems within the last decades. Some global key weed genera such as Echinochloa, Cyperus, Scirpus, or Fimbristylis species are, however, still dominating rice fields despite the decade long use of well performing herbicides. On the other side, general species shifts as a result of resistance have not been observed yet. Leptochloa species started to become major problems in Asia in the end of the last century and now in Europe also. Several modern herbicides allow the control of perennial weeds, such as Cyperus rotundus L. or Eleocharis kuroguwai Ohwi which makes them no longer serious threats. Some genera in rice such as Echinochloa and Oryza (weedy rice) are characterized by an enormous germplasm variability which makes species definitions difficult. The fact that weeds in rice have to adapt to wet or aquatic conditions reduces the biodiversity range in comparison to other arable crops. Water management has a considerable impact on weed spectra. The increase of rice acreages with reduced irrigation may end up in higher weed infestations. Long term results of weed surveys in rice as they exist for other crops are, however, not available. This makes predictions on biodiversity changes in this crop quite difficult. 相似文献
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《Crop Protection》1986,5(1):53-65
The technology of applying herbicides in irrigation water to control weeds selectively in crops has developed since the late 1960s. A review of the literature indicates that under the right conditions many herbicides applied through irrigation systems will control weeds selectively in crops. The greatest use of this technology has been with sprinkler irrigation systems, especially centre-pivots. Certain herbicides are also effective when applied through gravity flow irrigation systems, although uneven herbicide distribution and the potential for downstream contamination has limited the use of the technology in these systems. Although there is considerable interest in applying herbicides through trickle irrigation systems, problems associated with poor uniformity of herbicide application, rapid degradation of herbicides near the orifices, and potential health hazards to workers who might drink treated water, have prevented this technology from being adopted. Research is needed to determine how such factors as amount of water applied, soil texture, soil organic matter, soil moisture before and after herbicide application, water droplet size, timing of herbicide applications, herbicide concentration, herbicide properties, climatic factors, and the use of oils and other adjuvants affect the behaviour of herbicides applied through irrigation systems. 相似文献
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HUANGYunxiang ZHANGYangzhu ZouYingbin 《中国水稻研究通报》1999,7(2):8-9
Hunan Province of China,lying in the centralof subtropical zone,is one of the major pro-duction areas of double-season rice.Rice pad-dy is the main agricultural soil of the area.Mixed samples of plough horizon(0-20cm)ofmajor types of paddy soils were collected be- fore cultivation in the spring of 1996-1997.The chemical fractions of inorganic phosphatesand the relationships between inorganic phos- phates and olsen-available P in the soils werestudied by using the fractionation system of in-organic phosphates proposed by JIANG Baifanet al. 相似文献
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XIEGuanlin YUXuefang WuZhixian T.W.Mew 《中国水稻研究通报》2000,8(2):6-6
Itiswellknownthatriceseedcontainslargeamountofseedbornebacterialpathogens.However,littleisknownaboutantagonisticbacteriaofthericeseed.ThissurveywastakentounderstandthedifferenceofthebiologicalagentsofthericeseedinthePhilippines(tropic)andinZhejiangPr… 相似文献
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It is well known that rice seed contains large amount of seedborne bacterial pathogens. However, little is known about antagonistic bacteria of the rice seed. 相似文献
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Kaori Shishido 《茶叶》2013,(4):500-503
Caihe Second Elementary School,a public school in Hangzhou city of Zhejiang province in China,has shown excellent performance at practicing tea art education for students as a part of after-school activities it encourages.In this paper,the author figured out significance of tea art in Chinese society by discussing "why elementary students learn Chinese tea art" through observation on tea art education at Caihe Second Elementary School and interview with persons involved. 相似文献
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Effects of extrusion cooking on some functional properties of soy-sweet potato mixtures – A response surface analysis 总被引:3,自引:0,他引:3
Iwe MO 《Plant foods for human nutrition (Dordrecht, Netherlands)》2000,55(2):169-184
Mixtures of defatted soy flour and sweet potatoes wereextruded at 0:100, 25:75, 50:50, 75:25 and 100:0ratios in an Insta-Pro 600 single screw extruderoperated at 180, 200, 220 rpm.Oil (3–5%) was added into the mix before extrusion.A 5×32 fractional factorial central compositeresponse surface design was adopted forinvestigating the variables: feed composition, % oil,and screw rotation speed (RPM). Percent oil andscrew speed were randomly investigated at threelevels, while feed composition was randomlyinvestigated at five levels. Effect of extrusioncooking on functional properties: bulk density,expansion ratio, water absorption and solubilityindices and trypsin inhibitor were assessed.Results showed that feed composition and screw speedhad strong influences on the process. The effect ofadding oil, into defatted soybean significantly(p<0.05) affected only trypsin inhibitor content.High extrusion temperature (>130 °C), andaccompanying high shear, were the result of thenon-pasting nature of the extrudate. Therefore theproducts may have limited uses. 相似文献
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The plant regeneration frequencies of calli from plant tissue and cell culture, especially that of the calli from rice tissue culture and rice anther culture, and that of the foreign-DNA-transfor-matlon-derived rice calli is very low (usually 10-15%). It is therefor very important to improve the plant regeneration frequency of rice calli. 相似文献
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The development and dissemination of sawah rice eco-technology in Nigeria and Ghana as prerequisites for the actualization of green revolution in West Africa were described. It showed that the neglect of the eco-technology and the overemphasis of the biotechnology have rendered the ineffective transferability of the green revolution process from Asia to Africa. The sawah eco-technology increases yield up to 5 t/hm2 through bunding and the use of inlet and outlet connecting irrigation and drainage, which enhances effective water control and management, improves the efficiency of fertilizer, improves nitrogen fixation by soil microbes and algae, increases the use of wetlands, improves soil organic matter accumulation, suppresses weed growth, and enhances immune mechanism of rice through nutrient supply. The current experience has therefore established that the technology overcomes the constraints that have limited the realization of green revolution in West Africa. 相似文献
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In the winter of 1997, a semi-dwarf mutant was found inthe F6 population of M9056/ R8018 xuan in HainanProvince. In the spring of 1998, the seeds were sown inHefei, Anhui Province and the plant height of the popula-tion was measured at maturity. Results showed that29. 4% of the plants had the same height as the high par-ent had, and 70. 6% remained semi-dwarf. In the winterof 1998, the reciprocal crosses between the remained se-mi-dwarf line and the two wild-type parental lines were 相似文献
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《Field Crops Research》1999,63(3):199-210
The breeding of triticale (×Triticosecale Wittmack) is of great importance in those Mediterranean environments where low winter temperature and soil acidity interact with drought, increasing the adaptability of this species in comparison with other temperate cereals. In order to identify the way in which the various yield components contribute to the realisation of high yields in a Mediterranean environment, and the effect of a different phenology on these patterns, a two-year trial was carried out in Sardinia (Italy) with 271 pure lines grown under rainfed conditions. The relationships between characters were assessed by phenotypic correlation analysis after grouping the lines into phenological classes. In both years total biomass explained more of the variation in yield than harvest index and was little affected by earliness. Both total biomass and HI were strongly correlated with kernels m−2. More kernels m−2 are therefore essential to obtain high grain yields in triticale, regardless of earliness, highlighting the importance of the pre-anthesis period, even in conditions of increasing drought stress during spring. Grain yield showed a closer correlation with HI in the less favourable year, but became independent of HI above values of 20–25,000 kernels m−2 and HI values of 0.35. The winter types were taller, with less spikes m−2, and a longer and more fertile spike than the spring types. 相似文献