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1.
精米中微量元素铁铜锰锌的含量差异   总被引：12，自引：0，他引：12  
通过对精米中微量元素铁铜锰锌的含量测定 ,对比分析白色糯米和普通白米、有色米和白色米中的含量差异 .结果表明 :有色米、白色糯米中微量元素铁铜锰锌含量明显高于普通白米  相似文献   

2.
研究目的：阐明水稻穗内不同粒位间的主要矿质营养元素和植酸含量差异、粒位分布特点及其与品种穗型间的联系。 创新要点：将水稻品种的穗型变化与稻米营养品质结合起来,从水稻穗粒结构角度,对同一稻穗内不同籽粒间的主要矿质营养元素与植酸含量差异、粒位分布特点及其与水稻品种穗型间的相互关系进行了较系统的探讨分析。 研究方法：以典型的直立穗型和弯穗型粳稻品种为材料,通过对两类水稻品种在相同栽培条件下籽粒矿质营养元素和植酸含量的测定分析,并依据水稻籽粒在稻穗上的着生部位,将同一稻穗内的不同籽粒划分为六个粒位,比较分析了两类品种同一稻穗内不同部位间矿质营养元素和植酸含量的差异变化及其粒位分布特点。 重要结论：水稻穗型虽然与品种问的籽粒矿质营养元素和植酸含量高低没有直接关系,但对其穗内不同籽粒间的主要矿质营养元素和植酸含量存在着较大影响;与稻穗中下部的弱势粒相比,同一稻穗内着生在稻穗上中部的强势粒通常具有相对较高的锌、铁矿质元素含量,而籽粒植酸含量和植酸,锌（铁）摩尔比则有所降低,稻米营养品质也相对较好;不同矿质营养元素相比,粒位效应对铁矿质营养的影响作用要略大于对钙和锌营养元素含量。  相似文献   

3.
Zinc (Zn) is an essential micronutrient for humans, but Zn deficiency has become serious as equally as iron (Fe) and vitamin A deficiencies nowadays. Selection and breeding of high Zn-density crops is a suitable, cost-effective, and sustainable way to improve human health. However, the mechanism of high Zn density in rice grain is not fully understood, especially how Zn transports from soil to grains. Hydroponics experiments were carried out to compare Zn uptake and distribution in two different Zn-density rice genotypes using stable isotope technique. At seedling stage, IR68144 showed higher 68Zn uptake and transport rate to the shoot for the short-term, but no significant difference was observed in both genotypes for the long-term. Zn in xylem sap of IR68144 was consistently higher, and IR68144 exhibited higher Zn absorption ratio than IR64 at sufficient (2.0 μmol/L) or surplus (8.0 μmol/L) Zn supply level. IR64 and IR68144 showed similar patterns of 68Zn accumulation in new leaves at seedling stage and in developing grains at ripening stage, whereas 68Zn in new leaves and grains of IR68144 was consistently higher. These results suggested that a rapid root-to-shoot translocation and enhanced xylem loading capacity may be the crucial processes for high Zn density in rice grains.  相似文献   

4.
Bread wheat varieties as influenced by different nitrogen levels   总被引：4，自引：2，他引：2  
INTRODUCTION Dera Ismail Khan lies in Pakistan’s arid zone (71.07° longitude, 31.57° latitude and 500 m above sea level). This zone is in the extreme south of (NWFP) Pakistan at the bank of the River Indus. Dera Ismail Khan is bounded by Sulaiman Range to the West, the Indus River on the East, Marwat and Bhit- tani Ranges on the North and Vehowa Nala (Punjab) on the South. Besides certain local variability the area is comprised of four basic divisions viz mountains, a series …  相似文献   

5.
在杂交水稻汕优63始稳期，用15mmol／LCa(2 =)喷施叶面，能增加抽穗结实期间主茎旗叶的叶绿素和可溶性蛋白质含量，提高超氧物歧化酶（SOD）的活性．降低丙二醛（MDA）含量．延缓叶片衰老；同时，Ca(2 )能增加主德的实位数、结实串和千粒重，从而提高谷产量．  相似文献   

6.
通过田间小区试验 ,研究了Zn、B微肥配施对油菜生长发育及产量的影响。结果表明 :不同用量的Zn、B配合施用对油菜都有一定的增产作用 ,但产量并不是随施肥量的增加而增加 ,以基施硫酸锌 1 0kg/hm2 和硼砂 1 2kg/hm2 效果最好。Zn、B配施的增产原因主要提高了千粒重 ,而对角果数、角粒数无多大影响。  相似文献   

7.
Genotypic and environmental variation in Cd, Cr, As, Ni and Pb concentrations of grains, and the relationships between these heavy metals and Fe, Zn were investigated using 9 rice genotypes grown in 6 locations for two successive years. Significant genotypic variation was detected in the five heavy metal concentrations in grains, indicating the possibility to reduce the concentration of these heavy metals in grains through breeding approach. The environmental effect varied with metal, with Pb and Ni having greater variation than the other three metals. There was significant genotype-environment （location） interaction of the concentrations of all five heavy metals in grains, suggesting the importance of cultivar choice in producing rice with low heavy metal concentrations in grains for a given location. Correlation analysis showed that Cd and As, Cr and Ni, and As and Pb concentrations in rice grains were closely associated, and that Ni concentration in grains was negatively correlated with Zn concentration.  相似文献   

8.
玉米素和吲哚乙酸与水稻强弱势粒胚乳细胞发育、籽粒灌浆及产量形成关系密切：强势粒玉米素含量高峰早、峰值高,促进了胚乳细胞分裂,故强势粒胚乳细胞较多、体积较小;而弱势粒玉米素含量高峰迟、峰值低,吲哚乙酸含量虽然高峰迟,但峰值高,促进了胚乳细胞扩大,故弱势粒胚乳细胞数目较少,但体积较大.强弱势籽粒内源玉米素和吲哚乙酸含量动态与其灌浆强度动态基本一致,于抽穗期喷施玉米素能显著提高杂交水稻两优培九弱势粒的结实率和充实度,从而提高其产量,但对强势粒的结实率和充实度无显著影响.于水稻抽穗期喷施吲哚乙酸对杂交水稻两优培九的强弱势粒结实率和充实度以及产量均无显著影响.  相似文献   

9.
以威优64、陆青早1号为材料,免耕提高了植株和功能叶的含氮量、总糖量及可溶性糖的含量,增强了NR的活力,促进了碳水化合物的运转,说明提高茎鞘物质的“再积累”现象和库容量是提高免耕水稻产量的主要原因。  相似文献   

10.
The main objective of this work was to compare the applicability of the single leaf (the uppermost leaf L1 and the third uppermost leaf L3) modified simple ratio (mSR705 index) and the leaf positional difference in the vegetation index between L1 and L3 (mSR705L1-mSR705L3) in detecting nitrogen (N)-overfertilized rice plants. A field experiment consisting of three rice genotypes and five N fertilization levels (0, 75, 180, 285, and 390 kg N/ha) was conducted at Xiaoshan, Hangzhou, Zhejiang Province, China in 2008. The hyperspectral reflectance (350–2500 nm) and the chlorophyll concentration (ChlC) of L1 and L3 were measured at different stages. The mSR705L1 and mSR705L3 indices appeared not to be highly sensitive to the N rates, especially when the N rate was high (above 180 kg N/ha). The mean mSR705L1-mSR705L3 across the genotypes increased significantly (P<0.05) or considerably from 180 to 285 kg N/ha treatment and from 285 to 390 kg N/ha treatment at all the stages. Also, use of the difference (mSR705L1-mSR705L3) greatly reduced the influence of the stages and genotypes in assessing the N status with reflectance data. The results of this study show that the N-overfertilized rice plants can be effectively detected with the leaf positional difference in the mSR705 index.  相似文献   

11.
To investigate the effects of salt concentration and freeze-thaw （FT） on the first hydration shell of Zn2+ ions in Zn（NO3）2 aqueous solutions, extended X-ray absorption fine structure （EXAFS） spectroscopy was used to examine Zn K-edge EXAFS spectra of Zn（NO3）2 aqueous solutions with various concentrations before and after FT treatment. The influences of salt concentration and freeze-thaw on the structural parameters of the first hydration shell of Zn2+ ions, including hydration number, Zn-O distance and thermal disorder, were analyzed. The results show that Zn2+ ions have 3.2―6.8 nearest oxygen neighbors with the Zn-O distance being 0.202―0.207 nm. In highly concen-trated solutions, Zn2+ ions are hydrated with four water molecules in a tetrahedral form. The dilution of Zn（NO3）2 aqueous solutions increases the number of water molecules in the first hydration shell of Zn2+ ions to six with their octahedral arrangement. Both the hydration number in the first hydration shell of Zn2+ ions and the degree of thermal disorder increase when the FT treatment is operated in Zn（NO3）2 aqueous solutions.  相似文献   

12.
The genetic basis of heterosis was studied through mid-parent, standard variety and better parent for 11 quantitative traits in 17 parental lines and their 10 selected hybrids in rice (Oryza sativa L.). The characters were plant height. days to flag leaf initiation, days to first panicle initiation, days to 100% flowering, panicle length, flag leaf length. days to maturity, number of fertile spikelet/panicle, number of effective tillers/hill, grain yield/10-hill, and 1000-grain weight. In general the hybrids performed significantly better than the respective parents. Significant heterosis was observed for most of the studied characters. Among the 10 hybrids, four hybrids viz., 17A×45R, 25A×37R, 27A×39R, 31A×47R, and 35A×47R showed highest heterosis in 10-hill grain yield/10-hill. Inbreeding depression of F2 progeny was also studied for 11 characters of 10 hybrids. Both positive and negative inbreeding depression were found in many crosses for the studied characters, but none was found significant. Selection of good parents was found to be the most important for developing high yielding hybrid rice varieties. Project supported by the Foundation of Ministry of Science and Information and Communication Technology, People's Republic of Bangladesh  相似文献   

13.
A new site-specific nutrient management approach was developed to break the apparent attainable yield barrier of 6 t·ha−1 in the double rice cropping system of Zhejiang. On-farm experiments involving 21 rice-growing farmer families and NPK long-term experiments commenced in 1997 in the central part of Zhejiang Province to assess the status of soil fertility and productivity under intensive rice-rice cropping. A new site-specific nutrient management (SSNM) approach has been developed for this studied area. Field-specific fertilizer recommendations are calculated considering indigenous nutrient supply, reasonable grain yield targets and corresponding nutrient demand, nutrient balance and nutrient use efficiency, as well as socio-economic factors. The agronomic performance of SSNM was tested against the farmer's fertilizer practice (FFP) in four 1998–1999 cropping seasons. Across seasons and years, SSNM consistently increased plant nutrient uptake, grain yield and profit by about 10%–15% compared to the FFP. Yield levels of 7.5 t·ha−1 or more seem achievable and sustainable through introduction of SSNM and improved extension services in Zhejiang Province. Project supported by the International Fertilizer Industry Association(IFA), the Potash and Phosphate Institute, Canada (PPIC), and International Potash Institute(IPI).  相似文献   

14.
A commercial AA2618 alloy was treated through melt spinning at rotating speeds of 20 and 40 m·s−1. The as-melt spun ribbons were characterized by a combination of optical microscopy (OPM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The microstructural evolution of the ribbons in a continuous heating process was investigated, and the microhardness was also measured under different conditions. It was found that Al x FeNi is prone to precipitate in AA2618 alloy due to the minimal solubility of iron and nickel. Fine Al x FeNi particles appeared along the grain boundaries at the chilling sides of as-melt spun ribbons, and at both the grain boundaries and in the interior of grains at the free sides. On continuous heating Al x FeNi precipitated steadily and uniformly throughout the matrix until melting. The microhardness of as-melt spun ribbons decreased significantly from the chilling surfaces to free surfaces. Precipitation of Al x FeNi lowered the hardness of the alloy. Project supported by Special Research Foundation of High-Education Ph. D. Subjects, Education Ministry of P. R. China.  相似文献   

15.
We characterized yield-relevant characters and their variations over genotypes and environments (locations and years) by examining two rice varieties (9746 and Jinfeng) with high yield potential.9746 and Jinfeng were planted in two locations of Shanghai,China,during 2005 and 2006.The results show that there was a large variation in grain yield between locations and years.The realization of high yield potential for the two types of rice was closely related to the improved sink size,such as more panicles per square meter or grains per panicle.Stem and leaf biomasses were mainly accumulated from tillering stage to heading stage,and showed slow decline during grain filling.Meanwhile,some photosynthetic characters including net photosynthesis rate (Pn),leaf area index (LAI),specific leaf area (SLA),fluorescence parameter (maximum quantum yield of PSII,Fv/Fm),chlorophyll content (expressed as SPAD value),as well as nutrient (N,P,K) uptake were also measured to determine their variations over genotypes and environments and their relationships with grain yield.Although there were significant differences between years or locations for most measurements,SLA at tillering and heading stages,Fv/Fm and LAI at heading stage,stem biomass at heading and maturity stages,and leaf nitrogen concentration at tillering and heading stages remained little changed,indicating their pos-sible applications as selectable characters in breeding programs.It was also found that stem nitrogen accumulation at tillering stage is one of the most important and stable traits for high yield formation.  相似文献   

16.
Rice straw is always regarded as a by-product of rice production, but it could be a significant energy source for ruminant animals. Knowledge of the genetic variation and genetic architecture of cell wall traits will facilitate rice breeders by improving relevant traits through selective breeding and genetic engineering. The common wild rice, Oryza rufipogon Griff., which is considered to be the progenitor of Oryza sativa, has been widely utilized for the identification of genes of agronomic importance for rice genetic improvement. In the present study, the mapping of quantitative trait loci (QTLs) for acid detergent fiber (ADF), neutral detergent fiber (NDF), acid detergent lignin (ADL), and ADL/NDF ratio was carried out in two environments using a backcrossed inbred line (BIL) population derived from a cross between the recurrent parent Xieqingzao B (XB) and an accession of Dongxiang wild rice (DWR). The results indicated that all four traits tested were continuously distributed among the BILs, but many BILs showed transgressive segregation. A total of 16 QTLs were identified for the four traits, but no QTLs were in common in two environments, suggesting that environment has dramatic effects on fiber and lignin syntheses. Compared to the QTL positions for grain yield-related traits, there were no unfavorable correlations between grain yield components and cell wall traits in this population. The QTLs identified in this study are useful for the development of dual-purpose rice varieties that are high in grain yield and are also high in straw quality.  相似文献   

17.
同源四倍体水稻双受精过程的细胞学观察   总被引：4，自引：0，他引：4  
同源四倍体水稻的双受精比较特殊,花粉粒在其柱头上萌发比较慢,花粉管在花柱内的伸长比较迟缓,双受精延迟。退化胚囊的频率比较高（36．0％）,极核和反足细胞的形态异常,存在着一定频率的胚自发现象,由此认为,同源四倍体水稻的有性生殖能力已以明显变弱。  相似文献   

18.
长江流域西部地区 ,农业灌溉发展缓慢 ,灌溉面积偏小 ,粮食总量偏低 ,制约国民经济持续发展。提出对老化灌区进行更新改造 ,扩大灌溉面积 ,提高单位面积产量 ;实行节水灌溉 ,改革灌区管理体制 ,完善监督执法体系 ,增加粮食总量 ,为西部大开发创造有利条件  相似文献   

19.
粮食物性和粮层阻力实验研究   总被引：1，自引：0，他引：1  
对三种有代表性的粮食(大米、稻谷和玉米)在不同堆载高度下的物理性质和阻力特性作了比较详尽的实验研究。结果表明:粮食的孔隙率、粮层阻力与粮食堆载高度之间存在明显的非线性关系。在粮食机械通风数值模拟和工程应用中必须加以重视。  相似文献   

20.
<正>Porous Si3N4 self-reinforce ceramics were prepared by gelcasting using agarose solutions. By changing the agarose content in the slurries, the porous silicon nitride ceramics with different porosities, α→β-Si3N4 phase transformation, and mechanical properties were obtained. When the agarose content changed from 0.2% to 0.8% (w/w, based on powder), the porosities increased from 10.3% to 21.4%, while the fracture strength decreased from 455 to 316 MPa and the fracture toughness decreased from 6.6 to 5.5 MPa·m1/2. Many fibrous β-Si3N4 grains grown from the internal wall of the round pores is the typical microstructure of the gelcasting porous silicon nitride ceramic. Both elongated β-Si3N4 grains and suitable interfacial bonding strength contributes to high fracture toughness by favoring crack deflection and bridging. The growth mechanisms of fibrous grains resulted from the synergy of solution-diffusion-reprecipitation and vapor-liquid-solid (VLS).  相似文献   

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