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1.
A rich man in the Qi Kingdom had two silly sons, but he didn'tthink so.[第一段]  相似文献   

2.
A rich man in the Qi Kingdom had two silly sons, but the rich man loved his sons very much and they were the apples of his eye. One day, a man named Ai Zi said to the rich man, "Your sons are so stupid and know nothing about the world. How can they take y…  相似文献   

3.
齐国有一个富翁,他有两个笨儿子,可是他并不这样认为。一天,一个名叫艾子的人对这个富翁说:"您这两位少爷整天  相似文献   

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5.
INTRODUCTION The most obvious manifestation of gravitys effect on plants is the downward bending of roots and the upward growth of shoots. Gravity is an important factor in plant development (Barlow, 1995). The starch-statolith hypothesis proposed by Haberlandt and Nmec (Audus, 1962) is the most widely accepted view of how plants perceive gravity. Physiological data suggested that the amyloplast containing starch granules act as the statolith in higher plants. Sedimented amyloplasts ar…  相似文献   

6.
INTRODUCTIONRiceseedharborsadozenofplantpathogen icbacteria (Gotoetal.,1 988;Xieetal.,1 998) .Thebacterialpathogenscausearangeofricediseases,someverydestructivewhileothershavenoeffectonricecropgrowth .Inthisstudy ,wefoundalargenumberofbacteriaasso ciatedw…  相似文献   

7.
Targeting Induced Local Lesions IN Genomes (TILLING) is a reverse genetics strategy for the high-throughput screening of induced mutations. γ radiation, which often induces both insertion/deletion (Indel) and point mutations, has been widely used in mutation induction and crop breeding. The present study aimed to develop a simple, high-throughput TILLING system for screening γ ray-induced mutations using high-resolution melting (HRM) analysis. Pooled rice (Oryza sativa) samples mixed at a 1:7 ratio of Indel mutant to wild-type DNA could be distinguished from the wild-type controls by HRM analysis. Thus, an HRM-TILLING system that analyzes pooled samples of four M2 plants is recommended for screening γ ray-induced mutants in rice. For demonstration, a γ ray-mutagenized M2 rice population (n=4560) was screened for mutations in two genes, OsLCT1 and SPDT, using this HRM-TILLING system. Mutations including one single nucleotide substitution (G→A) and one single nucleotide insertion (A) were identified in OsLCT1, and one trinucleotide (TTC) deletion was identified in SPDT. These mutants can be used in rice breeding and genetic studies, and the findings are of importance for the application of γ ray mutagenesis to the breeding of rice and other seed crops.  相似文献   

8.
Machine vision inspection of rice seed based on Hough transform   总被引:1,自引:0,他引:1  
INTRODUCTION It is a common phenomenon that glumes ofrice seeds are incompletely closed, especially forhybrid rice. The average proportion of hybrid riceseed with incompletely closed glumes is about 26%in nature. The threshing and drying in post-harvesthandling will further increase the proportion. Thegermen segmentation is inhibited by ultravioletillumination from sunshine while the germen epi-dermis cell stops growing because of shortage ofwater due to the limited moisture. These …  相似文献   

9.
张瑛 《广西教育》2011,(16):34-35
[教学内容]三年级起点第三册"Module 5 Food"Do you want some rice?[教学目标]知识与能力目标:学习单词fast food,chopsticks,nice,difficult;学会在具体语境中运用句型Do you want a/an/some…?  相似文献   

10.
INTRODUCTIONCorrectlypinpointingsplicing sitesingenomicDNAsequencesisnotaneasytask ,whichisofgreatimportancetothegenomeannotationandgenefinding .Intronsaregenerallydividedinto3classes,namelycalssI,classIIandcommonnu cleuspre mRNA .IntronofclassIandIIcango…  相似文献   

11.
An ancient genome duplication (PPP1) that predates divergence of the cereals has recently been recognized. We report here another potentially older large-scale duplication (PPP2) event that predates monocot-dicot divergence in  相似文献   

12.
INTRODUCTION Drought stress is a major constraint to rice(Oryza sativa) production and yield stability in rainedecosystems (Dey and Upadhyaya, 1996). Rice mustbe made more drought tolerant, but this is a somewhatcontradictory objective considering that rice is mostcommonly grown under flooded conditions. Achiev-ing drought tolerance in rice will require a deeperunderstanding of the possible physiological mecha-nisms available for water stress tolerance and theidentification of favo…  相似文献   

13.
INTRODUCTIONPigmentsarecloselyrelatedtothephysiolog icalfunctionofleaves.Chlorophyllsabsorblightenergyandtransferitintothephotosyntheticpro cess.Carotenoids (yellowpigments)canalsocontributeenergytothephotosyntheticsystem .Becauseoftheimportanceofpigments…  相似文献   

14.
INTRODUCTIONInthelastdecade,remotesensinghasbeenincreasinglyidentifiedasanobjective,standardized,possiblycheaperandfastermethodologyforcropproductionsurveysthanconventionalfieldinves-tigations(Bauman,1992).Muchprogresshasbeenmadethroughintensivestudiesoninventoryandproductionforecastingformajorcrops,suchaswheat,rice,cottonandmaize(Tennakoonetal.,1992;Rayetal.,1994;Fangetal.,1998).China,adevelopingcountrywith1.2billionpeople,hasbeenpayingcloseattentiontoitsex-istingandfuturefoodproduction…  相似文献   

15.
INTRODUCTION Ribulose-1,5-bisphosphate carboxylase/oxy-genase (Rubisco) is a key enzyme that initiates bothphotosynthetic and photorespiratory carbon me-tabolism. However, Rubisco has to be activated andcarbamylated to become catalytically competent.Rubisco activase (RCA) can alter the activity ofRubisco by facilitating the dissociation of tightlybound sugar phosphates from Rubisco in a processthat requires ATP hydrolysis. RCA, a chloroplastprotein encoded by a nuclea…  相似文献   

16.
Purpose: This study examines the suitability of the system of rice intensification (SRI) for diverse small-scale farmers in Tanzania by exploring if poor and non-poor farmers adopt the system to a similar extent.

Originality: The suitability of low-external input technologies such as SRI for diverse African farmers is a contentious issue. Existing studies suggest that adoption may be skewed away from poorer farmers, but no studies have explicitly categorized farmers who participate in adoption of SRI.

Methods: Farmers exposed to SRI were randomly surveyed. Sample farmers were categorized into three socioeconomic groups – wealthier, middle-wealth, and poorer – using factor and cluster analysis approaches. Wealth category is then used in a logit model to determine probabilities of adopting SRI practices across the different groups.

Findings: The results indicate that middle-wealth group adopt SRI to a greater extent compared to the wealthier and poorer groups. The extent of adoption by wealthier and poorer groups is similar, although constraining circumstances differ. Access to factors that consistently explained adoption: contact with extension services, land with water, and labor, vary systematically among groups.

Theoretical implication: Low adoption is often assumed on reduced exposure to a technology, and non-adopters are expected to eventually adopt. The results suggest, however, that farmers, who have not adopted, may not do so, even after being exposed. SRI as a package does not fit their socioeconomic conditions.

Practical implications: To support adoption across all wealth categories, extension should focus on promoting individual practices rather than the package to enable farmers adopt practices that fit their socioeconomic characteristics.  相似文献   


17.
INTRODUCTIONAlthoughriceisanaturallyself-pollinatedcrop,strongheterosisisobservedintheirF1hybrids.HeterosisorhybridvigorismanifestedasimprovedperformanceforF1hybridsgeneratedbycrossingtwoinbredparents.Heterosiscanbedefinedquan-titativelyasanupwarddeviationofthemid-parent,basedonthemeanvaluesofthetwoparents(JohnsonandHutchinson,1993).Heterosismaybepositiveornegative.Dependinguponbreedingob-jectives,bothpositiveandnegativeheterosisareusefulforcropimprovement.Ingeneral,positiveheterosisisd…  相似文献   

18.
The objective of this study was to obtain spatial distribution maps of paddy rice fields using multi-date moderateresolution imaging spectroradiometer (MODIS) data in China. Paddy rice fields were extracted by identifying the unique characteristic of high soil moisture in the flooding and transplanting period with improved algorithms based on rice growth calendar regionalization. The characteristic could be reflected by the enhanced vegetation index (EVI) and the land surface water index (LSWI) derived from MODIS sensor data. Algorithms for single, early, and late rice identification were obtained from selected typical test sites. The algorithms could not only separate early rice and late rice planted in the same fields, but also reduce the uncertainties. The areal accuracy of the MODIS-derived results was validated by comparison with agricultural statistics, and the spatial matching was examined by ETM+ (enhanced thematic mapper plus) images in a test region. Major factors that might cause errors, such as the coarse spatial resolution and noises in the MODIS data, were discussed. Although not suitable for monitoring the inter-annual variations due to some inevitable factors, the MODIS-derived results were useful for obtaining spatial distribution maps of paddy rice on a large scale, and they might provide reference for further studies.  相似文献   

19.
INTRODUCTION Fungi cause most plant diseases of all groups of microbes. During their infection cycles, fungal pathogens must undergo two key processes: first, penetration through cuticles into host plant cells; second, colonization in host cells utilizing nutrients from their hosts. To penetrate host cells, fungi de-velop a series of specialized infection structures such as appressorium, penetration peg, and infection hypha. The appressorium-mediated penetration is a process typical of s…  相似文献   

20.
INTRODUCTIONAfterthewholericegenomewassequencedsuccessfully,moreandmoregenescanbepredictedwithdifferentsoftwaresandannotationsystem.However,thefunctionsofpredictedgeneshavetobefurtheridentifiedbybiologicalanalysis.Oneofthemostpowerfulmethodsassigningfunctiontogeneisthroughinsertionmutagenesiswithtrans-posableelementasDNAsequencetag.Ac/Dstrans-posonsystemhasbecomeaverypopulartoolforgenetaggingandfunctionalgenomicsinvariousplantspecies(Altmannetal.,1995;Chinetal.,1999;Enokietal.,1999;Gre…  相似文献   

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