Aggregate Stability and Its Relationship with Some Chemical Properties of Red Soils in Subtropical China

The stability of aggregates in the surface soil is crucial to soil erosion and runoff generation. Thus, to understand the stability and the breakdown mechanisms of soil aggregates as well as the relationship between aggregate stability and selected soil chemical properties, such as different forms of Fe and Al oxides, organic matter, CEC and clay content, the aggregates of slightly and severely eroded red soils derived from Quaternary red clay in subtropical China were analyzed using the routine wet sieving…

Adsorption of Cadmium by Soil Colloids and Minerals in Presence of Rhizobia

Experiments were conducted to study the adsorption of Cd on two soil colloids (red soil and yellow- brown soil) and three variable-charge minerals (goethite, noncrystalline Fe oxide and kaolin) in the absence and presence of rhizobia. The tested strain Rhizobium fredii C6, tolerant to 0.8 mmol L-1 Cd, was selected from 30 rhizobial strains. Results showed that the isotherms for the adsorption of Cd by examined soil colloids and minerals in the presence of rhizobia could be described by Langmuir equation. Within the range of the numbers of rhizobial cells studied, the amount of Cd adsorbed by each system increased with increasing rhizobial cells. Greater increases for the adsorption of Cd were found in red soil and kaolin systems. Rhizobia influence on the adsorption of Cd by examined soil colloids and minerals was different from that on the adsorption of Cu. The presence of rhizobia increased the adsorption sanity of soil colloids and minerals for Cd, particularly for the goethite and kaolin systems. The discrepancies in the influence of rhizobia on the adsorbability and affinity of selected soil colloids and minerals for Cd suggested the different interactions of rhizobia with various soil components. It is assumed that bacterial biomass plays an important role in controlling the mobility and bioavailability of Cd in soils with kaolinite and goethite as the major colloidal components, such as in variable-charge soil.

Effects of Phosphate Adsorption on Adsorption-Desorption and Availability of Cu and Zn Ions in Ultisols and Alfisols

Surface charge, secondary adsorption- desorption and form distribution of Cu2+ and Zn2+ in Ultisols and Alfisols having adsorbed phosphate were studied by potentiometric titration, adsorption equilibrium and sequential extraction method, respectively. The soil surface negative charges increased whereas the amount of positive charges decreased with increase of P adsorbed. The soil secondary adsorption capacity for Cu2+ and Zn2+ was positively significantly correlated with the amount of P adsorbed by the soils, which could be described by the Langmuir equation. The amounts of Cu2+ and Zn2+ desorption from soils were decreased after P adsorption by the soils and the relationship between them was linear. After the soils adsorbed P, form distribution of Cu2+ and Zn2+ in soils changed remarforbly.

Fractionation of Moderately and Highly Stable Organic Phosphorus in Acid Soil *1

The fractionation of moderately and highly organic phosphorus (P o) in acid soil was studied by two me thods. By the first method, after incubation for 40 d, the mineralization rates of eight constituents of stable P o in the soil were determined. By the second method, five constituents of precipitates of stable P o in the soil were separated, then the five precipitates were put back into the original soils and incubated for 40 d and 60 d. Then, mineralization rates of the five precipitates were determined. The same results were obtained by the two methods. When the pH of the alkali solution containing stable P o was adjusted from 3.00 to 3.10, the mineralization rate of moderately stable P o was rapidly raised. Therefore, the pH 3.00 is the critical point between moderately and highly stable P o.

Analysis of digenic epistatic effects and QE interaction effects QTL controlling grain weight in rice

Immortalized F2 population of rice (Oryza sativa L.) was developed by randomly mating F1 among recombinant inbred (RI) lines derived from (Zhenshan 97B×Minghui 63),which allowed replications within and across environments.QTL (quantitative trait loci) mapping analysis on kilo-grain weight of immortalized F2 population was performed by using newly developed software for QTL mapping,QTL Mapper 2.0. Eleven distinctly digenic epistatic loci included a total of 15 QTL were located on eight chromosomes.QTL main effects of additive,dominance,and additive×additive,additive×dominance,and dominance×dominance interactions were estimated.Interaction effects between QTL main effects and environments (QE) were predicted.Less than 40% of single effects,most of which were additive effects,for identified QTL were significant at 5% level.The directional difference for QTL main effects suggested that these QTL were distributed in parents in the repulsion phase.This should make it feasible to improve kilo-grain weight of both parents by selecting appropriate new recombinants. Only few of the QE interaction effects were significant.Application prospect for QTL mapping achievements in genetic breeding was discussed.

Effects of Variation in Activities of Starch-Sugar Metabolic Enzymes on Reducing Sugar Accumulation and Processing Quality of Potato Tubers

The experiment was designed, via storing potato tubers of cv. E-Potato1 and E-Potato3 indifferent temperatures, to explore the variation patterns of reducing sugar (RS) andtotal sugar (TS) contents and enzyme activities that are involved in the pathway ofstarch-sugar metabolism aiming at identifying the main factors that influence the chipcolor. The results showed that low temperature in storage was a main factor thataccelerated the accumulation of RS of the stored tubers and a very significant linearrelationship existed between RS content and chip color index (CCI) of the tubers. Furtheranalysis elucidated that when tubers stored at 4℃, the activities of ADP glucosepyrophosphorylase (AGPase), UDP glucose pyrophosphorylase (UGPase) and sucrose synthase(SuSy) were negatively exponential to the RS content significantly while that of acidinvertase and alkaline invertase was significantly linear to RS content. It suggestedthat these enzymes could play main roles in the cold sweetening of potato tubers throughregulating starch-sugar metabolism.

Altered expression of nuclear matrix proteins in etoposide induced apoptosis in HL-60 cells

The events of cell death and the expression of nuclear matrix protein (NMP) have been investigated in a promyelocytic leukemic cell line HL-60 induced with etoposide. By means of TUNEL assay, the nuclei displayed a characteristic morphology change, and the amount of apoptotic cells increased early and reached maximun about 39% after treatment with etoposide for 2 h. Nucleosomal DNA fragmentation was observed after treatment for 4 h. The morphological change of HL-60 cells, thus, occurred earlier than the appearance of DNA ladder. Total nuclear matrix proteins were analyzed by 2-dimensional gel electrophoresis. Differential expression of 59 nuclear matrix proteins was found in 4 h etoposide treated cells. Western blotting was then performed on three nuclear matrix acssociated proteins, PML, HSC70 and NuMA. The expression of the suppressor PML protein and heat shock protein HSC70 were significantly upregulated after etoposide treatment, while NuMA, a nuclear mitotic apparatus protein, was down regulated. These results demonstrate that significant biochemical alterations in nuclear matrix proteins take place during the apoptotic process.

Water Budget Analysis of Red Soils in Central Jiangxi Province, China

The daily soil water budgets in the red soil areas of central Jiangxi Province,southern China,were investigated with a large-scale weighing lysimeter and runoff plots. From 1998 to 2000,peanuts (Arachis hypogaea L.) and rape (Brassica napus L.) were planted in the lysimeter and in 1999,peanuts were planted in the runoff plots. The soil water budget components including rainfall,runoff,percolation and evapotranspiration were measured directly or calculated by Richards' equation and water balance equation. The results showed that most rainfall,including rainstorms,occurred from March to July,and induced the greatest soil water percolation during the year. The evapotranspiration was still large from July to September when rainfall was minimal. Thus,the lack of synchronization in soil water inputs and losses was disadvantageous to crops growing in this region. Among the soil water losses,percolation was the largest,followed by evapotranspiration,and then soil runoff. Runoff was very small on farmland with crops. It was significantly different from the uncultivated uplands where large-scale runoff was usually reported. The soil water storage fluctuated sinusoidally,with a large amplitude in the rainy season and a small amplitude in the dry season.

Characterization of the Main Effects, Epistatic Effects and Their Environmental Interactions of QTL on the Genetic Basis of Plant Height and Heading Date in Rice

Main-effect QTL, epistatic effects and their interactions with environment are important genetic components of quantitativetraits. In this study, we analyzed the QTL, epistatic effects and QTL by environment interactions (QE) underlying plantheight and heading date, using a doubled-haploid ( DH) population consisting of 190 lines from the cross between anindica parent Zhenshan 97 and a japonica parent Wuyujing 2, and tested in two-year replicated field trials. A geneticlinkage map with 179 SSR (simple sequence repeat) marker loci was constructed. A mixed linear model approach wasapplied to detect QTL, digenic interactions and QEs for the two traits. In total, 20 main-effect QTLs, 9 digenic interactionsinvolving 18 loci, and 5 QTL by environment interactions were found to be responsible for the two traits. No interactionswere detected between the digenic interaction and environment. The amounts of variations explained by QTLs of maineffect were 53.9% for plant height and 57.8% for heading date, larger than that explained by epistasis and QEs. However,the epistasis and QE interactions sometimes accounted for a significant part of phenotypic variation and should not bedisregarded.

Electrical Characteristics and Desorption Kinetics of Soil Boron

The status and activities of boron in soils were studied by the approach of electro-ultrafiltration (EUF). The samples of soils, including brown-red soil and calcareous alluvial soil, were collected from Hubei Province of China. The soil samples were incubated in saturated water and then their nutrients were ultrafiltrated with EUF equipment. Filtration and extraction were conducted in accordance with routine process, but fractions in anode and cathode were all collected. Analyses of B, K+, Mg2+, Ca2+, Cl- and pH in fractions supposed that boron existed not only in a simple form of borate but also in ion-pair with canons partly in acidic soil, and borate was the primary form existing in the calcareous soil. In studying desorption kinetics with EUF, the boron content of Fractions 2-6 was accumulated, and the accumulative quantities were fit to time factors in three kinetic equations: the zero-order, first-order, and parabolic diffusion equations. Fit degree of the parabolic diffusion equation was the best, followed by the zero-order equation, and the first-order equation was the worst.

Patterns of Cytosine Methylation in Parental Lines and Their Hybrids of Large White and Meishan Reciprocal Crosses

The extent and patterns of cytosine methylation in blood DNA were assessed, using thetechnique of methylation-sensitive amplified polymorphism(MSAP),in Meishan, Large White pigsand hybrids of their reciprocal crosses. In all, 1 508 fragments, each representing a reco-gnition site cleaved by either or both of the isoschizomers, MspI and HpaII, were amplifiedusing 20 pairs of selective primers. 10.3% of CCGG sites were methylated in Meishan pigs, 10.5%in Large White pigs, and 10.2% in the hybrids. Cytosine methylation was not significantlydifferent among parental lines and hybrids of reciprocal crosses. Four classes of patternswere identified in a comparative assay of cytosine methylation in the parents and hybrids: (1)the same level of methylation in both parental lines and the hybrids; (2) the same level ofmethylation in either parent or hybrid; (3) an increased level of methylation in the hybridscompared to the parents, and (4) a decreased level of methylation in the hybrids. 11 cross-specific methylation sites were detected in F1 hybrids of Large White ×Meishan, and 10 cross-specific methylation sites in the hybrid of Meishan ×Large White. In conclusion, (1) the wholemethylation status between parental lines and hybrids was not different, but specific siteswere differentially methylated; (2) specific sites were differentially methylated betweenreciprocal crosses; (3) demethylation and hypermethylation of many sites accounted for mostly(more than 50%) methylated sites in the hybrids compared to parental lines.

Analysis and Design of Soils and Terrain Digital Database (SOTER) Management System Based on Object-Oriented Method

A SOTER management system was developed by analyzing, designing, programming, testing, repeated proceeding and progressing based on the object-oriented method. The function of the attribute database management is inherited and expanded in the new system. The integrity and security of the SOTER database are enhanced. The attribute database management, the spatial database management and the model base are integrated into SOTER based on the component object model (COM), and the graphical user interface (GUI) for Windows is used to interact with clients, thus being easy to create and maintain the SOTER, and convenient to promote the quantification and automation of soil information application.

Phosphorus Nutrient Characteristics of Different Maize (Zea mays L.) Inbreds for Tolerance to Low-P Stress

Phosphorus nutrient characteristics of different maize inbred lines to low-P stress were studied at stages of seedling, steming, earing, silking under pot culture. In the periods of seedling and steming, P uptake efficiency was the main contributor to P tolerance, and the relative P content in P-tolerant genotypes, 99180 and 99239 were higher than that in sensitive genotype, 99152. At earing stage, P-tolerant genotypes, compared to P-sensitive ones, had higher accumulation of P in upper leaves. When came to the silking stage, P uptake and redistribution efficiency of P-tolerant genotypes were higher than those in 99152. The results also suggested that there are different mechanisms of P nutrient uptake and distribution in different P-tolerant genotypes. Inbred line 99239, according to the investigation, was considered as an efficient stock in the P-uptake while 99180 fallen to the efficient stock of P redistribution.

Temperature Effect on Boron Adsorption-Desorption Kinetics in Soils

The effect of temperature on the properties of boron adsorption-desorption in brown-red soil, yellowbrown soil and calcareous alluvial soil of Hubei Province was investigated with the mobile displacement technique. The experimental data of B adsorption-desorption amounts and reaction t line at 25 and 40℃ were fitted by the zero-order, first-order and parabolic diffusion kinetic equations. The adsorption process was in conformity with the parabolic diffusion law at both the temperatures, and the values of rate constant of the parabolic diffusion equation in B adsorption were 0.138, 0.124 and 0.105 mg kg-1 min-1/2 at 25℃, and 0.147, 0.146 and 0.135 mg kg-1 min-1/2 at 40℃ for the brown-red soil, yellow-brown soil, and calcareous alluvial soil, respectively. The relationship between amount of B desorption and reaction time could be well described by the first-order kinetic equation, and the corresponding values of rate constant were 0.0422, 0.0563 and 0.0384 min-1 at 25℃, and 0.0408, 0.042 3 and 0.0401 min-1 at 40℃ for the brown-red soil, the yellow-brown soil and the calcareous alluvial soil, respectively. Therefore, the desorption process of B might be related to the amount of B adsorbed in soil. The higher the temperature, the lower the amount of B adsorption for the same soil in the same reaction time. The values of the apparent activation energy of B adsorption in the three soils calculated with the rate constants of parabolic diffusion equation were 3.27, 8.44 and 12.99 kJ mol-1, respectively, based on the experimental data of B adsorption amounts and reaction time at 25 and 40℃.

Isolation and Characterization of Cucumber ACC Oxidase Gene and Its Upstream

Ethylene has been implicated as a sex-determining hormone in cucumber. Its exogenous application increases femaleness,and gynoecious genotypes were reported to produce more ethylene. 1-aminocyclopropane-1-carboxylate (ACC) oxidase(ACO) is the key enzyme in ethylene biosynthesis. In this study, a 1200 base pair (bp) candidate fragment was amplifiedfrom the cucumber genome with degenerated primers derived from the ACO amino acid consensus sequence amongdifferent plant species. The coding region and its upstream (1 155 bp) were obtained by vector-mediated inverse PCR. Thenovel gene was analyzed by bioinformatics tools. Four exons and three introns were identified in the coding sequence.The spliced length of mRNA was 933 nucleotides (nts) and it encoded 311 amino acids. Phylogenic analysis result of thenew gene (CsACO4, GenBank accession number AY450356) was in accordance with the evolution relationship of geneticsamong various plant species. Northern blotting showed that the gene expressed among female flowers of gynoecious andmonoecious genotypes, it could not express in other organs. This implied that the gene might be correlated with the femalebehavior positively. Further work is on the way to demonstrate the complexity of the relationship between the endogenousethylene and the sex determination.

Introduction of rol Genes into Cotton (Gossypium hirsutum L.) Genome and Effects of Transgene Expression on the Plant Development

The rol genes cloned from Agrobacterium rhizogenes were transferred to the cotton genomevia Agrobacterium-mediated transformation. Molecular analyses and developmentalidentification of the putative transgenic plants were carried out by means of PCR,Southern blotting and field characterization. The results showed that the expression ofrol genes greatly increased the rooting ability of the transgenic plants, and changed theplant development. Highly male-sterile plants with strong apical dominance and fertileplants with short internodes, stunted growth and improved economic characteristics weresegregated from the T1 transgenic lines of wild rol B gene and the rol B gene driven by35S promoter. The transgenic lines of rol ABC construct usually had normal boll settingand slow growth. Therefore we concluded that the rol genes, modified in suitable ways,could be used to create new cotton varieties with some highly valuable characteristics.

Characterization of Nuclear and Cytoplasmic Compositions of Somatic Hybrid Plants Between Sweet Orange and Sour Orange

Abstract In the present research, flow cytometry (FCM), simple sequence repeat (SSR) and cleavedamplified polymorphic sequence (CAPS) were employed to analyze somatic hybrid plants derived from electrofusion between embryogenic protoplasts of sweet orange (Citrus sinensis Osbeck cv. Shamouti) and leaf-derived protoplasts of sour orange (C. aurantium L). FCM showed that all of the somatic hybrid plants had two-fold fluorescence intensity values of the diploid control, indicating that they were tetraploids. SSR and CAPS were used to characterize the compositions of nuclear and cytoplasmic genomes of the somatic hybnd plants. As for SSR four primer pairs were tried and two showed polymorphisms between the fusion parents. With both pnmer pairs the somatic hybrid plants encompassed DNA bands from both parents, indicating that they were heterokaryonic hybrids. Amplification with some universal primers, followed by digestion with restriction endonucleases, could distinguish the fusion parents from each other. As far as mitochondrial and chloroplast DNA compositions were concerned the somatic hybrid plants shared the same banding patterns as the embryogenic parents for all of the polymorphic primer/enzyme combinations. The results herein demonstrated that the somatic hybrid plants inherited their nuclear genome from both fusion parents, whereas the cytoplasmic genomes were possibly only contributed by the embryogenic parent. Merits of the analytical methods and nuclear and cytoplasmic inheritance of citrus tetraploid somatic hybrids, together with their application, are discussed herein.

Genetic Diversity of Chinese and Swedish Rapeseed (Brassica napus L.) Analyzed by Inter-Simple Sequence Repeats (ISSRs)

We have compared genetic diversity of 24 Chinese weak-winter, Swedish winter and spring B. napus accessions by inter-simple sequence repeats (ISSRs). By cluster analysis (UPGMA) based on 125 polymorphism bands amplified with 20 primers, the 24 accessions were divided into three groups. Six Swedish winter lines and eight Chinese weak-winter lines were in the group I and the groupⅡwere two Chinese weak-winter lines XiangyoulS and Bao81. The third group contained eight Swedish spring lines. Principal co-ordinates analysis (PCO) showed similar groupings to cluster analysis. Results from cluster analysis and PCO analysis showed very clearly that Chinese weak-winter, Swedish spring and winter accessions were distinguished from each other and Chinese weak-winter accessions in this study were genetically closer to Swedish winter accessions than to Swedish spring accessions. The Chinese weak-winter accessions had larger diversity than Swedish spring or winter accessions did. This study indicated that ISSR is a suitable and effective tool to evaluate genetic diversity among rapeseed germplasm.

Effects of Sorbed Phosphate on Kinetics of Cn^（2＋） Sec－ondary Adsorption in Soils

The effects of sorbed phosphate on the kinetics of Cu￣2+ secondary adsorption on three major types ofsoils in southern and Central China were studied using the batch method and flow (or miscible displacement)techniques. Both of the methods showed that diffusions were the ratedetermining steps in the Cu￣2+ adsorp-tion by the soils. By the flow method, the course of Cu￣2+ adsorption kinetics consisted of two steps-sn initialrapid process and a later slow process of Cu￣2+ adsorption; while by the batch method, the 90% of Cu￣2+adsorption reaction was found to finish within first 1 minute. The results obtained using the flow method alsoindicated that for red soil and yellow-brown soil, Cu￣2+ adsorptions during the initial reaction periods wererestrained when the soils sorbed phosphate, whereas the adsorption reactions were stimulated at the finaltime. For grey Chao soil, sorbed phosphate retarded the Cu￣2+ adsorption in the whole reaction period. Theresults obtained using the batch method and flow techniques all implied that the different effects of sorbedphosphate would be attributed to its effects on Cu￣2+ ion diffusion in soil solution.

Goethite Morphologies of Some Soils in South of Central China

The morphologies of goethites in latosol, red soils, yellow-brown soil and the paddy soils developed from red soils were studied in comparison with the morphology of synthetic goethite by means of the X-ray distraction, transmission electron microscopy and energy dispersive X-ray analysis. The synthetic goethite displayed acicular particles elongated in the c-direction. The goethites in the latosol, red soils and yellowbrown soil were platy particles stretched in two directions or isodimensional particles, and those in the paddy soils from red soils were acicular, short columnar, platy or isodimensional particles. Various morphologies of the goethites probably suggested their different dominant crystal faces, surface charge distribution and surface adsorption characteristics.