Crop Yield,N Uptake and Nitrates in a Fluvo-Aquic Soil Profile

The effects of different chemical fertilizer combinations (N, P and K) on crop yield, N uptake and nitrate distribution and accumulation to a depth of 100 cm were studied in a cinnamon fiuvo-aquic soil profile (Beijing) with a continuous winter wheat-summer maize cropping system for nine years. The experiment consisted of 7 treatments: no fertilizer control (CK); N alone, N in combination with K (NK), P (NP), and P and K (NPK and N1PK); and P and K in combination without N (PK). The rate of N was 150 kg ha-1 for the N treatments except Treatment N1PK with higher N rate (195 kg ha-1), and the rates of P (P2O5) and K (K2O) were 75 and 37.5 kg ha-1, respectively. The applications of N combined with P and K (NK, NP and NPK) resulted in higher crop yields than a single application of N. The yields followed the order: NPK ＞NP ＞ N1PK ＞ PK ＞ NK ＞ N ＞ CK for winter wheat, and NPK ＞ N1PK ＞ NP ＞ NK ＞ N ＞ PK ＞ CK for summer maize. Supplement of N with P or K, or both P and K resulted in a higher average N uptake of the two crops, which was in a decreasing order NPK ＞ NP ＞ N1PK ＞ NK ＞ N ＞ PK ＞ CK. The combinations also increased apparent N recovery more than N alone and CK. The nitrate content in the profile was thus reduced more in the combination treatments. The nitrate accumulation in the soil profiles followed the order:N ＞ NK ＞ N1PK ＞ NPK ＞ NP ＞ CK ＞ PK. Higher N uptake by the adequately fertilized crops (Treatment NPK) reduced nitrate accumulation in the profile and thus reduced nitrate leaching. The optimum N:P:K ratio was thus of paramount importance in increasing yields and N uptake of crops and reducing nitrate leaching losses.

QTL Mapping for Drought Tolerance at Stages of Germination and Seedling in Wheat (Triticum aestivum L.) Using a DH Population

Drought is a major constraint in many wheat( Triticum aestivum L.) production regions. Quantitative trait loci (QTLs) conditioning drought tolerance at stages of germination and seedling in wheat were identified in a double haploid (DH) population derived from the cross, Hanxuan10×Lumai14, using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers. Interval mapping analysis revealed that QTLs for drought tolerance at germination stage were located on chromosomes 1B, 2B, 5A, 6B, 7A and 7B, respectively, and the most effective QTL was mapped on chromosome 2B, explaining 27.2% of phenotypic variance. The QTLs for drought tolerance at seedling stage were located on 1B, 3B and 7B, respectively, and the most effective QTL was mapped on chromosome 3B, explaining 21.6% of phenotypic variance. Their positions were different from those of QTLs conferring drought tolerance at germination stage, indicating that drought tolerance at germination stage and seedling stage was controlled by different loci. Most of the identified QTLs explained 18% or more of phenotypic variance for drought tolerance at germination and seedling stage, and would be useful in future for marker assisted selection programs and cultivar improvement.

Modern sedimentation rates in the intertidal zone on the west coast of the Bohai Gulf

On the basis of the measurement of 210Pbex and 137Cs activities in the sediment cores taken from the intertidal zone on the west coast of the Bohai Gulf, the average sedimentation rates of modern sediments are calculated. The results indicate that in the sandy area of the intertidal zone (from Daogouzi to the Duliujian River), the sedimentation rate from 1955 to 1963 is 3.43-4.06 cm/a, and is within the range of 0.65￣1.59 cm/a since 1963. The average sedimentation rate in the muddy area (around Qikou) is approximately 1.81 cm/a. The results above suggest that the sandy area of the intertidal zone has experienced rapid sedimentation from the 1950s to the 1960s, and the sedimentation slows down after the 1960s, and the sedimentation rates increase from north to south spatially. The rapid sedi- mentation from the 1950s to the 1960s in the sandy area is due to the fact that North China has plentiful precipitation during this period and the intertidal zone is supplied with abundant matter sources for sedimentation. After the 1960s, the weakened sedimentation may be a result of the reduction of sand transported to the intertidal zone, which is a consequence of diminished rainfall in North China and intensive human activities in the Haihe basin.

Mapping QTL for Heat-Tolerance at Grain Filling Stage in Rice

A mapping population of 98 lines (backcross inbred lines, BILs) derived from a backcross of Nipponbare/Kasalath// Nipponbare was planted at two experimental sites, Nanjing and Nanchang, and treated with high and optimal temperature during grain filling, respectively. The grain weight heat susceptibility index [GWHSI= (grain weight at optimum temperature-grain weight at high temperature) / grain weight at optimum temperature × 100] was employed to evaluate the tolerance of rice to heat stress. A genetic linkage map with 245 RFLP markers and a mixed linear-model approach was used to detect quantitative trait loci (QTLs) and their main effects, epistatic interactions and QTL× environment interactions (Q×E). The threshold of LOD score=2.0 was used to detect the significance of association between marker and trait. A total of 3 QTLs controlling heat tolerance during grain filling were detected, on chromosomes 1, 4 and 7, with LOD scores of 8.16, 11.08 and 12.86, respectively, and they explained the phenotypic variance of 8.94, 17.25 and 13.50 %, correspondingly. The QTL located in the C1100-R1783 region of chromosome 4 showed no QTL× environment interaction and epistatic effect, suggesting that it could be stably expressed in different environments and genetic backgrounds, and thus it would be valuable in rice breeding for heat tolerance improvement. This QTL allele, derived from Kasalath reduced 3.31% of the grain weight loss under heat stress. One located between R1613-C970 on chromosome 1 and the other between C1226-R1440 on chromosome 7, with additive effect 2.38 and 2.92%, respectively. The tolerance alleles of both these QTLs were derived from Nipponbare. Both of these QTLs had significant QTL× environment interactions, and the latter was involved in epistatic interaction also. Eight pairs of epistatic effect QTLs were detected, one pair each on chromosomes 1,2,3, 5, 7, 8, 10 and 12. The results could be useful for elucidating the genetic mechanism of heat-tolerance and the development of new rice varieties with heat tolerance during grain filling phase.

Distribution and Virulence Diversity of Phytophthora sojae in China

By investigating occurrence of Phytophthora root rot in fields and isolating P.sojae fromdiseased plants and soils, the distribution of P.sojae in China was surveyed. In addition tonortheast region, P.sojae existed in Huanghe-Huaihe basin and Yangtze basin too. Eighty- threeisolates of P.sojae isolated from different areas were identified on virulence using 13differential soybean cultivars, abundant virulence diversity was found in P.sojae. The greaterdiversity in virulence of P.sojae was in isolates from soil than from plants. And the greatestvirulence diversity of P.sojae was found in Yangtze basin.

Cloning of Soybean 24 kDa Oleosin Gene and Its Transient Expression as a Carrier for Foreign Protein

The genomic DNA sequence encoding soybean 24 kDa oleosin and its promoter were cloned andanalyzed for investigation of the potentials of the oleosin acted as a carrier forproduction of recombinant proteins in plant. The -300 box, GA-rich, G-box, SEF-3, SEF-4, RY box, ABA box, CAn and TATA box were found in the upstream region of the soybeanoleosin gene, which shows the functional oleosin promoter available. Homology comparisonreveals that the soybean 24 kDa oleosin shares the highest identity with the soybeanoleosin isoform A (U09118, GenBank), reaching to 98.4% in nucleotide. A soybean oleosin-hirudin fusion gene driven by the oleosin promoter was constructed and inserted intoplant binary expression vector. The intact tobacco plantlets were transformed by meansof vacuum infiltration approach, with the Agrobacterium tumefaciens harboring the abovevector. The transient correct expression of oleosin-hirudin fusion gene was identifiedby SDS/PAGE, western blotting and enterokinase treatment.

Sequence Analysis of mtDNA CO/Gene and Molecular Phylogeny of Different Geographical Populations of Bemisia tabaci (Gennadius)

Bemisia tabaci(Gennadius) is a serious pest in many cropping systems worldwide and occurs in different biotypes. ThemtDNA COI gene of the 12 Bemisia tabaci (Gennadius) populations from different regions and countries were analyzed.Based on mtDNA COI sequences, their biotypes were characterized and phylogenetic relationships among thesepopulations were established with the method of UPGMA. The results indicated the genetic similarity between thosepopulations from Beijing, Zhengzhou, Zaozhuang, Nanjing, Shanghai, Haikou, and the B-biotype populations fromCalifornia, Texas, Arizona reached 99.8-100%, which meant the nation-wide infested populations of B.tabaci in China inrecent years were B-biotypes. Another population collected from Kunming of Yunnan Province showed very high similaritywith Q-biotype B.tabaci from Spain and Morocco, which meant the Kunming population was Q-biotype. This is the firstreport on the invasion of Q-biotype into China.

Effects of salinity on activities of H^+-ATPase, H^+-PPase and membrane lipid composition in plasma membrane and tonoplast vesicles isolated from soybean(Glycine max L.) seedlings

The effects of NaCl stress on the H +-ATPase, H +-PPase activity and lipid composition of plasma membrane(PM) and tonoplast(TP) vesicles isolated from roots and leaves of two soybean cultivars(Glycine max L.) differing in salt tolerance(Wenfeng7, salt-tolerant; Union, salt-sensitive) were investigated. When Wenfeng7 was treated with 0.3%(W/V) NaCl for 3 d, the H +-ATPase activities in PM and TP from roots and leaves exhibited a reduction and an enhancement, respectively. The H +-PPase activity in TP from roots also increased. Similar effects were not observed in roots of Union. In addition, the increases of phospholipid content and ratios of phospholipid to galactolipid in PM and TP from roots and leaves of Wenfeng7 may also change membrane permeability and hence affect salt tolerance.

Field Evaluation of the Asian Corn Borer Control in Hybrid of Transgenic Maize Event MON 810

In this study, a transgenic Bt maize hybrid (event MON 810 from Monsanto Company) expressing Cry1Ab protein derived from Bacillus thuringiensis (Bt) and its negative isoline hybrid were evaluated for control of the Asian corn borer, Ostrinia furnacalis (Guenée) (Lepidoptera: Pyralidae), in a field trial. Maize plants were artificially infested with neonate larvae of Asian corn borer at the mid-whorl (first-generation), pre-tassel (first- and/or second-generation), and silk (second-generation) growth stages. The transgenic Bt maize hybrid sustained significantly less leaf feeding damage (rating 1.0±0.0) than its negative isoline control (rating 7.3±0.1). With the Bt maize, 1.36.8% of plants were damaged by corn borer tunneling with <0.5 cm tunneling per stalk under different levels of infestation, compared with 100% of plants damaged with 9.325.0 cm tunneling per stalk for the negative isoline control. On average, transgenic Bt maize hybrids had only 0.010.05 tunnels per stalk and no stems were broken. In contrast, the negative isoline control had 3.118.36 tunnels per stalk and 31.273.9% of stems broken. Yields were significantly higher in transgenic Bt maize than in the control. These results demonstrate that transgenic Bt maize can significantly minimize yield losses caused by the Asian corn borer through resistance to the first- and second-generation larvae.

Mycoparasitism of Nematode-Trapping Fungus Monacrosporium ellipsosporumand Its Biochemical Basis

Monacrosporium ellipsosporum, a nematode-trapping fungus, was isolated by baiting with sclerotiaof Sclerotinia sclerotiorum in soil from a tobacco field in Yuxi, Yunnan Province. Colonizationfrequency of the sclerotia by the fungus was 18% in natural soil. Reinoculation tests byplacing surface-sterilized sclerotia on fungal cultures for two weeks and then surface-sterilized again led to 32% sclerotia be infected. Dual culture tests in PDA plates did notgive rise to a suppression zone between the colonies of M. ellipsosporum and its counterpartfungi S. sclerotiorum and Rhizoctonia solani, suggesting there was little or no nutritionalcompetition and absent of antifungal compounds. However, M. ellipsosporum could grow overabsent of S. sclerotiorum and R. solani, and significantly inhibited their growth on agarplates. Scanning electron and light microscopic observations showed that hyphae of M. ellipsosporumgrew along and appressed on hypha of S. sclerotiorum and coiled around hyphae of R. solani.Assays of cell wall-degrading enzymes showed that M. ellipsosporum grew well in chitin agarmedia, with clear transparent hydrolysis zones. Activities of total chitinase, exo-chitinase,β-1, 3-glucanase and protease were 140.2±11.9, 82.9±4.1, 111.2±7.6 and 76.1±4.3 U respect-ively, after incubation for 4 days at 30 ℃ in liquid media containing ground sclerotia of S.sclerotiorum as sole nutrient source. These enzymes might be important in the mycoparasiticactivity of M. ellipsosporum.

A Study of Agricultural Tridimension Pollution and Discussion on Its Control

The paper outlines the background of the research on control of agriculture tridimensional pollution and its tendency.The new concept of agricultural tridimension pollution (ATriP) with its control theory is initially proposed as a result ofcontinuously increased agricultural pollution within the systems of hydrosphere, pedosphere, biosphere and atmospheredue to improper use of agricultural management measures. Furthermore, the high priority of the next 5-10 years nationalresearch domains and areas, and techniques for strengthening of ATriP prevention and control is discussed.

Study on the Sensitivity and Vulnerability of Wheat to Climate Change in China

Based on B2 climate change scenario produced by PRECIS (providing regional climates for impacts studies), which wasdeveloped by the UK Hadley Center, and the wheat yield data outputted by CERES-wheat model, the sensitivity andvulnerability of wheat production to the future climate change in China were studied through analyzing the yield variationusing the GIS (geographical information system) techniques. Results showed that, by the 2070s, there will be threenegative sensitive areas of rain-fed wheat, i.e., northeastern China, the region of the middle and lower reaches of theYangtze River, and part of the Loess Plateau. Irrigated wheat is generally sensitive to the future climate change for mostareas of China, with a lower sensitive degree and a distribution of sensitive areas similar to the rain-fed wheat. For theirrigated wheat, northeast and northwest of China are strongly negative sensitive, while the middle and lower reaches ofthe Yangtze River, the coastal areas of southern China and the southwest of China, are moderately negative sensitive tothe climate change. With the appropriate adaptation to the climate change, the rain-fed wheat in most regions of China willnot be vulnerable and even has a yield increase, while the irrigated wheat will still have a larger vulnerable area (occupyingabout 2/3 of its total area in China), with the highly vulnerable regions distributed in northeastern China and northwesternChina, and the medium and light vulnerable areas distributed along the middle and lower reaches of the Yangtze River,Yunnan and Guizhou provinces.

Status and Perspectives on the Researches of Rice Glutelin Mutants

Rice (Oryza sativa L. ) is one of the model plants for genomics research. As the raising of functional rice breeding for special usage, glutelin mutants play a more and more important role in the functional rice breeding as well as eukaryotic gene expression and regulation research materials. For example, the rice cultivar special for the patients suffering from kidney disease and diabetes could be developed from the rice glutelin mutants. In this paper, current researches on characterization, mutation mechanism and breeding usage of various rice glutelin mutants, especially the low glutelin content cultivars, were all discussed with perspectives on the trends of the glutelin mutant researches in the era of post-genomics.

Genetic Diversity of Chinese Temperate and Exotic Tropical, Subtropical Quality Protein Maize Inbreds by SSR Markers

Information on genetic relationship is of great value to maize (Zea mays L.) breeding. Theobjectives of this study were: 1) to classify 22 quality protein maize (QPM) inbreds intodifferent groups by using simple sequence repeats (SSR) markers, which included exotictropical, subtropical and domestic temperate QPM and normal maize inbreds; 2) to examine theconsistency of grouping results obtained from SSR, specific combining ability (SCA) analysis,and genetic backgrounds of these inbreds. A set of 39 polymorphic SSR primers was selected from70 primer pairs, which detected 136 alleles among the 22 lines. The mean polymorphisminformation content was 0.55. Based on analysis of genetic similarities, five groups wereidentified including Luda Red Cob, Sipingtou, Reid, Lancaster and a miscellaneous group withseveral tropical inbreds which could not be classified into the above four groups. The resultsgenerally agreed with previous results based on analysis of yield combining ability andpedigree data.

Study on the Separation,Extraction of Lycopene and Its Effects on Cell Cycle

The separation, extraction of lycopene and its effects on the proliferation and cells cycle of the chemical-induced cells were investigated in order to research on its extraction method and the mechanism in inhibiting neoplastic transformation. The best extraction condition of lycopene with super-critical carbon dioxide was under the pressure of 25MPa, the temperature of 50℃ and duration of 3. 0h. Lycopene could inhibit cell growth rate and cells proliferation significantly, while increase the cell numbers of G1 -phase and decrease that of S-phase and G2+M-phase. The potency of the effects of lycopene on cells cycle might be one of the important reasons for inhibiting neoplastic transformation.

Seed Germinability of 23 Crop Species After a Decade of Storage in the National Genebank of China

Seed viability of 18 576 accessions of 23 crops was monitored. After 10-12 years storage in National Crop Genebank ofChina (NCGC), more than 96.12% of the accessions maintained high germination percentage (>85%). The germination of95 accessions, accounting for 0.51% of the total, declined significantly from above 80% to below 70%. For each crop ofcarrot (Daucus carota var. sativa DC.), lettuce (Lactuca sativa L.), cotton (Gossypium sp. L.), flax (Linum usitatissimumL.) and castor-oil plant (Ricinus communis L.), the mean monitored germination percentage declined significantly as awhole, of which carrot and lettuce seeds lost viability more rapidly. Seed initial germination percentage and pre-storageenvironments affect subsequent seed viability in storage.

Effects of Soil Moisture on Dynamic Distribution of Dry Matter Between Winter Wheat Root and Shoot

The dynamic relationship of dry matter accumulation and distribution between winter wheat root and shoot was studied under different soil water conditions. The dry matter accumulation in root was greatly influenced by water stress, so as to the final root weight of the treatment with 40% field moisture capacity(FMC) was less than 1/4 of that of the treatment with 80% FMC on average. Water stress during the 3-leaf stage to the tillering stage had the greatest influence on root, and the influence of water stress during the jointing stage to the booting stage on shoot was greater than root. However, water stress during the tillering stage to the booting stage had a balanced effect on root and shoot, and the proportion of dry matter that distributed to root and shoot was almost the same after rewatering. Water recovery during the jointing stage to booting stage could promote R/S, but the increasing degree was related to the duration of water limitation. Soil water condition had the lowest effect on R/S during the flowering stage to the filling stage and the maximal effect on R/S during the jointing stage to the heading stage, R/S of 40% FMC treatment was 20.93 and 126.09% higher than that of 60% FMC and 80% FMC treatments respectively at this period.

Relationship Between Hybrid Performance and Genetic Diversity Based on SSRs and ISSRs in Brassica napus L.

To investigate the relationship between genetic distance (GD) and hybrid performance, two types of molecular markers, microsatellites (simple sequence repeats, SSRs) and intro-simple sequence repeats (ISSRs), were employed to detect the genetic diversity of 3 double low self-incompatible lines and 22 male parental varieties of Brassica napus from different geographical origins. Hybrids were produced in a NCⅡ mating design by hand-pollination. The result indicated that 25 parental varieties (lines) could be divided into six groups by Un-weighted Pair Group Mathematics Average (UPGMA) clustering based on GDs. SI-1300 and SI-1320 could be singly clustered into one group, respectively. Varieties from China could be separated into another group, SI-1310 and varieties from foreign countries could be separated into other three groups. The grouping was generally consistent with parental pedigrees and geographical origins. Significant differences in yield, quality and phenological period traits were observed among these parent groups. Although hybrid yield/plant showed significantly positive correlation with genetic distance based on SSR and ISSR markers, but the determination coefficient was low. It appeared to be unsuitable for using the genetic distance based on SSR and ISSR markers to predict heterosis and hybrid performance in Brassica napus.

Variation of Starch Property and Its Relationship with Dry White Chinese Noodle Quality in Common Wheat

In total, 185 wheat cultivars and lines from major Chinese wheat regions, Australia and USA in two trials, sown in four and two environments, respectively, were used to investigate starch property and its relationship with dry white Chinese noodle (DWCN) quality. Significant variations were observed in all starch parameters and DWCN quality. High pasting viscosity cultivars include Sunstate, Hartog, Eradu, Cunning-han, Gamenya, Karl92, Sunco, Yangmai5, Yangmail58, Mianyang26, Een1, Yumai41, Yumai49, Zheng81-1, Yumai54, Yumai2. Yumai47, Lu955159, Lumai15, Lumai21, Shaanyou225, Guanfeng2, Ji5099, Bainong4, and Jinmai2. Wheats from Australia, USA, South China Autumn-sown Spring Wheat Region and Yellow and Huai Valley showed better starch properties and DWCN quality than those from North China Plain. High peak viscosity, breakdown and flour swelling volume were significantly associated with good DWCN quality. A relatively high frequency of Wx-B1 null alleles was detected in Chinese wheats. Cultivars with null for Wx-Bl GBSS performed higher pasting viscosity and flour swelling volume, and better DWCN quality than normal type.

Progresses in Researches of the Application of Low-Amylose Content Rice Gene for Breeding

Amylose content is a key determinant of eating quality of rice. With the characteristics offluffy texture, glossy appearance when cooked, remaining soft when cooled and excellentpuffing ability, the low-amylose rice with amylose content 5-15% could be served as not onlycooked rice directly, but also good material for convenience, mixed rice and puffing foods.Current status on characterization, inheritance, molecular mechanism and breeding of low-amylose content rice was reviewed in this paper, strategy of related researches in the era ofglymics was mainly discussed furthermore. The future research should focus on screening andenhancing the germplasm, further elucidating the molecular mechanism on mutation of lowamylose content, utilizing the genes independent of Wx on low-amylose content rice breedingprogram, and developing high quality functional rice cultivars for special usage throughpyramiding low amylose gene and other special quality genes.