Table of Content

10 September 2005, Volume 38 Issue 09

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CROP GENETICS & BREEDING·GERMPLASM RESOURCES

Joint Analysis Method for Major Genes Controlling Multiple Correlated Quantitative Traits

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Scientia Agricultura Sinica. 2005, 38(09):  1717-1724 . 

Abstract ( 1119 )   PDF (342KB) ( 1013 )   Save

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Based on the major gene and polygene mixed inheritance model for multiple correlated quantitative traits, the authors proposed a new joint segregation analysis method of major gene controlling multiple correlated quantitative traits, which include major gene detection and its effect and variation estimation. The effect and variation of major gene are estimated by the maximum likelihood method implemented via expectation-maximization (EM) algorithm. Major gene is tested with the likelihood ratio (LR) test statistic. Extensive simulation studies showed that joint analysis not only increases the statistical power of major gene detection but also improves the precision and accuracy of major gene effect estimates. An example of the plant height and the number of tiller of F2 population in rice cross Duonieai×Zhonghua 11 was used in the illustration. The results indicated that the genetic difference of these two traits in this cross refers to only one pleiotropic major gene. The additive effect and dominance effect of the major gene are estimated as -21.3cm and 40.6cm on plant height, and 22.7 and -25.3 on number of tiller, respectively. The major gene shows overdominance for plant height and close to complete dominance for number of tillers.

QTL Mapping and Interactions Between QTL and Environment for Yield and Its Components Using a DH Population Derived from a Lowland and Upland Rice Cross

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Scientia Agricultura Sinica. 2005, 38(09):  1725-1733 . 

Abstract ( 1100 )   PDF (361KB) ( 986 )   Save

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To study the difference of QTLs for rice yield and its component traits between lowland and upland conditions, a DH (doubled haploid) population including 116 lines, derived from a cross between japonica upland rice IRAT109 and japonica lowland rice Yuefu, was evaluated for plant yield (YP) and its components including 1000-grain weight (GW), seed setting percentage (SP), number of panicles per plant (PN) and grains per panicle (GN). Additive and epistatic QTLs associated with plant yield and its components and interactions between QTL and environment in 2 years were obtained using the constructed molecular linkage map（including 94 RFLP and 71 SSR markers and covering 1535cM. A total of eleven additive QTLs and thirteen pairs of epistatic QTLs under lowland condition and eighteen additive QTLs and seventeen pairs epistatic QTLs under upland condition were detected for plant yield and its components. Two additive QTLs and one pair of epistatic QTLs for 1000-grain weight and an additive QTL for number of panicles per plant were both detected under upland and lowland conditions. Of the eleven pleiotropic or tightly linked QTL regions for yield and its components three regions were also found to be the co-localized regions for root traits. There were eight additive QTLs and eight pairs of epistatic QTLs for plant yield and its components with general contributions of over 10% to phenotypic variation. These QTLs might be useful for upland rice yield molecular marker assisted selection.

Variation of Pentosans in Chinese Soft Wheat Cultivars and Correlations with Cookie Quality

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Scientia Agricultura Sinica. 2005, 38(09):  1734-1738 . 

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High water absorbing capacity of pentosans is an important parameter to affect processing quality of common wheat. Seventeen genotypes of soft wheat were sown in three locations for two years to study the genetic variation of the water-soluble pentosans (WSP), water-insoluble pentosans (WIP), and total pentosans (TP), to investigate the effects of genotype, environment and their interaction on pentosans, and to determine the relationships between pentosans and other quality parameters. Significant difference in pentosans contents were observed in soft wheat genotypes, the range for WSP, WIP and TP were 0.54%-1.07%, 0.87%-1.43% and 1.51%-2.47%, respectively. They were mainly influenced by genotype and environment, and genotype was the most important factor determining WSP, and the effect of genotype and environment interaction was not significant. The WSP, WIP, and TP were positively correlated with Fairnograph water absorption, and the correlation coefficients were 0.51, 0.55 and 0.66, respectively. WSP was negatively correlated with peak viscosity, hold through, final viscosity, and peak time, and the correlation coefficients were -0.72, -0.72, -0.66 and -0.70, respectively. WSP and TP were negatively correlated with cookie width, the correlation coefficients were -0.70 and -0.69, respectively. Therefore, it is suggested that low pentosans are preferred for soft wheat cultivars.

Proteome Analysis on ABA Sensitivity of Wheat Embryo Isolated from Cultivars Resistant or Susceptible to Sprouting

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Scientia Agricultura Sinica. 2005, 38(09):  1739-1747 . 

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There is a significant relationship between resistance to sprouting and ABA sensitivity in wheat. Variance of protein expression will take place after ABA treatment. In this study, wheat embryos isolated from resistant cultivar Shanyou 225 and susceptible cultivar Jimai 1 at 25th day after anthesis were incubated with or without ABA solution to identify ABA sensitivity, and then protein expression in the embryos was studied by proteome analysis. The results indicated that seven protein spots could be recognized according to the level of expression. They are NAD(P)H dehydrogenase, late embryogenesis abundant (LEA) protein Dc3, actin-depolymerizing factor 5 (ADF-5), calmodulin-related protein, salt-stress root protein RS1, 20 kD calcium-binding protein and auxin-responsive protein IAA19. These proteins could be divided into two categories. The abundance of some proteins, such as LEA, in dormant embryo was higher than that of non-dormant embryo，the expression level of these proteins are up-regulated by ABA. On the other hand, the auxin-responsive protein IAA19 with higher abundance in non-dormant embryo than dormant embryo was identified, its expression level was down-regulated by ABA. The proteins up-regulated by ABA are prone to express in water than ABA treatment in embryos of sprouting resistant genotype. These data are useful to study protein expression process of sprouting resistant genes.

Molecular Markers Assisted Selection in Quality Protein Maize Breeding

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Scientia Agricultura Sinica. 2005, 38(09):  1748-1754 . 

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The SSR markers linked tightly with opaque-2 (o2) can be used effectively in the quality protein maize (QPM) breeding. In this study, the SSR primer phi057 was used in the evaluation of inbred lines developed in recent years, and QPM breeding program to convert the elite normal lines into QPM. Mutation on o2 was found during the improvement of the QPM populations CPop13 and CPop14 after detection of o2 gene frequency with the marker. The o2o2 genotypic frequency in CA, CD, CB, and R series derived from the improved populations was detected as 91.7%, 80.0%, 0.0, and 100%, respectively. It was indicated that homozygous o2o2 genotype in QPM could not be ensured in conventional breeding efforts. In order to enhance the QPM germplasm basis and convert elite normal lines into QPM, the markers were used to detect o2 gene in backcross generations, and it has proved that it is a powerful tool in the breeding.

Utilization of the Rust-Resistant and High-Yield Germplasm Shanyou 27 in Peanut Breeding

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Scientia Agricultura Sinica. 2005, 38(09):  1755-1760 . 

Abstract ( 1087 )   PDF (196KB) ( 880 )   Save

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Shanyou27 is a new peanut cultivar with moderately-resistant to rust, high and stable yield, broad adaptiveness. It was bred by Shantou Agricultural Science Research Institute. Many cultivars derived from Shanyou27 became the leading cultivars or spreading cultivars at different periods in South China. To study the importance of elite germplasm in peanut breeding, the pedigree, genetic property and genetic relationship with Shanyou27, of the excellent cultivars bred directly or indirectly with Shanyou27 as parent, were analyzed. The results showed that as a direct parent, 5 excellent cultivars were derived from Shanyou27, and in turn, more than 17 excellent cultivars were further derived from the 5 excellent cultivars. Among the 22 excellent cultivars derived from Shanyou 27, 6 cultivars have been released by National Crops Cultivar Approval Committee, such as Yueyou223, Yueyou79, Yueyou7, Yueyou9, Shanyou21 and Zhanyou30. All the derived cultivars have retained the good characters of Shanyou27 such as high yield and resistant to rust. So, the author concluded that Shanyou27 is an elite central parent with high general combining ability (GCA); It is very important to select right central parent for raising the efficiency of peanut breeding.

TILLAGE & CULTIVATION·PHYSIOLOGY & ECOLOGY

Study on the site-specific nitrogen management of rice in cold area of northeastern China

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Scientia Agricultura Sinica. 2005, 38(09):  1761-1766 . 

Abstract ( 941 )   PDF (374KB) ( 1159 )   Save

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Site-specific nutrient management (SSNM) technology was introduced from International Rice Research Institute (IRRI) to solve the problems in fertilizer application on rice in cold area. A plot experiment showed that there were significantly positive correlations (P﹤0.01)between chlorophyll meter values (SPAD values) and N content in leaves, leaf color chart(LCC)values at panicle initiation and heading stages. Therefore 38-40 was considered as the critical SPAD value, and 3.5 was the critical LCC value for N application. Compared with farmers′ fertilization practice (FFP), the site-specific nitrogen management reduced the total N input by 25%, and increased the 1000-grain weight by 0.75 g, and significantly increased fertilizer-N use efficiency. The results suggested that SSNM has a great potential for reducing N input without cutting down the grain yield. SSNM is a valid agricultural approach for applying N fertilizer on rice in cold area of Northeastern China.

Effects of Water Saving Treatment at Tillering Stage on Biological Characteristics of Rice

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Scientia Agricultura Sinica. 2005, 38(09):  1767-1773 . 

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Using 4 rice varieties, the dynamic changes of several biological characteristics were studied under different degrees of water saving treatment at tillering stage. The results showed that rice plant could change the transfer of organic matter and root characters to alleviate drought harm in the course of and after water saving treatments, suggesting strong self-adjustment ability. Water saving treatment reduced water consumption of rice plant in the course of treatment and after treatment, but the difference between rice varieties was significant or highly significant. Suitable drought at tillering stage could enhance water use efficiency (WUE) of rice plant significantly in the course of and after treatment. The differences in yield and rice quality between rice varieties in various water saving treatments were significant or highly significant. The effects of water saving treatments on yield and quality depended on rice varieties, suggesting that it is very important to select rice varieties in water saving cultivation.

Effects of Oxalate on Photosynthetic Apparatus and Xanthophyll Cycle in Cucumber Leaves under High Temperature Stress

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Scientia Agricultura Sinica. 2005, 38(09):  1774-1779 . 

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Effects of exogenous oxalate on photosynthesis, chlorophyll fluorescence and xanthophyll cycle in cucumber leaves under high temperature stress at 40℃ were studied. The cucumber leaves were sprayed by 5 mmol·L-1 oxalate solution for 3 days before high temperature stress. The results showed that oxalate pretreatment alleviated the decreases of photosynthetic rate (Pn), transpiration rate (Tr), intrinsic photochemical efficiency (Fv/Fm), quantum yield of PSII (φPSⅡ), photochemical quenching (qP) and non-photochemical quenching (NPQ) by higher temperature, but has no effect on stomatal conductance (Gs) was observed. The xanthophyll cycle pool and (A+Z)/(V+A+Z) (the de-epoxidation extent of xanthophyll cycle) pretreated by oxalate was evidently higher than the control. The decrease of xanthophyll cycle pool, chlorophyll and carotenoid content, and the later period decrease of (A+Z)/(V+A+Z) during high temperature stress was inhibited by oxalate pretreatment. These results suggested that oxalate has a protective role against the damage of photosynthetic apparatus during high temperature stress.

Research on Theories and Techniques of Irrigation for Safeguarding Seed Production of Two-Line Hybrid Rice

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Scientia Agricultura Sinica. 2005, 38(09):  1780-1786 . 

Abstract ( 1124 )   PDF (335KB) ( 931 )   Save

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By inducing frequency, intensity and duration of low temperature in the middle and last ten-day periods in August in China′s southern rice-growing area, increasing temperature for safe seed production of two-line hybrid rice was defined as 2℃. During the fertility sensitive period, the characters of panicle height and canopy structure of a TGMS rice, Pei'ai64S, were measured. Results showed that the temperature changes caused by irrigation in field was below 40 cm of rice plant, and heating effect was significant at 20 cm, as increased by 3.1℃. From the present study, irrigation techniques were putted forward: the water depth at 15-20 cm, current water, irrigating at 17:00 and bailing at 10:00 at sunny or cloudy weather, irrigating for all the day at shade or rainning weather, increasing inflows and outflows in large fields. In the present experiment, pollen fertility and self-fertilized seed setting rate approved that the techniques were feasible and effective for safeguarding seed production of two-line hybrid rice.

Intercropping Advantage and Contribution of Above-Ground and Below-Ground Interactions in the Barley-Maize Intercropping

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Scientia Agricultura Sinica. 2005, 38(09):  1787-1795 . 

Abstract ( 1048 )   PDF (230KB) ( 968 )   Save

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A microplot experiment and a root barrier technique were employed to investigate the intercropping advantage and the relative contribution of above- and below-ground interactions to the yield and nutrient uptaking in the barley-maize intercropping system with or without plastic sheet mulching. The results showed that the land equivalent ratios (LERs) of both grain yield and biomass were around 1 (average 1.06) for the intercropping of barley and maize without plastic sheet mulching, showing a yield disadvantage of the intercropping. In contrast, LERs with plastic sheet mulching were 1.32 for grain yield and 1.30 for biomass, indicating a significant yield advantage of the intercropping. There was no significant advantage of nutrient uptaking in the intercropping of barley and maize without plastic sheet mulching, whereas there was significant advantage of nutrient uptaking in the intercropping with plastic sheet mulching. The contribution of above-ground and below-ground interactions to the intercropping advantage of grain yield were 80% and 20%, respectively, for the intercropping with plastic sheet mulching. Similar results were observed for above-ground biomass. The contribution of above-ground and below-ground interactions to the increase of nutrient uptaking were 50% and 50% for nitrogen, 60% and 40% for phosphorus, 45% and 55% for potassium respectively, when intercropped maize was mulched with plastic sheet.

PLANT PROTECTION

Identification of AFLP Markers Linked to Lr19 Resistance to Wheat Leaf Rust

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Scientia Agricultura Sinica. 2005, 38(09):  1796-1800 . 

Abstract ( 1008 )   PDF (242KB) ( 877 )   Save

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AFLP analysis was carried out on Thatcher, twenty three near?isogenic lines and F2 generation of Tclr19×Thatcher and developed molecular markers for gene Lr19 resistance to wheat leaf rust. Seven markers linked to Lr19 resistance traits were obtained, which were P-AGT/M-GAG289bp (3.3cM), P-ACA/M-GGT102bp (4.1cM), P-ACA/M-GGT106bp (4.1cM), P-AAC/M- CAG123bp (4.9cM), P-AAC/M-GGT203bp (5.0cM), P-ACA/M-GGT290bp (5.7cM), and P-ATC/M-GAG293bp (9.6cM). All of these specific fragments were isolated from the polyacrylamide gels, re-amplified, cloned and sequenced. The research may facilitate genetic mapping, physical mapping, and eventual cloning of Lr19 gene.

Two AFLP Markers Linked to Avirulence Gene Avr1in Phytophthora infestans

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Scientia Agricultura Sinica. 2005, 38(09):  1801-1804 . 

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Bulked segregant analysis was used to analyse segregating fluorescent AFLP markers in F1 progeny of Phytophthora infestans cross 71 (NL-80029 X NL-88133) and to select AFLP markers linked to avirulence gene Avr1. All 256 PstI+2 and HhaI+2 primer combinations were screened and this resulted in five candidate AFLP markers linked to Avr1. When tested on 50 individual F1 progenies two out of five candidate AFLP markers appeared to cosegregate with Avr1 and these can be used to position Avr1 on the molecular genetic linkage map.

Molecular Characterization of Papaya leaf curl virus Infecting Carica papaya in Guangzhou and Its Biological Test

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Scientia Agricultura Sinica. 2005, 38(09):  1805-1810 . 

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A geminivirus isolate GT infecting papaya was detected and obtained from Guangzhou, Guangdong Province. The complete nucleotide sequence of DNA-A of GT was determined to be 2 769 nucleotides in length, and had typical genomic organization of a begomovirus, encoding six ORFs with two ORFs [AV1(CP) and AV2] in virion-sense DNA and four ORFs (AC1-AC4) in complementary-sense DNA. The comparison of complete and intergenic region nucleotide sequences and encoded amino acid sequences for ORFs with other begomoviruses indicated that GT had the highest sequence identity with isolate papaya leaf curl Guangdong virus isolate GD2. The biological test of isolate GT suggested that GT could infect tobacco, tomato and papaya by whiteflies (Bemisia tabaci) transmission.

The Screen of Zwittermicin A- producing strains of Bacillus thuringiensis and cloning and expression of zmaR gene

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Scientia Agricultura Sinica. 2005, 38(09):  1811-1816 . 

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One hundred and sixty isolates of Bacillus thuringiensis were screened by PCR, and 94 of these isolates were zmaR-positive. It was found that 67 zmaR-positive isolates showed inhibitory effects on the growth of Erwinia herbicola OS, and the inhibitory activity of 21 isolates were higher than those of others. Bacillus thuringiensis isolate G03, which has cry1Ac, cry1Aa, cry1Ca and cry2Ab genes, was identified with zmaR gene and highly active to Erwinia herbicola OS. The zmaR gene was cloned from G03, and sequence analysis showed that zmaR consisted of 1 125 bp DNA fragment and encoded a protein containing 375 amino acids with 43.5 kD. The isoelectric point was pI4.945. The zmaR gene was inserted into pET-21b to generate pET-21b::zmaR, and then this recombinant plasmid was introduced into E. coli BL21 (DE3) for high-level expression. The 43.5 kD peptide could be detected by SDS-PAGE in the transformants with Zwittermicin A resistance.

Molecular Cloning and Sequence Analysis of Genes Encoding GOBP1 and PBP in the Antenna of Helicoverpa assulta（Guenée）

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Scientia Agricultura Sinica. 2005, 38(09):  1817-1824 . 

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Genes encoding GOBP1 and PBP in the antenna of Helicoverpa assulta（Guenée）were sequenced. Two pairs of primers were designed based on the comparison of GOBP1 and PBP gene sequences of Helicoverpa armigera reported previously. Two specific bands (about 400 bp in length) were amplified from cDNA of H. assulta antenna. Two segments were cloned into T-easy vector, respectively. Sequencing and structural analysis showed that the full-length of GOBP1 ORF was 441bp, 147 amino acid residues were encoded. The predicted MW and PI were 17.2 kD and 4.71, respectively. The full length of PBP ORF is 405bp, 135 amino acid residues were encoded. The predicted MW and PI were 15.1 kD and 5.2.The two sequences were deposited in GenBank and the accession number is AY864774 and AY864775.

SOIL & FERTILIZER·WATER-SAVING IRRIGATION

Delineation and Scale Effect of Precision Agriculture Management Zones Using Yield Monitor Data over Four Years

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Scientia Agricultura Sinica. 2005, 38(09):  1825-1833 . 

Abstract ( 997 )   PDF (416KB) ( 1128 )   Save

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Precision agriculture management zones were delineated using yield data over four years from the combine harvester equipped with yield monitor and DGPS receiver in this study. Relative yields measured in each year were interpolated to 4 m square grid size using ordinary kriging. This resulted interpolated yield maps were averaged across years to create a map of the mean relative yield, which was then used for cluster analysis. The 4-m mean yield map of postclassification was processed by applying majority filtering with window sizes that were equivalent to the grid sizes of 12, 20, 28, 36, 44, 52 and 60 m. The scale effect of management zones was evaluated using relative variance reduction, test of significant differences of the means of yield zones, spatial fragmentation and spatial agreement. The results showed that the postclassification majority filtering (PCMF) removed lots of isolated cells or patches caused by random variation while preserving the yield means, a high variance reduction, the general yield patterns and high spatial agreement. The zoned result can be used as yield goal map for preplant or in-season fertilizer recommendation algorithms in precision agriculture.

Modelling the relationship between summer maize NPK uptake and yield on the basis of the soil fertility indices

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Scientia Agricultura Sinica. 2005, 38(09):  1834-1840 . 

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The QUEFTS (QUantitative Evaluation of the Fertility of Tropical Soils) model was calibrated for summer maize using the soil fertility data and fertilizer trials results at different sites in Huanghe-Huaihe-Haihe Plain. The essence of QUEFTS model takes into accoun of the interactions among nitrogen (N), phosphorus (P) and potassium (K). QUEFTS describes the relationship between soil parameters and yield in four steps: (1) assessment of the potential supply of N, P and K on the basis of chemical soil data; (2) calculation of the actual uptakes of N, P and K, as functions of the potential supplies determined in step 1; (3) designation of yield ranges as functions of the actual uptakes of N, P and K determined in step 2;(4) calculation of the ultimate yield estimate by combining the three yield ranges established in step 3. New equations were established in step 1. The relationships between N, P and K recovery fractions and their applied amount were established, respectively. The contents of minimum and maximum accumulation (kg grain kg-1) of N, P, and K for summer maize are set to（21-64）,（126-384）and（20-90）,respectively. The simulated values showed a good consistence with the observed one.

Effects of Long-Term Fertilization on Distribution of Organic Matters and Nitrogen in Cinnamon Soil Aggregates

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Scientia Agricultura Sinica. 2005, 38(09):  1841-1848 . 

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Soil samples, collected from the 25-year long-term fertilizer experiment carried out on the manual loessial soil situated sub-humid farmland ecological system, were used to study the distribution of soil organic matters, total nitrogen, nitrate nitrogen, and ammonium nitrogen in different grades of soil aggregates in order to study the effects of long-term application of organic manures in combination with chemical fertilizers. Result showed that the percentage of mass of the soil macro-aggregates with long-term application of fertilizers, whose sizes are between 5-2 mm, is increased compared with that of the samples with no fertilizer. It is easier to form lager size soil macro-aggregates because of the long-term application of organic manures in combination with chemical fertilizers. As the results show that the contents of organic matters, total nitrogen and nitrate nitrogen are all higher after those treatments with different combinations of fertilizers, while there is a little effect on the contents of ammonium nitrogen after the same treatments. The contents of organic matters, total nitrogen in the grades of soil macro-aggregates from the plough layers of those treated farmland exhibit significant difference. Moreover, the contents of organic matters and total nitrogen in the soil macro-aggregates with the size of 1-0.25 mm is the highest in all types of treated soil samples. The contents of nitrate nitrogen in soil macro-aggregates increase with the increasing of soil macro-aggregate size except those of soil samples with the application of chemical fertilizer and lower amount of straw. The results of correlation analysis reveal that there exists a significant positive correlation between the percentage of mass of soil macro-aggregates with the size of 5-2 mm and the contents of organic matters and total nitrogen and the nitrate nitrogen in the soil samples. However, the correlation between the percentage of mass of soil macro-aggregates with the size of 1-0.25 mm and the contents of total nitrogen and nitrate nitrogen is significantly negative. From the study it is also showed that the highest contributing rates of macro-aggregates fractions in soil fertility is from the soil macro-aggregates fraction with the size of 1-0.25 mm in most of the cases.

Leached Nitrate in Vegetable Field Under Different Water and Nitrogen Fertilizer Management Practices

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Scientia Agricultura Sinica. 2005, 38(09):  1849-1855 . 

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During 3 consecutive years (1999-2001), a field experiment was conducted in an intensively irrigated vegetable soil in Northern China. The main objective was to study leached nitrate (NO3--N) characteristics in vegetable field under traditional and improved water and nitrogen fertilizer management practices during vegetable growing seasons. The soil water content, soil water potential and extract of the soil solution were determined by a combination of TDR (time domain reflectometry) probe, tensiometers and ceramic suction cups. The results showed that the amount of nitrate leached decreased because water drainage was reduced when applied water was reduced. Cumulative leached NO3--N amount under traditional water treatment was 4.4 times and 4.5 times of that of improved in traditional and improved nitrogen fertilizer application management. When nitrogen fertilizer applied was reduced the amounts of leached nitrate also decreased obviously. Cumulative leached nitrate amount under improved nitrogen fertilizer management was 20% and 19% of that of traditional management in traditional and improved water treatments, respectively. The amounts of nitrogen fertilizer applied were the main factor affecting nitrate concentration in soil solution at the depth of 90 cm in soil profile. Nitrate concentration in soil solution at the depth of 90 cm under traditional nitrogen fertilizer management was higher than that of improved nitrogen fertilizer management. In the whole experiment the amount of nitrate leached was 549 kg·ha-1, which was 27% of the nitrogen applied under traditional water and nitrogen fertilizer management practices and nitrate leaching amount was 24 kg·ha-1, which was 5% of the nitrogen applied under improved water and nitrogen fertilizer management practices. Improved water and N-fertilizer management practices greatly decreased nitrate leaching without reducing vegetable yield.

HORTICULTURE

Cloning and Sequence Analysis of Cold and Longday Induced Expressed Genes from Sugar Beet (Beta vulgaris L.) Seedlings

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Scientia Agricultura Sinica. 2005, 38(09):  1856-1862 . 

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cDNA representational difference analysis (cDNA-RDA) was applied to clone genes specifically expressed in cold and longday induced sugar beet (Beta vulgaris L.). One cDNA fragment was obtained after 3 rounds of subtractive hybridization and amplified by 3′-RACE and 5′-RACE. A sequence of 609 bp cDNA named Ty7Br600 and 855 bp DNA named Ty7Br900 were obtained respectively by RT-PCR and PCR after cloning and sequencing. Blasting in GenBank shows no homology with them, suggesting that it may be a novel gene of sugar beet. Results of Northern blotting and Southern blotting showed that the cDNA clone was only expressed in the cold induced sugar beet and low copy in sugar beet genome.

Research on Heredity Trend of Some Characters in F1 Progenies of Apricot

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Scientia Agricultura Sinica. 2005, 38(09):  1863-1868 . 

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Inheritance of some characters including self-compatibility, the rate of fertile flowers, average fruit weight, and sweet or bitter kernel were studied with 5-6 years old seedlings of F1 progenies from Katy × Xinshiji, Katy × Hongfeng, Katy × Taianshuixing and Taianshuixing × Katy. The results were as follows: Firstly, the S-locus of Katy was heterozygous, and self-compatibility was dominant to self-incompatibility. Secondly, a very extensive segregation in self-pollinated fruiting rate, fertile flower rate and average fruit weight was observed in the F1 populations, and averages of these traits were lower than that of mid-parent means. Therefore, these traits were confirmed to be quantitative. But significant differences were found in coefficient of variation(CV) and broad-sense heritability (H2) of the three characters: CV and H2 of self-pollinated fruiting rate were both greatest, with the variation mainly resulted from inheritance, and high inheritance potential; H2 of fertile flower rate was the least and its variation was less from inheritance; CV of average fruit weight was the least and its inheritance potential is small. Thirdly, the ratios of sweet to bitter kernel of F1 progenies in positive and reverse crosses between Katy and Taianshuixing were 18∶16 and 13∶12, and were both in agreement with a 1∶1 segregation by χ2 test, which demonstrated that the bitter kernel character of Katy was heterozygous.

Classification of Wheat Cultivar by Digital Image Analysis

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Scientia Agricultura Sinica. 2005, 38(09):  1869-1875 . 

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Digital image analysis was used to develop a pattern recognition algorithm to classify individual kernels of seven Chinese spring wheat cultivars grown at 4 locations. Totally, 20 morphological parameters and 12 color parameters were extracted. Three hundred kernels per sample were used as the training data set to develop identification model, and another 200 kernels were used as the test set. For the test set, the classification accuracy of wheat cultivars was 100% in each growing location. Except for Xinkehan 9 with 98.3%, the correct discrimination of the training set of collective samples is 100% for wheat cultivar. For the test set, the correct discrimination of Longmai 26 and Qingchun 566 were 97.5% and 95.0%, the others is 100%. For the origin of wheat grains, the classification of Gansu, Ningxia, Xinjiang and Heilongjiang were 88.6%, 92.9%, 72.9% and 95.7%, respectively. The results show that it is feasible to identify and classify wheat cultivar (grains) using digital image analysis.

Relationship Between the Extrusion Properties and Quality Properties of Maize

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Scientia Agricultura Sinica. 2005, 38(09):  1876-1881 . 

Abstract ( 1068 )   PDF (257KB) ( 883 )   Save

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The 53 maize varieties from the Huanghe, Huaihe and Haihe Plain, China's main maize-producing zone, were studied using a Brabender Lab-station of DSE-25 Twin-Screw Extruder. Relationship between the extrusion properties and quality properties of maize varieties was studied. The results showed that there were great differences in radial expansion ratio, bulk density, water-solubility index (WSI), water-absorption index (WAI), and hardness among extrudates of the varieties. Compared with the summer maize varieties, spring maize varieties had higher radial expansion ratio, higher WAI, higher output, lower WSI and lower specific mechanical energy (SME). Except the test weight, 100-kernel weight and 100-kernel volume of the varieties were correlated significantly with radial expansion ratio, torque, the 5th zone pressure and output of extrudates. Extrudates of maize varieties with higher starch content, lower protein content and lipid content had higher radial expansion ratio, lower bulk density, lower hardness, higher torque, higher the 5th zone pressure and SME. Pasting properties of maize varieties were correlated with extrusion properties. Pasting-parameter could be used to predict extrusion properties of maize varieties.

Relations Between Cartenoids and Aromatic Components from the Cartenoids in Flue-Cured Tobacco (Nicotinna tobacum L.) Leaves at Different Mature Periods

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Scientia Agricultura Sinica. 2005, 38(09):  1882-1889 . 

Abstract ( 868 )   PDF (455KB) ( 1387 )   Save

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The quantitative determination results on cartenoids and aromatic components of the cartenoids in flue-cured tobacco leaves from Panxi region, Sichuan Province at different mature periods. The results showed that the contents of cartenoids decreased gradully during the mature periods of flue-cured tobacco leaves in Panxi region. The contents of aromatic components of the cartenoids in the lugs of flue-cured tobacco leaves increased gradully during the end of mature period, but there were not in cutters. The contents of damascenone increased gradully during the mature period of flue-cured tobacco leaves from Panxi region, but the contents of dihydroactinolide decreased gradully. The content of β-inone was little during the mature period of flue-cured tobacco leaves and it was non at the end. The contents of megastigmatrienones increased during the mature period.

ANIMAL SCIENCE·VETERINARY SCIENCERE·SOURCE INSECT

The Levels of Genetic Differentiation of Small Tailed Han Sheep and Tan Sheep Populations Using Structural Loci

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Scientia Agricultura Sinica. 2005, 38(09):  1890-1897 . 

Abstract ( 876 )   PDF (337KB) ( 666 )   Save

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Using the method of " random sampling in typical colonies of the central area of the habitat " and several electrophoresis techniques, the variations of 17 structural loci encoding blood proteins in 60 Small Tailed Han sheep and 73 Tan sheep were examined and compared with those of 14 other sheep populations in China and other countries to explore their levels of genetic differentiation. The average heterozygosity of Small Tailed Han sheep and Tan sheep was 0.2360 and 0.2587, respectively. The average polymorphic information content valued 0.1974 and 0.2102, respectively. The average effective numbers of alleles were 1.5723 and 1.5751, respectively. The coefficients of gene differentiation in four groups (including 4, 6, 13, 16 sheep populations, respectively) were 0.049323, 0.059987, 0.1728 and 0.201256, respectively, indicating that the degree of gene differentiation at structural loci in Hu sheep, Tong sheep, Small Tailed Han sheep and Tan sheep was least, that in above-mentioned four sheep populations and two Mongolian sheep populations was the second, and that in sheep populations belonging to Mongolian sheep group, South Asian sheep and European sheep was the highest. The earlier researchers' conclusions that Small Tailed Han sheep and Tan sheep both evolved from Mongolian sheep was further verified by the results in this study. Hu sheep, Tong sheep, Small Tailed Han sheep and Tan sheep were decreasingly affected by the bloodline of Mongolian sheep. The relationships among sheep populations were not closely related to the distances among sheep populations.

Development of a Molecular Clone of Chinese Equine Infectious Anemia Virus Donkey Adapted Strain

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Scientia Agricultura Sinica. 2005, 38(09):  1898-1904 . 

Abstract ( 965 )   PDF (495KB) ( 899 )   Save

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An equine infectious anemia virus donkey adapted strain (designated as DV), which has lethal virulence to horse and donkey, was obtained through serials passaging in donkeys in vivo used a wide-type EIAV isolate. Three fragments covering entire genome of DV were amplified by PCR techniques from DV infected donkey leucocyte culture. The full-length genome was cloned into a low-copy number vector pLG338 using molecular clone strategies and a recombinant plasmid (designated pD70344) was obtained. pD70344 was used to transfect fetal donkey dermal cell culture in vitro and passaged in donkey leucocyte cells. The supernatants of passages were tested to be positive by reverse transcriptase activity (RT) assay and EIAV special RT-PCR. Cytopathogenic effects were observed by 5-6 days post infection in donkey leukocyte infected with the pD70344 derived virus. EIAV-like virions were also observed by electronic microscope in donkey leukocyte passages. And sequence analysis of this derived virus shows highly coincident with original DV strain. Tow donkeys were inoculated with this virus and developed typical equine infectious anemia symptom. These results showed that a pathogenic infectious molecular clone of EIAV DV was obtained, and it has provided an important tool for evaluating of gene function on EIAV attenuation.

Effects of Low Concentration Enrofloxacin on SPF Mice Intestinal Microflora

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Scientia Agricultura Sinica. 2005, 38(09):  1905-1910 . 

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In this study, SPF mice model has been developed to study the effects of enrofloxacin on fecal aerobic and anaerobic populations, selection of bacteria resistant to ciprofloxacin, maintenance of the intestinal barrier against exogenous E.coli. Enrofloxacin was administered via drinking water(1, 10 and 100 mg·L-1) to SPF femal mice for 48 d. Total aerobic flora counts, Enterococci counts and Bacteroides counts decreased significantly following exposure to 100 mg·L-1 enrofloxacin. Total aerobic flora counts were also affected by 10 mg·L-1 enrofloxacin. Enrofloxacin exposure at 1, 10 and 100 mg·L-1 increased the percentage of aerobic populations resistant to 1 ?g·ml-1 ciprofloxacin. 100 mg·L-1 enrofloxacin also increased the percentage of Bacteroides resistant to 16 ?g·ml-1 ciprofloxacin. The resistance colonization of some SPF mice was impaired at 1, 10 and 100 mg·L-1 enrofloxacin.The results indicated that enrofloxacin can partly decrease the aerobic populations, but pose little effects on anaerobic populations. In conclusion, the effects of low concentrations enrofloxacin on SPF mice fecal bacteria population and resistance colonization were not significant, the most important impact of low concentrations enrofloxacin on SPF mice intestinal microflora may be resistance selection and increase the percentage of resistant aerobic flora to ciproflxacin. The ADI of enrofloxacin and ciprofloxacin established by Ministry of Agriculture may affect human intestinal microflora by selecting resistant aerobic flora.

Effect of Chinese Herbal Medicinal Ingredients on IL-2mRNA Levels of T Lymphocytes in Mice Measured with Semi-quantification RT-PCR

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Scientia Agricultura Sinica. 2005, 38(09):  1911-1916 . 

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In this study, the IL-2 mRNA levels of T lymphocytes in normal mice stimulated by nine Chinese herbal medicinal ingredients(CHMIs) were measured with a reverse transcription and semi-quantification polymerase chain reaction. The results showed that astragalus polysaccharide(APS), epimedium polysaccharide(EPS), Chinese angelica polysaccharide(CAPS), propolis flavone(PF)and astrogaloside(AS) promoted IL-2 mRNA levels in T lymphocytes in vitro and in vivo in different degrees, and the level of IL-2 mRNA induced by propolis polysaccharide(PPS) in vitro was higher than that of the control, which differed from that of PPS in vivo.

Expression of PKCα in Pulmonary Arterioles and Its Association with Pulmonary Vascular Remodeling in Broilers with Pulmonary Hypertension Induced by Cold Temperature Exposure

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Scientia Agricultura Sinica. 2005, 38(09):  1917-1922 . 

Abstract ( 857 )   PDF (400KB) ( 788 )   Save

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The present study was conducted to examine the expression of protein kinase Cα (PKCα) in pulmonary arterioles in broilers with pulmonary hypertension induced by cold temperature exposure and the relationship between PKCα and pulmonary vascular remodeling. One hundred and sixty Avian-2000 broilers were divided equally into a normal temperature control group (NT) and a low temperature group (LT) at 14-day-old of age. The group LT was subjected to low temperatures by lowering 1-2°C per day from 28 °C (day 14) down to 14-12 °C (day 21), and remained constant until the end of the experiment, while the group NT was still reared at normal temperatures (house temperature was 20 °C from day 21 on). PHS incidence was recorded. Ratio of right/total ventricle (RV/TV), packed cell volume (PCV) and hemoglobin (Hb) were measured at 24, 32, 39 and 45-day-old of age, respectively. Vessel wall area to vessel total area (WA/TA), mean media thickness in pulmonary arterioles (mMTPA) were determined using computer-image analytic software, and expression of PKCα in the pulmonary arterioles labeled by immunohistochemistry and quantified by measuring optical density (OD) using computer-image analytic software. PHS incidence amounted to 3.75% and 12.5% in groups NT and LT, respectively (P < 0.05). PCV in the group LT was elevated after day 32 (P < 0.05), and RV/TV ratio increased on day 45 (P < 0.05). Both the WA/TA and mMTPA of broilers in the group LT were significantly elevated (P < 0.05). There were no differences in OD value between the two groups before day 32 (P > 0.05). However, one week later (at day 39 of age), the OD value of broilers in the group LT was significantly increased (P < 0.05). The increased OD values were positively correlated with mMTPA and WA/TA. These results demonstrated that PKCα expression was increased in broilers with pulmonary hypertension, and increased expression of PKCα might enhance pulmonary vascular remodeling.

RESEARCH NOTES

Detection of QTL Conferring Resistance to Bacterial Leaf Streak in Rice Chromosome 2 (O. sativa L. spp. indica)

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Scientia Agricultura Sinica. 2005, 38(09):  1923-1925 . 

Abstract ( 926 )   PDF (222KB) ( 792 )   Save

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A F2 population from a cross between two indica rice cultivars, Minghui86 and Jiafuzhan, which are moderately and highly resistant to bacterial leaf streak (BLS) respectively, was established. One QTL conferring the resistance to BLS was detected in the region between microsatellite markers RM279 and RM154 on chromosome 2 of rice (O.sativa L. spp. indica) using SSR (simple sequence repeats) marker, which could explain 13.7% of the phenotypic variation. Its additive effect from Jiafuzhan is 0.9576.

Differences of Panicle Trait Index Among Varieties and Its Relationship with Yield and Quality of Rice in Liaoning

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Scientia Agricultura Sinica. 2005, 38(09):  1926-1930 . 

Abstract ( 865 )   PDF (268KB) ( 1175 )   Save

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Using rice varieties bred recently in Liaoning as materials in this study. The results showed that the characters of panicle and characters of quality were significantly different among different varieties. It was advantageous to increase processing quality by increasing numbers of panicle and 1000-grian weight, and it was advantageous to improve the appearance qualities by increasing seed setting rate or that of secondary branch especially. The effects of high seed setting rate of secondary branch on processing qualities and appearance qualities or eating qualities were negative. It was put forward that using panicle trait index (PTI, the ratio between the number of axis internode whose number of grains of secondary branch was almost the primary branches and number of primary branch) to show the distribution characteristic of the number of grains of secondary branches on the axis. The PTI of these materials distributed between 0.29 and 0.61. These materials were classified into superior-on-the-upper-part type (SUT) and superior-on-the-middle-part type (SMT) or superior-on-the-lower-part type (SLP) according to the PTI. When the number of grains of secondary branches were superior on the middle or upper part, in other words the number of PTI was bigger, it is advantageous to increase not only the seed setting rate and yield but also improve quality.

Heterosis and Inheritance Analysis of Ear Shape and Quality Characters in Super Sweet Corn

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Scientia Agricultura Sinica. 2005, 38(09):  1931-1936 . 

Abstract ( 972 )   PDF (317KB) ( 1063 )   Save

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Heterosis and inheritance of commodity characters were studied by heterosis analysis and Hayman. The results indicated that bald length and kernels per row in super sweet corn were easily affected by parents which the additive effect made main rule. Inheritance of sugar content and pericarp thickness conformed to the “additive-dominant” model and the characters were controlled by more than 3 pairs of genes, which the heritability in a narrow sense were respectively 53.0% and 29.6%.Sugar content was controlled by additive effect having more importance than dominant effect and pericarp thickness was controlled by dominant effect having more importance than additive effect . there existed super dominant effect.