Scientia Agricultura Sinica

Analysis of Interaction Between QTL and Environment on Chlorophyll Contents in Rice

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Scientia Agricultura Sinica. 2005, 38(10): 1937-1943 .

Abstract ( 1084 )

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The aim of the paper is to dissect the genetic factors controlling chlorophyll content of rice leaf by QTL analysis. A linkage map consisting of 207 DNA markers were constructed by using 247 recombinant inbred lines derived from an indica-indica rice cross Zhenshan 97B Milyang46. In 2002 and 2003, the chlorophyll a and b contents of the parents and 247 RILs were measured on the top first leaf, top second and top third leaves, respectively. The software QTLMapper 1.6 was applied to detect quantitative trait loci (QTLs), additive by environment interactions and epistatic by environment interactions. A total of 8 QTLs in 4 intervals were detected to have significant additive effects on chlorophyll a and b contents at different leaf positions with 1.96%- 9.77% phenotypic variations explained by a single QTL, and 2 QTLs with significant AE interactions were detected. Epistasis analysis detected 9 significant additive-by-additive interactions on chlorophyll a and b contents, and one pair of QTLs with significant AAE interactions was detected. On comparison with QTLs for yield traits detected in the same population, it was frequently found that QTLs for chlorophyll a and b contents and those for yield traits were located in same intervals.

Allelic Variation at the Glu-1 and Glu-3 Loci and Presence of 1B/1R Translocation, and their Effects on Processing Quality in Cultivars and Advanced Lines from Autumn-Sown Wheat Regions in China

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Scientia Agricultura Sinica. 2005, 38(10): 1944-1950 .

Abstract ( 1102 )

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Storage protein composition played an important role in determinating the processing quality in common wheat. Totally, 251 Chinese wheat cultivars and advanced lines from autumn-sown wheat regions in China were used to investigate the high molecular weight glutenin subunits (HMW-GS) and low molecular weight glutenin subunits (LMW-GS) composition controlled by the Glu-1 and Glu-3 loci, as well as the presence of 1B/1R translocation, and to determine the association of storage protein composition with protein content, SDS sedimentation value, and dough properties. HMW-GS of Null, 7+9, 2+12, and LMW-GS of Glu-A3a and Glu-B3j associated with poor quality were the dominant glutenin subunits, and their frequencies were 39.4%, 45.0%, 59.8%, 37.1% and 44.6%, respectively. Less significant effect of glutenin subunits and glutenin subunit interaction was observed on protein content. According to the glutenin subunit contribution to SDS sedimentation value, mixing time and mixing tolerance, different glutenin subunit loci could be ranked as: Glu-D1>Glu-B3>Glu-B1>Glu-A3>Glu-A1. At Glu-A1, 1>2*>N; at Glu-B1, 7+8> 14+15>7+9; at Glu-D1, 5+10>4+12>2+12; at Glu-A3，Glu-A3d>Glu-A3a>Glu-A3c>Glu-A3e; at Glu-B3, Glu-B3d>Glu-B3b> Glu-B3f>Glu-B3j. Lines carrying 1B/1R translocation showed significantly deleterious effect on gluten quality such as SDS sedimentation, mixing time and mixing tolerance.

Mapping QTL for Seedling Root Traits in Common Wheat

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Scientia Agricultura Sinica. 2005, 38(10): 1951-1957 .

Abstract ( 1592 )

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A doubled haploid (DH) population with 150 lines, derived from a cross between two common wheat varieties Hanxuan10 and Lumai14, was used in this research. Several root traits including root number (RN), maximum root length (MRL), root fresh weight (RFW), root dry weight (RDW), ratio of root fresh weight to shoot fresh weight (RFW/SFW) and ratio of root dry weight to shoot dry weight (RDW/SDW) per plant of hydroponic seedlings were measured under water stress and control conditions, respectively. Quantitative trait loci (QTL) and G×E interactions for these traits were detected using mixed-model-based composite interval mapping method. A total of 11 additive QTL and 15 pairs of epistatic QTL associated with root traits were mapped on all chromosomes except 5A, 4B, 2D, 6D and 7D. Among these QTL, 3 QTL with additive effects and 2 pairs of epistatic QTL controlling root number, 3 QTL with additive effects and 3 pairs of epistatic QTL controlling maximum root length, 2 QTL with additive effects and 2 pairs of epistatic QTL controlling root fresh weight, 2 QTL with additive effects and 3 pairs of epistatic QTL controlling root dry weight, 2 pairs of epistatic QTL controlling ratio of root fresh weight to shoot fresh weight and 1 QTL with additive effects and 3 pairs of epistatic QTL controlling ratio of root dry weight to shoot dry weight were detected. One additive QTL × environment and three pairs of epistatic QTL × environment interaction effects were also identified. The possibility of using marker-assisted selecting root traits and drought tolerance in wheat was discussed.

Breeding and Characterization of Wheat-Thinopyrum intermedium Alien Substitution Line Shannong 0095

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Scientia Agricultura Sinica. 2005, 38(10): 1958-1964 .

Abstract ( 1187 )

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A new wheat germplasm, Shannong0095, was produced from the hybrids of BC2F4 derived from the progeny of Triticum aestivum cultivar, Yannong15, crossing with Thinopyrum intermedium after the hybrid F1 back-crossing with the Yannong 15 two times and three self-crossings. And it was characterized by using morphology, cytology, alcohol soluble protein- poly acrylamide gel electrophoresis (A-PAGE), random amplified polymorphic DNA (RAPD) and genomic in situ hybridization (GISH) analysis. The results were as follows: Shannong 0095 had plant height of 78 cm, ear length of 17.3 cm, number of mean spike of 74, flag leaf length of 36.3 cm, flag leaf width of 3.03 cm, stout haulm, and more flowers and more seeds, which showed that it was more luxuriant than that of Yannong 15. The chromosome number of Shannong 0095 in root tip cell was 2n=42 and its chromosome configuration at PMC MI was 2n=21Ⅱ. Two univalent were observed in most of PMC MI of the hybrids F1 of the crossing between Shannong 0095 and Yannong 15. The mean chromosome configuration of the hybrids F1 was 2n＝20.08Ⅱ+1.84Ⅰ. A-PAGE result testified that a specific Thinopyrum intermedium band in β area was observed in Shannong 0095. Among 180 RAPD primers, the primer S186(5?-GAT ACC TCGG -3?) revealed a specific Thinopyrum intermedium DNA band, about 900bp, that presented in Shannong 0095 and was designed as S186900. The result of GISH with the probe of Thinopyrum intermedium genomic DNA and the blocker of Chinese Spring (C.S) genomic DNA further conformed that Shannong 0095 contains 2 intact chromosomes of Thinopyrum intermedium and is a wheat- Thinopyrum intermedium alien disomic substitution line.

Molecular Identification of the Sterile Cytoplasm of NCa of a Cytoplasmic Male Sterile Line in Rapeseed ( Brassica napus L.)

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Scientia Agricultura Sinica. 2005, 38(10): 1965-1972 .

Abstract ( 1310 )

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PPrevious research on the NCa, a cytoplasmic male sterile (CMS) line in Brassica napus, showed that it might hold a new type of sterile cytoplasm. RFLP analysis of the mitochondrial (mt) DNA of the 5 CMS lines, i.e., NCa, pol, nap, ogura and tour CMS, combining 14 probes originated from mt genes with 4 endonuclease, such as EcoR I, BamH I, Hind III and Pst I, was performed and detected that 42 combinations of probe/enzyme out of the total 54 combinations could discover the different bands among the 5 CMS lines and then distinguish some of them from the others. Moreover, 5 combinations of atp1/EcoR I, atp1/Hind III, atp6/EcoR I, atp8/BamH I, and orf139/BamH I, could powerfully distinguish the 5 CMS lines from each other. These 5 combinations of probe/enzyme could be exploited as markers to identify the cytoplasmic type of rapeseed CMS. These results definitely demonstrated the NCa CMS hold a new type of sterile cytoplasm different from pol, nap, ogura and tour CMS. Twenty-two primers were designed according to the Arabidopsis mt genome and the mt regions which controlled the cytoplasmic male sterility of pol, nap, ogura CMS lines, and were used in PCR analysis of mt DNA from the above five CMS lines. The PCR results proved that no one of the 22 primers could distinguish the NCa CMS from the other four.

Variations in the Milling Quality of Grains at Different Positions Within a Rice Panicle

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Scientia Agricultura Sinica. 2005, 38(10): 1973-1979 .

Abstract ( 1227 )

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Milling quality of the grain is one of the most important quality indexes of rice. However, little is known what difference in the milling characters among the grains at different positions within a rice panicle. This study has investigated the distribution of the percentages of brown rice (BR), milled rice (MR) and head rice (HR) for different grains on a panicle. Two rice cultivars, Yangdao 6 (indica rice) and Wuyujing 3 (japonica rice), were field-grown. Three levels of nitrogen, 0, 120 kg·ha-1, and 240 kg·ha-1, were applied at pre-planting and topdressing. All primary branches on a panicle were evenly divided into three parts of the upper, middle and basal. The grains were numbered as 1 to 6 on a primary branch and 1 to 3 or 4 on a secondary branch from the top to base. Generally, BR, MR and HR for the grains on a primary branch were greater than those on a secondary branch at the same part of a panicle. On a secondary branch, the grain 1 had the least BR, MR and HR, and the grain 3 or 4 had the greatest. On a primary branch, the grain 2 had the greatest BR and HR, and the grain 1 had the least; the distribution of MR at different positions within a rice panicle or on a secondary branch varied with the amount of nitrogen applied. The milling quality of the grains at different parts in a panicle of Wuyujing 3 was better than those of Yangdao 6, especially the grains on a secondary at the same part of a panicle. Application of nitrogen fertilizer could improve the milling quality of rice when the amount of nitrogen was between 0 and 240 kg·ha-1.

Differences in Characteristics of Quality and Related Enzymes Activity of Different Wheat Cultivars

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Scientia Agricultura Sinica. 2005, 38(10): 1980-1988 .

Abstract ( 996 )

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Nine wheat cultivars with different protein contents, GMP content, wet gluten content, SDS sedimentation, and dough stability time at maturity were classified into three groups: high GMP content and high dough stability time, low GMP content and low dough stability time, and medium GMP content and medium dough stability time. The dynamic changes in the content of soluble protein and the activity of the enzymes in relation to protein synthesis and degradation and their relationships to characteristics of processing quality were studied during grain filling. The results showed that protein content was not related to wet GMP content, SDS sedimentation, and dough stability time but GMP content was significantly related to the said indices, implying that GMP content was more representative to processing quality than protein content. During the early period of grain filling NR and GS activities had significants effect on soluble protein content and during the later period EP, CP and AP activities has significant effects. The group with high GMP content had higher soluble protein content than other groups. The above results indicated that during grain filling, higher soluble protein level, namely high NR and GS activities during the prophase and metaphase, and high EP, CP, and AP activities during the metaphase and anaphase, was the physiological basis for high GMP content.

Assessment of Cotton Delayed Cool Injury by Heat Index and Significance in Xinjiang

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Scientia Agricultura Sinica. 2005, 38(10): 1989-1995 .

Abstract ( 985 )

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【aim】To assess cotton delayed cool injury objectively, 【method】 The calculation method of heat index was designed to assess heat on the growth of cotton in this paper. Based on the average temperature of a period of ten days collected from nine representative stations located in three cotton regions in Kashi, Akesu and the north of Xinjiang，heat index were calculated at five growth stages and heat index at the beginning, middle, end and the whole growth stage were obtained. 【result】 Analysis showed that heat index could qualify for assessing heat not only at the whole cotton growth stage but also at every period of ten days, certain or several growth stages. As the index values have corresponded well with the year of yield reduction due to climate, it can be used as a reference of cotton production and distribution of types. Moreover, it could better reflect the occurrence status and extend of delayed cool injury in cotton. 【conclusion】Therefore, heat index is a proper index in assess ment of cool injury.

EST-Markers Flanking the Rice Bacterial Blight Resistance Gene Xa23 and Their Application in Marker-Assisted Selection

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Scientia Agricultura Sinica. 2005, 38(10): 1996-2001 .

Abstract ( 1228 )

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A F2 population, with 2 562 individuals, of JG30/CBB23 was constructed for molecular mapping of the bacterial blight resistance gene Xa23 in rice. Inoculation test of the F2 plants showed that the segregation ratio of resistant and susceptible fits to 3:1. Based on the amthors previous mapping of Xa23 gene, 12 EST markers from Rice Genome Program (RGP) database were surveyed in the susceptible F2 plants and two markers, C189 and CP02662, were found flanking the Xa23 gene, with genetic distance of 0.8cM and 1.3cM, respectively. These two EST markers were successfully used in rice breeding program. The results showed that efficiency of C189 marker-assisted selection (MAS) for Xa23 gene was almost 100%. Three elite hybrid rice restore lines with Xa23 gene and improved bacterial blight resistance have been developed.

Changes of Several Important Materials in Transgenic Bt Rice

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Scientia Agricultura Sinica. 2005, 38(10): 2002-2006 .

Abstract ( 1179 )

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In order to provide metabolism evidence for ecology and safety assessment of transgenic Bt rice, several important materials in transgenic Bt rice "Shanyou 63" with cry1Ab/cry1Ac genes and non-transgenic "Shanyou 63" without cry1Ab/cry1Ac genes were analyzed. Results showed that the contents of most amino acids in stems and leaves of transgenic Bt rice "Shanyou 63" and in non-transgenic rice "Shanyou 63" had significant or highly significant differences at heading stage. And during the majority growth stages, the contents of N, P and Si in two rice lines had significant or very significant difference, but their trends of change with time were basically accordant: The contents of N and P gradually decreased after stem-drawing stage, while the contents of Si gradually increased with the growth of rice. In the early growth stage, water-soluble sugar and reducing sugar contents in transgenic Bt rice "Shanyou 63" were significantly lower than those of non-transgenic "Shanyou 63", but in late growth stage, were significantly higher than those of non-transgenic "Shanyou 63".

Cross-Resistance and Relative Fitness of Lambda-Cyhalothrin Resistant Near-Isogenic Lines in Spodoptera exigua (Hübner)

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Scientia Agricultura Sinica. 2005, 38(10): 2007-2013 .

Abstract ( 997 )

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The cross-resistances to 13 insecticides in different resistant NILs-RR and NILs-RS strains of Spodoptera exigua to Lambda-cyhalothrin were determined in the laboratory. The results indicated that the high resistance strain (NILs-RR) showed a high level to all of the tested pyrethroids (15.2- to 92.6- fold), middle level to fipronil, abamectin, methomyl, and methylaminoavermectin (14.1- to 67.5-fold), and low level to chlorpyrifos, chlorfenapyr, tebufenozide and phoxim(3.0- to 7.2-fold). However, it was found that the low resistance strain (NILs-RS) possessed much high level to fipronil and abamectin (13.3- to 14.3-fold), moderate level to α-cypermethrin, fenvalerate, methomyl, chlorfenapyr and methylaminoavermectin (5.8- to 9.9-fold), and low level to beta-cyfluthrin, deltamethrin and fenpropathrin (2.6- to 2.9-fold). Relative fitness experiments for the populations of lambda-cyhalothrin-susceptible (SS), NILs-RR and NILs-RS strains of Spodoptera exigua, showed that relative finesses of NILs-RS and NILs-RR were 0.870 and 0.893, in comparison with that of SS strain. The intrinsic rates of natural increase of SS, NILs-RR and NILs-RS were 624.7, 543.6, and 557.8 respectively. There was no significant difference in the fitness between SS and different resistant lambda-cyhalothrin genotypes (NILs-RS and NILs-RR) of Spodoptera exigua. From the research, other pyrethroids, fipronil and abamectin are the high cross-resistance level insecticides to the lambda-cyhalothrin resistance of Spodoptera exigua, and couldn't be mixtured and rotated; But phoxim, tebufenozide and chlorpyrifos could be used with lambda-cyhalothrin for the lower cross-resistance risk. In the high lambda-cyhalothrin resistance level area, immigrated into the susceptible population maybe a good approach for resistance management.

Bioactivities and Physiological Effects of Extracts of Peganum harmala Against Bursaphelenchus xylophilus

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Scientia Agricultura Sinica. 2005, 38(10): 2014-2022 .

Abstract ( 1008 )

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Peganum harmala L. is a resistant plant distributed in the desert area of China. The rising intensity of moisture, level of resinosis and index of disease of pine infected by mixed instar of Bursaphelenchus xylophilus were not significantly different from CK when pine branch were treated with 250 ?g?ml-1 of n-butanol extract of P. harmala in water-potted test, which indicated n-butanol extract of P. harmala shows control effects superior to petroleum ether, chloroform and water extract against B. xylophilus. The total alkaloid extract, harmaline, harmine and 8 fractions named A1-A8 were obtained from n-butanol extract. Result of these fractions' nematocidal toxicity test showed that harmaline, fraction A1 and A6 would be the main nematocidal components of P. harmala, their values of LC50 were 135.74,160.40 and 86.02 ?g?ml-1 after 48 h against mixed instar B. xylophilus, respectively. The n-butanol extract, total alkaloid, harmaline, harmine, fraction A1 and A6 all could not significantly inhibited the activities of aldaline phoisphatase, but AChE and acid phosphatase in vivo. After 6 h when mixed instar of B. xylophilus were treated at the concentration of 100 ?g?ml-1, the activities of AChE and acid phosphatase were inhibited by 50.15%-73.14% and 38.56%-48.37%, respectively. The inhibition rate of α-carboxylesterase activity were 39.78%, 33.80%, 34.85% and 54.22% after 12 h treated with total alkaloid extract, harmaline, harmine and fraction A1 at concentration of 100 ?g?ml-1. However, n-butanol extract, harmine and fraction A1 significantly suppressed the activity of β-carboxylesterase than other extracts, the inhibition rate of activity got 42.79%, 33.66% and 30.02%, respectively after 12 h treated at the same concentration of 100 ?g?ml-1. Based on these experimental results, it is inferred that one of the nematocidal mode of action may inhibit the activity of AChE for P. harmala extract. More researches are needed on nematocidal components of P. harmala to search the main active compounds and develop some new kinds of biorational nematocide.

Current Developments of Heat Shock Proteins in Insect

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Scientia Agricultura Sinica. 2005, 38(10): 2023-2034 .

Abstract ( 1230 )

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Heat shock proteins, or Hsps, are a small number of highly conserved protein synthesized in cultured cells or whole organisms, which exposed to elevated temperatures. It has been observed in every organism in which it has been sought, from prokaryote to eukaryote . This paper briefly reviews recently studies and focus on the traits of the major hsps family, cohorts assisting hsps , regulation of heat shock gene expression, and the possibility of signal transduction pathways. And then analyses the functions of hsps with regard to being molecular chaperone, inducing thermotolerance and stabilizing cytoskeleton. Aging and evolutional importance, biomarker and therapeutic application of Hsps are also discussed.

Estimation of Soil Organic Matter Mineralization in the Plough Layer and CO2 Emission Under Different Farming Practices in China's Huang-Huai-Hai Plain

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Scientia Agricultura Sinica. 2005, 38(10): 2035-2042 .

Abstract ( 1354 )

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Huang-Huai-Hai plain is the most important region for grain production with winter wheat-summer corn rotation in one year as its dominating cropping system in China. Soil organic matter (SOM) dynamics and management in intensive agricultural soils is significant for sustainable crop production. Based on the 10-20-years data of 7 independent long-term soil fertility and fertilizer efficiency experiments total in 76 treatments, SOM dynamics in the plough layer were simulated by the modified CQESTR model. The results shows: the SOM mineralization rate (MR) in the plough layer increases with the magnitudes of annual organic inputs, indicating improvement in SOM quality, the inter-annual mean value of which ranges from 2.16% to 5.95% in the 76 treatments; at the respective sites the inter-annual mean MR of minimum is 54.2% that of maximum. Both quantity and quality of SOM will rise upon the increment of inorganic manure and/or organic manure applied. The inter-annual mean carbon dioxide flux (FCO2) mineralized from organic compounds in the plough layer ranges from 337.1 g CO2·m-2·a-1 of minimum to 2 144.3.7 g CO2·m-2·a-1 of maximum, on the average the mean FCO2 of minimum is 31.9% that of maximum at the respective sites. Statistical analysis shows that MR enhances 0.22 percent point and FCO2 enhances 96.5 g CO2·m-2·a-1 when annual crop yield increases 1 t·ha-1; the annual apparent soil respiration efflux (EFCO2) from whole soil profile reflects not merely the intensity of soil organism and plant metabolism, but the SOM MR in the plough layer with regression coefficient r2 of 0.31 on 1235 pairs of data between MR and EFCO2

Effect of Long-Term Fertilization on Soil Productivity and Nitrate Accumulation in Gansu Oasis

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Scientia Agricultura Sinica. 2005, 38(10): 2043-2052 .

Abstract ( 1306 )

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A long-term (1982-2001) field experiment was conducted on a calcareous soil at Zhangye, Gansu under wheat (Triticum aestivum L.)-wheat(Triticum aestivum L.)-corn (Zea mays L.) rotation system in order to determine the effects of long-term fertilization on crop yield, content and accumulation of nitrate-N in soil profiles. Twenty-four plots in a split-plot include eight treatments [nitrogen (N), phosphorus (P), potassium (K) and farmyard manure (M) application] and 3 replicates were designed. Main treatments were M and no M, and the sub-treatments were no-fertilizer (CK), N, NP and NPK. In P and K were part of treatments, their ratio to N was 1N﹕0.22P﹕0.42K. All M, P and K fertilizers were applied as the basal dressing. The crops were harvested for grain yield in all years and for straw yields from 1988 to 1997. After crop harvest in 2000, the soil was sampled from the 0-20, 20-60, 60-100, 100-140 and 140-180 cm depths to determine NO3--N content. The twenty-year grain yield decreased in the order of MNPK≥MNP＞NPK＞MN＞NP＞M＞N＞CK. Corn yield of CK in 2000 was only 28.2% of that in 1984, and wheat in 2001 was 25.7% of that in 1982. Average impact of fertilizers on grain yield decreased in the order of N＞M＞P＞K. Yield response to N and P fertilizers increased with progression of the experiment. K fertilizer showed no effects on increase of grain yield during the initial 6 years (1982-1987), moderate effects in the next 5 years (1988-1992), and dramatic effects in the last 9 years (1993-2001). The straw yield trend was similar to grain yield. Accumulation and distribution of NO3--N in soil was significantly affected by annual fertilizations. Chemical fertilizers (NP and NPK) caused NO3--N accumulation in most subsoil layers, with major impact in the 20-140 cm depth. The combination of chemical fertilizers and M (MNP and MNPK) reduced soil NO3--N accumulation as compared to chemical fertilizers alone. In conclusion, long-term fertilization significantly improved grain and straw yield in this rotation. The findings suggest that it is important to balance the application of chemical fertilizers and manure in order to protect soil and underground water from potential NO3--N pollution while keeping high productivity in the Oasis agro-ecosystem.

Nitrous Oxide Emission from Cropland and Its Driving Factors Under Different Crop Rotations

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Scientia Agricultura Sinica. 2005, 38(10): 2053-2060 .

Abstract ( 1031 )

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Field experiments were carried out from June 2003 to May 2004. Three crops of maize, soybean and rice were planted in summer season of 2003 followed by winter wheat. A static opaque chamber-GC technique was used to detect the emissions of N2O and CO2 in situ. Soil temperature, moisture and relevant crop parameters were measured. Results showed that there was a significant difference in the annual N2O emissions from different rotation plots. Higher N2O emission was observed in the plot of maize-wheat rotation with an annual amount of (18.5±0.7) kgN·ha-1. Lower N2O emissions were found in the plots of rice-wheat and soybean-wheat rotation with the annual amounts of (11.7±0.7) kgN·ha-1 and (13.2±0.4) kgN·ha-1, respectively. The soybean-growing season did not receive any additional fertilizer in the soybean-wheat rotation. In the rice-wheat plot, no-plowing practice before wheat sowing enhanced N2O emission significantly (P<0.001) in wheat-growing season from sowing to the winter as compared with that from the plowing plot, while no significant increase was observed over the wheat-growing season. A further investigation suggests that a stepwise regression function of y=a·W+b·T+c·L+d can be employed to quantify the influence of soil moisture (W), temperature (T) and leave area index (L) on N2O emission. The y is expressed as ln (FLUXN2O). The function did not show significant correlation between y and L for the maize plot, and thus c=0. The y did not correlate with W and T for the soybean plot, and thus a=0 and b=0. In the irrigated rice paddy, the y did not correlate with L. In addition, N2O emission was generally correlated to ecosystem respiratory rate for the plots of soybean, rice and wheat, while no significant correlation was found for the maize plot.

Effect of Alternate Partial Root-Zone Drip Irrigation on Yield and Water Use Efficiency of Cotton

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Scientia Agricultura Sinica. 2005, 38(10): 2061-2068 .

Abstract ( 1042 )

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Afield experiment was conducted in the oasis region of Shiyang River basin, Gansu Province to research the effect of alternate partial root-zone drip irrigation(ADI) and conventional drip irrigation(CDI) on soil water distribution, cotton growth, yield and water use efficiency(WUE). The results showed that ADI provided smaller stomata opening to reduce the useless luxury transpiration loss, the height of cotton under ADI was restricted under low irrigation level, but not significant under high level. Results showed that compared with CDI, seed cotton yield under ADI increased by 21.1% with total water use efficiency and irrigation water use efficiency being improved by 17.9% and 20.9%, respectively. Results also showed that seed cotton yield under ADI had no significant difference with 30.8% water being saved. It suggesteds that ADI is a practiced irrigation method which should be researched and applied in cotton producing of arid areas.

Effects of Plastic Film Mulching of Millet on Soil Moisture and Temperature in Semi-Arid Areas in South Ningxia

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Scientia Agricultura Sinica. 2005, 38(10): 2069-2075 .

Abstract ( 1311 )

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The effects of film mulching of millet on soil water content were studied in semi-arid areas in loess plateau of South Ningxia. Different mulching methods including water micro-collecting farming(WF), water micro-colleting farming in winter fallow(WW)，hole seeding on film(HF), hole seeding on film in winter fallow(HW) were compared to determine the effects of mulching methods on soil water collecting and conservation during millet growth periods of 2003-2004, the variation tendency of water after rainfall, output of millet and water use efficiency(WUE). The experimental results in successive two years indicated that water micro-collecting farming had the function of better collecting water after rainfall, and side infiltrated water was stored under its ridge and the top layer 0-40 cm soil water changes were greater. WF had obvious water collection and preservation of soil moisture f. WF effectively improved the water supply capacity by about 19.05% in the end of growth seasons. The storage of HW and WW increased by 24.9 and 7.1 mm compared with CK, and output of yield were obviously increased. Film mulching increased the yield of millet and enhanced water use efficiency (WUE). During different growth periods, WF had better water storage, the lower amount of water consumption, and demonstrated better social and ecological benefits.

Effct of Continuous Cropping of Different Vegetables on DNA Polymorphorism of Soil Bacterial

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Scientia Agricultura Sinica. 2005, 38(10): 2076-2083 .

Abstract ( 1455 )

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Soil bacterial communities were examined by culture-independent means, namely, 16S rDNA-nested PCR-DGGE profiling. Crude DNA was extracted from soil grown with different vegetables for different years, amplified with bacterial specific primers of 16S rDNA by PCR, and separated by denaturing gradient gel electrophoresis (DGGE). Subsequently, bands on DGGE gels were cloned, sequenced and the resultant information was used to infer the diversity of bacteria in different soils. The results showed that soil samples collected from same area had the high identity in DGGE bands patterns. Bacterial community structure was significantly influenced by continuous cropping system. The effects were closely related to the kind of vegetables and the history of continuous cropping. The sequence results showed that most of the bacteria belong to Proteobacteria; Acidobacteria, Sphingobacteria and Actinobacteria also appeared in the continuously cropped soils.

A Preliminary Analysis of Genetic Relationships for Prunus mume Sieb. et Zucc. by AFLP

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Scientia Agricultura Sinica. 2005, 38(10): 2084-2089 .

Abstract ( 1005 )

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The genetic relationships among a variety, a hybrid and 18 Mei flower cultivars were preliminarily investigated using AFLP. Nineteen selected primer combinations revealed 918 legible loci, 324 of which were polymorphic ones that accounting for 35.29% of the total. Based on the SAS average similarity cluster analysis, 20 Mei samples were classified into four groups as λ=0.9759. P. mume var. cernua showed the highest polymorphism among these samples. 'Duoezhusha' and 'Fubanxiaogongfen' showed less polymorphism than P. mume var. cernua. In the group IV, AFLP and cluster analysis results were as follows: Parentages of some Mei flower cultivars were successfully identified. The results showed differences between 'Xiaogongfen', 'Jiangnanzhusha' and their hybrids which would be useful to clear the confusions of homonyms and synonyms. There were close genetic relationships among cultivars of pendulous group, which supported traditionally classified system using branch gesture as the important morphological character in Mei flowers. The pendulous cultivars were more evolutionary than others, which is in conform with their cultivated history. These results demonstrate that AFLP technique is an efficient method for evaluating the genetic relationships and diversity of Mei flower.

Effect of Deacetylation in Course of Konjac Glucomannan Carboxy Methylation and Structure Characterization of the Products

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Scientia Agricultura Sinica. 2005, 38(10): 2090-2095 .

Abstract ( 1170 )

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The acetyl groups are attached to konjac glucomannan (KGM), deacetyltion occurs on alkaline treatment and causes the association of molecular chains. The improved method of konjac glucomannan (KGM) carboxy methylation was proposed in this paper according to the effects of deacetylation. Carboxymethyl KGM (CMK) were synthesized by blending KGM with etherification agent first and then basifying and catalyzing in ethanol. Basifying first and then etherifying prepared traditional carboxymethyl KGM (TCMK). Using both degree of substitution (DS) and apparent viscosity (η) as evaluation indexes, the reaction conditions were determined. The contrast of two modification methods show different sequence of deacetyltion and the results indicate that the CMK has better value of DS=0.5278 (70℃, pH 12 for 3 hours) and η=15.57 Pa·s (55℃, pH 9 for 2 hours) and excellent hydrated rate. The structure of products was characterized by means of infrared spectra, wide-angle X-ray diffraction and differential scanning caloriimetry and the effect of deacetylation in course of konjac glucomannan carboxy methylation was analyzed.

Study on Analysis of Mogrosides by HPLC/ESI/MS2

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Scientia Agricultura Sinica. 2005, 38(10): 2096-2101 .

Abstract ( 1422 )

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【aim】A HPLC/ESI/MS2 method was developed for the qualitative analysis of mogrosides from fruits of Siratia grosvenori.【method】HPLC/ESI/MS2 was used to separate and analyze mogroside extracts from fruits of Siratia grosvenori. 【result】The main components of mogroside in mogroside extracts were 11-oxo-mogroside-V, mogroside-V, mogroside-IV, mogroside-VI and siamenoside-I according to mass spectrometry analysis of main chromatogram peaks. 【conclusion】HPLC／ESI/MS2 is a convenient, rapid and effective method for separation and qualitatively analysis of mogrosides from fruits of Siratia grosvenori.

Study on Fresh-Keeping Physiological Activity of Dong Jujube Using Low Temperature Combined with Hypobaric and Ozone Treatments

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Scientia Agricultura Sinica. 2005, 38(10): 2102-2110 .

Abstract ( 1016 )

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The effects of low temperature, hypobaric and ozone treatments on physiological activities and biochemical attributes of Dong Jujube fruit during storage were studied, and suitable conditions for storage of Dong Jujube fruit were obtained. The results showed that hypobaric or ozone treatment reduced respiratory rate, inhibited the activities of amylase and ascorbic acid oxidase, slowed down degradation rates of starch and ascorbic acid, inhibited reproduction of mold spores, reduced fruit rot and kept fruit firmness. Application of hypobaric storage reduced chilling injury of Dong Jujube fruit and, thus lower storage temperature could be used. Based on the orthogonal experiments, Zhanhua Dong Jujube fruit treated with 300 mg·m-3 ozone for 0.5 h at 10 days intervals were stored at -2℃ and 40.5 kPa under the condition of enough humidity, the accepted fruit percentage was 92.6% after 140 days of storage.

Effects of IGF-I, TGF-α, bFGF on Porcine Oocytes Maturation in vitro and Oocytes Cleavage

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Scientia Agricultura Sinica. 2005, 38(10): 2111-2116 .

Abstract ( 1175 )

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Effects of IGF-I, bFGF, TGF-α separation or combination on porcine oocytes maturation in vitro and cleavage after parthenogenetic activation were studied. The results showed that : (1)The maturation rate and the cleavage rate derived from oocytes matured in medium supplemented with 20 ng·ml-1 IGF-I is significantly higher compared with control and 10, 30, 40, 50, 100 ng·ml-1 groups[ (85.3 ±2.11)%, (85.4±2.81)%; (71.1 ±1.91)%, (62.5 ±0.98)%; (77.5 ±2.5)%, (59.1 ±3.93)%; (61.9 ±1.72)%, (54.3 ±3.48)%; (58.6 ±4.26)%, (53.1 ±1.23)%; (44.4 ±5.10)%, (49.8 ±3.55)%; (33.9 ±3.48)%, (46.1 ±3.59)%, P<0.05]，however when IGF-I solution arrive to 100 ng·ml-1, the maturation rate and the cleavage rate is greatly significant lower than other group (P<0.05)； (2)The maturation rate (85.0 ±1.70)% and the cleavage rate (85.0±2.82)% derived from oocytes matured in medium supplemented with 20 ng·ml-1 bFGF is greatly significant higher than other group (P<0.05)；(3) The maturation rate (86.9±0.46)% and the cleavage rate (86.3±2.01)% derived from oocytes matured in medium supplemented with 15 ng·ml-1 TGF-α is greatly significant higher than other group (P<0.05)；(4) The maturation rate and the cleavage rate derived from oocytes matured in medium supplemented with 15 ng·ml-1 TGF-α and 20 ng·ml-1 bFGF is significantly higher compared with 20 ng·ml-1 bFGF and 20 ng·ml-1 IGF-I group；15 ng·ml-1 TGF-α and 20 ng·ml-1 IGF-I group, 20 ng·ml-1 bFGF, 20 ng·ml-1 IGF-I and 15 ng·ml-1 TGF-α combation group.[(89.2±1.44)% and (88.8±0.17)%. (75.6±0.98)% and (78.3±1.65)% ; (77.2±2.54)% and (80.2±2.26)%; (76.4±1.28)% and (77.4±3.73)%, P<0.05].

Molecular Cloning of 45W Gene Family of Taenia solium Oncosphere

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Scientia Agricultura Sinica. 2005, 38(10): 2117-2123 .

Abstract ( 1239 )

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45W related genes were amplified by RT-PCR from the hatched and activated oncospheres of Taenia solium, cloned and sequenced. A total of 16 transcripts were obtained, suggesting that 45W related genes had far more than five members as previously reported. The 45W-4B clone in our study was found to be highly conversed. The protein encoded by 4B transcript would be a good candidate for the development of recombinant vaccine against cysticercosis in pigs. The modified transcripts A3E/X and B2E/X were expressed in the form of GST fusion protein in E. coli. The fusion proteins of GST-A3E/X and GST-B2E/X could not be detected using sera from humans infected with cysticercosis. Also, GST-A3E/X fusion protein could not be detected by sera raised from pigs infected with oncospheres. Transcripts of this family encode glycoproteins with a transmembrane region located at the C terminal. The secondary structures of 45W proteins were characterized with Cn-Em repeat units and a 16-17 amino acids comprised α-helix structural unit. In the processing of 45W proteins, the phosphorylated modification on which some functions are depended may be important. These results suggest that 45W proteins' functions are complicated, related with the regulation of gene expression and maintance of the cellular cytoskeleton and so on.

Cloning and Expression of 3A, 3B, 3C Gene Fragments of Foot-and-Mouth Disease Virus and Antibody Dynamic of Expressed Products

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Scientia Agricultura Sinica. 2005, 38(10): 2124-2128 .

Abstract ( 1000 )

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3A, 3B, 3C gene fragments were successfully subcloned from 3ABC gene of the foot-and-mouth disease virus ( FMDV ) Taibao strain and their expressing plasmids were constructed by inserting the target gene fragments into Pgex-4T-1 or 24B11 vectors，respectively. The expressed proteins were analysed by Western blotting. The results showed that the 3A and 3B expressing products could specifically react with FMDV positive serum while the reaction of the 3C product was negative. Indirect ELISAs were developed using purified 3A and 3B proteins as antigens respectively, and 4 groups of background-known cattle sera were tested. Negative results were obtained for the non-vaccinated control group and the vaccinated group. On the contrary, positive results were achieved for the infected group and part of the infected post-vaccination group. In the infected group and infected post-vaccination group, the longest duration of the antibodies against 3A and 3B lasted for at least 90 days. The earliest appearing times of 3A, 3B antibodies were 5th and 10th days after infection, respectively.

The Cloning, Expression and Bioactivity Research of Recombinant Chicken IGF-Ⅰ

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Scientia Agricultura Sinica. 2005, 38(10): 2129-2133 .

Abstract ( 1166 )

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With the reverse transcription polymerase chain reaction (RT-PCR), the DNA sequence encoding the chicken's insulin-like growth factor Ⅰ (IGF-Ⅰ) was amplified, which was then cloned into vector pMD18-T and sequenced. The sequencing result showed that there was 100% homology among the documented sequences and sequence reported here, which was successfully inserted into the expressing plasmid pRLC and was highly expressed in E coli. The Tricine-SDS-PAGE result showed that the cloned recombinant protein expressed in the form of inclusion bodies in the E.coli cell with molecular weight of 7.6 kD and amounted to 23 % of the whole protein in the E.coli cell, and Western blotting indicated that recombinant protein had the antigenicity of IGF-Ⅰ. The inclusion bodies were subsequently dissolved in 7 mol·L-1 guanidine chloride and renatured with dilution in refolding buffer containing 0.5 mol·L-1 arginine. In order to obtain pure protein, the renatured chicken IGF-Ⅰ was desalted by Hiprep 26/10 and purified by Hiprep Sephacryl S-200 chromatography. The biological activities of IGF-Ⅰproduct was assayed in NIH 3T3 cells and osteoblastic cells of embryonic chicken by using MTT method. The results showed that the expressed IGF-Ⅰ obviously stimulated NIH3T3 cells and osteoblastic cells to proliferate at the concentration ranging from 0.1 mg·ml-1、0.2 mg·ml-1、0.4 mg·ml-1、0.8 mg·ml-1, suggesting that the protein has its biological activities.

Molecular Coning and Sequence Analysis of MyoD in Grass Carp (Ctenopharyngodon idella)

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Scientia Agricultura Sinica. 2005, 38(10): 2134-2138 .

Abstract ( 1050 )

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Total RNA was isolated from grass carp embryos at 22 h post-fertilization to clone the MyoD cDNA by using rapid cDNA end amplification, and the sequence was analyzed with other animals. The results showed that: the full-length of grass carp MyoD is 1 597 bp, with 825 bp open read frame enconding 275 amino acids, including a bHLH domain which composes of 1th to 84th amino acids and 98th to 141th amino acids, without signal peptide; Compared grass carp MyoD with other animals, the results showed that the length of MyoD peptide is related to the evolution of animal, and the homology of nucleotide and amino acid accords with genetic relationship among the animals; Cloning of grass carp MyoD is meaningful for researching the mechanism of fish's muscle development and dominate, it is also helpful for improving the muscle quality of fish artificially.

SSR Fingerprinting Analysis on Distinct Mutants of Fiber Development in Gossypium hisutum

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Scientia Agricultura Sinica. 2005, 38(10): 2139-2146 .

Abstract ( 1128 )

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The polymorphism and cluster analysis based on genetic similarity matrices of SSR markers were used to identify three groups of isogenic lines genetically distinct in fiber development. The three groups of isogenic mutants includes: (1) fuzzless-lint mutant GZNn, GZnn, n2, fuzzed-lint line NN2-2 and the upland cotton genetic standard line TM-1; (2) fuzzless-lintless mutant XZ142w and its wild type XZ142. (3) fuzzless-lintless mutant Xinxiang xiaojie wuxu (Xin) which maybe derived from CCRI No.12 or Yumian No.4. SSR markers and morphologic analysis indicated that the mutant fuzzless-lintless Xin maybe the mutant of Yumian No.4. The molecular marker analysis indicated that the mutant XZ142w possessed lots of mutant genes and genetic differences compared with that of the wild type. .Moreover, the results of research showed that the polymorphic SSR primers can groupe the mutants with similar phenotypes together. This indicated that the variability of germplasm phenotypes accorded with the cluster analysis of SSR markers. Therefore, SSR marker technology is one kind of effective techniques for analysis germplasm genetic differences and biodiversity.

Genetic Analysis of Combining Abilities and Heterosis in Contents of Soybean Isoflavone and Its Components Among the Soybean Varieties [Glycine max (L.) Merr.]

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Scientia Agricultura Sinica. 2005, 38(10): 2147-2152 .

Abstract ( 855 )

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In this study the genetic analysis of soybean isoflavone contents and its components were carried out based on the NCⅡMating Design in eight soybean varieties. The results showed that the isoflavone contents and its components of soybean seed are quite different among the tested materials, the contents of isoflavone and daidzein are controlled not only by additive effects but also by non-additive effects, while the content of genistin is dominated by non-additive effects, and genistein, glycitin and daidzin are mainly controlled by additive effects. There are significant differences in the contents of isoflavone and its components among the different combinations derived from different parents. The results also indicated that the tested traits of this study are negative heterosis except for the contents of daidzein. Daidzin are positive heterosis based on the data of the GCA and SCA in average heterosis values. It is suggested that soybean variety with high isoflavone contents should be used as one of the parents in breeding program, and it is the best choice that the combinations crossed between two high isoflavone varieties or a high variety and a low one.

Establishment of the PCR Method for Detection of Suis Eperythrozoonsis

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Scientia Agricultura Sinica. 2005, 38(10): 2153-2156 .

Abstract ( 1430 )

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The 16s ribosomal RNA gene of suis eperythrozoon was amplified using gene specific primers from DNA that had been extracted from the blood of infected pig. The 936bp positive product was obtained by PCR and was cloned into the pMD18-T sector. The fragment was sequenced after restriction enzyme analysis and further defined with PCR. The sequence data demonstrated that the complete sequence was similar with the published. PCR assay for identification of eperythrozoonosis was developed. Results show that PCR assay has specificity.

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