The Optimization for Crop Planning and Some Advances for Water-Saving Crop Planning in the Semiarid Loess Plateau of China

The establishment of water-saving crop planning is an inevitable choice of the water-saving agriculture for the water-deficiency region in the arid and semiarid Loess Plateau of China and the world. The water-saving crop planning refers to the planting structure that centres the adjustment of the crop's adaptation to water, the optimization of temporal and spatial layout for crops, the local natural resources, marketing resources, human resources and financial input to enable region or basin with limited water resources to achieve the maximum economic, social and ecological benefits of planting industry under certain technology and economy. After the analysis on the research progress of optimization theory, optimization goals, optimization methods of water-saving cultivation structure and macro-control measures, it is pointed out that the main deficiencies of the current research of water-saving cultivation pattern optimization are lacking of a strong theoretical basis, and the immaturity of optimization technologies. The future crucial research direction will focus on five aspects such as the special optimization theory system, the division methods by studying the watershed unit and using 3S technology, optimization model based on multi-objective evolutionary algorithm, evaluation of rationality and macro-control measures on the basis of the public participation.     

Starch Content and Granule Size Distribution in Grains of Wheat in Relation to Post-Anthesis Water Deficits

Post-anthesis soil moisture condition is closely associated with grain yield and quality in wheat ( Triticum aestivum L.). To investigate the effect of post-anthesis water deficit (WD) on starch content and granule size distribution, pot-experiments were conducted in 2006–2007 and 2007–2008 growing seasons, using five wheat cultivars with different amylose content. The result showed that the grain starch granules had a bimodal curve in the volume and surface area distribution, and a unimodal curve was found in number distribution. Post-anthesis WD reduced the B-granules (<10 μm in diameter) volume % and surface area % in Nuomai50206 and Gaocheng8901, increased the proportion in Weimai10, whereas the effect on those in Jinan17 and Shannong15 was not significant. Post-anthesis WD decreased the number % of <2 μm starch granules, significantly in all cultivars. The amylose content was negatively correlated with the volume of <10 μm and positively correlated to >15 μm starch granules, respectively, suggesting that small starch granules (<10 μm) are low in amylose content, whereas, big starch granules (>15 μm) are high. The results indicate that the grain starch granule size distributions of Jinan17 and Shannong15 with high amylose content were less affected by WD, than those of Nuomai50206 and Gaocheng8901 with low amylose content.     

大豆品种的再生性能及对EHA 101农杆菌的敏感性

大豆转化可利用农杆菌和子叶节转化系统,bar基因作为选择标记,草丁膦作为选择试剂.用5-6 d发芽的种子的子叶节作外植体,在子叶节处划5-6下,用含pPTN 140的农杆菌EHA 101感染后,共培养3 d,用含抗生素的洗液洗去外植体上的农杆菌,将外植体放入5 mg/L草丁膦的长芽培养基,两周后统计不同大豆品种的再生率,4周后做GUS染色对含pPTN1     

Intensification of New Zealand beef farming systems

This study used whole-farm management, nutrient budgeting/greenhouse gas (GHG) emissions and feed formulation computer tools to determine the production, environmental and financial implications of intensifying the beef production of typical New Zealand (NZ) sheep and beef farming systems. Two methods of intensification, feeding maize silage (MS) or applying nitrogen (N) fertiliser, were implemented on two farm types differing in the proportions of cultivatable land to hill land (25% vs. 75% hill). In addition, the consequences of intensification by incorporating a beef feedlot (FL) into each of the farm types were also examined.Feeding MS or applying N fertiliser substantially increased the amount of beef produced per ha. Intensifying production was also associated with increased total N leaching and GHG emissions although there were differences between the methods of intensification. Feeding MS resulted in lower environmental impacts than applying N even after taking into account the land to grow the maize for silage. Based on 2007/08 prices, typical NZ sheep and beef farms were making a financial loss and neither method of intensification increased profitability with the exception of small annual applications of N, especially to the 75% hill farm. These small annual additions of N fertiliser (<50 kg N/ha/yr applied in autumn and late winter) resulted in only small increases in annual N leaching (from 11 to 14 kg N/ha) and GHG emissions (from 3280 to 4000 kg CO₂ equivalents/ha). Limited N applications were particularly beneficial to 75% hill farms because small increases in winter carrying capacity resulted in relatively large increases in the utilisation of pasture growth during spring and summer than the 25% hill farms. Intensification by incorporating a beef feedlot reduced environmental emissions per kg of beef produced but considerably decreased profitability due to higher capital, depreciation and labour costs. The lower land-use capability farm type (75% hill) was able to intensify beef production to a proportionally greater extent than the higher land-use capability farm (25% hill) because of greater potential to increase pasture utilisation associated with a lower initial farming intensity and inherent constraints in the pattern of pasture supply.     

Short-term effects of nitrogen on methane oxidation in soils

 The short-term effects of N addition on CH₄ oxidation were studied in two soils. Both sites are unfertilized, one has been under long-term arable rotation, the other is a grassland that has been cut for hay for the past 125 years. The sites showed clear differences in their capacity to oxidise CH₄, the arable soil oxidised CH₄ at a rate of 0.013 μg CH₄ kg^–1 h^–1 and the grassland soil approximately an order of magnitude quicker. In both sites the addition of (NH₄)₂SO₄ caused an immediate reduction in the rate of atmospheric CH₄ oxidation approximately in inverse proportion to the amount of NH₄ ⁺ added. The addition of KNO₃ caused no change in the rate of CH₄ oxidation in the arable soil, but in the grassland soil after 9 days the rate of CH₄ oxidation had decreased from 0.22 μg CH₄ kg^–1 h^–1 to 0.13 μg CH₄ kg^–1 h^–1 in soil treated with the equivalent of 192 kg N ha^–1. A ¹⁵N isotopic dilution technique was used to investigate the role of nitrifiers in regulating CH₄ oxidation. The arable soil showed a low rate of gross N mineralisation (0.67 mg N kg^–1 day^–1), but a relatively high proportion of the mineralised N was nitrified. The grassland soil had a high rate of gross N mineralisation (18.28 mg N kg^–1 day^–1), but negligible nitrification activity. It is hypothesised that since there was virtually no nitrification in the grassland soil then CH₄ oxidation at this site must be methanotroph mediated. Received: 31 October 1997     

有机肥对水稻根际土壤中微生物和酶活性的影响

利用根际箱在红壤上研究了有机肥对水稻根际有效磷、根际微生物和土壤酶活性的影响。试验结果表明,有机肥明显地提高水稻根际和非根际土壤真菌、放线菌和细菌的数量及土壤有效磷的含量。根际土壤各类微生物的数量大于非根际土壤,表现出明显的根际效应。施用有机肥使根际效应增加,其效应为细菌 放线菌 真菌。有机肥还明显地促进水稻根际无机磷溶解菌和有机磷分解数量以及磷酸酶和脲酶的活性,同时对水稻根际土壤磷转化速率有明显的提高,从而加速了土壤养分的转化。     

Antioxidant capacity of oat (Avena sativa L.) extracts. 1. Inhibition of low-density lipoprotein oxidation and oxygen radical absorbance capacity

Milled oat groat pearlings, trichomes, flour, and bran were extracted with methanol and the fractions tested in vitro for antioxidant capacity against low-density lipoprotein (LDL) oxidation and R-phycoerythrin protein oxidation in the oxygen radical absorbance capacity (ORAC) assay. The oxidative reactions were generated by 2,2'-azobis(2-amidinopropane) HCl (AAPH) or Cu(2+) in the LDL assay and by AAPH or Cu(2+) + H(2)O(2) in the ORAC assay and calibrated against a Trolox standard to calculate Trolox equivalents (1 Trolox equivalent = 1 TE = activity of 1 micromol of Trolox). The antioxidant capacity of the oat fractions was generally consistent with a potency rank of pearlings (2.89-8.58 TE/g) > flour (1.00-3.54 TE/g) > trichome (1.74 TE/g) = bran (1.02-1.62 TE/g) in both LDL and ORAC assays regardless of the free radical generator employed. A portion of the oat antioxidant constituents may be heat labile as the greatest activity was found among non-steam-treated pearlings. The contribution of oat tocols from the fractions accounted for <5% of the measured antioxidant capacity. AAPH-initiated oxidation of LDL was inhibited by the oat fractions in a dose-dependent manner, although complete suppression was not achieved with the highest doses tested. In contrast, Cu(2+)-initiated oxidation of LDL stimulated peroxide formation with low oat concentrations but completely inhibited oxidation with higher doses. Thus, oats possess antioxidant capacity most of which is likely derived from polar phenolic compounds in the aleurone.     

Fractional extraction of compounds from grape seeds by supercritical fluid extraction and analysis for antimicrobial and agrochemical activities

White grape seeds were subjected to sequential supercritical fluid extraction. By increasing the polarity of the supercritical fluid using methanol as a modifier of CO(2), it was possible to fractionate the extracted compounds. Two fractions were obtained; the first, which was obtained with pure CO(2), contained mainly fatty acids, aliphatic aldehydes, and sterols. The second fraction, obtained with methanol-modified CO(2), had phenolic compounds, mainly catechin, epicatechin, and gallic acid. The fractions were bioassayed. Antimicrobial activities were checked on human pathogens, and a high degree of activity was obtained with the lipophilic fraction. Agrochemical activities on phytopathogenic fungi and activities on the etiolated wheat coleoptile bioassay were also checked. The more polar fraction was active in the latter bioassay.     

甘蓝黑腐病菌rPf基因簇对胞外蛋白酶Ⅰ基因表达的调控

甘蓝黑腐病黄单胞菌（ＸａｎｔｈｏｍｏｎａｓｃａｍｐｅｓｔｒｉｓＰｖ．ｃａｍｐｅｓｔｒｉｓ）产生的胞外蛋白酶Ⅰ在致病的早期阶段起重要作用，该酶以及其它胞外酶和胞外多糖的合成受一致病因子调控基因簇（ｒＰｆ基因簇）的正向调控。本研究利用带有β－半乳糖苷酶报道基因（ｌａｃＺ）的转座子Ｔｎ５－Ｂ２０诱变蛋白酶Ⅰ基因克隆，获得了ｌａｃＺ在蛋白酶Ⅰ基因启动子控制下表达的Ｔｎ５－Ｂ２０插入突变质粒。通过将这种突变质粒导入野生型和各ｒｐｆ基因突变体菌株后，测定ｌａｃＺ基因在细胞生长周期中的表达水平，不仅进一步证实了这些ｒｐｆ基因对蛋白酶Ⅰ基因的正向调控作用，而且明确了它们的调控水平．发现ｒｐｆＡ、ｒｐｆＣ、ｒｐｆＥ、ｒｐｆＧ或ｒｐｆＨ突变后，蛋白酶Ⅰ基因的转录会降低９０％左右，而ｒｐｆＢ突变后，蛋白酶Ⅰ基因的转录只降低４８％。     

In situ net N transformations in pine,fir, and oak stands of different ages on acid sandy soil, 3 years after liming

Summary The effect of liming on in-situ N transformations was studied in two stands of different ages of each of Scots pine (Pinus sylvestris L.), Douglas fir [Pseudotsuga menziesii (Mirb.) Franco], and common oak (Quercus robur L.). The stands were located on acid sandy soils in an area with high atmospheric N input. The organic matter of the upper 10-cm layer of the soil, including the forest floor, had a relatively high N content (C: N ratio <25) in all stands. Using a sequential core technique, N transformations were measured in both control plots and plots that had been limed 3 years previously with 3 t ha^-1 of dolomitic lime. Limed plots had a higher net NO _inf3 ^sup- production and a higher potential for NO _inf3 ^sup- leaching than the controls in all stands except that of the younger oak. Net N mineralization did not differ significantly between limed and control plots in oak stands and younger coniferous stands but was significantly lower in the limed plots of the older coniferous stands. It is concluded that long-term measurements of net N mineralization in limed forest soils are needed to evaluate the effect of liming with respect to the risk of groundwater pollution.