大豆田中大豆蚜天敌昆虫群落结构分析

为了明确大豆田中大豆蚜Aphis glycines Matsumura天敌昆虫的群落结构特点,采用系统调查法对大豆蚜天敌的种类及数量进行调查。结果表明,大豆蚜天敌昆虫主要有5目11科19种,另外还有一些捕食性蜘蛛。主要优势种为小花蝽Orius minutus、龟纹瓢虫Propylaea japonica、中华草蛉Chrysopa sinica以及蚜小蜂Aphelinus sp.和异色瓢虫Leis axyridis,捕食性蜘蛛其中小花蝽的相对丰盛度达到0.26以上。小花蝽和龟纹瓢虫发生较早,是大豆蚜发生初期的主要控制因素。物种多样性、均匀度、丰富度、物种数和个体数整体趋势表现为先增加后降低,在7、8月达最大;而优势集中性和优势度则表现为先降低后增加的趋势,群落较稳定。     

Protein bodies of the soybean

Some microscope observations of the protein bodies of the cotyledon cells of the soybean (Glycine max) are described, together with changes in their appearance which occur on germination. Density gradient centrifugation permits the isolation of protein bodies from soymeal. They contain about 70% of the protein of the bean. Only 1 protein could be detected in them: glycinin, the major soybean protein.

The protein bodies were fractionated to light and heavy fractions. The former contained 97.5% protein, the latter 78.5%. RNA, phytic acid and lipids were also present. The 2 fractions probably differ only in the extent of contamination by other cell fragments.

     

High-efficiency induction of soybean hairy roots and propagation of the soybean cyst nematode

Cotyledon explants of 10 soybean [Glycine max (L.) Merr.] cultivars were inoculated with Agrobacterium rhizogenes strain K599 with and without binary vectors pBI121 or pBINm-gfp5-ER possessing both neomycin phosphotransferase II (nptII) and β-glucuronidase (gus) or nptII and green fluorescent protein (gfp) genes, respectively. Hairy roots were produced from the wounded surface of 54–95% of the cotyledon explants on MXB selective medium containing 200 μg ml⁻¹ kanamycin and 500 μg ml⁻¹ carbenicillin. Putative individual transformed hairy roots were identified by cucumopine analysis and were screened for transgene incorporation using polymerase chain reaction. All of the roots tested were found to be co-transformed with T-DNA from the Ri-plasmid and the transgene from the binary vectors. Southern blot analysis confirmed the presence of the 35S-gfp5 gene in the plant genomes. Transgene expression was also confirmed by histochemical GUS assay and Western blot analysis for the GFP. Attempts to induce shoot formation from the hairy roots failed. Infection of hairy roots of the soybean cyst nematode (Heterodera glycines Ichinohe)-susceptible cultivar, Williams 82, with eggs of H. glycines race 1, resulted in the development of mature cysts about 4–5 weeks after inoculation. Thus the soybean cyst nematode could complete its entire life cycle in transformed soybean hairy-root cultures expressing GFP. This system should be ideal for testing genes that might impart resistance to soybean cyst nematode. Received: 13 July 1999 / Accepted: 8 August 1999     

Non-target impacts of soybean rust fungicides on the fungal entomopathogens of soybean aphid

Soybean aphid, Aphis glycines, has caused serious economic damage to soybean across the North Central US since its introduction to North America in 2000. The management of another invasive soybean pest, Asian soybean rust, Phakopsora pachyrhizi, using foliar fungicide applications has the potential to impact soybean aphid populations by suppressing beneficial fungal entomopathogens. In 2005 and 2006, we applied recommended soybean rust fungicide treatments, consisting of strobilurin and triazole fungicides, to small soybean plots in two locations to assess if such applications might suppress aphid fungal epizootics. In Lamberton, MN, in 2005, during the epizootic, fungicide-treated plots averaged 2.0 ± 0.7% (mean ± SE) disease prevalence while untreated plots averaged 14.2 ± 5.6%. In 2007, we applied strobilurin and strobilurin-triazole mix fungicides to single-plant microplots either before or after release of Pandora neoaphidis, the most commonly observed aphid pathogen in 2005 and 2006. Treatments that contained a mixture of two active ingredients significantly lowered peak and cumulative aphid disease prevalence in both early and late reproductive stage soybeans indicating that fungicide mixtures used to manage soybean rust can negatively impact an aphid-specific fungal pathogen. However, no consistent soybean aphid population response was observed in these studies of low levels of aphid fungal infection.     

Fine mapping the soybean aphid resistance gene Rag1 in soybean

The soybean aphid (Aphis glycines Matsumura) is an important soybean [Glycine max (L.) Merr.] pest in North America. The dominant aphid resistance gene Rag1 was previously mapped from the cultivar ‘Dowling’ to a 12 cM marker interval on soybean chromosome 7 (formerly linkage group M). The development of additional genetic markers mapping closer to Rag1 was needed to accurately position the gene to improve the effectiveness of marker-assisted selection (MAS) and to eventually clone it. The objectives of this study were to identify single nucleotide polymorphisms (SNPs) near Rag1 and to position these SNPs relative to Rag1. To generate a fine map of the Rag1 interval, 824 BC₄F₂ and 1,000 BC₄F₃ plants segregating for the gene were screened with markers flanking Rag1. Plants with recombination events close to the gene were tested with SNPs identified in previous studies along with new SNPs identified from the preliminary Williams 82 draft soybean genome shotgun sequence using direct re-sequencing and gene-scanning melt-curve analysis. Progeny of these recombinant plants were evaluated for aphid resistance. These efforts resulted in the mapping of Rag1 between the two SNP markers 46169.7 and 21A, which corresponds to a physical distance on the Williams 82 8× draft assembly (Glyma1.01) of 115 kilobase pair (kb). Several candidate genes for Rag1 are present within the 115-kb interval. The markers identified in this study that are closely linked to Rag1 will be a useful resource in MAS for this important aphid resistance gene.     

传统大豆发酵食品中大豆低聚糖的生理功能研究

大豆低聚糖是大豆中可溶性碳水化合物的总称,在大豆和传统大豆发酵食品中含量丰富。近年研究发现大豆低聚糖在改善肠胃道功能、抗肿瘤、调节血脂等方面具有着重要的生理活性,因此引起了国内外研究人员的广泛关注。大豆低聚糖的研究,不仅能为功能性大豆制品的开发提供理论基础,也能为人们合理的膳食提供参考。本文综述了近年来国内外对大豆低聚糖生理保健机能的研究进展。     

Fine mapping of the soybean aphid-resistance gene Rag2 in soybean PI 200538

The discovery of biotype diversity of soybean aphid (SA: Aphis glycines Matsumura) in North America emphasizes the necessity to identify new aphid-resistance genes. The soybean [Glycine max (L.) Merr.] plant introduction (PI) 200538 is a promising source of SA resistance because it shows a high level of resistance to a SA biotype that can overcome the SA-resistance gene Rag1 from ‘Dowling’. The SA-resistance gene Rag2 was previously mapped from PI 200538 to a 10-cM marker interval on soybean chromosome 13 [formerly linkage group (LG) F]. The objective of this study was to fine map Rag2. This fine mapping was carried out using lines derived from 5,783 F₂ plants at different levels of backcrossing that were screened with flanking genetic markers for the presence of recombination in the Rag2 interval. Fifteen single nucleotide polymorphism (SNP) markers and two dominant polymerase chain reaction-based markers near Rag2 were developed by re-sequencing target intervals and sequence-tagged sites. These efforts resulted in the mapping of Rag2 to a 54-kb interval on the Williams 82 8× assembly (Glyma1). This Williams 82 interval contains seven predicted genes, which includes one nucleotide-binding site-leucine-rich repeat gene. SNP marker and candidate gene information identified in this study will be an important resource in marker-assisted selection for aphid resistance and for cloning the gene.     

小麦-大豆间作中小麦对大豆磷吸收的促进作用

采用塑料膜,２０μｍ尼龙网分司以及不分隔两种俄根系的盆栽装置研究了小麦,大豆间作种间磷吸收的促进作用。结果表明,两种作物根系用尼龙网分隔后,即种间磷竞争作用基本消除后,小麦对大豆磷吸收具有明显的促进和,表现为大豆生物学产量明显提高,是塑料膜分隔的２．５倍,是无分隔４．６倍,尼龙网分隔,大豆分隔,大豆的根系活力高于塑料膜分隔４５．２％,达显著水平,此外,尼龙网分隔形成小麦根面,大豆的根系呈偏向小麦根     

Jasmonate-dependent plant defenses mediate soybean thrips and soybean aphid performance on soybean

Insect herbivores from different feeding guilds induce different signaling pathways in plants. In this study, we examined the effects of salicylic acid (SA)- and jasmonic acid (JA)-mediated defenses on performance of insect herbivores from two different feeding guilds: cell-content feeders, soybean thrips and phloem feeders, soybean aphids. We used a combination of RT-qPCR analysis and elicitor-induced plant resistance to determine induction of SA and JA signaling pathways and the impact on herbivore performance. In the early interaction between the host plant and the two herbivores, SA and JA signaling seems to occur simultaneously. But overall, soybean thrips induced JA-related marker genes, whereas soybean aphids increased SA and ABA-related marker genes over a 24-h period. Populations of both soybean thrips and soybean aphids were reduced (47 and 25 %, respectively) in methyl jasmonate (MeJA)-pretreated soybean plants. SA treatment has no effect on either herbivore performance. A combination pretreatment of SA and MeJA did not impact soybean thrips population but reduced soybean aphid numbers which was comparable with MeJA treatment. Our data suggest that SA–JA antagonism could be responsible for the effect of hormone pretreatment on thrips performance, but not on aphid performance. By linking plant defense gene expression and elicitor-induced resistance, we were able to pinpoint the role for JA signaling pathway in resistance to two herbivores from different feeding guilds.     

Effect of pH and soybean cultivars on the quantitative analyses of soybean rhizobia populations

Quantitative analyses of fast- and slow-growing soybean rhizobia populations in soils of four different provinces of China (Hubei, Shan Dong, Henan, and Xinjiang) have been carried out using the most probable number technique (MPN). All soils contained fast- (FSR) and slow-growing (SSR) soybean rhizobia. Asiatic and American soybean cultivars grown at acid, neutral and alkaline pH were used as trapping hosts for FSR and SSR strains. The estimated total indigenous soybean-rhizobia populations of the Xinjiang and Shan Dong soil samples greatly varied with the different soybean cultivars used. The soybean cultivar and the pH at which plants were grown also showed clear effects on the FSR/SSR rations isolated from nodules. Results of competition experiments between FSR and SSR strains supported the importance of the soybean cultivar and the pH on the outcome of competition for nodulation between FSR and SSR strains. In general, nodule occupancy by FSRs significantly increased at alkaline pH. Bacterial isolates from soybean cultivar Jing Dou 19 inoculated with Xinjiang soil nodulate cultivars Heinong 33 and Williams very poorly. Plasmid and lipopolysaccharide (LPS) profiles and PCR-RAPD analyses showed that cultivar Jing Dou 19 had trapped a diversity of FSR strains. Most of the isolates from soybean cultivar Heinong 33 inoculated with Xinjiang soil were able to nodulate Heinong 33 and Williams showed very similar, or identical, plasmid, LPS and PCR-RAPD profiles. All the strains isolated from Xinjiang province, regardless of the soybean cultivar used for trapping, showed similar nodulation factor (LCO) profiles as judged by thin layer chromatographic analyses. These results indicate that the existence of soybean rhizobia sub-populations showing marked cultivar specificity, can affect the estimation of total soybean rhizobia populations indigenous to the soil, and can also affect the diversity of soybean rhizobial strains isolated from soybean nodules.     

Sequence organization of the soybean genome

The total complexity of one constituent soybean (Glycine max) genome is estimated to be 1.29 . 10(9) nucleotide pairs, as determined by analysis of the reassociation kinetics of sheared (0.47 kilobase) DNA. Single copy sequences are estimated to represent from 53 to 64% of the genome by analysis of hydroxyapatite binding of repetitive DNA as a function of fragment length. From 65 to 70% of these single copy sequences have a short period interspersion with 1.11--1.36 kilobase lengths alternating with 0.3--0.4 kilobase repetitive sequence elements. The repetitive sequences of soybean DNA are interspersed both among themselves and among single copy regions of the genome.     

Introduction of the soybean to Illinois

Events leading to the planting of the first soybeans in Illinois and the subsequent distribution of the seed throughout the United States are documented. In December 1850 theAuckland left Hong Kong for San Francisco. The ship came across a Japanese junk floundering on the sea. The Japanese crew was removed from the junk and placed on board theAuckland, which continued on to San Francisco. In March 1851 Dr. Benjamin Franklin Edwards obtained soybean seeds from the Japanese and brought the seeds to Alton, Illinois. Mr. John H. Lea of Alton planted the soybeans in his garden in summer 1851. These events took place 3 yr prior to the famous introduction of soybeans from Japan into the United States by the Perry Expedition.     

大豆过氧化物酶在毕赤酵母中功能表达

【目的】大豆过氧化物酶(SBP)作用底物广泛、比活高、热稳定性好,使其在免疫检测、工业污染废水处理领域有着广泛的应用潜力。现有的生产方法主要是从大豆壳中提取,这种方法产量低,成本高,远不能满足于工业应用要求,本研究希望实现在毕赤酵母中高效表达有功能活性的大豆过氧化物酶。【方法】将大豆过氧化物酶基因以及C末端截短20个氨基酸的基因克隆pPIC-9K载体中,并在毕赤酵母X-33中诱导表达。同时还将糖基化位点的天冬酰胺突变成为谷氨酰胺,研究糖基化位点对表达的影响。【结果】全长SBP在毕赤酵母中表达是无活性的,只有截短的SBP△20在试管发酵的表达活力达23.5 U/mL,经过糖基化位点的突变表明130、144、185、197对酶活非常重要,不能突变;211和216位点去糖基化突变对酶活有所提高。【结论】经过发酵条件的优化,在5 L的发酵罐中发酵液上清最高酶活力达510 U/mL,是目前报道的最高水平。     

A soybean mapping population specific to the early soybean production system.

The objective of this research was to create a soybean [Glycine max (L.) Merr] genetic resource in the form of a publicly available, well-characterized mapping population specific to maturity groups (MG) used in the early soybean production system. A total of 568 simple sequence repeat (SSR) markers were tested for polymorphism between soybean breeding line DS97-84-1 (MG IV) and germplasm line DT97-4290 (MG IV). A 90-genotype subset of an F2 population from a cross between these lines was evaluated for genetic linkage using 162 polymorphic SSRs, plant height, pod color (L2/l2), flower color (W1/w1) and stem termination (Dt1/dt1). A 1514 cM (Kosambi) genetic map covering 65% of the soybean genome based on 157 linked SSR markers was created. Comparison with the composite soybean genetic map was used to verify map order. Loci for pod color, flower color and stem termination fell in the expected position on the map indicating this is a normally segregating mapping population. Loci for height were identified on linkage groups C2, D1a, D1b, H, L, M and O. MG IV and V soybean genotypes are critical for the early soybean production system widely used in the midsouthern US. However, only two mapping populations have been reported in Soybase for MG IV and V genotypes. Additionally, the parents used in this cross are known to differ in their response to soybean cyst nematode and charcoal rot, which constitute two major pathology threats to Midsouth soybean production. The population and map reported herein represent an important genetic resource for the early soybean production system.     

Macronutrient concentrations of soybean infected with soybean cyst nematode

Soybean cultivars (Glycine max(L.) Merr.) infected with soybean cyst nematode (SCN; Heterodera glycinesIchinohe) often show symptoms similar to K deficiency. The objectives of this experiment were to determine if SCN infection affected macronutrient concentrations in soybean seedling vegetative tissues, determine whether increased K fertility can overcome these possible effects, and to determine if these possible effects are localized at the site of infection or expressed systemically throughout the root system. Soybean plants were grown with root systems split into two halves. This allowed differential K (0.2, 2.4 and 6.0 mM K nutrient solutions) and SCN (0 and 15 000 eggs/plant) treatments to be applied to opposite root-halves of the same plant. Thirty days after plants were inoculated with SCN, macronutrient concentrations of shoot and root tissues were determined. Potassium concentration in leaf blades was not affected; but K concentrations in leaf-petiole and stem tissues were increased with SCN infection. Roots infected with SCN contained lower K concentrations than uninfected roots, but only for the 2.4 mM K treatment. Thus, at the medium level of K fertility, SCN reduced K concentration in soybean roots, and increasing K fertility to the high level overcame the effect. Because K concentrations in the shoot tissues were not reduced by SCN infection, above ground portions of the plant may be able to overcome limitations that occur in roots during the first 30 days of infection. Increasing K fertility level in soybean fields may not benefit vegetative growth of soybean infected with SCN.     

Antagonistic effects of soybean viruses on soybean aphid performance

Although there is long-standing recognition that pest complexes require different management approaches than individual pests, relatively little research has explored how pests interact. In particular, little is known of how herbivorous insects and plant pathogens interact when sharing the same host plant. The soybean aphid, Aphis glycines Mastumura, a recently introduced pest of soybean in the upper midwestern United States, and a complex of plant viruses vectored to soybean by insects have become a major concern for growers in the region. Given the abundance of soybean aphid and the increase in virus incidence in recent years, soybean aphids often use soybean infected by plant viral pathogens. We tested the hypothesis that soybean aphid performance is affected by virus infection of soybean plants. We conducted a series of field and laboratory experiments that examined how infection of soybeans with the common plant viruses, alfalfa mosaic, soybean mosaic, and bean pod mottle viruses, influenced soybean aphid performance. Soybean plants (in the field and laboratory) were hand inoculated with individual viruses, and aphids were allowed to colonize plants naturally in field experiments or added to the plants in clip-cages or within mesh bags in laboratory assays. In the field, aphid density on uninfected control soybean plants was nearly double that on infected plants. In laboratory assays, aphid population growth rates were on average 20% lower for aphids on virus infected compared with uninfected plants. Life table analyses showed that increased mortality on virus-infected plants likely explain differences in aphid population growth. Although there was some heterogeneity in the significance of treatment effects among different experiments, when independent experiments are taken together, there is on average an overall negative effect of these viruses on soybean aphids.     

The interaction of soybean aphids and soybean cyst nematodes on selected resistant and susceptible soybean lines

Soybean aphids, Aphis glycines Matsumura, and soybean cyst nematodes, Heterodera glycines Ichinohe, are economic pests of soybean, Glycine max (L.) Merr., in the north‐central United States. Combined, these pests may account for 20–50% of yield reductions in a soybean crop. Only limited information is available concerning the interaction of these two pests on soybean production. During the summers of 2006 and 2007, we conducted a field‐experiment near Urbana, IL, to evaluate the effect of resistant and susceptible soybean lines on the development and reproduction of both pests in combination with each other. We also examined how each pest, as well as their interaction, affected the yield of susceptible and resistant soybean lines. Soybean plants grown within caged plots were infested with soybean aphids and soybean cyst nematodes; cumulative aphid days and soybean cyst nematode egg densities were determined at the end of each growing season. Soybean aphids were able to survive on all four soybean lines in both years of this study; however, aphid‐resistant lines generally had fewer cumulative aphid days than aphid‐susceptible lines. Likewise, nematode‐resistant lines typically had fewer eggs than nematode‐susceptible lines. During both years, we failed to observe a significant interaction between these two pests on the reproduction of one another. Yield data from 2006 was inconclusive; however, results from 2007 suggest that yield‐loss when soybean aphids and soybean cyst nematodes occur jointly is not significantly greater than when these two pests occur independently. The relationship between these two pests, and our inability to observe an interaction, are discussed.     

高效液相色谱法测定大豆乳清提取物中大豆异黄酮的含量

建立了大豆乳清提取物中大豆异黄酮含量的高效液相色谱测定方法。采用Nova-Pak C₁₈（3.9×150 mm,4 μm）色谱柱;以甲醇：0.4%磷酸=30：70（v/v）为流动相分析染料木苷和黄豆苷;流速为0.7 mL·min^-1;柱温为30℃;检测波长为260 nm。试验结果表明,大豆乳清提取物中的大豆异黄酮含量为72.5%,其组成以染料木苷和黄豆苷为主,二者比例接近1∶1,苷元型大豆异黄酮未检出。染料木苷和黄豆苷的平均回收率分别为98.1%和98.4%,相对标准偏差（RSD）分别为0.7%（n=5）和0.8%(n=5)。该方法快速、准确、重复性好。