Effect of Simulated Lodging on Soybean Yield

Soybean ( Glycine max [L.] Merr.) grain yields may be reduced when the plants lodge. The magnitude of yield reduction is dependent on the growth stage at which lodging occurs. The stage of plant development most vulnerable to yield reduction from lodging has not been conclusively determined. The objective of this two-year study was to determine soybean yield reduction caused by simulated lodging at three stages of reproductive development: the onset of flowering (R1), beginning pod (R3) and beginning seed (R5). At each developmental stage the plants were lodged at either 45° or 90°. A natural lodging control and an artificially maintained erect treatment were included.
The 1976 results indicated no yield differences due to any of the lodging treatments. In 1977, yields were significantly reduced for the R3 lodging treatments. Soybeans lodged 90° at the R1, R3, and R5 growth stages yielded 2.63, 1.88 and 2.26 Mg ha⁻¹, respectively. The natural lodging and erect treatments yielded 2.73 and 2.43 Mg ha⁻¹, respectively.
Lodging treatments applied at the R1 stage produced plants with a two-year average of 30% of their seeds on the main stems, compared to 62% of the seeds on the main stems for the R5 stage treatments. The percentage of seeds on the main stem was 69% on the erect plants, as compared with 45% on the 90° lodged plants. In 1977, lodging treatments also reduced pods per plant, seeds per plant, 100 seed weight and seed weight per plant.     

Uniformity, Performance and Seed Quality of Soybean (Glycine max (L.) Merrill) Seed Crops Grown from Sub-samples of One Seed Lot Obtained after Selection for Physical Seed Attributes

In a glasshouse experiment it was examined whether narrow grading and selection from a commercial soybean seed lot cultivar 'IAS-5', could improve the uniformity of the seed crop grown from it and thereby enhance yield, quality and uniformity of seeds produced. The classes created were: Control (original seed lot); Size-graded seeds (projected area measured by image analysis 37–46 mm²); Non-cracked seeds; Yellow seeds; Size-graded sound seeds (size-graded, non-cracked, yellow, non-wrinkled, non-etched). Compared to the control, percentage of emergence, survival and number of yielding plants were enhanced in crops from non-cracked, yellow or size-graded sound seeds. Differences in plant numbers did not result in differences in crop yield. The different seed lots also did not differ in crop uniformity: time interval between stages of plant development, plant height 20 days after sowing, yield components, physical or physiological quality attributes of seeds produced, and respective coefficients of variation were similar. Fewer plants survived in crops showing a larger variation in plant height 20 days after sowing, thus reducing differences in initial plant-to-plant variation. Creating more uniform crops by additional grading or selection of commercial seed lots may therefore not be promising.     

大豆叶片性状QTL的定位及Meta分析

利用Charleston×东农594重组自交系构建SSR遗传图谱,采用WinQTLCartographer Ver. 2.5软件的CIM和MIM分析方法对2006—2010年(F_2:14~F_2:18)连续5年的大豆叶长、叶宽以及叶柄长数据进行QTL定位,检测到8个与叶长有关的QTL,位于染色体Gm01、02、05、11和18上;9个与叶宽有关的QTL,位于染色体Gm01、03、05、06、11、12和16上;8个与有关叶柄长的QTL,位于染色体Gm01、03、05、06、11、17和18上。2年以上均检测到的叶长QTL为qLL5a、qLL5b、qLL1a和qLL18;叶宽QTL为qLW5a、qLW11a、qLW11b和qLW12;叶柄长QTL为qLSL11b。另外,利用BioMercator2.1的映射功能将国内外常用的大豆图谱上的叶长、叶宽QTL通过公共标记映射整合到大豆公共遗传连锁图谱Soymap2上,将搜集到的35个叶长QTL、37个叶宽QTL和本研究得到的QTL整合分析,最终得到5个大豆叶长的“通用”QTL,位于Gm09、18和19,其置信区间最小可达5.66 cM;4个大豆叶宽的“通用”QTL,位于Gm07、Gm18和Gm19,其置信区间最小可达5.67 cM,为今后对大豆叶片性状QTL精细定位, 提供了有利科学信息。     

缺硼对大豆植株生长和根瘤固氮活性的影响

以普通结瘤大豆Ｂｒａｇｇ ｃｖ．（Ｇｌｙｃｉｎｅ ｍａｘ（Ｌ．）Ｍｅｒｒ．）及其超结瘤突变体ｍｔｓ３８２为试验材料,用营养液培养方法研究了缺硼对大豆植株生长和根瘤固氮作用的影响,结果表明,在缺硼条件下,植株根系生长受到抑制,变粗变短,颜色加深;地上部生长点坏死,使植株长得矮小,干重降低;根系结瘤能力和根瘤固氮活性明显下降,说明硼不仅对维持植株的正常生长,同时对根瘤的形成及其固氮活性都起着重要作用。     

Genistein and Daidzein Concentrations and Contents in Seedling Roots of Three Soybean Cultivars Grown under Three Root Zone Temperatures

Daidzein and genistein are plant-to-bacterium signal compounds involved in soybean nodule formation. They can induce nod gens expression in Bradyrhizobium japonicum. The objective of this study was to determine whether the production of signal molecules was affected by low root zone temperatures (RZTs) in a manner that varied among soybean cultivars. Daidzein and genistein concentrations of soybean seedling roots were measured at three RZTs by high performance liquid chromatography (HPLC). The results indicated that daidzein content and concentration per plant were higher at 15 and 17.5°C than those at 25°C. AC Bravor had higher daidzein contents and concentrations than did Maple Glen and KG20. At 17.5°C. KG20 had higher genistein content and concentration levels than Maple Glen, and no difference existed for the two cultivars at 15 and 25 C. Daidzein contents and concentrations of Maple Glen and AC Bravor increased with harvest time. However, for cultivar KG20, the content and concentration decreased at 19 days after inoculation. Genistein contents and concentrations of the three cultivars increased under each RZT up to the last harvest. There was an interaction between soybean cultivar and RZT for root genistein and daidzein contents and concentrations. The content and concentration of daidzein in soybean seedling roots were much higher (more than five times) than those of genistein.     

Cultivar Maturity and Reproductive Growth Duration in Soybean

Twenty-seven soybean ( Glycine max L. (Merrill)) cultivars from maturity groups (MG) 00 through V were grown in a field at Lexington, Kentucky (38° N latitude), for 2 years, to evaluate the relationship between the duration of reproductive growth and total growth duration. Reproductive growth stages were measured at weekly intervals and dates of R1 (initial bloom) and R5 (beginning seed fill) were estimated by linear interpolation. The date of physiological maturity (growth stage R7) was based on measurements made at two day intervals. The total growth duration increased from 84 days (averaged across years) for MG 00 to 134 days for MG V. Vegetative growth (planting to R5) increased in direct proportion to the total growth cycle. The flowering and pod set period (Rl to R5) was similar for MG 00 and 0, but increased from MG I to IV. The seed filling period, estimated from R5 to R7 and by the effective filling period, increased from MG 00 to I, but there was no change from MG I through V. These data indicate that the duration of seed fill does not always increase as the total growth cycle increases.     

Effect of Inoculant Rate on Nodulation and Various Agronomic Traits of Soybean

In a soil lacking indigenous Bradyrhizobium japonicum , soybean ( Glycine max [L.] Merr.) nodulation depends upon the number of rhizobia applied with the inoculum. This field study reports the effect of different rates of applied rhizobia on nodulation, dry matter and nitrogen content in soybean in a Mediterranean soil lacking B. japonicum.
Treatments included six rates of B. japonicum , ranging from 2.5 × 10⁴ to 6.075 × 10⁶ rhizobia cells per seed applied to the seed as peat inoculant at planting, 100 kg N ha⁻¹ and an uninoculated control. The experiment was conducted in an Entisol soil. Regression analysis showed linear relationship between the rate of applied rhizobia and the number of the nodules per plant or the dry weight per nodule. In early stages of development (32 and 68 days after planting) plant dry weight was not affected by inoculation rate. At harvest a rate of 7.5 × 10⁴ rhizobia cells per seed was necessary for maximum total and stover dry weight. A higher rate, 6.75 × 10⁵ rhizobia cells per seed, was required to obtain maximum grain yield, total N content in plant tops and grain N content. Grain percentage N was increased up to 2.025 × 10⁶ rhizobia cells per seed. Nitrogen application increased grain yield, total N content and grain N content at the same level as the lower inoculation rate.     

Soybean Nodule Development and Nitrogenase Activity During the Reproductive Phase: Statistical Modeling Approach

Nitrogenase activity during the reproductive phase of the Hodgson 78 soybean variety was tested in a growth chamber experiment to evaluate its relationships with number, weight and specific nitrogenase activity of the nodules. A multiple regression model is proposed.
The number of nodules did not change, while the total nodule dry weight increased with the increase of the average dry weight.
The regression model adopted showed that the main factors affecting the total nitrogenase activity were the specific activity and the nodule mass, but the former induces the wider variations.
Unlike other crops the counting of the nodules cannot be considered as an indirect predictor for nitrogen fixation.     

大豆籽粒维生素E含量的QTL分析

维生素E(VE)具有提高人体免疫力、抗癌、预防心血管疾病等保健作用,从大豆中提取的VE安全性更高。本研究采用高效液相色谱技术(HPLC)检测大豆BIEX群体(Essex×ZDD2315)维生素E的α-生育酚、γ-生育酚和δ-生育酚含量。应用QTLNetwork 2.1软件分别检测到8个和12对控制大豆维生素E及组分含量的加性和互作QTL。α-生育酚含量加性和互作QTL累计贡献值分别为8.68%(2个)和15.57%(4对),γ-生育酚含量加性和互作QTL累计贡献值分别为8.59%(2个)和11.57%(2对),δ-生育酚含量加性和互作QTL累计贡献值分别为5.44%(1个)和17.61%(3对),维生素E总含量的加性和互作QTL累计贡献值分别为11.39%(3个)和9.48%(3对)。未检测到维生素E及组分含量和环境互作的QTL。未定位到的微效QTL累计贡献值为66.16%~75.32%,说明未定位到的微效基因的变异占2/3以上。各性状的遗传构成中,未检测出的微效QTL份额最大,加性QTL和互作QTL贡献相差不大。在育种中应考虑常规方法聚合微效QTL与标记辅助方法聚合主要QTL相结合。     

国家大豆区域试验品种(系) SSR位点纯合度分析

利用30对SSR引物,检测2005—2009年参加国家区域试验的1 068份大豆品种(系)的位点纯合度。每年区试品种(系)的平均纯合度为94.9%~97.6%,纯合度高于85%和90%的品种(系)所占比例分别为95%和91.4%,纯合度低于85%的品种(系)有42份(占3.93%),主要为北方春大豆和黄淮夏大豆。位点纯合度低于85%的参试品种(系)的产量比较表明,只有11份品种(系)比对照增产5%以上,20份比对照减产0.04%~13.08%;与纯合度为100%的材料比较发现,位点纯合度较低的材料在区试中产量也较低。建议国家区试品种(系)纯合度标准不低于90%,以保证审定品种的特征特性,为大豆新品种的持续推广利用提供科技支撑。     

Behaviour of the Root Nodules in Soybean in the Presence of Nitrogen: The Use of a Statistical Simulation Model

Two varieties of soybean were grown in large pots out of doors. At the R2 stage, a state of temporary root anoxia appeared caused by a heavy rainfall and in R3, nitrogen was applied. The nitrogenase activity of the nodules was measured at weekly intervals (ARA test).
During the vegetative stage, the number of nodules and their weight increased rapidly, although the anoxia caused a slowing down followed by a recovery in the successive stages (R3–5). The same effect was apparent in consequence of a late nitrogen fertilization; both varieties attaining values close to those of the control 15 days after the treatment. Nitrogenase activity also showed an inhibition caused by the anoxia but it appeared earlier. During the latest stages of the cycle (R6–7), the nitrogen treatment increased the rate of nitrogen fixation in Hodgson 78 only. The use of a multiple regression model allowed a verification that the parameters controlling nitrogen fixation acted in a similar way in both varieties. In the field, the weight of the nodules, both single and total, appeared to be particularly important in determining the total nitrogen fixation rate.     

大豆细胞质遗传芽黄突变体的发现

本研究新发现一个大豆芽黄突变体NJ89-3。该突变体典型表现为，从第一对真叶开始，新生叶表现明显黄化，但随叶片充分伸展定形，逐渐变为正常绿色。植株最后一张叶片充分伸展定形后，芽黄植株与正常绿色植株并无明显区别。研究表明NJ89-3的芽黄性状由细胞质基因突变引起，属细胞质遗传，建议将此细胞质基因命名为cyt-Yv。     

大豆资源的筛豆龟蝽[Megacopta cribraria (Fabricius) ]抗性鉴定

在观察筛豆龟蝽发生情况及其在大豆上的危害特征基础上,比较了田间自然危害条件下各种抗性鉴定指标,以茎枝黑霉程度结合叶片紫斑数为抗性分级指标鉴定了国内外大批资源,筛选出58份抗、感食叶性害虫的大豆材料,其筛豆龟蝽抗性结果表明,品种间、观察日期间和区组间都有极显著差异,品种×观察日期互作也极显著,最终筛选出PI227687、安陆小黄豆、花柒黄毛豆、沔阳白毛豆等高抗种质,并提出了一套鉴定方法和指标。     

Annual Medicago as a Smother Crop in Soybean

Use of conservation tillage and narrow row spacing in soybean [Glycine max (L.) Merr.] production has led to increased use of herbicides for weed control. Some producers are seeking alternative weed control methods, such as smother crops, that would reduce dependence on chemical weed control. A successful smother crop must compete strongly with weeds but minimally with the crop. In four environments, we intercropped three annual Medicago spp. (medics) with soybean to test their utility as a smother crop for weed control. Annual medics were intercropped with soybean at rates of 0, 85, 258, or 775 seeds m^?2, and the intercrops were grown with and without weed control. Increasing medic seeding rate decreased weed yields but also reduced soybean herbage and grain yields. For the weed‐controlled treatment, average soybean grain yields declined 7 kg ha^?1 for every 10 seeds m^?2 increase in medic seeding rate. Soybean grain yield was lower when grown with Medicago scutellata L. cv. Sava than when grown with Medicago polymorpha L. cv. Santiago or Medicago lupilina L. cv. George. Soybean grain yield was negatively related (r=?81) to medic herbage production. In the autumn following soybean harvest, medic residue ranged from 200 to 3700 kg ha^?1 depending on the location and seeding rate. Medics provided residue for soil protection, suppressed weeds, but also reduced soybean yields.     

影响大豆胞囊线虫生理小种鉴定因素探讨

大豆胞囊线虫(soybean cyst nematode,SCN)引起的病害能给大豆生产造成严重损失。探索影响大豆胞囊线虫(soybean cyst nematode,SCN)生理小种鉴定的因素对指导抗线育种工作具有重要意义。本研究以Lee68为材料,接种一定浓度的SCN4虫卵,在不同温度梯度的培养箱中培养,研究温度对大豆胞囊线虫生长的影响;以Riggs鉴定模式中的5个寄主为材料,接种一定浓度梯度的SCN2虫卵,研究接种浓度对鉴定结果的影响;从土壤相对含水量方面研究水分对大豆根系发育的影响。研究结果表明:在设定的温度梯度中,培养温度25℃/22℃(光/暗),Lee68上生长的胞囊数目最多,与其它几个温度培养条件相比,单株胞囊平均数达到差异显著水平,是胞囊生长最适宜温度;接种虫卵为1 200~24 000个/杯时,鉴定结果是正确的,超出这个接种范围,鉴定结果不稳定;一天浇水两次,浇水前/后土壤含水量为4%~7%/15%~18%,最有利于根系发育。本研究结果可为大豆胞囊线虫生理小种鉴定和抗线育种工作提供参考。     

大豆叶片表面结构与蒸腾的关系

用光镜和扫描电镜对大豆叶片进行观察的结果表明,气孔和表皮毛密度及表皮毛分布方式在上下表皮间存在差异。中层叶片气孔密度高于上层和下层叶片;而中层叶片表皮毛密度则低于上层和下层叶片。不同品种叶片表面结构状态有所不同。蒸腾速率测定结果表明,大豆多数品种蒸腾日变化呈单峰曲线,中层叶片的蒸腾速率大于上层和下层叶片     

大豆不同生育时期叶绿素含量QTL的定位及其与产量的关联分析

利用来自波高×南农94-156的151个RI家系检测与4个不同生育时期叶绿素含量（累积量、净增量）有关的QTL,并分析其与籽粒产量、表观生物学产量和表观收获指数的关系。结果表明,与叶绿素累积量有关的QTL位于D1a+Q、F、G、H、L和M连锁群上,每个QTL可解释表型变异的6.9%~23.4%。V6和R2期没有检测到2个年份均表达的QTL,而在R4期检测到4个在2个年份均表达的QTL（qccF.1、qccG.2、qccH.1和qccM.1）,R6期仅检测到1个QTL（qccH.1）在2个年份均表达,该QTL在R4也表达。与叶绿素含量净增量有关的QTL位于B2和L连锁群上,在V6-R2时期没有检测到与叶绿素净增量有关的QTL,在B2和L连锁群上的两个QTL（qccB2-1.1和qccL.1）在R2-R4和R4-R6时期均表达,qccB2-1.1可解释表型变异的6.4%~9.8%,而qccL.1所解释表型变异达29.5%~31.3%。但这两个QTL在R2-R4和R4-R6时期表达的性质不同,且与2年均表达的籽粒产量QTL共位。这印证了生育后期叶绿素含量与籽粒产量间存在的极显著正相关。     

Soybean Yield and Yield Components in Two Planting Patterns

Soybean [Glycine max (L.) Merr.] plant density for maximum yield in Japan is usually from 16 to 25 plants m⁻². The objective of this study was to compare yield and yield components, especially node number between square- and zigzag- (an equilateral triangle-planting pattern or plants in the row offset from each other) planting patterns within a range of plant populations (16, 20 and 25 plants m⁻²).
Field experiments with cultivar Enrei (Maturity Group VII) were conducted in the field at Niigata University on a loamy sand soil in 1991, 1992 and 1993.
Yield increased as density decreased in 1991 and as density increased in 1992 and 1993. This result seemed to be due to adverse weather conditions during seed filling in 1991. Yield tended to be higher in zigzag- than in square-planting patterns except at 20 plants m⁻². Seed number m⁻² due to increased yield was highly correlated with branch node number. The yield increase was caused by an increase in total node number, especially branch node number m⁻² (about 60 % contribution at 16 plants m⁻² and about 40 % contribution at 25 plants m⁻²).     

结瘤和非结瘤大豆同位基因系种子荚皮发育中POD和SOD活性的比较

1.大豆果实发育过程中种子和荚皮地过氧化物酶（Peroxidase-POD,不同)和超氧化物岐化酶（Superoxide Dismutase-SOD，不同)活性均有变化。结瘤大豆的两种酶活性高于非结瘤大豆，这种差异在POD活性上表现尤为显著。 2.SOD和POD均高于发育早期就基本合成齐全，而POD同工酶随发育逐渐增多。 3.种子SOD和POD均高于荚皮中的活性