Interaction Amongst Soybean [Glycine max (L.) Merrill] Genotype, Soil Type and Inoculant Strain with Regard to N2 Fixation

The nitrogen (N₂)‐fixing bacterial inoculant strain for soybean [Glycine max (L.) Merrill] is not indigenous to South African soils. The interaction between soybean genotype, soil type and inoculant strain, however, has a definite influence on soybean production and compatibility should be optimized. This paper reports a growth chamber study using three different soybean genotypes (Barc‐9, Avuturda and Talana), three Bradyrhizobium japonicum inoculant strains (WB108, WB112 and WB1) and three soil types (Avalon, Arcadia and sand) to evaluate the effectiveness of N₂ fixation by different genotype × soil type × inoculant strain combinations, using different measuring parameters. These parameters included nodule fresh mass (NFM), amount of N₂ fixed (P_fix), as determined by the ureide method, seed protein content (SPC), average seed mass per plant (SMP) and average foliar N content (FNC). The comparison amongst the three‐way interactions, genotype × soil type × inoculant strain, did not differ significantly for the parameters used. Significant two‐way interactions were soil × inoculant for FNC, P_fix and SMP; soil × genotype for FNC and SMP, and inoculant × genotype for FNC (P < 0.05). The soil × inoculant strain interaction was significant for P_fix (P < 0.05). NFM, P_fix, FNC, SMP and SPC correlated positively with soil pH and negatively with soil clay content and soil NO₃^– and NH₄⁺ content (P < 0.05). SPC was significantly different (P < 0.05) for soil type, genotype and inoculant strain. P_fix and NFM did not reflect the protein content of the seeds, indicating that nodule evaluation should be used with caution as a N₂ fixation parameter. Low soil pH and high mineral N content inhibited N₂ fixation. NFM correlated negatively with the clay content of the soil. This finding confirms that soybean production in South Africa can be improved by appropriate selection of genotypes and inoculant strains for their compatibility in different soils.     

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.     

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。     

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。     

Non-destructive Limits to Seed Growth and Leaf Protease Activities in Nodulating and Non-nodulating Soybean Isolines

Leaf senescence leads to a progressive decline in the photosynthetic competence of the leaf. This paper describes some effects of source:sink imbalance on leaf protein catabolism and senescence in soybean. We manipulated pod growth by restricting 100 or 50 % (PR-100 or PR-50, respectively) of young pods at the R4 stage in plastic drinking straws. This effectively reduces final seed mass without interrupting the vascular connections of pods. Nodulating (NOD+) and non-nodulating (NOD−) isolines of the 'Clay' soybean were grown in drainage lysimeters and three pod-restriction (PR) treatments were compared. Pod restriction decreased seed biomass per plant as a result of lower individual seed mass, which was only partially balanced by the increase in seed number. The nitrogen concentration in seeds remained unchanged in NOD+ plants, while it increased with the degree of sink restriction in seeds of NOD− plants. Leaf soluble protein, CO₂ exchange rate and seed nitrogen content were consistently lower in NOD− plants; the leaf protein level remained stable with time in PR-100 plants, decreased for PR-50 and dropped for controls. Endoprotease (HBase) and carboxypeptidase (CPase) activities were significantly lower in leaves from PR-100 plants, while aminopeptidase activity was enhanced, indicating a de novo synthesis of leaf protein. This is consistent with the reported accumulation of vegetative storage proteins (VSPs) in soybean and other legumes after moderate or severe sink reduction. Thus, small modifications of the source:sink ratio such as those obtained by the non-destructive PR technique have an impact on leaf protein catabolism. Nodulating and non-nodulating soybean isolines showed similar responses to PR in terms of leaf senescence initiation and progression, but the rate of the processes appear to be largely influenced by plant N status.     

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。     

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.     

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.     

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.     

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.     

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     

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).     

黄淮海地区大豆品种苗期根系性状的遗传变异及与耐逆境胁迫的关系

从83份黄淮海地区代表性大豆地方品种和育成品种(系)中按根系类型选取32份,用以研究苗期根系性状的遗传特点、与地上部性状的相关以及与逆境胁迫的关系。大豆苗期一级侧根数、主根长、根干质量、总根长和根体积等性状,在品种间、各苗龄间均存在显著遗传变异;根系性状与整株干质量呈高度相关;根干质量、根总长和根体积的相对值与耐旱平均隶属函数值,一级侧根数、主根长、总根长、根体积、根干质量的相对值与耐铝毒平均隶属函数值呈极显著相关,且根系性状的相对值在品种间存在显著变异,可用做耐逆性选择的根系指标。     

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。     

获得转反义PEP基因超高油大豆新材料

利用基因工程技术进行植物高油育种,是当前国际上植物基因工程研究的热点之一.大豆是世界上植物油和植物蛋白质最重要的来源,随着人们生活水平的不断提高和养殖业的迅速发展,我国高油大豆需求量急剧增加.在不增加大豆面积的前提下,提高单位面积含油量的重要手段之一就是培育栽培高油大豆品种.由此,从2000年作者利用农杆菌介导法将反义PEP基因导入大豆的基因组,相继获得了转基因大豆植株,经多代连续筛选、鉴定,获得了稳定的超高油（脂肪25%）大豆品系.本研究首次报道利用基因工程手段大幅度提高大豆含油量.     

The Effect of Cyst Nematode Race 3 and Bradyrhizobium japonicum Interactions on Nodulation and Other Agronomic Characters of Three Soybean Genotypes

The effect of soybean cyst nematode (SCN) race 3 and strains of Bradyrhizobium japonkum interactions on nodulation and other agronomic characters of several soybean genotypes was investigated. Nodule weight was reduced in soybean cultivar Ogden treated with SCN plus Bradyrhizobia strains USDA 110 and 6 and on soybean cultivar Essex treated with SCN plus strain USDA 6. The result was reversed on soybean cultivar Essex treated with SCN plus strain USDA 110. The nodule number also decreased on soybean cultivars Ogden and Essex treated with SCN plus strains USDA 110 and 6. The fresh root weights of soybean cultivars Ogden and Essex treated with SCN plus strain USDA 110 were heavier than the fresh root weight of Essex treated with SCN plus strain USDA 6. Lower nitrogen content of stems and leaves was noted only in cultivar Essex treated with SCN plus strains USDA 110 and 6. Bradyrhizobia strain USDA 110 was more efficient in the initiation of nodules in cultivars Ogden and Essex than strain USDA 6. The nitrogen-fixing capacity of strain USDA 6 in Ogden was better than strain USDA 110. The differences in the agronomic performances of the various soybean genotypes were due to their degree of susceptibility to SCN and Bradyrhizobia strains and also to their genetic make-up.     

中国栽培和野生大豆农艺品质性状与SSR标记的关联分析 I. 群体结构及关联标记

关联作图是一种利用连锁不平衡(linkage disequilibrium, LD)检测自然群体中基因位点及其等位变异的方法。利用60个SSR标记, 对全国大豆地方品种群体(393份代表性材料)和野生大豆群体(196份代表性材料)的基因组变异进行扫描, 分析两类群体的连锁不平衡位点、群体结构, 并采用TASSEL软件的GLM (general linear model)方法对16个农艺、品质性状观测值进行标记与性状的关联分析。结果表明: (1)在公共图谱上不论共线性的或是非共线性的SSR位点组合都有一定程度的LD, 说明历史上发生过连锁群间的重组; 栽培群体的连锁不平衡成对位点数较野生群体多, 但野生群体位点间连锁不平衡程度高, 随距离的衰减慢。(2) 群体SSR数据遗传结构分析发现, 栽培群体和野生群体分别由9和4个亚群体组成, 亚群的划分与群体地理生态类型相关联, 证实地理生态类型划分有其遗传基础。(3) 栽培群体中累计有27个位点与性状相关; 野生大豆种质中累计有34个位点与性状相关。部分标记在两类群体中都表现与同一性状关联, 检出的位点有一致性, 也有互补性; 一些标记同时与2个或多个性状相关联, 可能是性状相关乃至一因多效的遗传基础; 关联位点中累计有24位点(次)与遗传群体连锁分析定位的QTL一致。     

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。     

Response of Soybean [Glycine max (L.) Merr.] Cultivars to Genistein-Preincubated Bradyrhizobium japonicum: Nodulation and Dry Matter Accumulation under Canadian Short-Season Conditions

The addition of genistein, a plant-to-bacteria signal molecule, to Bradyrhizobium japonicum cells prior to use as inocula has been shown to increase nodule number and promote soybean N₂ fixation at low root zone temperatures. Previous greenhouse and field experiments involving only two cultivars have indicated that soybean [ Glycine max (L.) Merr.] cultivars can vary in their response to genistein application. The objective of this study was to evaluate a range of soybean cultivars for response to genistein application under short-season cool-spring Canadian conditions. A 2-year field study was conducted in 1997 and 1998 with a range of soybean cultivars recommended for Quebec. The 11 cultivars tested represented a range of yield potentials and maturity groups. They were inoculated with genistein-preincubated B. japonicum inocula or regular inocula, applied into the furrow at the time of planting. The results of these experiments indicated that neither maturity nor yield was correlated with increases in nodulation, biomass, and plant total nitrogen content resulting from genistein treatment and that all maturity groups responded to genistein application in essentially the same way. Thus, response of soybean cultivars to genistein addition is regulated by genotype characteristics other than maturity or yield level.