大豆成苗期抗旱性与根系生长的关系

选择抗旱性强、中、弱的大豆品种各5个,在试验室条件下研究成苗期抗旱性与根系生长、胚轴伸长的关系。结果表明:抗旱性强的品种发根早,主根长,侧根数量多,侧根总长度长,胚轴长,成苗率高。在干旱条件下的趋势更为明显。     

硼处理下大豆根系性状与产量关系的研究

缺硼可导致大豆不结实,根系是缺硼最敏感的部位.本试验采用盆栽方法,对生产中普遍使用并对硼敏感的大豆品种(Glycine max(L.)Merrill)北9395的根系性状与产量关系进行研究.结果表明:B 处理的主根长、主根粗、主根干重、侧根数、侧根总长度、侧根干重、须根干重、根干重、根体积和根系总吸收面积均有所增加,其中主根粗、侧根数、总侧根长与BO对比差异达到0.01显著水平;硼在一定程度上能增加单株粒数和单株粒重;根系性状及其与产量之间存在一定程度的相关性,主根生长的好坏可以作为评价其它根系性状的重要指标;主根干重和根干重与产量之间的相关系数在0.05水平上均达到显著,可以作为判断大豆产量的重要指标.     

乙烯对低磷胁迫下大豆根形态和生理特性的影响

利用沙培方法研究了乙烯对磷胁迫下大豆幼苗的生理影响。结果表明:磷胁迫下大豆主根长度降低50%,侧根长度增加46%,侧根数目增加64%。缺磷时大豆根系磷含量降低,根系活力和根系组织酸性磷酸酶活性分别是全磷培养植株的1.2和1.3倍;与供磷植株相比,缺磷时大豆干物质累积量显著降低,缺磷主要抑制了地上部分干物质累积,而根系干物质累积几乎不变,根冠比增大。磷胁迫使大豆乙烯含量增加,但乙烯释放量被乙烯拮抗剂Co2+抑制。外源乙烯利抑制全磷大豆主根伸长,促进缺磷大豆侧根生长;乙烯拮抗剂Co2+逆转了低磷和乙烯对主根的抑制,减少侧根数目。乙烯利能够增加大豆幼苗根系活力和根系组织酸性磷酸酶活性,降低大豆生物量,增加根冠比,且磷胁迫时效果更为明显。     

套作弱光胁迫对大豆苗期根系形态和生理活性的影响

研究玉米-大豆带状套作弱光环境下大豆苗期根系形态特征、生理特性和生物量积累,明晰苗期大豆根系对套作荫蔽的响应规律,筛选适宜玉米-大豆带状套作的大豆品种,为改良大豆对荫蔽胁迫的适应能力提供理论依据。以NTS1007、桂夏3号和南豆12等3个根系特征不同的大豆品种(系)为试验材料,在盆栽试验条件下,采用挖掘法考察根系形态特征,并对根系活力、表面积、伤流量和生物量积累等指标进行测定和分析。结果表明,与单作相比,玉豆带状套作下大豆主根长和侧根长均显著下降,侧根下降81.8%,主根下降42.8%,侧根下降更为明显;根系可溶性糖含量显著下降,导致根系活力降低,伤流量减少;大豆根系表面积和活跃吸收表面积显著减小,降幅均与一级侧根总长度的降幅呈极显著正相关;大豆植株生物量显著下降,其中地下部下降55.2%,地上部下降37.9%,根冠比减小。不同品种(系)大豆根系对套作的响应程度不同,南豆12的主根长、一级侧根长、根体积降幅最小(33.9%、74.4%、65.3%);桂夏3号的根系表面积和生物量降幅最大(67.1%、48.3%);NTS1007则根冠比、根系活力和伤流量冠比降幅最大(35.4%、39.2%、38.9%)。套作遮荫条件下大豆根系的伸长生长比根系生理性状更能够准确地反映植株根系生长状况,根系长度可作为判定对荫蔽胁迫适应能力的一个重要指标。南豆12在玉米-大豆套作下能够更为合理地分配同化产物,减小荫蔽胁迫对根系形态建成和生理活性的抑制作用,保证根系生物量积累。     

对肥水条件反应不同的大豆品种根系性状的比较研究

采用盆栽方法，对黑龙江省和吉林省的3份抗旱性大豆品种和5份喜肥水性大豆品种的根系性状进行了比较研究。结果表明：不同特性大豆品种的根系性状存在差异，与喜肥水性大豆品种相比，抗旱性大豆品种根系比较发达，具有相对较大的根系重量、较大的根体积、较强的根系吸收活性及较发达的主根和下部侧根。     

大豆育苗断根移植对植株生长发育特性的效应

本文采用育苗断根移植的方法研究了大豆植株的生长发育特性。切断主根解除了根的顶端优势,促使侧根大量形成。从分枝到鼓粒期,根容量、根干重均比对照高,到结荚期达到高峰,断根移植后增加了根瘤数量,特别是中小根瘤比对照增加明显,并提高了根瘤固氮活性,固氮量比对照增加3.6—5.5(mg/株·天),改进了大豆氮素供应状况。断根移植后还增加了叶绿素的含量,光合速率高,植株生长繁茂,表现单株鲜重、单株叶面积均比对照高。从产量构成因素看,断根移植后株高变矮,分枝数、单株荚数、单株粒数、百粒重均比对照明显增加,大豆产量可提高15％以上。     

大豆不同抗旱性品种根系性状的比较研究 Ⅰ、形态特征及解剖组织结构

1985—1986年,我们分别观察研究了夏播和春播大豆不同抗旱品种的根系形态及解剖组织结构,结果表明,在北京地区,大豆抗旱品种根系的主要性状是:幼苗发根力强,根的生长速度快;主根扎得深,根系发达,根的干物重大,深层根量多,属于“深根型”;根系活跃吸收表面积较大;根的输导组织较发达.     

无限结荚习性与亚有限结荚习性大豆品种根系性状的比较研究

采用盆栽方法，对黑龙江省和吉林省的19份无限结英习性大豆品种和17份亚有限结荚习性大豆品种的根系性状进行了比较研究。结果表明：两种不同结荚习性大豆品种根系性状存在差异，与无限结荚习性大豆品种相比，亚有限结荚习性大豆品种根量多，根体积庞大，根表面积大，侧根发达。     

杂交水稻苗期发根性状与生育后期根系活力及穗部性状的关系

采用沙培方法,对10个杂交稻组合苗期发根性状与生育后期根系SOD活性、TTC还原力及穗部性状的关系进行了研究。结果表明:苗期发根数、发根鲜重和发根力与孕穗期根系TTC还原力呈极显著正相关,与结实率呈显著或极显著正相关;发根数还与乳熟期SOD活性极显著正相关,与齐穗期TTC还原力显著负相关;发根鲜重和发根干重分别与大部分穗部性状密切相关。回归分析表明,用“发根数×平均发根长”表示发根力能全面地评价杂交水稻苗期发根性状。     

NaCl和Na_2CO_3胁迫对水稻根系生长的影响

采用根箱土培的方法对NaCl和Na_2CO_3胁迫下水稻不同土层根系生物量(即根系鲜质量)和主根的长度、根系生长速率及侧根的生长等进行了研究。结果表明,水稻根系生物量随着土层深度的增加逐渐减少,每个区段的根系生物量均表现为Na_2CO_3胁迫处理低于NaCl胁迫处理,Na_2CO_3胁迫处理在土表下20 cm以下部分没有根系分布。同一Na~+浓度下,水稻主根的长度、根系生长速率和侧根的长度、数量和直径等指标值均表现为Na_2CO_3胁迫处理低于NaCl胁迫处理。100 mmol/L NaCl胁迫显著(P0.05)降低了水稻主根的长度、根系生长速率,极显著(P0.01)降低了侧根的数量;50 mmol/L(Na~+浓度)Na_2CO_3胁迫处理显著降低了水稻根系生长速率和侧根数量。     

过湿条件下大豆不定根的发生及其生理作用研究

大豆是实行水旱轮作的重要作物之一,在缺乏良好排水条件的水田中实行水旱轮作时,长期涝渍所致的伤害成为大豆生长不良及产量低的重要原因.通过盆栽和大田试验在大豆生育初期进行过湿处理,调查培土或无培土条件下不定根的发生情况,揭示不定根对伤流速度,氮素的吸收运转等的影响,讨论了不定根与大豆耐湿性的关系.淹水条件下培土对不定根及根瘤的发生产生较大的影响,淹水条件下发生的不定根的量占总根重的43.1%,这些不定根提供了81.4%的伤流速度.不定根的呼吸速度为2.61 mg CO2g-1h-1,是初生根的近3倍.淹水导致全叶位叶片的叶色变淡,不定根的发生改变了伤流液中不同形态氮素的组成和全氮含量,可使下位叶的叶色维持较高水平.淹水条件下大豆的冠根比比对照小.不定根取代了受涝渍伤害而失去功能的初生根的作用,积极地进行养分和水的吸收,确保了涝渍逆境下物质生产的顺利进行.     

No-Tillage Enhanced the Dependence on Surface Irrigation Water in Wheat and Soybean

Abstract

No-tillage often affects crop root development due to the higher mechanical impedance to root elongation, resulting in yield reduction under an unfavorable rainfall pattern, such as drought. In this study, we analyzed the changes in water source of wheat and soybean under drought stress in a continuous no-tillage field. Deuterium-labeled irrigation water was applied at different growth stages of crops to analyze their water uptake pattern. Mechanical impedance of the surface soil was 3.5 and 4.4 times higher in the no-tillage than in the conventional tillage under wet and drought conditions, respectively. Root length density and root branching index (the length of lateral roots per unit axile root length) of soybean in the surface soil layer were higher in the no-tillage field. This indicates that the increased branching by the higher mechanical impedance of undisturbed surface soil causes roots to accumulate in the surface soil layer. The deuterium concentration in the xylem sap of both crops was significantly higher in the no-tillage than in the tillage under a drought condition. This indicates that the crops in the no-tillage field depend highly on the newly supplied easily accessible water (irrigation water and/or rainfall) as compared with those in the conventional tillage field under a limited water supply. In conclusion, enhanced surface root growth in the no-tillage condition would result in higher dependence on surface supplied irrigation water than in the conventional tillage under drought.     

The effect of aluminum treatments on the root growth and cell ultrastructure of two soybean genotypes

Since aluminum (Al) toxicity often negatively affects the growth and production of crops in acidic soil, understanding the mechanisms of plant physiological response to Al toxicity would facilitate the development of more Al-tolerant crops. The objective of this research is, therefore, using transmission electron microscope and spectrophotometer to study the physiology and cell ultrastructure changes of two soybean cultivars of distinctly different sensitivities to Al toxicity, Zhechun 2 (Z.2, Al-resistant) and Zhechun 3 (Z.3, Al-sensitive) after Al treatments. Using these two cultivars, we conducted a 14-day nutrient solution experiment with Al concentrations set at 0, 10, 30, 60 and 90 mg L⁻¹. The results demonstrated that Al inhibited the growth of soybean root systems and severely damaged root cells. In contrast to the Al-resistant cultivar, the Al-sensitive cultivar Z.3 showed a larger plasma membrane permeability than Z.2 when treated with Al. In addition, the root elongation, activity, appearance of root tips and root hair zone were all altered by Al treatments. For example, after the 10 mg L⁻¹ Al treatment, the number of mitochondria had proliferated significantly in the root tip cells; plasmolysis was observed in the 30 mg L⁻¹ Al treatment; and the cell wall had ruptured and the cellular contents had disappeared in the high-level Al treatments. The results of our study showed in detail how soybean roots changed physiologically in response to Al stress.     

大豆疫霉根腐病的几种实验室检验方法

大豆疫霉根腐病(Soybean Phytophthora Root Rot)是我国一类检疫对象。近年,大豆疫霉根腐病的检验技术研究也相继开展起来,本文综述了大豆疫霉根腐病的土壤检测、病植检测、种子检测等几种实验室检测方法。     

Anatomy of Nodal Roots in Tropical Upland and Lowland Rice Varieties

abstract

Nodal root anatomy was compared among twelve upland and lowland rice (Oryza sative L.) varieties with tropical origin which were grown in hydroponic culture and under field conditions. The traditional upland japonica varieties showed the largest diameter of root, stele, and xylem vessel followed by modern upland varieties. There was a clear varietal difference in the ratio of stele to root diameter, which was associated with the genetic group rather than with the ecosystems. The japonica varieties had a significantly larger stele diameter relative to the root diameter than indica and aus varieties. The indica and aus varieties displayed more xylem vessels per unit area of stele than the japonica varieties, but the diameter of xylem vessel was smaller. Equivalent xylem vessel diameter (De) was more dependent on the number of xylem in the indica varieties than in the japonica varieties. Distinctly different types of sclerenchyma anatomy were identified among the varieties. The development of sclerenchyma was classified into four different types based on thickening of cell wall in the outer cortical parenchyma and the number of sclerenchymatous cell layers. Like the xylem anatomy, the varietal differences in sclerenchyma development were more associated with genetic group rather than the ecotype. The japonica varieties had higher frequency of the types which have a doubled cell layer in sclerenchyma with thick cell wall than indica and aus. The difference among the genetic groups was nearly consistent across growing conditions, aerobic and submerged soils. These results indicated that sclerenchyma development is controlled by a genetic factor.     

Nodulation control of crack fertilization technique reduced the growth inhibition of soybean caused by short-term waterlogging at early vegetative stage

Waterlogging is the constraint for soybean growth and yield, because soybean is often cultivated in upland fields converted from paddy in Japan. However, efficient cultivation techniques for alleviating the adverse effects have not been developed. We have proposed the new soybean cultivation technique named crack fertilization which enables yield increase due to enhancing new root growth and N acquisition by increasing nodulation. Waterlogging induces N deficiency due to the suppression of nutrient uptake by the inhibition of root growth and nodule activity. Thus, it is hypothesized that crack fertilization would be effective to alleviate the inhibition of soybean growth and yield. The soybean cultivar of Sachiyutaka was planted in 1/5000 a Wagner pots and root boxes. Two separate waterlogging treatments were imposed to soybean plants at different growth stages, V1 and R4, and crack fertilization was done at V3. After these treatments, soybean plants were sampled at R5 in 2012 and 2013 experiments, respectively. Waterlogging at V1 and R4 inhibited the growth and yield of soybean and nodule growth, and the decreases in physiological parameters of soybean such as photosynthesis, chlorophyll content, and xylem sap exudation rate were observed. The adverse effects of waterlogging at V1 were alleviated by crack fertilization at V3, whereas crack fertilization could not alleviate the adverse effects of waterlogging at R4. Thus, crack fertilization after waterlogging at early vegetative stage would be the cultivation technique that enables to alleviate the adverse effects.     

基于玉米-大豆轮作的不同施肥体系对大豆开花后根系形态及产量的影响

探讨玉米-大豆轮作条件下，降低生产成本、减少环境污染的大豆施肥模式，是目前东北大豆生产需要解决的技术问题。本研究基于建立的玉米-大豆轮作体系设置了5种施肥处理，分别为：T1：玉米施用化肥，大豆不施肥；T2：玉米施用化肥，大豆施用有机肥；T3：玉米施用化肥，大豆施用1/2量的化肥；T4：玉米施用化肥，大豆施用化肥；T5：玉米与大豆所需化肥总量一次性全部施入到玉米种植年份，大豆不施肥。分析了不同施肥模式对大豆不同生育期0~10、10~20、20~30cm土层深度内大豆根系干物质积累、根系形态特征时空变化以及与产量的关系。结果表明，经两个轮作周期，T2处理大豆产量最高为 2959kg·hm-2，比T4处理显著高出7.3%，产量提高主要体现在大豆的株高、主茎节数、单株荚数和单株粒数等性状的改善，而T1、T3、T5处理的大豆产量比T4处理显著低出15.4%，8.5%和5.0%。T2处理显著增加了大豆R6期0~10cm土层的根重密度，比T4处理显著高出42.3%，且与产量呈显著正相关，相关系数为0.655(p < 0.01)；T2处理也明显增加了大豆R1期0~10、10~20cm土层以及R6期20~30cm土层的根长密度，分别比T4处理显著高出25.3%、71.3%和27.6%，且与产量呈显著正相关，相关系数为0.692 (p < 0.01)。与T4处理相比，尽管T3处理显著增加了大豆R1期10~20、20~30cm土层的根重密度和R6期10~20cm土层的根长密度及根表面积密度，但均与产量呈显著负相关。T4处理只显著增加R1期单位体积的根表面积，而对大豆根平均直径和其它时期单位体积的根表面积的影响不大。因此，不同施肥措施影响大豆根系特征及其产量的关系问题比较复杂。施用有机肥可通过增加表土层根的重量以及深土层根的长度从而提高大豆的产量。因此在有机肥源供应充足的地区，玉米、大豆两区轮作基础上，玉米收获后秋施15t·hm-2有机肥，是提高大豆产量，降低生产成本，减轻化肥应用负面环境影响的替代措施。     

不同土壤水分条件下吲哚丁酸钾对大豆根系形态建成及生理代谢的影响

为了研究吲哚丁酸钾（IBA-K）在减轻干旱对大豆根系的伤害中的作用,以垦丰16（干旱敏感型）和合丰50（耐旱型）为材料,采用盆栽法研究IBA-K拌种对两个品种大豆在正常供水、干旱和复水条件下根系形态建成及生理代谢的影响。结果表明,与正常供水相比,干旱胁迫抑制了大豆根系的生长发育,而IBA-K处理后,大豆根系干物质积累量、形态建成、抗氧化酶活性和渗透调节物质含量在不同土壤水分条件下均高于其干旱对照,膜受损程度减轻。IBA-K处理下,大豆根系SOD活性、POD活性、可溶性糖和脯氨酸含量在干旱条件下均显著高于其干旱对照;MDA含量、相对电导率显著低于其干旱对照。IBA-K处理下的两个品种大豆根表面积、根平均直径、根体积、POD活性和CAT活性在复水条件下分别高于其干旱对照,均未达到显著性差异。复水后,IBA-K处理下的垦丰16根干重和总根长分别较其干旱对照显著增加了3.13%和24.51%,合丰50根干重和总根长较其干旱对照未达到显著性差异。IBA-K处理下的合丰50相对电导率和MDA含量分别较其干旱对照显著降低11.80%和15.09%,SOD活性和可溶性糖含量分别较其干旱对照显著增加14.90%和3.94%,垦丰16相对电导率、MDA含量、SOD活性和可溶性糖含量较其干旱对照未达到显著性差异。IBA-K处理下的两个品种大豆根系脯氨酸含量分别较其干旱对照显著增加了10.62%和10.70%。IBA-K处理和不同土壤水分处理对两个品种大豆根系形态和生理指标存在显著或极显著影响,二者间的交互作用无明显调控作用。综上,IBA-K通过提高根系干物质积累量、抗氧化酶活性和渗透调节物质含量,降低MDA含量和相对电导率,减轻干旱胁迫对苗期大豆根系的伤害。     

Plasticity in root system architecture of rice genotypes exhibited under different soil water distributions in soil profile

ABSTRACT

The root system architecture (RSA) has been reported to be determined by several root traits such as branching, elongation, and growth angle. This study aimed to evaluate the genotypic variation of plasticity in RSA in response to different soil water distributions in a soil profile. IR64 (shallow root system), YTH183 (adapted to rainfed lowland conditions due to high plasticity in root elongation), and Kinandang Patong (KP – deep root system) were grown in PVC root boxes for 34 days under continuously waterlogged conditions and with soil moisture fluctuations (SMF). For SMF, watering was done from the top of the root box (TI-SMF) or from the bottom of the root box (BI-SMF). A water gradient was observed more clearly in BI-SMF than in TI-SMF, while mean soil moisture content in the root box was kept at around 23% (v/v) after first irrigation in both SMF treatments. RSA changed drastically with SMF in all cultivars, all of which tended to shift root distribution to deeper soil layers in response to SMF. Such changes in RSA resulted from different degrees of plasticity exhibited mainly in nodal root and L-type lateral root development. YTH183 showed a greater ability to change its root growth angle and thus its root distribution in the deeper soil layer compared to IR64 and KP under SMF, indicating that YTH183 could help to improve RSA in cultivars adapted to SMF.     

胞囊线虫侵染不同抗性大豆品种根系的组织病理学差异研究

为明确对大豆胞囊线虫病具有不同抗性的小黑豆品种的抗性机制,利用石蜡切片技术对线虫侵染不同抗性大豆品种根系的组织病理学差异进行了研究。结果表明:在侵染初期,抗感品种侵入根内的线虫数量没有明显差异,抗病品种形成合胞体的时间要早于感病品种辽豆15,哈尔滨小黑豆较早地在中柱内形成了合胞体,抗侵入能力较弱。随着线虫的侵染,抗病品种逐渐形成过敏性坏死反应,阻止线虫发育使根内形成非常少量的雌虫,其中灰皮支黑豆根内几乎没有雌虫形成,抗发育能力最强。感病品种辽豆15根内没有发生过敏性坏死反应形成了大量雌虫。在寄主维管束中,侵染后期中柱内形成的合胞体会使感病品种辽豆15木质部外移,根内导管数量减少,不利于水分运输的安全性。而3个抗病品种小黑豆的木质部组织结构没有发生病变,利于大豆的正常生长。