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1.
不同水稻品种对难溶性磷利用能力的初步研究 总被引：9，自引：0，他引：9
采用子母盆栽水平分根试验,研究了水稻耐低磷品种莲塘早3号和低磷敏感品种新三百粒对Fe-P、Al-P、Ca-P3种难溶性磷的利用能力。结果表明,与母盆营养液中含正常磷的处理相比,子盆和母盆均不含磷的处理两品种的生物量、根系氧化力下降、MDA含量上升,以难溶性磷为唯一磷源加入子盆石英砂的处理其变化幅度更小,磷含量也比完全缺磷的明显要高,说明根系对难溶性磷的主动活化在起作用;耐低磷品种较高的生物量、磷含量和根系氧化力以及较低的MDA含量表明其活化利用难溶性磷的能力比低磷敏感品种强;不同难溶性磷处理间,各指标的差异与不同形态难溶性磷对水稻有效性的差异有关。另外,缺磷或低磷条件下根冠比增加;磷的有效性越低,其根冠比越高。 相似文献
2.
低磷胁迫下箭筈豌豆和毛叶苕子根际过程的差异比较 总被引：2，自引：1，他引：1
采用我国北方两个豆科绿肥品种: 箭筈豌豆（Vicia sativa L.）与毛叶苕子（Vicia villosa Roth）,在控制条件下通过不同供磷处理的营养液培养,研究了不同绿肥作物适应低磷胁迫根际过程的差异,并揭示其高效利用磷的机理。试验通过分次取样的方法,测定了两种豆科作物在缺磷与供磷条件下的生物量、根系质子释放速率、根系有机酸分泌速率以及根表酸性磷酸酶活性的动态。结果表明,箭筈豌豆与毛叶苕子在生长前期对低磷胁迫的响应存在明显差异。箭筈豌豆主要靠增大质子释放量和提高酸性磷酸酶活性来适应低磷胁迫; 而毛叶苕子主要通过提高根冠比、扩大根系生物量来对外界环境中的缺磷状况做出响应,在缺磷时其根表酸性磷酸酶的活性显著提高。箭筈豌豆与毛叶苕子可通过协调根系形态和生理的适应性变化提高对磷的吸收。 相似文献
3.
田间玉米和蚕豆对低磷胁迫响应的差异比较 总被引：1，自引：1，他引：0
【目的】植物在长期进化过程中形成了一系列适应机制,以应对低磷胁迫。本文提出玉米主要通过根系形态变化适应低磷胁迫的假设,并通过与蚕豆植株在根系形态与生理方面对低磷胁迫反应的比较试验加以验证。【方法】在中国农业大学上庄长期定位试验田进行两年田间实验,玉米和蚕豆分别单作,重复3次。在玉米抽雄前的拔节至大喇叭口期和蚕豆的初花至盛花期两次取样(两年的两次取样时间间隔10~12天),比较研究了不供磷和供磷100 kg/hm2下玉米和蚕豆生长和磷素吸收、根系在0—40 cm土层中分布、以及根际p H值和酸性磷酸酶活性的差异。【结果】1)玉米植株的生物量和含磷量远远高于蚕豆;第一次取样时蚕豆的根冠比高于玉米,而且两种植物低磷下的根冠比高于供磷充足处理。两次取样时玉米的总根长大于蚕豆,两种植物的大部分根系分布在0—20 cm表层土壤,玉米根系在0—10 cm土层的分布更多。2)蚕豆根系的比根长明显大于玉米,但单位根长吸磷量低于玉米,两种植物间的上述差异不受取样时间和供磷水平的影响。3)两次取样时,蚕豆根表的酸性磷酸酶活性均明显高于玉米。玉米根表的酸性磷酸酶活性在两个供磷水平下没有差异。第一次取样时,缺磷蚕豆根表的酸性磷酸酶活性高于供磷充足的蚕豆植株。4)缺磷蚕豆的根际土壤p H值明显低于供磷充足蚕豆;但玉米根际土壤p H值在缺磷和供磷充足条件下无显著差异。【结论】低磷条件下两种植物的根冠比均明显增加。玉米根系单位根长的吸磷量高于蚕豆,并且在含磷量丰富的表层土壤分布有更多根系,但缺磷条件下玉米没有增加根系的质子和酸性磷酸酶的分泌,主要以根系形态变化来适应低磷胁迫。结果支持本文提出的玉米主要通过根系形态变化适应低磷胁迫的假设。但蚕豆在低磷条件下除了增加根系生长外,还具有通过增加质子分泌和根表酸性磷酸酶活性提高根际土壤有效磷浓度的潜力。 相似文献
4.
磷是植物生长和发育中最重要的必须元素之一。尽管土壤中磷资源很丰富,但大部分磷是以植物不能吸收利用的固定态和有机态存在,特别是以酸性土壤为主的南方稻田,水稻缺磷现象非常严重。理解和掌握水稻对低磷的适应机制有助于利用分子手段培育磷高效利用水稻品种。为阐明蔗糖提高水稻耐低磷的机制,本研究对水稻幼苗进行不同磷、糖处理,分析水稻幼苗在不同磷糖配比培养基中的根系结构、无机磷、酸性磷酸酶活性的变化,并利用定量RT-PCR技术分析水稻磷酸转运蛋白基因(OsPT)和酸性磷酸酶基因(OsSAP1)的表达。试验设2个磷浓度:无磷和85 mg·L?1KH2PO4,2个蔗糖浓度:无糖和3%蔗糖,正交设计。结果表明,在低磷胁迫时添加蔗糖,能使水稻幼苗的根总长度、总根数、根冠比显著增加,根分泌的酸性磷酸酶活性降低,但水稻体内的磷酸转运酶活性提高。11个与磷具有高度亲和力的磷酸转运酶的表达发生了改变,其中根优势表达的4个基因OsPT2、OsPT3、OsPT4、OsPT6对磷、糖的影响最为敏感,暗示了蔗糖是通过调节磷转运蛋白维持磷的吸收和平衡。增加根系的蔗糖分配能够提高水稻幼苗对磷胁迫的耐受性。 相似文献
5.
为探究盐碱条件下柳枝稷(Panicum vigatum L.)对供磷水平的响应,以不同品种柳枝稷(Alamo加倍体、Alamo、Pathfinder)为材料进行根箱试验,分析比较了不同磷浓度(0、10、100 mg/kg)处理对柳枝稷根系形态、生理特征及土壤理化性质的影响。结果表明:随着施磷水平的增加,各品种柳枝稷生物量、根系形态、根系活力及土壤有效磷含量整体呈上升趋势,而根冠比、土壤pH值和酸性磷酸酶活性呈下降趋势,均在高磷(100 mg/kg)处理下达到最大值和最小值。与高磷处理相比,低磷(10 mg/kg)处理下3个品种柳枝稷土壤pH值分别增加了0.31、0.28、0.23个单位,酸性磷酸酶活性平均提高了58.0%、42.0%、13.5%。低磷条件下,Alamo加倍体具有较大的根表面积,并保持较高的根系活力,表现出较强的适应性,有利于降低土壤pH,提高土壤酸性磷酸酶活性。总体而言,Alamo加倍体对盐碱低磷胁迫的适应能力优于Alamo、Pathfinder。同时增加供磷水平能够促进盐碱地柳枝稷根系生长、改善土壤环境,提高其生物质产量。 相似文献
6.
小麦不同磷效率品种对不同磷源的利用差异及酸性磷酸酶的作用 总被引：3，自引：0，他引：3
以小麦磷高效利用品种(03-2917)和低效利用品种(S-10-1)为材料,在水培条件下,测定其生物量、磷含量、根系分泌酸性磷酸酶、根系及叶片酸性磷酸酶活性等,研究不同磷素利用效率小麦品种有机磷吸收利用的差异.结果表明:(1)不同供磷条件下,磷高效品种干物质量、磷积累量较低效品种的大,而磷含量低于低效品种.小麦不同磷素利用效率品种均表现为无机磷处理下根冠比大于有机磷处理,磷高效品种在不同施磷处理下根冠比均较大.(2)不同磷效率小麦品种根系分泌酸性磷酸酶活性在低无机磷处理(0.05mmolP·L-1,Ⅳ)下最大,1/2无机磷+1/2有机磷处理(0.30mmolP·L-1,Ⅱ)大于正常有机磷处理.不同磷处理下,高效品种根系分泌酸性磷酸酶活性均大于低效品种.(3)不同磷效率小麦根系与叶片酸性磷酸酶活性呈现为正常无机磷(Ⅰ)＜1/2无机磷+1/2有机磷(Ⅱ)＜正常有机磷(Ⅲ)＜低无机磷(Ⅳ)的处理,且低效品种大于高效品种.(4)无机磷总量在磷处理及品种间表现与酸性磷酸酶相反的趋势,正常无机磷(Ⅰ)＞1/2无机磷+1/2有机磷(Ⅱ)＞正常有机磷(Ⅲ)＞低无机磷(Ⅳ)的处理,高效品种大于低效品种. 相似文献
7.
低磷胁迫下马尾松无性系磷效率性状对氮沉降的响应 总被引：2，自引：0，他引：2
8.
低磷胁迫对豇豆幼苗叶片光合特性及根系生理特性的影响 总被引：8，自引：2，他引：6
利用营养液培养方法研究了豇豆幼苗对磷胁迫的生理响应。结果表明,磷胁迫下豇豆根系最大根长增加43%,侧根数目增加33%,根系体积增加;但是缺磷时叶片面积变小,且发育延迟。缺磷时豇豆幼苗根系活力和根系表面酸性磷酸酶活性分别是全磷培养植株的2.3和1.7倍;与供磷植株相比,缺磷植株光合速率和蒸腾速率均下降30%;气孔器变小,气孔密度减少(减少20%)。磷胁迫下豇豆干物质累积量显著降低,缺磷主要影响了地上部分干物质累积,而根系干物质累积几乎不变,因此根冠比增大。磷胁迫对地上的影响大于对根系的影响。 相似文献
9.
小麦代换系幼苗根系对低磷胁迫的生理响应暗示的染色体效应 总被引：1，自引：0，他引：1
10.
为了阐明小麦苗期耐低氮、低磷胁迫的生物学响应特征,以矮抗58品种为试验材料,采用水培试验法研究了小麦在不同营养环境中(全营养、低氮胁迫、低磷胁迫)的地上部生物学特性(地上部干重、株高、叶面积)、根系形态学特性(最大根长、总根数、根系总长度、根系干重和根冠比)和根系生理特性(根系活力、根系吸收面积),以及小麦苗期氮、磷素吸收与根系形态之间的关系。结果表明,在低氮和低磷胁迫下,小麦的株高、叶面积、茎叶干重、含氮量、根系干重、总根长、总根数及根冠比均明显降低,其中低磷胁迫下根系干重、总根长及根冠比的下降幅度大于低氮胁迫,低氮下最大根长的增加幅度较低磷增加7.3%;在低磷条件下小麦的含氮量下降了57.7%。低氮、低磷胁迫下小麦根系的总吸收面积、活性吸收面积及根系活力均明显降低;正常条件下的小麦氮、磷素吸收量与根系形态指标之间相关性较差,在低氮和低磷条件下小麦的氮、磷吸收量与根系干重、总根长、总吸收面积、活性吸收面积及根系活力呈极显著正相关。总之,该小麦品种根系对低磷环境反应较为敏感,而对低氮胁迫具有较好的适应性,小麦通过改变根系形态增加对低氮、磷胁迫的适应。 相似文献
11.
Previous studies describe the suitability of a new type of phosphorus (P) fertilizer, called “rhizosphere‐controlled fertilizer” (RCF), to supply available P to plants while reducing soil phosphorus fixation. In order to explore the involvement of organic acid root exudation in P uptake from RCF, we investigated the relationship between shoot and root P concentrations, and the concentration of the main polycarboxylic organic acids in roots, shoots, and plant exudates. Plant species with different P‐acquisition efficiency (low: maize; medium: chickpea; high: lupin) were grown in hydroponics with three different P fertilizers: The water‐insoluble P fraction of RCF (RCF); Phospal, a slow‐release source of phosphate composed of calcium and aluminum phosphates (PH); monopotassiumphosphate (KP), and a control treatment without P (P–). RCF was as efficient as KP in supplying P to plants in the case of chickpea and lupin, and slightly less efficient than KP in maize. However, P from PH was not available for maize and less available compared to KP and RCF in chickpea and lupin. This variation reflects the different efficiencies in P acquisition for the three plant species. Except in the case of maize, plants receiving KP presented the lowest concentration of organic acids in roots and exudates, while those plants suffering severe P deficiency (P– and PH) showed the highest organic acid concentration. However, RCF had a high concentration of organic acids in roots and exudates, as well as a high P concentration in the shoot indicating that P uptake from RCF is enhanced due to root release and action of specific organic acids. 相似文献
12.
I.M. Rao V. Borrero J. Ricaurte R. Garcia M.A. Ayarza 《Journal of plant nutrition》2013,36(2):323-352
Identification of plant attributes that improve the performance of tropical forage ecotypes when grown as monocultures or as grass+legume associations in low fertility acid soils will assist the development of improved forage plants and pasture management technology. The present work compared the shoot and root growth responses of four tropical forages: one grass and three legumes. The forages were grown in monoculture or in grass+legume associations at different levels of soil phosphate. Two infertile acid soils, both Oxisols, were used: one sandy loam and one clay loam. They were amended with soluble phosphate at rates ranging from 0 to 50 kg ha‐1. The forages, Brachiaria dictyoneura (grass), Arachis pintoi, Stylosanthes capitata and Centrosema acutifolium (legumes), were grown in large plastic containers (40 kg of soil per container) in the glasshouse. After 80 days of growth, shoot and root biomass production, dry matter partitioning, leaf area production, total chlorophyll content in leaves, soluble protein in leaves, root length, and proportion of legume roots in grass+legume associations were determined. The grass, grown either in monoculture or in association responded more to phosphorus supply than did the three legumes in terms of both shoot and root production. At 50 kg ha‐1 of phosphorus, the grass's yield per plant in association was greatly enhanced, compared with that of grass in monoculture. The increase in size of grass plants in association compared with that in monoculture may have been caused by reduced competition from the legumes. These differences in shoot and root growth responses to phosphorus supply in acid soils between the grass and the three legumes may have important implications for improving legume persistence in grass+legume associations. 相似文献
13.
14.
Abstract The distribution of secretory acid phosphatase and organic acids enhanced by phosphorus deficiency in lupin rhizosphere was investigated using a rhizobox system which separated the rhizosphere soil into 0.5 mm fractions. In the soil fraction closest to the root surface, the lupin exudates displayed an acid phosphatase activity of 0.73 u g?1 dry soil and citrate concentration of 85.2 μmol g?1 dry soil, respectively. The increase of the acid phosphatase activity-induced an appreciable depletion of organic P in the rhizosphere, indicating that lupin efficiently utilized the organic P from soil through the enzyme activitye The sterile treatments demonstrated that the acid phosphatase in the rhizosphere was mainly derived from lupin root secretions. The secretory organic acids enhanced considerably the solubility of the inorganic P in three types of soil and a sludge. However, the secretory acid phosphatase and organic acids from lupin roots were only detected in a considerable amount in 0-2.5 mm soil fractions from root surface. 相似文献
15.
Root-induced changes in the rhizosphere may affect mineral nutrition of plants in various ways. Examples for this are changes in rhizosphere pH in response to the source of nitrogen (NH4-N versus NO3-N), and iron and phosphorus deficiency. These pH changes can readily be demonstrated by infiltration of the soil with agar containing a pH indicator. The rhizosphere pH may be as much as 2 units higher or lower than the pH of the bulk soil. Also along the roots distinct differences in rhizosphere pH exist. In response to iron deficiency most plant species in their apical root zones increase the rate of H+ net excretion (acidification), the reducing capacity, the rate of FeIII reduction and iron uptake. Also manganese reduction and uptake is increased several-fold, leading to high manganese concentrations in iron deficient plants. Low-molecular-weight root exudates may enhance mobilization of mineral nutrients in the rhizosphere. In response to iron deficiency, roots of grass species release non-proteinogenic amino acids (?phytosiderophores”?) which dissolve inorganic iron compounds by chelation of FeIII and also mediate the plasma membrane transport of this chelated iron into the roots. A particular mechanism of mobilization of phosphorus in the rhizosphere exists in white lupin (Lupinus albus L.). In this species, phosphorus deficiency induces the formation of so-called proteoid roots. In these root zones sparingly soluble iron and aluminium phosphates are mobilized by the exudation of chelating substances (probably citrate), net excretion of H+ and increase in the reducing capacity. In mixed culture with white lupin, phosphorus uptake per unit root length of wheat (Triticum aestivum L.) plants from a soil low in available P is increased, indicating that wheat can take up phosphorus mobilized in the proteoid root zones of lupin. At the rhizoplane and in the root (root homogenates) of several plant species grown in different soils, of the total number of bacteria less than 1 % are N2-fixing (diazotrophe) bacteria, mainly Enterobacter and Klebsiella. The proportion of the diazotroph bacteria is higher in the rhizosphere soil. This discrimination of diazotroph bacteria in the rhizosphere is increased with foliar application of combined nitrogen. Inoculation with the diazotroph bacteria Azospirillum increases root length and enhances formation of lateral roots and root hairs similarly as does application of auxin (IAA). Thus rhizosphere bacteria such as Azospirillum may affect mineral nutrition and plant growth indirectly rather than by supply of nitrogen. 相似文献
16.
通过盆栽试验研究钼硒配施对水培小白菜钼硒形态及硒价态的影响。结果表明:施硒增加了小白菜地上部及地下部醇溶态和水溶态钼含量,降低了小白菜地上部及地下部盐溶态及醋酸溶态钼的含量,增加了地下部盐酸溶态钼含量,对地上部盐酸溶态钼含量没有太大的影响。施钼对小白菜地上部醇溶态、水溶态硒含量影响不大,增加了盐溶态及盐酸溶态硒的含量,降低了醋酸溶态硒的含量;施钼对小白菜地下部醇溶态硒含量影响不大,降低了水溶态硒的含量,增加了盐溶态、醋酸溶态及盐酸溶态硒的含量。施用四价的亚硒酸钠对小白菜可食部位硒的有机化较为有利,并且施钼也能促进高硒水平下小白菜体内硒的有机化。因此,钼硒配施虽然对小白菜体内钼和硒的各赋存形态有拮抗作用也有协同作用,但是有利于生产富含有机硒的作物。 相似文献
17.
The ability of buckwheat (Fagopyrum esculentum) roots to acquire phosphorus (P) was characterized by investigating P uptake, morphological features, and chemical changes in the rhizosphere. Over a range of nutrient solution P concentrations (5–500 μmol · L?1), maximum shoot growth was achieved with a P supply between 5 and 100 μmol · L?1. Root weight and root length, as well as length and frequency of root hairs, were higher at low P levels. Root surface and the root surface/shoot dry weight ratio reached high values. Though P uptake rates were only moderate (0.15 pmol · cm?1 root · sec?1), shoot P concentrations were high (1.8% of dry weight with 100 μM P) predominantly being inorganic (80%). Phosphorus efficiency was characterized by a high specific absorption rate (810 mmol P · kg?1 root dry wt · d?1) rather than by an efficient utilization for dry weight production. Root exudates of low-P plants had lower pH values than exudates of high-P plants and increased the solubility of FePO4 and MnO2 to a greater extent. Amounts of exuded organic acids and phenolics were low and could not account for the observed solubilization of FePO4 and MnO2. Enhanced hydrolysis of glucose-6-phosphate by exudates from low-P plants was due to an increased “soluble” acid phosphatase activity, and root surface phosphatase activity was also slightly enhanced with P deficiency. In the rhizosphere soil of buckwheat, some depletion of organic P forms was observed, and in pot trials with quartz sand, buckwheat utilized glucose- 6-phosphate as a P source at the same rate as inorganic P. 相似文献
18.
外源有机酸对两种生态型东南景天吸收和积累锌的影响 总被引：15，自引：1，他引：15
通过溶液培养试验,比较研究了外源有机酸对两种生态型东南景天生长和锌吸收与积累的影响。结果表明,外加柠檬酸或草酸能明显增强非超积累生态型东南景天的耐锌毒能力,叶片、茎和根系的生物量均有增加;而对锌超积累生态型东南景天的生长没有显著性影响。外加柠檬酸、草酸或柠檬酸+草酸,锌超积累生态型根系Zn含量显著增加,但叶片和茎组织中Zn含量无明显变化;而非超积累生态型叶片、茎和根系Zn含量均显著增加,尤其是根系Zn含量,与单独Zn处理相比外源有机酸处理增加4～5倍。同样,外加柠檬酸、草酸或柠檬酸+草酸明显提高Zn在非超积累生态型根系和地上部的积累量,且对地上部Zn积累量的促进程度大于根部;柠檬酸的促进作用又比草酸及2种酸混合处理高1倍。然而,有机酸处理对Zn超积累生态型根系Zn积累量有所增加,但对叶片和茎中Zn积累量无影响。叶片和茎中水溶态Zn含量也受外源有机酸的影响,2种生态型叶片、茎中水溶态Zn含量均受有机酸处理而提高。Zn超积累生态型叶片和茎中水溶态Zn含量占总Zn含量比例也受有机酸处理而增大,但非超积累生态型则显著降低。上述结果表明,柠檬酸和草酸可能作为其Zn吸收的配基,促进根系对Zn吸收与积累,叶片和茎中的Zn可能与可溶性有机化合物或无机盐结合。 相似文献
19.
Brachiaria are tolerant to low phosphorus (P) soils and may enhance P soil availability. The identification of mechanisms driving this effect is important. Our objective was to determine responses of palisade grass and ruzigrass to mineral oxide-bound P. Palisade grass (Brachiaria brizantha) and ruzigrass (Brachiaria ruziziensis) were grown in nutrient solution (NS), where P was supplied as goethite and amorphous aluminum-oxide (Al-oxide). Only half of each pot received P. Dry matter yields of Brachiaria species having oxide-P as the sole P source were similar to those grown with water-soluble P. Inorganic P was found in the NS after 7 days, and organic P at 14 days after plant emergence. The presence of dissolved organic carbon (DOC) indicates an intense and quick response of the root system to the treatments. Results indicate enzyme and/or organic acids (OAs) root exudation as a strategy of these plants to access soil sparingly soluble P forms. 相似文献