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1.
缺磷对不同作物根系形态及体内养分含量浓度的影响   总被引:3,自引:1,他引:2  
采用营养液培养方法,以水稻、 小麦、 玉米和大豆为试验材料,研究了短期缺磷(2周)诱导根表沉积铁氧化物是否为水稻特有的性质,以及缺磷对不同作物根系形态及其吸收钾、 钙、 铁、 锰、 铜、 锌营养元素的影响。结果表明,供磷和缺磷处理并没有影响小麦、 玉米和大豆3种作物根系的颜色,而缺磷处理水稻根表沉积了铁氧化物而呈红(黄)棕色,且铁氧化物不均匀地富集在根细胞壁的孔隙中; 缺磷促进了水稻,小麦,玉米和大豆根系的生长,分别比供磷处理伸长了11%、 11%、 20%和11%(P0.05)。此外,缺磷胁迫下水稻根表铁氧化物增强了钙、 铁、 锰、 铜和锌在根表的富集而成为其进入根系的缓冲层。缺磷处理水稻根中铁浓度明显高于供磷处理(P0.05),而地上部铁的浓度仅为磷营养正常水稻植株的18%,这说明缺磷诱导的铁氧化物促进了根系对铁的吸收但抑制了铁由根系向地上部的转运。短期缺磷对其他养分在水稻根中和地上部的浓度没有明显影响。对于其他 3 种作物,短期缺磷没有明显影响钾、 钙、 铁、 锰、 铜和锌在其根表富集及在植物体内的浓度。因此,在供试的4 种作物中,由于磷胁迫诱导根表形成铁氧化物是水稻特有的性质,铁氧化物的沉积可促进铁的吸收但抑制了铁向地上部的转运,而短期缺磷并没有影响其他3种作物对钾、 钙、 铁、 锰、 铜和锌养分的吸收和转运。  相似文献   

2.
采用溶液培养研究了以硝酸铵和尿素作为氮源时,缺镍对水稻植株的生长、脲酶和谷氨酸胺合成酶活性、植株中尿素态N和总氮含量的影响。结果表明,以硝酸铵作为氮源时,缺镍不影响植株的生长;但以尿素作为氮源时植株生长受到明显影响,植株生长停滞,叶片黄化,叶尖坏死干枯。缺镍植株中脲酶活性非常低,地上部仅为供镍植株的0.05%左右;谷氨酰胺合成酶活性除供应尿素氮缺镍植株较低以外,其它处理没有明显差异。缺镍植株中尿素态N含量明显高于供镍植株,特别是供应尿素态氮缺镍植株地上部尿素态N大量累积。供应尿素态氮缺镍植株含氮量明显低于其它处理。  相似文献   

3.
采用一种缺锰土壤,二种缺铁土壤和一种铁,锰丰富的土壤进行盆栽试验研究了移栽灵混剂对水稻旱育秧苗生长及铁,锰营养的影响,结果表明,在铁,锰供应充足土壤上,移栽灵轻度抑制时秧生长,缺锰和轻度缺铁土壤上移栽灵增加旱秧分蘖并促进生长;但在严重缺铁土壤上则无明显效果。移栽灵防治旱秧铁,锰缺乏和促进旱秧生长的效果均不如传统单 育秧技术中硫黄调酸处理。植株分析发现仅在缺锰土壤上移栽灵增加了旱秧铁,锰吸收量,其余  相似文献   

4.
硫化氢促进缺磷条件下水稻根系细胞壁磷的再利用   总被引:2,自引:0,他引:2  
朱春权  朱晓芳  沈仁芳 《土壤》2018,50(1):51-58
在缺磷条件下,外源添加10 nmol/L H_2S供体Na HS可以显著提高水稻体内的有效磷含量。进一步研究发现,H_2S主要通过提高水稻根系细胞壁中的果胶含量和果胶甲酯酶的活性来增加水稻细胞壁磷的释放,从而确保水稻在缺磷条件下的存活。添加H_2S的清除剂亚牛磺酸后进一步验证了H_2S对水稻根系细胞壁磷再利用的调控作用。同时,测定3个负责水稻体内磷转运的磷转运子基因的表达,结果显示H_2S主要通过上调磷转运子OsPT6和OsPT8基因的表达来提高水稻体内磷从根部往地上部的转运。  相似文献   

5.
研究了不同P营养基因型小麦(Triticum aestivum L.)“81(85)5-3-3-3”和“NC37”在苗期对根系局部供P(0.1mmol/L)后的反应。结果表明,只有3cm根段处于完全营养液(LHL)中的小麦植株不能正常生长,其干物质量分别为全部根系处于完全营养液(HHH)中的小麦植株的54.0%和49.6%。但给绝大部分根系供P,只有3cm根段处于缺P营养液(HLH)中的小麦植株的干物质量、株高、叶面积、根长、根轴长和侧根数等均明显高于全部根系处于完全营养液处理,此时的植株含P量正常。这表明小麦根系接受局部缺P刺激后,加速了小麦苗期的生长发育;缺P信号和常量P信号的刺激具有协同作用,体内不缺P小麦植株可以接受缺P信号并产生正效应。不同基因型小麦对局 部施P的反应有一定差异。  相似文献   

6.
在严重缺锰土壤上进行旱育秧培育供试植株,在分蘖末期淹水处理使水稻秧苗缺锰症基本消失后施入3水平用量较大的铁,锰,硼,铜,钼5种微量元素肥料,观察铁,锰,硼,铜钼大量施用时水稻生长和产量的影响。  相似文献   

7.
大剂量锰对小麦生长的影响   总被引:1,自引:0,他引:1  
小麦缺锰时,施锰有良好效果;但土壤中含锰量过高,小麦就引起锰中毒。潮土施加Mn大于250mg/kg,小麦籽实产量下降13.7%,差异达显水平;加Mn大于1000mg/kg,小麦拔节期生长高度明显下降,植株分蘖少且下部叶片尖端枯萎;加Mn2500mg/kg,植株瘦小,不分蘖,旗叶叶尖估萎,穗小,顶部小穗不孕呈白色,成熟推迟;加Mn5000mg/kg,植株死亡。土壤施加锰的安全浓度应小于250mg/  相似文献   

8.
采用盆栽试验方法研究了猪粪对缺锰土壤上水稻旱育秧苗生长的影响及猪粪在淹水后秧苗缺锰症恢复中的作用结果表明,在不施锰肥的条件下旆用高量猪粪处理,旱育秧功仍表现严重缺锰症状,但较不施猪粪自理有所减轻,更没有出现猪粪加重植株缺锰的情况;在施锰和不施锰条件下,随猪粪用量的增加,旱育秧苗的分蘖和地上部干重均明显增加,因此猪粪可促进缺锰土壤上旱育 生长;在淹水后猪粪可以使土训氧化还原电位下除更快,土壤Mn^2  相似文献   

9.
采用营养液培养法,研究了不同pH和供Zn条件下高浓度HCO3-(10 mmol L-1)对小麦幼苗生长,尤其是对锌营养的影响,结果表明:当营养液起始pH为6时,HCO3-在缺Zn时对小麦根系生长的抑制作用较为明显,而正常供Zn时的影响较小。当营养液起始pH为8时,不论缺Zn还是供Zn,添加HCO3-对根系和地上部均未表现出明显的抑制作用。HCO3-在酸性营养液中能极大促进小麦植株根系和地上部尤其是根系对Zn的吸收,而在碱性条件下则抑制小麦幼苗根系和地上部对Zn的吸收。此外,HCO3-能显著抑制Zn从根系向地上部分的转运,从而造成在根系中的大量积累。HCO3-加入营养液后会生成少量的CO32-,并使营养液pH维持在较高水平上。  相似文献   

10.
为研究燃煤烟气对土壤-小麦系统中汞积累和分布的影响,在小麦苗期和成熟期采集河南省商丘市某燃煤电厂周围农田土壤和小麦植株样品,用ZYG-Ⅱ型智能冷原子荧光测汞仪测量样品中的汞含量。结果表明,小麦苗期和成熟期,土壤样品中汞含量没有超过土壤环境质量标准(GB15618—1995)二级标准的限值。燃煤电厂周围表层土中汞含量要明显高于深层土,呈表层富集现象,苗期小麦根的汞含量高于茎叶,其根、茎叶的汞含量与表层土的汞含量呈显著正相关。小麦从苗期到收获期,表层土、小麦根和茎叶的汞浓度升高。小麦从苗期到收获期,茎叶面积迅速增加,小麦叶片直接从大气中吸收燃煤烟气中的汞,使小麦茎叶通过叶面吸收的汞浓度增加,收获期燃煤电厂周围小麦各器官汞含量为茎叶〉根〉颖壳〉籽粒。成熟期小麦根的汞含量与表层土的汞含量呈显著正相关,而茎叶汞含量与表层土的汞含量无相关性。因此,燃煤烟气中汞沉降影响燃煤电厂周围种植的小麦各器官对汞的吸收和累积。  相似文献   

11.
《Journal of plant nutrition》2013,36(12):2677-2688
ABSTRACT

Under field conditions, wheat cultivar PBW 343 produced 1.5 times higher grain yield than PDW 233, when grown on low manganese (Mn) soil. To explain the differences in Mn efficiency a pot experiment was conducted using Mn deficient Typic ustochrept loamy sand soil treated with 0, 50, and 100?mg?Mn?kg?1 soil. In no-Mn treatment, both the wheat cultivars showed Mn deficiency symptoms and cultivar PBW 343 produced 30% of the maximum dry matter yield (DMY) attained at high Mn supply, while PDW 233 produced only 18% of its maximum DMY after 40 days of growth. With application of 50?mg?Mn?kg?1 soil, the DMY significantly increased to 87% and 50% of the maximum for PBW 343 and PDW 233, respectively. These results indicate that aestivum cultivar PBW 343 was more Mn efficient than durum cultivar PDW 233. Manganese efficient cultivar PBW 343 had a lower internal Mn requirement than PDW 233 because at the same shoot Mn concentration PBW 343 produced more DMY. The root growth of both wheat cultivars was similar at sufficient Mn supply, the root length (RL)?:?DMY ratio being equal. At decreasing Mn supply root growth was depressed more strongly than shoot growth, the inhibition being more severe in Mn inefficient cultivar PDW 233, indicating the importance of root system size for Mn efficiency between these two wheat cultivars. A nutrient uptake model closely described Mn influx in both the cultivars, indicating that calculated concentration profiles were realistic and that chemical mobilization of Mn in the rhizosphere was not responsible for higher Mn efficiency of PBW 343. Calculated concentration profiles showed that in soil not fertilized with Mn, initial soil solution Mn concentration of 0.23?µM decreased to only 0.21?µM at the root surface after 27 days of uptake. This 7.4% decrease in Mn concentration at the root surface indicated that roots could not decrease Mn concentration to a lower value which would have caused higher transport of Mn to root surface and hence resulted in higher Mn influx.  相似文献   

12.
Manganese (Mn) deficiency is reported worldwide and often decreases crop yield. However, plant species differ in their susceptibility to Mn deficiency. Poaceae are often inefficient, whereas Brassicaceae seem to be efficient in Mn uptake. The objective of this paper was to determine the relevance of Mn‐uptake kinetics, root‐system size, and Mn mobilization for differences in Mn efficiency of wheat, oat, and raya. To determine Mn‐uptake kinetics, wheat (Triticum aestivum L. cv. PBW 343), raya (Brassica juncea L. cv. RLM 619), and oat (Avena sativa L. cv. Aragon) were grown in a growth chamber together in complete nutrient solution having an average Mn concentration of 90, 180, 360, 910, and 2270 nmol L–1. For determining Mn efficiency of the three species in soil, the plants were grown for 22 d in pots filled with 3 kg of a loamy soil low in Mn availability (pH (CaCl2) 7.4; DTPA‐extractable Mn: 3.5 mg (kg soil)–1). The soil was fertilized with 0, 1, 2, 4, and 8 mmol Mn (kg soil)–1 resulting in Mn soil‐solution concentrations ranging from 40 to 90 nmol L–1, hence lower than in the solution experiment. In order to determine Mn soil‐solution concentration close to the root surface, the root length density was increased by growing two plants of raya and four plants of wheat in only 250 mL soil columns for 25 d. In solution culture at high concentrations, raya showed a higher Mn uptake compared to wheat and oat. However, at low Mn supply, all three species were comparably Mn‐efficient, i.e., plant growth was similar, and also the uptake was similar. In soil, the highest yield was achieved for raya in the unfertilized treatment whereas the Poaceae needed at least a fertilization of 1 mmol Mn (kg soil)–1. The Poaceae showed a yield reduction of about 40% in the unfertilized treatment. Manganese concentration in the shoot dry weight was always higher in raya than in wheat or oat. This was due to a higher Mn uptake whereas relative shoot‐growth rate and root‐to‐shoot ratio were similar among the species. The higher Mn uptake of raya in soil was in contradiction to the comparable Mn‐uptake kinetics of the three crops at low Mn concentration in solution. This points to plant differences in their ability to affect Mn availability in the rhizosphere. In the bulk soil, all the crops decreased Mn solution concentration, but this effect was somewhat less for raya. But in the rhizosphere, raya increased Mn soil‐solution concentration significantly to 58 nmol L–1, as compared to 37 nmol L–1 of the unplanted control soil. In contrast, wheat showed a Mn solution concentration of 25 nmol L–1 which was not significantly different from the control. The results indicate that differences in Mn efficiency among the crops studied are related to their ability to affect the solubility of Mn in the rhizosphere.  相似文献   

13.
Manganese (Mn) deficiency limits wheat productivity on sandy loam, calcareous and alkaline soils cropped with rice. Variation of wheat genotypes to sustain production and Mn use from Mn deficient condition was investigated to screen efficient genotypes. Forty-seven diverse wheat genotypes were evaluated on Mn sufficient (0.195 µM) and Mn deficient (0 µM) nutrient solution to elucidate physiological basis of Mn deficiency tolerance and to develop manganese deficiency tolerance index (MDTI). Shoot dry weight and mean Mn accumulation was 136.7% and 76.5% enhanced when Mn nutrition was improved, respectively. Efficient genotypes under limited Mn had lower root length/shoot weight ratio but higher relative shoot growth rate with higher shoot demand on root which reflected higher Mn influx. Genotypes were classified as tolerant (>0.66), semi-tolerant (0.33–0.66) and sensitive (<0.33) on the basis of MDTI (0–1 scale). Manganese efficient genotypes are most desirable for sustainable production of wheat under low Mn.  相似文献   

14.
Wheat cultivars differ widely in manganese (Mn) efficiency. To investigate the reasons for different Mn efficiencies, a pot experiment with soil, a solution‐culture experiment, and model calculations were carried out. The pot experiment was conducted with wheat (Triticum aestivum L. cvs. PBW 373, PBW 154, PBW 343, PBW 138, and Triticum durum L. cvs. PBW 34 and PDW 233) grown in a screen house in India. The soil was a loamy sand with pH 8.1, DTPA‐extractable Mn 1.62 mg (kg soil)–1, and initial soil solution Mn concentration (CLi) of 0.19 μM. When fertilized with 50 mg Mn (kg soil)–1, CLi increased to 0.32 μM. At CLi 0.19 μM, wheat cv. PBW 373 produced 74% of its maximum shoot dry weight (SDW) with 64% of its maximum root length (RL), while cv. PDW 233 produced only 25% of its maximum SDW with 11% of its maximum RL. The other wheat cultivars were between these extremes. Manganese deficiency caused a reduction in shoot growth, but more strongly reduced root growth. The low Mn efficiency of T. durum cv. PDW 233 was related to a strong depression of its root growth. Manganese influx was similar for all cultivars. In solution culture below 1 μM Mn, under controlled climate‐chamber conditions, Mn influx was linearly related to Mn concentration. Both the efficient cv. PBW 343 and the inefficient cv. PDW 233 had a similar influx. Uptake kinetic parameters from the solution experiment together with soil and plant parameters from the pot experiment were used in a mechanistic nutrient‐uptake model. Calculated values of Mn influx for wheat grown in soil were 55% to 74% of measured values. A sensitivity analysis showed that increasing CLi or the slope of the uptake isotherm by about 30% would be enough to reach the observed influx. The results of this research indicate that an increase of Mn solubility by microbial or chemical mobilization would increase Mn uptake. But on the other hand, no chemical mobilization would be required to increase Mn uptake if the plant improved its uptake kinetics. Low Mn efficiency of some wheat cultivars was related to their reduced root growth at low soil Mn supply.  相似文献   

15.
Tolerance to zinc (Zn) deficiency was examined for three wheat (Triticum aestivum L.) and three barley (Hordeum vulgare L.) varieties grown in chelator‐buffered nutrient solution. Four indices were chosen to characterize tolerance to Zn deficiency: (1) relative shoot weight at low compared to high Zn supply (“Zn efficiency index”), (2) relative shoot to root ratio at low compared to high Zn supply, (3) total shoot uptake of Zn under deficient conditions, and (4) shoot dry weight under deficient conditions. Barley and wheat exhibited different tolerance to Zn deficiency, with barley being consistently more tolerant than wheat as assessed by all four indices. The tolerance to Zn deficiency in the barley varieties was in the order Thule=Tyra>Kinnan, and that of wheat in the order Bastian=Avle>Vinjett. The less tolerant varieties of both species accumulated more P in the shoots than the more tolerant varieties. For all varieties, the concentrations of Mn, Fe, Cu, and P in shoot tissue were negatively correlated with Zn supply. This antagonism was more pronounced for Mn and P than for Cu and Fe. Accumulation of Cu in barley roots was extremely high under Zn‐deficient conditions, an effect not so clearly indicated in wheat.  相似文献   

16.
[目的]研究外源供锌对小麦幼苗根系发育、光合作用、金属离子平衡以及锌铁转运蛋白ZIP基因的表达,以期深入了解小麦的锌营养作用机理.[方法]采用水培试验方法,供试材料为冬小麦'百农207',试验共设置了5个锌(Zn)浓度处理:0?(Zn0)、0.05?(Zn0.05)、0.25?(Zn0.25)、1.0?(Zn1.0)和...  相似文献   

17.
Abstract

Greenhouse experiments were carried out to study the influence of gyttja, a sedimentary peat, on the shoot dry weight and shoot concentrations of zinc (Zn) and boron (B) in one bread wheat (Triticum aestivum L., cv. Bezostaja) and one durum wheat (Triticum durum L., cv. Kiziltan) cultivar. Plants were grown in a Zn‐deficient (DTPA‐Zn: 0.09 mg kg?1 soil) and B‐toxic soil (CaCl2/mannitol‐extractable B: 10.5 mg kg?1 soil) with (+Zn = 5 mg Zn kg?1 soil) and without (?Zn = 0) Zn supply for 55 days. Gyttja containing 545 g kg?1 organic matter was applied to the soil at the rates of 0, 1, 2.5, 5, and 10% (w/w). When Zn and gyttja were not added, plants showed leaf symptoms of Zn deficiency and B toxicity, and had a reduced growth. With increased rates of gyttja application, shoot growth of both cultivars was significantly enhanced under Zn deficiency, but not at sufficient supply of Zn. The adverse effects of Zn deficiency and B toxicity on shoot dry matter production became very minimal at the highest rate of gyttja application. Increases in gyttja application significantly enhanced shoot concentrations of Zn in plants grown without addition of inorganic Zn. In Zn‐sufficient plants, the gyttja application up to 5% (w/w) did not affect Zn concentration in shoots, but at the highest rate of gyttja application there was a clear decrease in shoot Zn concentration. Irrespective of Zn supply, the gyttja application strongly decreased shoot concentration of B in plants, particularly in durum wheat. For example, in Zn‐deficient Kiziltan shoot concentration of B was reduced from 385 mg kg?1 to 214 mg kg?1 with an increased gyttja application. The results obtained indicate that gyttja is a useful organic material improving Zn nutrition of plants in Zn‐deficient soils and alleviating adverse effects of B toxicity on plant growth. The beneficial effects of gyttja on plant growth in the Zn‐deficient and B‐toxic soil were discussed in terms of increases in plant available concentration of Zn in soil and reduction of B uptake due to formation of tightly bound complexes of B with gyttja.  相似文献   

18.
石灰性土壤上小麦锌缺乏问题在世界范围内广泛存在,而高含量的HCO3-被认为是造成缺锌的主要原因之一。本试验采用土培试验方法,选用3种小麦基因型(中育6号、S02-8、远丰998),研究了不同HCO3-浓度水平对小麦生长及Zn营养的影响。结果表明,HCO3-对小麦植株生长(尤其是对根系)及Zn吸收有一定的抑制作用,且在较低浓度(15 mmol/L)条件下表现更为明显。另外,高浓度HCO3-对土壤中有效锌含量及对锌从小麦根系向地上部的转运率均会产生不利的影响,在HCO3- 30 mmol/L条件下,与未进行HCO3-处理的对照相比,土壤有效锌及锌向地上部的转运率分别下降11.1%和5.0%,表明HCO3-对小麦锌营养的影响可能主要是通过以下途径实现的:1) 对土壤中有效锌的钝化;2) 对小麦根系生长的抑制;3) 抑制锌从小麦根系向地上部的转运,其中前两个途径可能起着更为重要的作用。总体来看,土壤中高含量的HCO3- 对供试的3种冬小麦基因型的生长及Zn吸收的抑制作用比较轻微,这可能与它们对高浓度的HCO3-具有较高的耐性有关。  相似文献   

19.
低氮胁迫下水稻根系的发生及生长素的响应   总被引:5,自引:0,他引:5  
采用水培实验,研究了5个氮(N)浓度下(0.01~5 mmol L-1)水稻的生物量、体内氮浓度、根系发育、体内生长素浓度以及生长素外流蛋白OsPIN家族基因的表达情况。结果表明,与正常供氮水平(2.5mmol L-1)相比,低氮(0.01 mmol L-1)胁迫下水稻根冠比增加28%,地上部全氮浓度降低约20%,根系全氮浓度降低约33%,种子根长度增加25%,种子根上的侧根密度降低26%,倒一叶中的生长素含量增加140%,而根茎结合处和根系的生长素浓度分别下降22%和60%;RT-PCR的结果表明,低氮(0.01 mmol L-1)胁迫下水稻根系中OsPIN1a-b、OsPIN2、OsPIN5a-b和OsPIN9基因表达显著下调;而外源生长素α-萘乙酸(NAA)和生长素极性运输抑制剂1-萘氨甲酰苯甲酸(NPA)的施加均能影响到水稻种子根长和种子根上的侧根密度。由此推论,低氮胁迫下水稻体内生长素从倒一叶到根系极性运输减少是水稻根系对低氮胁迫响应的生理机制之一。  相似文献   

20.
  【目的】  磷素是植物生长发育过程中必需的大量元素之一,土壤磷水平的高低对植物地上部和地下部性状有着显著的影响。探究高、低磷水平对小麦地上和地下部性状变化以及地上和地下部性状相关性变化的影响,为研究不同磷环境对小麦生长的影响,选育适应不同磷环境的优良小麦品种提供参考。  【方法】  小麦品种和磷水平双因素盆栽试验在河北农业大学温室内进行,供试土壤有效磷含量为5.50 mg/kg。试验设置0和200 mg/kg两个施磷水平;选用10个小麦品种。小麦分别在两个磷水平下生长35天后收获,测定小麦幼苗地上部性状(干重、相对生长速率、地上部磷吸收量、地上部磷含量和叶绿素含量)和根部性状(根干重、根长、根冠比、比根长、根直径、细根比例、根组织密度、根际土壤pH和酸性磷酸酶活性)。  【结果】  与高磷处理相比,低磷处理小麦地上部干重、地上部磷吸收量以及地上部磷含量分别显著降低了57.9%~72.2%、85.7%~89.8%、61.3%~71.7%,小麦根长、细根比例、根组织密度、根冠比以及比根长分别增加了50.9%~249.5%、32.5%~442.5%、–34.5%~400.0%、27.4%~198.9%、74.4%~395.3%,酸性磷酸酶活性提升了–8.1%~120.9%。在低磷条件下,小麦有32组地上和地下部性状间显著相关,在高磷条件下只有20组性状显著相关;低磷处理小麦地上和地下部协同相关性较高磷处理提升了60%。  【结论】  低磷条件下,小麦地上和地下部性状关联性较高,高磷供给弱化了小麦地上和地下部性状的关联性。  相似文献   

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