重金属富集植物黑麦草对Zn的响应

采用根袋土培试验研究了重金属Zn胁迫对黑麦草（Loliurn perenne L．）生长、抗氧化酶活性、游离脯氨酸含量、根系活力及锌积累的影响。结果表明，黑麦草对重金属锌有很强的抗性和耐性．即使在高锌下（16mmol Zn／kg）。黑麦草生长也未受到抑制。黑麦草地上部干重、根系千重在8mmol Zn／kg下达到最大值。分别较对照增加48．8％，52．2％;高锌处理（16mmol Zn／kg）的植株地上部千重也较对照增加11．2％。黑麦草POD活性随Zn胁迫增加，先下降，然后回升SOD活性则随锌胁迫增加而下降。随Zn胁迫增加，叶脯氨酸、根系活力先增加，然后下降。地上部、根系Zn含量随Zn胁迫增加而增加，最大值分别为746．5，521．0mg／kg DW（16mmol Zn／kg）。高锌处理下（≥4mmol／kg）Zn转运率（S／R）〉1．0。     

锌胁迫对菖蒲抗氧化酶活性和富集特性的影响

试验研究了不同Zn~(2+)浓度(0,100,200,500,1000 mg kg~(-1))对菖蒲的外部形态和体内超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)3种抗氧化酶随土壤中Zn~(2+)浓度的变化以及菖蒲对土壤中Zn~(2+)富集效果。结果表明:(1)在处理浓度Zn~(2+)200 mg kg~(-1)时,三种酶的活性与对照值相比有明显的提高,植株未出现明显的外伤症状,叶片中叶绿素含量上升,未对菖蒲表现出明显的负面影响;(2)当Zn~(2+)200 mg kg~(-1)时三种酶的活性开始出现下降,下降程度与受污染的程度正相关,菖蒲出现明显外伤症状并加剧,叶片叶绿素含量不断下降,叶片中丙二醛(MDA)和脯氨酸的含量不断上升,细胞质膜透性逐渐增加。(3)菖蒲体内Zn~(2+)含量的分布规律均为根(地下部分)茎、叶(地上部分),菖蒲各器官Zn~(2+)浓度随着处土壤浓度增加而升高。(4)四种土壤酶活性都随着Zn~(2+)浓度的增加而不断下降。菖蒲可用于轻度锌污染土壤修复。     

Zn胁迫对黑麦草幼苗生长、生理生化及Zn吸收的影响

采用营养液培养法,研究了不同Zn浓度(0,0.25,0.50,1.00,2.00 mmol/L)对黑麦草幼苗生长、过氧化物酶活性、脯氨酸、根系活力及Zn吸收的影响。结果表明,低锌胁迫对黑麦草幼苗生长无抑制,过度锌胁迫(Zn≥2 mmol/L)将降低黑麦草地上部干质量。幼苗叶内游离脯氨酸含量随锌胁迫时间、锌浓度增加而增加。随Zn胁迫时间增加幼苗POD活性先降后升、根系活力先升后降,锌处理的植株地上部POD活性随锌浓度增加先降低,然后增加,而根系活力随锌浓度增加而增加。黑麦草幼苗地上部和根系Zn含量随Zn浓度的增加而增加,当Zn浓度为2.00 mmol/L时,地上部Zn含量最大值为775.0 mg/kg。     

黑麦草幼苗对镉耐性能力及吸收积累和细胞分布特点研究

通过盆栽试验研究了镉（Cd）胁迫下黑麦草（LoliumperenneL.）幼苗的耐性能力（包括生长反应和生理生化特性）以及对Cd的吸收、积累、分布特征。结果表明,当Cd浓度为10mg.kg-1时,黑麦草的生长和发育没有受到明显抑制（P〉0.05）,当Cd浓度为20、60、100mg.kg-1时,黑麦草生物量、叶绿素含量、根系活性都显著降低（P〈0.05）;超氧阴离子（O2-.）、MDA含量显著增加（P〈0.05）;SOD、POD活性先增加后降低。黑麦草体内Cd积累量随着Cd浓度增加而显著增加（P〈0.05）;Cd在亚细胞内积累量：F1（细胞壁）〉F3（可溶部分）〉F2（细胞器）。黑麦草在Cd浓度为10、20mg.kg-1时,富集系数〉1.0,对Cd有较强的富集能力,转移系数〈1,富集的Cd主要累积在根部,表明黑麦草能够有效富集土壤中的Cd,且富集的Cd主要积累在根部。     

锌锰肥对玉米吸收氮磷钾及干物质积累的影响

石灰性中肥力土壤,玉米施用锌、锰肥具有明显的增产效果,平均每公顷增产玉米３２８．５ｋｇ,增产６．４％。锌、锰可促进玉 Ｎ、Ｐ、Ｋ的吸收及茎叶、子粒干物质积累;但锌锰配合施用的子粒干物质量低于单施锌。     

不同施肥处理对白菜的物质积累与养分吸收的影响

研究了在洞庭湖平原的冲积性菜园土条件下,不同施肥结构对白菜生育期间的物质积累与白菜对N,P,K养分的吸收规律以及土壤有效N,P,K养分的动态变化.结果表明,不同处理白菜的产量相差较大,各施肥处理比不施肥对照平均增产达33.1%,但各施肥处理之间产量差异不显著.白菜对N,P,K养分的吸收都是在移栽30 d以后的生长中、后期,与其地上部生物产量的积累规律一致.专用肥处理和有机无机肥配施处理明显促进白菜对N,P,K养分的吸收.从而提高白菜对肥料养分的利用率.当地习惯施肥处理的N,P施用量明显过大,浪费肥料,也对当地水体及环境造成污染.其施K量明显低于白菜一季的总吸钾量,既影响白菜产量和品质,也造成土壤K素的耗竭.根据不施肥对照和4个平衡施肥处理白菜地上部分的养分吸收总量结果,以白菜对肥料N,P,K的当季利用率分别为40%,25%和60%计算,供试土壤条件下白菜一季所需N,P_2O_3,K_2O的施用量分别为195.25 kg/hm~2,145.60 kg/hm~2,228.53 kg/hm~2.其N:P_2O_5: K_2O值为1:0.75-1.17.     

酸胁迫对不同基因型玉米生长和养分吸收的影响

采用盆栽试验研究了4个不同耐酸特性的玉米自交系在几个关键生育期的氮、磷、钾营养特性和生长状况。结果表明,耐酸自交系在苗期、拔节期和开花期对氮、磷、钾的吸收和累积均高于酸敏感自交系;不同生育期耐酸自交系的营养利用率和再分配特征存在差异,苗期表现为氮的利用率较高,开花期表现为磷、钾营养的再分配能力强。不同耐酸材料对酸胁迫土壤反应不同,耐酸自交系在不同生育阶段始终能较好生长,尤其是Z01,即使在pH4.6的酸性土壤上干物质累积几乎不受酸胁迫影响;中等耐酸自交系则受酸的危害,且随着发育进程而加剧,而酸敏感自交系表现出与中等耐酸材料相同的趋势,但各生育阶段受到的危害更大。     

能源植物荻对铜胁迫的耐性和积累特性

通过盆栽试验研究不同Cu2+浓度(0,200,400,800,1 600,3 200 mg/kg)和不同时间(50 d和120 d)铜胁迫对荻叶片生理指标、植株生长及Cu积累特征的影响.结果表明:(1)不同生长期荻叶片的O2 产生速率、MDA含量和质膜透性均随Cu胁迫浓度的升高而增大,当Cu≥1 600mg/kg时,与对照相比三者均显著上升(P＜0.05).(2)脯氨酸和可溶性糖含量总体呈先升后降趋势.(3)荻叶片中的SOD、POD及CAT活性随Cu浓度的增加呈先升后降趋势,当Cu≥1 600 mg/kg时,与对照相比酶活性均显著下降(P＜0.05).(4)当Cu≤800 mg/kg时,光合色素含量与对照之间均无显著性差异(P＞0.05),荻的生长也未受到明显影响(P＞0.05);当Cu≥1 600mg/kg时,光合色素含量显著下降(P＜0.05),其生长受到明显抑制(P＜0.05).(5)荻对Cu的积累能力较强且主要分部在地下部,其将Cu运输到地上部的能力较弱.研究表明,荻不是Cu的超积累植物,但是对Cu具有较强的耐性和稳定化能力,在Cu污染土壤修复方面有一定的应用潜力.     

Maturity Effects on Mineral Concentration and Uptake in Annual Ryegrass

ABSTRACT

Annual ryegrass (Lolium multiflorum Lam.) provides livestock feed and captures nutrients from fields receiving manure application. The objective of this study was to determine relationships among maturity and yield, mineral uptake, and mineral concentration. Primary spring growth of ‘Marshall’ ryegrass was harvested every 7 d to 56 d maturity and was fertilized with swine effluent containing 254 and 161 kg nitrogen (N) and 42 and 26 kg phosphorus (P) ha^?1 for two years. Yield increased linearly to a maximum of 13.6 mg ha^?1 after 49 d in 2001 and 8.0 mg ha^?1 after 56 d in 2002. Mineral uptake was highly correlated (r > 0.95) with yield and attained a maximum single harvest of 192 kg N ha^?1 and 32 kg P ha^?1 (mean of two years). Concentration of all minerals except calcium (Ca) declined as ryegrass matured. Low magnesium (Mg) concentration (< 2 g kg^?1 dry matter) increases the risk of hypomagnesemic grass tetany.     

不同Zn浓度对黑麦草根分泌物、根际Zn形态及植物Zn蓄集的影响

A glasshouse experiment was conducted using a root-bag technique to study the root exudates, rhizosphere Zn fractions, and Zn concentrations and accumulations of two ryegrass cultivars (Lolium perenne L. cvs. Airs and Tede) at different soil Zn levels (0, 2, 4, 8, and 16 mmol kg-1 soil). Results indicated that plant growth of the two cultivars was not adversely affected at soil Zn level≤8 mmol kg-1. Plants accumulated more Zn as soil Zn levels increased, and Zn concentrations of shoots were about 540 /μg g-1 in Aris and 583.9μg g-1 in Tede in response to 16 mmol Zn kg-1 soil. Zn ratios of shoots to roots across the soil Zn levels were higher in Tede than in Airs, corresponding with higher rhizosphere available Zn fractions (exchangeable, bound to manganese oxides, and bound to organic matter) in Airs than in Tede. Low-molecular-weight (LMW) organic acids (oxalic, tartaric, malic, and succinic acids) and amino acids (proline, threonine, glutamic acid, and aspartic acid, etc.) were detected in root exudates, and the concentrations of LMW organic acids and amino acids increased with addition of 4 mmol Zn kg-1 soil compared with zero Zn addition. Higher rhizosphere concentrations of oxalic acid, glutamic acid, alanine, phenylalanine, leucine, and proline in Tede than in Airs likely resulted in increased Zn uptake from the soil by Tede than by Airs. The results suggested that genotypic differences in Zn accumulations were mainly because of different root exudates and rhizosphere Zn fractions.     

Seasonal Biomass Accumulation and Nutrient Uptake of Pea and Lentil on a Black Chernozem Soil in Saskatchewan

ABSTRACT

Close relationships usually exist among biomass accumulation, nutrient uptake, and seed yield during the growing season. Field experiments with pea (Pisum sativum L.) and lentil (Lens cultinaris L.) were conducted in 1998 and 1999 at Melfort, Saskatchewan, Canada, to determine relationships of biomass accumulation and nutrient uptake with days after emergence (DAE) or growing degree days (GDD). For both biomass accumulation and nutrient uptake, maximum rates and amounts increased with time at early growth stages and reached a maximum value at late growth stages. The R² values for cubic polynomial regressions were highly significant, indicating their suitability to estimate the progression of biomass accumulation and nutrient uptake as a function of days after emergence (DAE). Both pulse crops followed a similar pattern in biomass accumulation and nutrient uptake, which increased in the early growth stages and reached a maximum late in the growth cycle. Pulse crops usually reached their maximum biomass accumulation rate and amount at early to late bud formation (42–56 DAE or 390–577 GDD) and at medium pod formation to early seed filling (75–82 DAE or 848–858 GDD) growth stages, respectively. Maximum biomass accumulation rate was 175–215 kg ha^{? 1}d^?1 for pea and 109–140 kg ha^{? 1}d^{? 1} for lentil. Maximum nutrient uptake rate and amount usually occurred at branching to early bud formation (28–49 DAE or 206–498 GDD) and at the flowering to seed filling (66–85 DAE or 672–986 GDD) growth stages, respectively. Maximum uptake rate of nitrogen (N), phosphorus (P), potassium (K), and sulfur (S), respectively, was 4.6–4.9, 0.4–0.5, 5.0–5.3 and 0.3 kg ha^{? 1}d^{? 1} for pea, and 2.4–3.8, 0.2–0.3, 2.0–3.4 and 0.2 kg ha^{? 1}d^{? 1} for lentil. In general, maximum nutrient uptake rate and amount occurred earlier than maximum biomass accumulation rate and amount, respectively; and the maximum accumulation rates of both biomass and nutrients occurred earlier than maximum amounts. The findings suggest that adequate supply of nutrients from soil and fertilizers at early growth stages, and translocation of biomass and nutrients to seed at later growth stages are of great importance for high seed yield of pulse crops.     

Nutrient Accumulation in Faba Bean Varieties

Increasing the amount of nutrients in plant-based foods will help to improve the nutritional status of people in the World. Faba bean (Vicia faba L.) as a staple food in developing countries has the potential to provide many nutrients in human diets. The objective of this study was to characterize the nutrient concentrations in leaf, pod, and seed of faba bean varieties. A field study was conducted with six faba bean varieties. Variation in the elemental concentrations of nutrients and protein occurred among varieties and different parts of the plants. The highest concentrations of nitrogen, phosphorus, potassium, zinc, or copper and protein were in the seeds. However, the highest accumulation of calcium, magnesium, iron, or manganese was in the leaves. We recommend that faba bean can be considered as a valuable crop in the diet of nutrient-deficient consumers due to high concentration nutrients in edible parts of the plant.     

Effect of Organic Materials on Yields and Nutrient Accumulation of Wheat

ABSTRACT

This experiment was conducted under greenhouse conditions using a sandy clay loam treated with garbage and mushroom composts, cattle and chicken manures, or municipal sludge at rates of 0, 30, or 60 ton ha^?1. The organic materials were applied to the pots and incubated for 15 d. The soil samples were watered at field capacity. In this experiment, wheat (Triticum aestivum L.) was used as a test crop. At the end of the experiment, it was found that treating sandy clay loam with the organic materials increased plant total and grain yields, protein content, 1000-kernel weight, number of grains in spike, and accumulation of nitrogen (N), phosphorus (P), potassium (K), iron (Fe), zinc (Zn), and manganese (Mn) by wheat compared with the control treatment, depending on the organic material applications. Thus, the increases were found to be statistically significant (P ≤ 0.05). Among the types of organic materials, the sewage sludge was the most effective material in increasing N, P, K, Fe, Zn, and Mn content of leaf, grain, and stem samples of the wheat plant. It was followed by mushroom compost and cattle manure. Based on the results, sewage sludge and garbage compost are suggested for use as an amendment for the soil studied. Comparing the beneficial effects of the organic materials applied for improving plant growth and nutrient accumulation, the materials can be arranged in the following descending order: municipal sludge > chicken manure > cattle manure > garbage compost > mushroom compost. It is suggested that recycling of organic materials for agricultural usage as an organic-matter resource is an alternative, organic fertilization option in Turkey.     

锌对汞胁迫下小麦种子萌发的影响

通过溶液培养研究了不同浓度锌（Zn）对汞（Hg）胁迫下小麦种子萌发率、芽长、根长以及萌发过程中α淀粉酶、蛋白酶、过氧化氢酶活性的影响。结果表明,单独Hg（15mg·L-1）胁迫下,小麦种子萌发率降低,根长与芽长受到抑制,α淀粉酶与过氧化氢酶活性降低,蛋白酶活性升高。加入10~100mg·L-1Zn后,种子萌发率未表现出明显变化,根长、芽长及α淀粉酶受抑制情况缓解,缓解程度随Zn浓度升高而下降,表明Zn可在一定程度上缓解Hg对小麦种子的毒害,但须在一定浓度范围内;10mg·L-1Zn减弱了Hg单独胁迫对小麦种子蛋白酶活性的促进作用,使其恢复至接近对照水平,20~100mg·L-1Zn则表现出对蛋白酶的抑制作用,使其活性低于对照水平,并且随Zn浓度升高呈下降趋势。Zn的加入对Hg单独胁迫下活性降低的过氧化氢酶未表现出缓解抑制的作用,反而进一步抑制了酶的活性,并且随着Zn浓度升高,抑制作用逐渐加强。因此,Zn的加入可在总体上缓解Hg胁迫对小麦种子萌发的影响,最适Zn浓度为10mg·L-1,但这种缓解作用只表现在部分方面。     

重金属Zn Cu对香根草生理生化指标的影响及其积累特性研究

采用水培方法,研究了不同浓度Zn、Cu对香根草生物量、含水量、叶绿素、MDA、可溶性蛋白质含量、根系活力以及Zn、Cu在香根草体内的积累和分布的影响。结果表明,低浓度的Zn、Cu刺激了香根草的生长,提高了香根草的生物量、含水量、叶绿素含量以及根系活力;高浓度的Zn、Cu使香根草生物量、含水量、叶绿素、可溶性蛋白质含量和根系活力均不同程度地下降,MDA含量增加;香根草根系中积累的重金属含量随处理浓度的增加逐渐增加,当处理浓度为60mg·L-1时,根系干重富集的Zn、Cu分别达到2581和6528mg·kg-1。两种重金属在香根草植株内的分布主要以根部积累为主,地上部积累的重金属含量极少。