外源水杨酸对冷藏枇杷果实木质化及相关酶活性的影响

以“解放钟”枇杷为试材,研究了外源水杨酸(SA)对4℃冷藏枇杷果实木质化的影响。试验结果表明：采用1.0 g/L SA浸果20 min处理能抑制枇杷果实苯丙氨酸解氨酶(PAL)、多酚氧化酶(PPO)、肉桂醇脱氢酶(CAD)和过氧化物酶(POD)的活性,从而抑制果实木质素的形成,降低果实硬度,说明SA具有减缓冷藏枇杷果实木质化的作用。     

Effect of exogenous salicylic acid supply on nodule formation of hypernodulating mutant and wild type of soybean

Soybean plant is characterized by a systemic autoregulatory control system of nodulation (autoregulation) by initial infection with rhizobia, and plants commonly display a systemic acquired resistance (SAR) to pathogenic microbe infection related to salicylic acid (SA) signal transmission. We investigated the effect of exogenous SA supply on soybean nodulation to determine whether SA affects the autoregulation of nodulation. Seedlings of the hypernodulating mutants NOD1-3, NOD2-4 and their parent cv. Williams were treated or not treated (control) with a 100 μmS-SA solution at 5 d before the inoculation of Bradyrhizobium japonicum strain USDA110. The nodule dry weight and the number of nodules of the wild type soybean Williams exhibiting autoregulation drastically decreased by the addition of 100 μm SA. The decrease in the nodule number was not caused by the reduction of the rhizobium number in the medium. Salicylic acid inhibited only early nodule formation and did not affect the growth of formed nodules. The inhibitory effect of SA on the nodulation of NOD1-3 and NOD2-4 was significantly less pronounced than that in Williams. These results indicate that SA is directly involved in signal transmission in the autoregulation, and that SA or the SAR induced by SA stimulates the autoregulation of nodulation in soybean.     

Silicon-induced changes in growth,ionic composition,water relations,chlorophyll contents and membrane permeability in two salt-stressed wheat genotypes

We investigated the effect of exogenously applied silicon (Si) on the growth and physiological attributes of wheat grown under sodium chloride salinity stress in two independent experiments. In the first experiment, two wheat genotypes SARC-3 (salt tolerant) and Auqab 2000 (salt sensitive) were grown in nutrient solution containing 0 and 100 mM sodium chloride supplemented with 2 mM Si or not. Salinity stress substantially reduced shoot and root dry matter in both genotypes; nonetheless, reduction in shoot dry weight was (2.6-fold) lower in SARC-3 than in Auqab 2000 (5-fold). Application of Si increased shoot and root dry weight and plant water contents in both normal and saline conditions. Shoot Na⁺ and Na⁺:K⁺ ratio also decreased with Si application under stress conditions. In the second experiment, both genotypes were grown in normal nutrient solution with and without 2 mM Si. After 12 days, seedlings were transferred to 1-l plastic pots and 150 mM sodium chloride salinity stress was imposed for 10 days to all pots. Shoot growth, chlorophyll content and membrane permeability were improved by Si application. Improved growth of salt-stressed wheat by Si application was mainly attributed to improved plant water contents in shoots, chlorophyll content, decreased Na⁺ and increased K⁺ concentrations in shoots as well as maintained membrane permeability.     

Grain filling and yield of mung bean affected by salicylic acid and silicon under salt stress

Two experiments were carried out in 2013 and 2014, to investigate changes in grain filling rate (GFR), grain filling duration (GFD) and yield of mung bean in response to salicylic acid (SA) and silicon (Si) under salt stress (0, 3, 6 and 9 dS m^?1). In experiment 1, four levels of SA (0, 0.5, 1 and 1.5 mM), but in experiment 2, two levels of SA (0 and 1 mM) and Si (0 and 2 mM) were applied. In experiment 1, GFR, GFD, yield components, biological and grain yields and harvest index were decreased with increasing salt stress. Application of different levels of SA, especially 1 mM, increased GFR, but decreased GFD. In experiment 2, GFD under salinity was shorter than that under non-saline condition, resulting in comparatively smaller grains. Application of Si and particularly SA accelerated grain development under all salinity treatments. The superiority of SA treated plants in GFR, grain weight and grains per plant resulted in greater grain yield per plant under saline and non-saline conditions.     

不同水分条件下秸秆生物炭对高粱生长和养分含量的影响

【目的】 研究不同水分条件下秸秆生物炭对高粱生长、养分含量以及土壤理化性质和养分含量的影响,以探明秸秆生物炭对高粱生长的作用效果。 【方法】 以高粱“晋杂34号”为供试作物,石灰性褐土为供试土壤进行盆栽试验。试验设3个水分处理,分别为正常供水,田间持水量的85% (W₁);轻度胁迫,田间持水量的65%(W₂);重度胁迫,田间持水量的45% (W₃)。设5个秸秆生物炭添加量,分别占土壤干重的0、0.5%、1%、3%和6%。高粱出苗后70天调查株高,采集地上部 (茎和叶),测定生物量、N、P、K、Ca、Mg、Fe、Mn、Cu和Zn的含量,同时采集土样测定pH值、EC、有机质、全氮、有效磷、速效钾、交换性Ca和Mg、有效Fe、Mn、Cu和Zn的含量。 【结果】 干旱胁迫显著降低了高粱生物量和株高;施用0.5%秸秆生物炭显著增加了重度干旱胁迫条件下高粱生物量,但是当施用量 > 1%时不同水分条件下高粱生物量和株高均显著降低。干旱胁迫降低了高粱P含量,增加了K、Ca、Mn和Zn的含量;秸秆生物炭提高了高粱K和Zn含量,降低了N、P和Mg的含量;随着水分含量的减少,作物收获后土壤有效Mn和有效Zn含量降低;添加生物炭显著提高了土壤速效K和有效Zn的含量,但是当施用量大于1%时,土壤交换性Mg、有效Fe和有效Mn的含量显著降低。 【结论】 供试条件下,施用0.5%秸秆生物炭能够提高高粱钾和锌的含量,促进干旱胁迫条件下 (45%田间持水量) 高粱的生长,但过量施用 (> 1%) 会对高粱生长产生抑制作用。      

氮肥运筹对夏玉米产量、品质及植株养分含量的影响

通过田间试验研究了不同氮肥运筹方式对夏玉米产量、 品质及植株养分含量的影响。结果表明,在氮肥施用量较低时,玉米籽粒产量及粗蛋白、 粗淀粉和粗脂肪等营养品质指标随氮肥用量的增加而提高; 当氮肥用量达到一定数量之后,则不随氮肥用量的增大而增加,甚至有所降低。在氮肥施用量为 N 300 kg/hm2,基肥∶拔节肥∶大喇叭口期追肥比例为5∶0∶5（A2）时玉米籽粒产量最高为10902 kg/hm2,比不施肥（对照）增产140.5%,比相同施氮量条件下其他基追比处理增产4.6%~12.3%。随着施氮量增加玉米籽粒氮、 磷、 钾含量呈先增后减趋势; 增施氮肥能显著提高夏玉米籽粒粗蛋白含量,在相同施氮量条件下,玉米籽粒氮素和粗蛋白含量在A2运筹方式下最高,说明该氮肥运筹方式能改善玉米籽粒的品质。     

K-priming positively modulates growth and nutrient status of salt-stressed cotton (Gossypium hirsutum) seedlings

Being macronutrient, K⁺ is involved in a number of metabolic processes including stimulation of over 60 enzymes. The present study was conducted to investigate whether K-priming could alleviate the effects of salinity on the growth and nutrient status of cotton seedlings. The seeds of two cotton cultivars, namely FH-113 and FH-87, were primed with solutions of three potassium sources (KNO₃, K₂SO₄ and K₂HPO₄) using three concentrations (0%, 1.25% and 1.5%) of each potassium source. After 1 week of germination, the seedlings were subjected to salinity (0 and 200 mM NaCl) stress. The results showed that salinity significantly affected growth and nutrients status of cotton seedlings. The K-priming alleviated the stress condition and significantly improved dry matter as well as nutrient uptake in cotton seedlings. Of the priming treatments pre-sowing treatment with KNO₃ (1.5%) was most effective in increasing shoot and root lengths and biomass of cotton seedlings. The seedlings raised from seed treated with KNO₃ (1.5%) showed varied accumulation of cations (Ca²⁺, Na⁺ and K⁺) and faced less oxidative stress irrespective of cotton cultivars under salt stress. The results suggested that pre-sowing seed treatment with KNO₃ (1.5%) might be recommended for synchronized germination and sustainable production of cotton crop under saline environments.     

Morpho-physiological and yield responses to exogenous moringa leaf extract and salicylic acid in maize (Zea mays L.) under water stress

Two field experiments were executed to investigate the effects of foliar-applied moringa (Moringa oleifera) leaf extract (MLE; 1:30 w/v) and salicylic acid (SA; 0.5 mmol), singly or in combination, on growth, physio-biochemical, yield attributes and water use efficiency (WUE) of maize (Zea mays L., Three Ways Cross 329) under full and deficit irrigation conditions. Deficit irrigation was carried out by withholding water for 36 d from 12 to 48 days after sowing (DAS). At vegetative stage, deficit irrigation signi?cantly decreased all growth criteria, chlorophyll a concentration, and relative water content (RWC). In contrast, deficit irrigation considerably increased the concentrations of carotenoids, proline, membrane permeability (MP) and malondialdehyde (MDA). Similarly, grain yield, most yield components and WUE were significantly depressed in drought-stressed plants. However, foliar-applied treatments particularly MLE+SA signi?cantly increased growth traits, photosynthetic pigments, RWC and proline accumulation associated with a simultaneous decrease in MP and MDA concentration under full and deficit irrigation conditions. The application of MLE+SA markedly increased grain yield, yield components and WUE over control (spray tap water). Overall, the combined application of MLE and SA could be used for alleviating the adverse effects of growth, physiology, yield criteria and WUE in drought-stressed maize plants.     

Effect of humic acid multinutrient fertilizers on yield and nutrient use efficiency of potato

A field experiment was conducted to study the effect of humic acid multinutrient fertilizers like Grow Flow 45H and HA-NPK complex on crop yield, nutrient content and uptake, and nutrient use efficiency of potato. Application of Grow Flow 45H (humic acid multinutrient liquid fertilizer) at recommended dose increased the tuber yield by 9.3% as compared to chemical fertilizer. Nitrogen (N), phosphorus (P) and potassium (K) content of the Grow Flow 45H treated plants were 2.89, 0.33 and 1.58% in shoots and 1.89, 0.21 and 1.03% in tubers, respectively which were significantly higher than the other treatments. Grow Flow 45H increased the N, P and K use efficiencies by 16.4%, 9.3% and 18.3% respectively over chemical fertilizer. Though HA-NPK complex fertilizer (developed in the laboratory) was not significantly different from chemical fertilizer in respect of yield, the contents and uptake, and use efficiencies of N, P and K; however the former was found better than the latter.     

施肥对饲草高粱生长及营养品质的影响

研究施用氮、磷,钾肥对饲草高粱生长及营养品质动态的影响结果表明,氮肥、磷肥和钾肥配合施用可大幅提高饲草高粱生物产量,增加饲草高粱植株粗蛋白质、粗纤维和粗脂肪的单位面积产出量;氮素是影响高粱生物产量的首要养分因素,其次为磷素,第三是钾素;饲草高粱植株高度以及粗蛋白质、粗纤维和粗脂肪含量的变化规律,主要取决于品种特性;施肥主要通过影响饲草高粱生物产量,对饲草高粱植株粗蛋白质、粗纤维和粗脂肪的单位面积产出量产生作用.从饲草高粱的生物产量和品质综合考虑,确定饲草高粱的适宜收割期,以开花末期至成熟中期之间为宜,过早收割饲草高粱生物产量较低,过晚收割则饲草高粱生物产量较低且品质变劣.     

不同养分配比对高粱根系生长及养分吸收的影响

为探明高粱养分吸收和根系生长对氮、磷、钾胁迫的响应,通过长期定位试验,在高粱/玉米轮作条件下研究了不同养分配比NPK、PK、NK、NP、CK对高粱根系生长及养分吸收的影响。结果表明:与NPK相比,长期不施氮肥(PK)条件下高粱总根长增加18.29%,总根体积降低26.52%,且根系主要分布在0~10 cm土层,直径小于0.5 mm细根所占比例显著增加。不施磷肥(NK)显著抑制了高粱根系生长,总根长、总根表面积和总根体积分别降低24.03%、27.48%和41.29%。不施钾肥(NP)对细根生长有明显抑制作用。不施氮、磷、钾均降低高粱对相应养分的吸收和累积,不施氮促进了营养器官中氮和钾素向籽粒转运,不施磷或钾肥抑制了氮、磷及钾的转运。高粱对养分的吸收、积累和转运与根系形态有关,不同养分积累与运转与根系形态关系表现不尽相同:氮素、钾素积累和转运与根系形态具有较好的相关性,氮素的积累和转运与植株生物量和产量的相关性大于磷素和钾素。综上,高粱根系形态及养分吸收对氮、磷及钾胁迫响应不同,该研究可为不同养分瘠薄地高粱高效栽培提供理论依据。     

Effect of salicylic acid and salt on wheat seed germination

Abstract

The effects of pretreatment with salicylic acid on wheat seed germination (Triticum aestivum L. cv. Roshan), lipid peroxidation, and superoxide dismutase, catalase, polyphenol oxidase, and peroxidase activity were studied under conditions of salt stress. Seeds treated with different concentrations of salicylic acid were used for measuring germination traits. Salt stress was induced by sodium chloride solution. Seeds were soaked in salicylic acid solution for 24 h, dried with sterile paper, transferred to sterile Petri dishes, and treated with 10 ml NaCl solution at different concentrations. After 1 week, the number of germinated seeds, root length, seedling length, and dry weight were recorded. Antioxidant enzyme activity and lipid peroxidation were also assayed. Salinity decreased seed germination. Thus, a high concentration of NaCl (200 mM) decreased germination by 17.6% compared with control treatment. Salicylic acid significantly increased germination in stressed and control seeds. Salicylic acid increased the level of cell division of seedlings and roots, which increased plant growth. Salt stress significantly increased the activity of the antioxidative enzymes catalase, superoxide dismutase, peroxidase, and polyphenol oxidase in wheat seedlings, and salicylic acid reduced the activity of antioxidant enzymes as stress signal molecules. Our results indicated that scavenging of reactive oxygen species was effective, especially by salicylic acid, and that membrane damage was limited. The aim of the present work was to study the character of changes in enzymatic systems induced by NaCl and salicylic acid in wheat seedlings under conditions of salt stress. In brief, salicylic acid treatment reduced the damaging action of salinity on embryo growth and accelerated a restoration of growth processes; thereupon it may be effective for the improvement of seed germination in arid and semi-arid regions.     

Physiological and biochemical effects of salicylic acid on Pisum sativum exposed to isoproturon

In the present study, attenuation of isoproturon (IPU) toxicity by salicylic acid (SA) was observed. Seven-day-old seedlings of pea (Pisum sativum L. cv. Azad P-1) were treated with 10 mM IPU. IPU influenced physiological and biochemical parameters. IPU significantly inhibited growth variables like shoot and root height, fresh and dry biomass of the pea. The contents of carotenoids, chlorophylls, protein and activity of nitrate reductase were inhibited significantly. IPU enhanced the accumulation of H₂O₂, ion leakage and lipid peroxidation due to induction of oxidative stress in pea. The activities of antioxidant enzymes, namely superoxide dismutase, catalase and ascorbate peroxidase increased while the activities of guaiacol peroxidase decreased. However, exogenous SA regulated the toxic effects of IPU. The indices of oxidative stress appeared to be alleviated by SA. Pigment content and activities of enzymes increased approximately up to the level of control. IPU caused non-target phytotoxicity to P. sativum. The natural growth regulator/allelochemical has potential to overcome the adverse effects caused by IPU.

Abbreviations: CAT: catalase; EL: electrolyte leakage; IPU: isoproturon; LP: lipid peroxidation; MDA: malondialdehyde; NR: nitrate reductase; POD: guaiacol peroxidase; SOD: superoxide dismutase; TCA: trichloroacetic acid     

施肥对酸性菜园土壤莴笋硝酸盐和叶片养分形态的效应

通过田间试验研究了3种酸性菜园土壤(强酸性、酸性和微酸性土壤)不同氮磷钾配比及其与硝酸盐复合控制剂配施对莴笋产量、硝酸盐及叶片养分形态的影响。结果表明,莴笋产量以微酸性土>酸性土>强酸性土,酸性和强酸性土壤上配施硝酸盐复合控制剂可使莴笋显著增产(达6.2％～18.2％),而微酸性土壤则相反。HNK配施硝酸盐复合控制剂在3种土壤上分别降低莴笋茎和叶硝酸盐含量25.1％～76.3％和3.1％～27.7％(微酸性土除外),降低作用以茎>叶,以HNK+C2处理效果最好。莴笋叶片硝酸盐含量以酸性土壤>微酸性土壤>强酸性土壤,茎中硝酸盐以酸性土壤为最高。莴笋叶片氮、磷、钾形态分别以蛋白氮、非蛋白磷、非蛋白钾为主,HNK配施硝酸盐复合控制剂(HNK+C3除外)提高莴笋叶片蛋白氮占全氮、蛋白磷占全磷和蛋白钾占全钾的比例。莴笋叶片硝酸盐含量与全氮、蛋白氮、全磷、蛋白磷和蛋白钾含量呈极显著负相关。     

Effect of aluminum on growth and chemical composition of marigolds

Marigold (Tagetes erecta L. cv. ‘Discovery Yellow’, “Perfection Yellow’, ‘Inca Yellow’, and ‘Merrymum Yellow') were grown in aluminum (Al) solution culture concentrations of 0, 1, or 4 mg/L. Aluminum increased root length and weight, but had no effect on stem and leaf weight. Uptake and stem and leaf tissue nutrient concentration of phosphorus (P), calcium (Ca), and magnesium (Mg) were reduced by the Al treatments. The Al treatments increased stem and leaf concentrations of potassium (K) and decreased the concentrations of manganese (Mn), iron (Fe), copper (Cu), and zinc (Zn). No typical Al‐toxicity symptoms were observed in the roots. Root stunting caused by Fe toxicity was alleviated by the Al treatments.     

营养液浓度对甜瓜幼苗生长和光合特性的影响

以厚皮甜瓜皇后为试材,研究了不同营养液浓度对基质积盐和甜瓜幼苗生长、光合特性的影响。结果表明,EC2mS/cm的高浓度营养液导致幼苗根际出现盐分的积累,影响幼苗光合特性;叶片细胞超微结构出现一定程度的盐害症状,细胞质空泡化,叶绿体肿胀、球形化,超微结构发生解体,净光合速率下降;但单株叶面积、叶绿素含量与营养液浓度呈正相关。因此,甜瓜穴盘育苗,营养液浓度不应超过2.0mS/cm,以保持在1.5～2.0mS/cm之间为宜。     

硅钙钾镁肥及引入柠檬酸对红壤和潮土pH值及养分含量的影响

通过土壤培养试验研究了硅钙钾镁肥(SCPM)及引入柠檬酸的复混肥(CA-SCPM)在酸性红壤和石灰性潮土上的养分供给和酸碱度调节能力.硅钙钾镁肥添加量设置为6 g/kg,硅钙钾镁肥与柠檬酸(CA)的比例为88％:12％.与对照处理相比,培养至150 d时,SCPM肥及CA-SCPM肥提高红壤pH值约1.16个单位,提高...     

模拟降雨条件下聚丙烯酰胺应用对径流、侵蚀和土壤养分流失的影响

Soil erosion affects soil productivity and environmental quality.A laboratory research experiment under simulated heavy rainfall with tap water was conducted to investigate the effects of anionic polyacrylamide(PAM) application rates(0,0.5,1.0,and 2.0 g m-2) and molecular weights(12 and 18 Mg mol-1) on runoff,soil erosion,and soil nutrient loss at a slope of 5°.The results showed the two lower rates of PAM application decreased runoff while the highest rate increased runoff as compared with the control.Sediment concentration and soil mass loss increased significantly with the increasing PAM application rate.Compared with the control,PAM application decreased K+,NH4+,and NO3-concentrations in sediment and K+ and NH+4 concentrations in runoff,but significantly increased the mass losses of K+,NH4+,and NO-3 over soil surface except for the NH4+ at PAM application rate lower than 1.0 g m-2.PAM application decreased the proportion of K+ loss with runoff to its total mass loss over soil surface from 60.1% to 16.4%.However,it did not affect the NH4+ and NO3-losses with runoff,and more than 86% of them were lost with runoff.A higher PAM molecular weight resulted in less soil erosion and K+ mass loss but had little effect on runoff and NH+4 and NO3-losses.PAM application did not prevent soil erosion and the mass losses of K+ and NO3-under experimental conditions.     

有机肥化肥配施对冬油菜养分吸收、籽粒产量和品质的影响

以杂交冬油菜湘杂油763为供试材料,采用大田小区试验研究了有机肥配施化肥对油菜养分吸收、籽粒产量和品质及土壤养分变化的影响。结果表明:在本试验条件下,各处理籽粒产量大小顺序为10%OM﹥0%OM﹥30%OM﹥50%OM,10%OM(10%有机氮替代化肥氮)产量达2 055.00 kg/hm2,显著高于其它处理,比0%OM(纯化肥)增产8.26%,3个有机肥处理中,籽粒产量随有机肥施用量的增加逐渐下降;产量构成因素中每角果粒数和千粒重、籽粒品质中氨基酸和蛋白质含量变化规律与产量一致,且有机肥施用量较多的处理(50%OM)籽粒氨基酸和蛋白质含量较低,油分含量最高;氮、磷、钾、硼素积累量的变化规律与产量基本一致;土壤速效养分变化规律不明显。在本试验中,油菜植株养分吸收、土壤速效养分变化等都可反映籽粒产量,10%OM为较合适的有机肥配施比例。     

Fortified cassava peel compost amendment for Amaranthus: Influence on plant growth,nutrients uptake and on soil nutrient changes

Nutrient supply through organic sources usually requires fortification for timely and optimum release of plant nutrients to achieve optimum crop performance. A pot experiment was conducted in a screen house to determine the optimum rate of cassava peel compost (CPC) fortification that supports optimum Amaranthus (Amaranthus cruentus L.) plant nutrient contents and residual soil nutrient contents. A compost of cassava peel and poultry manure was applied at 2.5; 5.0 and 7.5 t ha^?1each complemented with either 25 or 50 kg nitrogen (N), using nitrogen, phosphorus and potassium (NPK) 20-10-10 at 2 weeks before sowing Amaranthus. An unfertilized treatment served as control. Seeds were sown in plastic containers with a surface diameter of 24 cm filled with 5 kg soil, with a drain underneath. Seedlings were thinned to 4 plants/pot 2 weeks after planting. Plants were harvested at 5 weeks by ratooning and plant re-growth also harvested after 5 weeks. Soil pH was lower with high rates of 5.0 and 7.5 t ha^?1 CPC while the organic matter content was increased with increased CPC rate. Soil N was reduced but reflected in increased plant shoot and root N, with compost application. Soil P was generally increased but was not reflected in plant contents. Soil K contents were reduced and were reflected in increased plant contents. Application of 2.5 t ha^?1 CPC, fortified with either 25 or 50 kg N ha^?1 gave the optimum Amaranthus shoot nutrient contents with optimum residual soil nutrient contents.