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1.
不同价态硒缓解小油菜镉胁迫的生理机制   总被引:3,自引:0,他引:3  
【目的】 硒有利于提高植物对环境胁迫的抗性,缓解植物受到的非生物胁迫。研究不同价态硒对小油菜缓解重金属镉胁迫的影响,可为治理农田土壤重金属镉污染提供参考。 【方法】 采用盆栽试验,选取三种价态硒,分别为硒代甲硫氨酸 Se (–2)、亚硒酸钠 Se (+4) 和硒酸钠 Se (+6),硒浓度均为 1 mg/kg,设置镉胁迫浓度 0、低浓度镉 (2 mg/kg) 和高浓度镉 (5 mg/kg),共计 12 个处理,采用原子吸收光谱法测定植物的镉含量,分析调查了对小油菜生长及生理特性的影响。 【结果】 未加外源镉时,与对照 (CK0) 相比,各价态 Se 均能显著促进小油菜生长,且 Se (–2) 处理对小油菜生物量、株高、根长的促进效果优于无机硒 Se (+4) 和 Se (+6) 处理;低浓度镉胁迫下,与对照 (CK2) 相比,经 Se (–2) 和 Se (+4) 处理后,小油菜地上部镉含量分别降低 13% 和 5%,而 Se (+6) 处理却增加了 25%;在高镉胁迫下,与对照 (CK5) 相比,经 Se (–2) 和 Se (+4) 处理后,小油菜根部及地上部镉含量降幅可达 13%~41%,而 Se (+6) 处理后,小油菜根部及地上部镉含量分别增加了 38% 和 17%。当存在镉胁迫时,施用 Se (–2) 和 Se (+4) 处理可有效提高植物体内超氧化物歧化酶 (SOD)、过氧化物酶 (POD) 和过氧化氢酶 (CAT) 等酶的活性,增加小油菜叶片内抗坏血酸 (AsA) 和还原型谷胱甘肽 (GSH) 的含量,但Se (+6) 降低了其抗氧化酶的活性,减少了小油菜叶片中 AsA、GSH 的含量。 【结论】 在镉胁迫下,Se (–2) 在促进小油菜生长、抑制镉在小油菜体内的积累及增强小油菜生理特性方面的作用均优于 Se (+4) 和 Se (+6)。因此,Se (–2) 处理最能有效缓解小油菜镉胁迫,Se (+4) 次之,Se (+6) 却增加了镉对小油菜的胁迫作用。   相似文献   

2.
This study investigated the effects of salinity stress at different growth stages on the growth, yield, fruit quality, and water-use efficiency (WUE) of tomato (Solanum lycopersicum) plants cultivated under soilless conditions. Six different growth stages were exposed to the same salinity stress treatments using a completely randomized design, with three pots (six plants) per treatment. It was found that short-term (<21 days) salinity stress during any of the growth stages did not affect tomato growth or WUE, and during the vegetative stage did not affect yield. Salinity stress during the flowering and fruiting stages caused a reduction in tomato yield, which was due to a reduction in the number of fruit produced rather than the fruit size. However, salt exposure at the fruiting stage also improved fruit quality. The effect of salinity stress on the yield and fruit quality of the frontal and later truss depended on the developmental stage of the truss at the time when the stress occurred.  相似文献   

3.
This study was conducted to investigate the effects of salinity stress and flower number on growth, yield, water use efficiency (WUE), and fruit quality of cherry tomatoes cultivated under soilless conditions. The experiment was conducted in a plastic house (5-m wide × 11-m long) located in Gifu University. The seedlings were transplanted in a randomized complete block design with six plants per treatment (NT1 and ST1 were with four plants), giving a total of 44 plants in 22 pots (two plants per pot). Two different salinity levels [no-salinity and salinity with electrical conductivity: 0.8 and 3.0 dS m?1, respectively] and four flower number treatments (8, 13, 18, and free per truss) were investigated in the experiment. The results showed that salinity stress negatively affected tomato growth, yield, and marketable yield, but improved tomato fruit quality. The number of flowers had no effect on tomato growth variables and WUE, but the yield significantly increased with increasing flower number. However, the fruit quality was decreased with increased flower number. A reasonable control for fruit load can increase marketable yield in commercial cultivation. Under salinity stress conditions, properly increasing the number of flowers can avoid yield reduction.  相似文献   

4.
以耐热差异明显的海岛棉品种‘新海43号’(XH43)和‘新海49号’(XH49)为材料,于盛花期在田间搭设塑料棚进行为期3d(H3)、6d(H6)和9d(H9)的增温处理,增温结束后立即恢复自然温度,以田间不搭棚的自然温度为对照(CK),研究不同天数高温处理对海岛棉净光合速率、成铃率及不同部位果枝产量和品质的影响。结果表明:(1)高温胁迫降低了XH43和XH49的产量及产量构成因素,其中H6、H9处理均达到显著水平;高温胁迫显著降低了中部果枝的铃数、单铃重、衣分和籽棉产量,但显著增加了上部果枝铃数,促进了上部果枝产量的提高。(2)高温胁迫对XH43和XH49的纤维品质无显著影响,但导致两品种中部果枝棉铃上半部平均长度、整齐度指数和断裂比强度显著降低。而高温胁迫显著提高了上部果枝棉铃的断裂比强度,其中H6、H9处理均达到显著水平,较对照分别增加2.19%~5.12%和4.48%~7.59%。(3)高温胁迫下XH49各部位产量和品质变化幅度均大于XH43,表明高温胁迫对XH49影响更为严重。(4)花铃期短期高温胁迫,导致中部果枝棉铃大量脱落及发育受阻。在生殖生长后期,H6、H9处理后的棉株净光合速率显著高于对照,增温处理增强了棉株后期光合生产能力,进而提高了上部果枝的铃数、产量和断裂比强度。  相似文献   

5.
生长延缓剂对忍冬枝条生长和花蕾产量与品质的影响   总被引:1,自引:0,他引:1  
为了研究能否用抑制枝叶生长的方法提高花类药材的产量和品质,用不同浓度的3种植物生长延缓剂(矮壮素,缩节胺,烯效唑),在花前和开花初对忍冬植株进行喷施。结果表明:适宜浓度的生长延缓剂可以明显抑制忍冬枝条的生长而不影响花蕾的生长,还可以通过增强花芽分化,提高花蕾数量而提高加产量;其中以100和200 mg/L的缩节胺增产效果最佳,花蕾产量增幅达45%以上;150~200 mg/L的烯效唑也有较显著的效果;不同浓度的缩节胺处理可使花蕾中绿原酸和总黄酮含量增加,二者增幅最高可达14.3%和27.5%;其它两种延缓剂处理不能明显提高金银花品质。综合来看,100~150 mg/L的缩节胺对金银花的产量和品质提高效果最佳,说明通过适宜的处理控制忍冬枝条的生长以提高花蕾产量和质量是可行的。  相似文献   

6.
研究了冬季主干环割和花期主枝环割处理对鸡嘴荔成花率和坐果率的影响,试验结果表明:冬季主干环割能有效地控制冬梢的抽生,促进花芽分化,提高末级枝条成花率;花期主枝环割能明显增加雌花数,并提高坐果率;冬季主干环割结合花期主枝环割的处理效果最显著,是提高鸡嘴荔产量的有效途径。  相似文献   

7.
  【目的】  我们研究了大气重金属沉降高风险区菜地重金属的污染状况及污染来源,评价了研究区种植的蔬菜对不同人群(男性、女性、成人和青少年)产生的健康风险,并筛选了低累积重金属的蔬菜类型。  【方法】  在河南省大气重金属沉降风险高的蔬菜产区进行调查。分别采集设施栽培和露地条件下种植的叶类(青油菜、青菜、香菜)、葱蒜类(大蒜)、茄科类(茄子、辣椒、番茄)、瓜果类(苦瓜、黄瓜)、豆类(长角豆、四季豆)和块根类(萝卜)蔬菜样品,分析了蔬菜可食用部位Cd、Pb含量及富集能力,讨论了其主要的污染来源,并利用Monte Carlo模拟,对不同种类蔬菜可食用部位进行概率非致癌健康风险评价。  【结果】  设施栽培和露地条件下,蔬菜可食用部位Cd的富集系数均高于Pb。不同类别的蔬菜对重金属的吸收能力存在明显差异,瓜果类蔬菜为Cd、Pb低累积蔬菜,设施栽培条件下瓜果类蔬菜可食用部位积累的Cd、Pb含量最低,Cd、Pb含量分别为0.020、0.036 (黄瓜)和0.008、0.055 (苦瓜) mg/kg,低于食品重金属污染限值。对比设施栽培和露地条件下种植的蔬菜可食用部位的污染程度发现,露地条件下蔬菜Cd、Pb的污染程度更高,大部分叶类蔬菜和葱蒜类蔬菜为重度污染,其中青油菜Cd内梅罗综合污染指数(PN)达到10.26,PN (Pb)达到了10.00。概率风险评价结果表明,不同人群摄入Cd、Pb污染蔬菜产生的复合非致癌健康风险差别不大,其中摄入瓜果类和块根类蔬菜对人体没有明显的负面影响,尤其是瓜果类蔬菜,设施栽培下,成年男性摄入苦瓜产生的总目标危险系数的P75 (第75百分位点)仅为0.120。  【结论】  不同类型蔬菜的Cd、Pb富集能力差异显著,叶类蔬菜对Cd、Pb富集能力最强,瓜果类较弱,尤其是苦瓜。污染区设施栽培的瓜果和豆类蔬菜可安全食用。大气沉降是蔬菜Pb污染的重要来源之一,建议在大气重金属沉降高风险区进行设施栽培,选择低积累Cd、Pb的瓜果类蔬菜,降低重金属对人体健康产生的风险。  相似文献   

8.
苗期昼夜温差对番茄产量形成因子的影响分析   总被引:4,自引:4,他引:0  
为了了解苗期昼夜温差对番茄成株期生长发育和产量形成的影响,试验利用微电脑人工气候箱(SPX-250IC),在20℃平均温度下,研究了昼夜3个不同温差0(昼温和夜温均为20℃)、6(昼温和夜温分别为23和17℃)和12℃(昼温和夜温分别为26和14℃)对番茄苗期物质积累和花芽分化的影响,并观察了定植后的开花、坐果和产量形成状况。结果表明,与0昼夜温差相比,12℃昼夜温差可增加幼苗单株干物质量48.77%~55.73%;可提早花芽分化始期,但苗期处理结束时(28d)减少花芽分化数17.0%~18.2%;前3穗果的开花和坐果时间平均提前2.3和1.9d;但是番茄现蕾数减少了9.2%~19.7%、开花数减少了12.4%~23.3%、坐果数减少了1.5%~30.0%,单株采收果实数减少了5.8%~17.0%,单果质量降低了7.8%~8.3%,前期产量降低了14.3%~16.3%。0昼夜温差不利于番茄干物质积累和后期的持续高产。6℃昼夜温差处理时,番茄幼苗单株干物质量比0昼夜温差时显著增加,前3穗果的开花数、坐果数、单株采收果实数都比12℃昼夜温差时显著增加,单果质量和产量也显著增加。因此,平均温度20℃时,6℃左右的昼夜温差是番茄植株物质积累、花芽分化和产量形成的平衡点,有利于番茄的营养生长和产量形成。该研究可为番茄苗期温度调控提供参考。  相似文献   

9.
氮素在果树成花过程中的作用   总被引:1,自引:0,他引:1  
李文庆  樊小林  林常华 《土壤通报》2007,38(6):1203-1207
综述了氮素在果树成花过程中的作用,认为氮及含氮化合物是果树成花过程中重要的物质,其影响到果树从营养生长向生殖生长的转化,影响花粉的可育性和雌雄花的比例,影响花的质量。花芽的生理分化及形态分化期间都伴随氮素及含氮物质的波动,不同形态的含氮物质在成花过程中的作用也不同。花芽诱导措施都强烈地影响果树体内氮素及含氮化合物的水平。  相似文献   

10.
The protective effect of selenium against the cadmium-induced oxidative effect in broccoli ( Brassica oleracea) plants was studied. Plants grown in hydroponic culture were supplied with selenium [as Se(IV)] and cadmium [as Cd(II)], individually or simultaneously. Cadmium accumulation in roots was noticeably higher than in the aerial parts of the plants, and this effect was even more acute when selenium was simultaneously added. Cadmium phytotoxicity was evidenced by an increase in the malondialdehyde (MDA) concentration in the roots and a decrease of photosynthetic pigment and tocopherol concentration in the aerial parts of the plant. The simultaneous addition of selenium alleviated cadmium-induced stress in the roots after 40 days of exposition. In the leaves, a more remarkable decrease of tocopherol and chlorophyll concentration was observed in the cadmium-enriched plants after 10 days of exposure. The results provided evidence that selenium supplementation helps the plant to minimize the cadmium oxidant effect. Tocopherol concentration in broccoli fruit of cadmium-supplied plants was not affected in comparison to control. However, the proportion of alpha-tocopherol increases with the addition of selenium. This response is important not only for the protective effect against oxidative damage in the plant but also in terms of human nutrition.  相似文献   

11.
巨峰葡萄对硒元素的吸收运转规律   总被引:2,自引:2,他引:2       下载免费PDF全文
以4年生露地栽培巨峰葡萄(砧木为贝达)为试材,研究氨基酸硒的不同施用方法和不同施用量条件下巨峰葡萄对硒的吸收、分布和积累特性。试验结果表明:(1)盛花期叶面喷施0.01%氨基酸硒(最适浓度)和土施0.3 g/株氨基酸硒(最适浓度)后,从花后至成熟巨峰葡萄的叶片、叶柄、果肉和单果硒含量均呈现先升高后降低的变化趋势。(2)与对照相比,施硒处理后,硒含量的累积顺序发生了变化,叶喷处理硒含量的累积顺序是叶片果肉叶柄,土施处理硒含量的累积顺序是果肉叶片叶柄。(3)不同施用方式影响硒在果实中积累与分布,土施硒肥处理,硒的积累顺序是先累积到种子,再到果肉,最后到果皮;叶面喷施硒肥处理,硒的积累顺序是先累积到果皮,再到果肉,最后才到种子。(4)无论叶喷还是土施氨基酸硒肥都在盛花期施用效果较好;当外源硒施入量增加时,巨峰葡萄果实各部位硒含量增加。  相似文献   

12.
土壤施硒对覆膜花生相关性状的影响   总被引:1,自引:1,他引:0       下载免费PDF全文
在覆膜条件下,研究土施硒肥对不同花生品种开花期和结荚期生理特性、农艺及产量性状的影响.结果表明,土施硒肥对3个花生品种结荚期的生理特性(黑玉珍的叶片POD活性除外)和农艺性状影响不大,而开花期的生理特性和百果重、饱果率、单株果数和单株生产力等产量性状较对照都显著提高,但不同花生品种间存在差异.其中,鲁花4号施硒后,其开...  相似文献   

13.
硒对胡萝卜含硒量、产量及品质的影响   总被引:9,自引:1,他引:9  
采用不同浓度Na2SeO3进行胡萝卜叶面喷施的田间试验,研究胡萝卜对硒的吸收、转化特点和硒对胡萝卜产量、品质等的影响。结果表明,叶面施硒可明显提高胡萝卜中各形态硒含量,随施硒量的增加,有机硒转化率上升;其总硒、有机硒含量在最大处理浓度(500.mg/kg)呈最高,分别是CK的15.9和26.6倍。施硒胡萝卜产量较对照降低,但未达显著水平。营养品质中除Vc下降,P变化不一外,总糖、胡萝卜素、粗纤维、Ca、Mg、Fe、K在一定浓度下有不同程度提高。综合分析硒对胡萝卜含硒量、产量、各品质因素以及对人、畜食用的安全性,施硒量以不超过1.0mg/kg为宜。  相似文献   

14.
陕西富士系苹果花期霜冻灾害气象指标的修订   总被引:4,自引:0,他引:4  
将8~10a树龄的陕西富士系苹果树的花枝放入人工霜箱内,以子房受冻为观测标准,在10~-5℃的温度区间对样本进行降温处理,得到花朵子房组织温度随时间的变化曲线,由温度曲线确定其过冷却点和结冰点;在此基础上,利用人工气候箱模拟7组不同低温条件和持续时间,观测苹果花的受冻率,确定苹果花期霜冻指标;通过对历史实际灾情的调查,得到果树自身修复影响因子,获得新的苹果花期霜冻指标。结果表明,陕西富士系苹果花的过冷却点为-2.5~-4.0℃;苹果花受冻既与低温强度有关,也与低温持续时间密切相关,温度越低或持续时间越长,受冻率越高;研究区实际调查结果显示,花朵受冻后可部分恢复坐果,果树的这种自身修复可使花朵受冻率减少约18个百分点,据此建立了新的陕西富士系苹果花期霜冻灾害气象指标;经比较,新指标对霜冻灾情的吻合率大于原指标,且霜冻级别越高吻合程度越高。  相似文献   

15.
采用土培试验的方法研究了盐胁迫条件下硒对小白菜抗氧化活性及膜脂过氧化作用的影响。结果表明,盐胁迫条件下,硒对小白菜的生物量没有显著影响。硒能显著提高小白菜叶片的谷胱甘肽过氧化物酶、过氧化氢酶、过氧化物酶、超氧化物歧化酶的活性以及还原型谷胱甘肽的含量和硒含量,抗氧化活性显著增强。硒显著降低小白菜体内氧自由基和丙二醛的含量;降低了膜脂过氧化作用,抑制小白菜质膜透性的升高。土壤施硒0.9 mg/kg,可提高小白菜对盐分胁迫的适应能力。  相似文献   

16.
This study was carried out to evaluate the effect of small additions of ion exchange substrate, Biona‐312, to soil on the yield and mineral composition of cherry tomato cv. ‘Koralik’ and cucumber cv. ‘Hermes F1.’ The test plants were grown under greenhouse conditions and subjected to 0, 2, and 5% (mass) Biona‐312 doses introduced into the soil. The study results showed that Biona‐312 introduced into soil significantly increased the yield of the test species at the flowering and fruiting stage. Soil enrichment with 2 and 5% Biona additions generally increased the nitrogen–phosphorus–potassium (N‐P‐K) content in tomato and cucumber organs at the flowering and fruiting stage with parallel magnesium (Mg) and calcium (Ca) content decrease. Introduction of nutrients together with the ion exchange substrate did not cause negative effects of overfertilization, and thus the ion exchange substrate can be recommended as a fertilizer in tomato and cucumber cultivation.  相似文献   

17.
地表覆盖对日光温室黄瓜生长发育及生理特性的影响   总被引:1,自引:2,他引:1  
试验研究了秸秆覆盖、地膜覆盖和秸秆加膜覆盖对结瓜期日光温室嫁接和未嫁接黄瓜生长发育与生理特性的影响。结果表明,地表覆盖可有效促进植株生长,有利于雌花分化、提高坐瓜率、降低畸形瓜比例、缩短成瓜时间以及增加单瓜重、早期产量和总产量,其中以秸秆加膜覆盖效果最明显,秸秆覆盖和地膜覆盖次之,嫁接效果优于未嫁接。秸秆覆盖、地膜覆盖和秸秆加膜覆盖均可不同程度提高黄瓜净光合速率、光能利用效率和水分利用效率,且以秸秆加膜覆盖效果最好,嫁接优于未嫁接。秸秆覆盖与秸秆加膜覆盖均可显著增加黄瓜叶片叶绿素含量,增强黄瓜根系活力,而地膜覆盖却使叶绿素含量低于对照,根系活力在结瓜后期低于秸秆覆盖与秸秆加膜覆盖处理,但仍高于对照。  相似文献   

18.
以"金粉5号"番茄为试材,在人工气候箱内设置4个低温寡照处理,即14/4℃(日最高/最低温度)′400μmol·m~(-2)·s~(-1)(光合有效辐射PAR),14/4℃′200μmol·m~(-2)·s~(-1),12/2℃′400μmol·m~(-2)·s~(-1),12/2℃′200μmol·m~(-2)·s~(-1),每个处理持续时间均分别为2、4、6、8、10d,以适宜生长条件25/18℃′800μmol·m~(-2)·s~(-1)为对照(CK),观察番茄开花、坐果特性,并测定果实产量及品质等指标。结果表明:(1)低温寡照胁迫使番茄现蕾和开花速度明显减慢,且胁迫程度越强增长速度越慢,12/2℃′200μmol·m~(-2)·s~(-1)处理不同天数后单株花蕾增长数均为0,开花数也最少,处理6d后才有新开花朵,为每株0.33朵。(2)番茄坐果数随处理时间呈"S"型变化,低温寡照处理4d以上番茄植株的坐果期明显延迟,其中12/2℃′400μmol·m~(-2)·s~(-1)处理10d的坐果时间最晚,较CK延迟了10.5d。(3)低温寡照胁迫下,番茄畸形果发生率随胁迫程度的加深而增加,单株产量与处理天数呈负相关关系,其中不同低温寡照处理2d对番茄产量无明显影响,而处理8d以上的番茄减产率则达到70%以上。(4)同一温度相同处理天数下,果实的维生素C、可溶性固形物含量和糖酸比随PAR的减弱而减小,而在相同PAR和相同处理天数下,维生素C、可溶性固形物含量和糖酸比随处理温度的降低而降低;有机酸含量则呈相反趋势。  相似文献   

19.
Soybean (Glycine max (L.) Merrill) plants normally abort a high percentage of flowers and pods. This study was conducted to determine the effect of P nutrition on flower and pod abscission in soybean. Williams 82 soybeans were established in hydroponic culture in the greenhouse at four levels of P (0.45 mM, 0.20 mM, 0.10 mM or 0.05 mM), and main stem flowers and pods were counted every two days from flowering to maturity. The two highest P treatments had similar flower production, pod production, pod abortion, seed weight and seeds per pod, but the 0.20 mM P treatment had 20% lower dry matter production and 19% lower seed yield. At P supplies of 0.10 or 0.05 mM, flower production, pod production, flowers per node, pods per node, seed yield, seed number and weight per seed were less (P < 0.05) than at 0.20 mM. Flowers produced per main stem node and seeds per pod were largely unaffected by limited P. Plants supplied 0.10 or 0.05 mM P aborted more flowers and pods than did those supplied 0.45 or 0.20 mM P. At P supply of 0.05 mM, flower, pod and total abortion was 80%, 49% and 90%, respectively. Flower and pod production were 50% and 78% less, while plant dry weight, seed yield and weight per seed were 83%, 90% and 23% less, respectively for the 0.05 mM P treatment compared to control. The data indicate that the primary effect of limited P on reproductive growth of soybean is to increase flower and pod abortion.  相似文献   

20.
硒对苦荞硒、总黄酮和芦丁含量、分布与累积的影响   总被引:6,自引:0,他引:6  
采用盆栽试验探讨土壤施硒对苦荞硒、总黄酮和芦丁含量、分布与累积的影响。结果看出,在土壤施硒0.5~2.0 mg/kg范围,苦荞根在苗期(40 d)大量吸收并累积硒,全生育期各器官硒含量极显著提高;在生长中后期(60~80 d) 硒的累积最快,累积量最多。硒在苦荞各器官中的分布为:在40 d时,根>叶>茎;60 d时Se0.0处理为叶>根>花>茎,施硒各处理则为花>根>叶>茎;80 d时Se0.0处理以花>根>叶>茎>子粒,Se0.5处理以花>叶>子粒>茎>根,施硒≥1.0 mg/kg的处理则为花>叶>茎>根>子粒。土壤施硒≤1.0 mg/kg促进苦荞生长,提高地上部各器官干重和植株总干重以及各器官总黄酮和芦丁含量与累积量,不改变总黄酮和芦丁的器官分布,增加苦荞中后期对总黄酮的累积;以Se0.5处理效应最佳,各差异达显著水平。过量的硒(Se1.5~2.0 mg/kg)显著抑制苦荞生长,降低各器官干重、总黄酮和芦丁含量与累积,不利于硒在子粒中富集和总黄酮在子粒中分布。表明在低硒土壤上栽培苦荞,土壤施硒以不超过1.0 mg/kg为宜,既能最大限度的提高苦荞各器官硒、总黄酮和芦丁含量和累积量,又可降低施用硒肥的成本和减少硒肥对环境的影响。  相似文献   

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