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1.
作物化感作用研究现状及前景展望 总被引：58，自引：6，他引：58
作物化感作用研究是一个相对较新的研究方向，尽管2000年前就有关于植物间克生现象的描述，化感作用在农业生产实践中的应用很有潜力，从化感作用的概念着手总结了近20年来的研究成果，包括化感作用物质研究，作用机制研究，种质资源，生物检测方法和遗传特性研究等，并阐明了作物化感作用的研究意义，研究存在困难以及应用途径与前景。 相似文献
2.
化感效应和资源竞争在作物抑草中起重要作用。为区分低氮胁迫下小麦抑草作用的化感效应与资源竞争,以强化感小麦品种‘115/青海麦’、‘92L89’和弱化感小麦‘抗10103’为材料,设置氮水平为25 mg·L-1、50mg·L-1、100 mg·L-1和200 mg·L-1的水培试验,通过小麦与看麦娘共培、应用含小麦根系分泌物的小麦-看麦娘共培液处理看麦娘,分别测定了小麦对看麦娘的生物干扰作用、化感效应及资源竞争效应。结果表明,不同化感潜力的小麦对看麦娘的抑制能力存在显著差异,抑制率大小为‘115/青海麦’(55.1%~73.9%)‘92L89’(48.9%~65.9%)‘抗10103’(15.4%~45.5%),且抑制率随氮水平的降低而增大。在小麦的抑草作用中,化感效应与资源竞争并存。低氮胁迫条件下,强化感小麦抑草能力增强主要通过提高化感效应实现;弱化感小麦抑草能力增强主要通过提高资源竞争实现。不同化感潜力小麦的抑草作用在低氮胁迫下表现出不同的生态策略。小麦抑草作用的化感效应均随氮水平降低而增大,其抑制率随氮水平的变化可用一元二次方程加以拟合。 相似文献
3.
泡桐、杨树叶水浸液对作物种子萌发的化感作用 总被引：2，自引：0，他引：2
为了研究农林复合生态系统中树种对农作物种子萌发的影响,以泡桐和杨树为对象,采用振荡溶解的方法提取泡桐和杨树叶浸出液,通过测定种子萌发率,研究树叶水提取物对小麦、玉米、大豆种子萌发的化感作用。结果表明：（1）杨树和泡桐叶水提取物质量浓度达到50 mg/mL对大豆的发芽率、发芽速率有明显抑制作用;杨树叶水提取物质量浓度达到10 mg/mL和泡桐叶水提取物质量浓度高于20mg/mL对小麦、玉米有显著的抑制作用。（2）杨树叶水浸液对3种作物种子萌发的化感作用（RI=15.147）大于泡桐叶（RI=13.973）。（3）杨树和泡桐叶水浸液对3种作物种子的化感抑制作用强度依次为小麦>玉米>大豆,而且随着杨树和泡桐叶水浸液质量浓度的上升其化感抑制作用越来越强,作物种子的发芽率也越来越低。 相似文献
4.
综述了作物自毒现象、作物间他感作用以及作物与杂草间他感互作的研究进展,指出化感作用在克服连作障碍、构建高效间套复合群体、防除病虫草害和生物调控方面的应用潜力。 相似文献
5.
针对干旱和种间作用下,外源化感物质对作物根系作用机制研究薄弱问题,本文以小麦间作蚕豆为参试对象,在不同土壤含水量水平下(田间持水量的75%,60%,45%),研究了小麦根系分泌物丁香酚(2-甲氧基-3-烯丙基苯酚)对单作和间作蚕豆根系形态和活力的影响,以期为通过化感作用途径调控间作群体探索新的思路。结果表明:土壤中浓度为300×10-6mol·kg-1的丁香酚对单作和间作蚕豆根系活力和根体积、根干重和根长等形态特征均具有抑制作用,表现为化感负效应;随供水水平的提高丁香酚对蚕豆根系的化感效应呈减弱趋势,不同供水水平下化感效应绝对值表现为在土壤含水量为田间持水量的45%时最大,60%居中,75%最小。蚕豆根系活力的化感效应值在75%和60%供水水平下,均与45%供水水平之间存在显著差异,单作和间作蚕豆化感效应值在75%供水水平处理下,较45%供水处理分别降低64.0%和56.8%;而种植模式、丁香酚和供水水平对蚕豆根系活力、根体积、根长和根干重的互作效应不显著。因此,生产实践中,可通过优化水分管理达到弱化化感物质对间套作作物间根系的负效应,从而达到克服间套作群体中因某一种作物化感物质累积而造成的毒害作用。 相似文献
6.
植物化感作用类型及其在农业中的应用 总被引：8，自引：2，他引：6
本文总结前人研究成果的基础上,对不同植物化感作用类型及其作用机制和在农业中的应用进行了探讨。植物化感作用包括化感偏害作用、自毒作用、自促作用和互惠作用。植物化感偏害作用是由植物根系分泌物介导下的植物与特异微生物共同作用的结果。利用植物化感偏害作用控制田间杂草是一项环境友好型的可持续农业技术,并已在水稻化感抑草研究方面取得了较突出的成果。植物化感自毒作用(作物连作障碍)是造成作物产量降低、生长状况变差、品质变差、病虫害频发的现象。药用植物,特别是以根部入药的药用植物中,连作障碍表现更为突出。近年来研究结果认为根系分泌物生态效应的间接作用及土壤微生物区系功能紊乱是导致植物连作障碍的主要因素。因此,改善土壤生长环境,恢复和修复根际土壤微生物结构平衡,增强生态系统机能是克服作物连作障碍的关键。植物化感自促作用(连作促进作用)是在植物根系分泌物促进下,根际土壤微生物之间此消彼长,有益微生物之间互利协作,土壤肥力和营养补给能力明显改善,从而增强植物根系抗性,促进植物生长发育,提高产量和品质的结果。牛膝的连作促进作用明显,有学者试图通过牛膝与其他不耐连作药用植物间作套种或轮作,实现药用植物生产的可持续发展。植物间的正相互作用(互惠作用)是作物间套种系统超产和养分等资源高效利用的重要机制,根系分泌物在介导根际微生物与植物的有利互作中起到重要作用。最后作者强调指出,存在于根际土壤的微生物群落的宏基因组组成是决定植物能否健康生长的关键。深入研究存在于土壤生态系统中的植物体外基因组的组成与演化机制,将成为借用现代合成生物学原理与技术,定向控制植物根际生物学过程,促进作物生产可持续发展的优先研究领域。 相似文献
7.
不同供水水平下间甲酚和间作对小麦、蚕豆耗水特性及产量的影响 总被引：6，自引：2，他引：4
通过盆栽试验,研究了3个供水水平(田间持水量的45%、60%和75%)和间甲酚对小麦间作蚕豆耗水量及产量的影响。结果表明:间作总耗水量较相应单作总耗水量的加权平均低12.87%～31.56%,间甲酚对不同作物全生育期总耗水量的作用不显著,但供水和种植模式与作物总耗水量间的相关性极显著。间甲酚对小麦、蚕豆的产量均具有负效应,提高供水量可弱化间甲酚对小麦产量的负效应,但不同供水水平下间甲酚对蚕豆经济产量的化感作用差异不显著。间作生物产量和经济产量较相应单作的加权平均分别高15.3%～37.41%和5.98%～31.27%,间作同时具有弱化间甲酚对蚕豆化感负效应的作用。 相似文献
8.
当归营养期的化感作用 总被引：5，自引：0，他引：5
为探讨当归(Angelica sinensis)自毒作用与连作障碍的关系并建立合理的轮作制度,利用4个浓度当归营养期根部及茎叶部水浸液对当归及其种植区常见作物油菜(Brassica campestris)、小麦(Triticum aestivum)和燕麦(Avena sativa)的种子和幼苗进行了生物测定。分析结果表明,当归具明显的自毒作用(敏感指数M3=-0.258 3),茎叶部分的自毒效应强于根部,且作用强度随浓度增加而增强;小麦和燕麦对当归的化感作用有一定的耐受能力,综合敏感指数(M)分别为-0.075 5和-0.144 7;而油菜对当归的化感作用较为敏感,综合敏感指数为-0.307 9,这一结果与实际种植情况不符,推断可能与当归化感物质在土壤中的转化导致化感作用降低有关。在种间化感作用的研究中发现根部的化感作用强于茎叶,并有高抑制低促进的浓度效应。试验结果说明当归的自毒作用是造成连作障碍的原因之一;当归对小麦和燕麦的化感作用较弱,可以用于当归轮作体系,缓解因自毒作用而引起的连作障碍。 相似文献
9.
农业生态系统中的化感作用 总被引：12，自引：0，他引：12
化感作用体现了植物之间的生化相生相克关系，且广泛存在于农业生态系统之中。由于化感物质的作用，某些种类的作物不宜混种，而有些种类之间实行间作则提高产量。因为自毒作用的影响，重茬种植作物会出现减产，因而选择适宜品种进行轮作可避免此况发生。开发、利用化感物质作为植物源杀虫剂、土壤灭菌剂也已成为当前植保工作的热点。通过杂交和转基因等生物工程手段筛选、培育携带抑草基因的栽培品种，或将普通作物与抑草作用显著的品种进行间作，均可有效减少除草剂的使用。更为直接的方法是将化感物质发展为除草剂，并进一步探讨其人工合成和化学修饰的可能性，从而提高作物产量，减少化学除草剂对农业环境的污染。 相似文献
10.
根系分泌物的化感作用及其对土壤微生物的影响 总被引：11，自引：0，他引：11
总结了根分泌化感物质的种类及其化感效应,分析了生物和非生物因素与根系分泌化感物质之间的关系。此外,根系分泌化感物质的研究手段对于所取得的研究结果至关重要,其中根分泌物收集系统是收集根分泌化感物质的常用而可行的方法之一。对于根分泌化感物质的分离鉴定技术有多种,可根据需要选择适宜的分离方法。还列举了一些作物根分泌的化感物质对根际微生物产生的影响,阐明了根分泌的化感物质所起的重要化感作用。根分泌物化感作用的研究已成为土壤生态学领域的热点与前沿课题,自然条件下原位收集鉴定植物根系分泌物中的化感物质等诸多问题是该领域今后的研究重点。 相似文献
11.
Summary A crop of barley was grown on plots which had previously supported pure stands of lupins, canola, ryegrass, and wheat. The plots were labelled with 15N-enriched fertilizers at the time of sowing of the antecedent crops. The crop of lupins, which derived 79% of its N from symbiotic N2 fixation at physiological maturity, conferred an N benefit to barley of 3.4 g N m-2 when compared to barley following wheat. Lupins used less fertilizer N and less unlabelled soil N compared to the other crops, but the ratios of these sources of N in the plant tops were similar. The apparent sparing of soil+fertilizer N under lupins compared with wheat was 13.6 g N m-2, which was much larger than the measured N benefit. Barley following lupins was less enriched in 15N compared to barley following wheat, and the measured isotope dilution was used to estimate the proportion of barley N derived from biologically fixed N in the lupin residues. This in turn enabled the N benefit to be partitioned between the uptake of spared N and the uptake of fixed N derived from the mineralization of legume residues. Spared N and fixed N contributed in approximately equal proportions to the N benefit measured in barley following lupins compared to barley following wheat. 相似文献
12.
Economic conditions are forcing farmers to grow crops with high revenue leading to cereal-dominated crop rotations with increasing risk due to unfavourable preceding crops or preceding crop combinations. Based on a long-term field trial (1988–2001) with 15 different rotations including winter oilseed rape (OSR), winter wheat, winter barley, spring peas and spring oats, the effects of different preceding crops, pre-preceding crops and crop rotations on the grain yield of mainly OSR, winter wheat and winter barley were quantified. In the subsequent 2 years (2001/2002 and 2002/2003), winter wheat was grown on all plots in order to test the residual effects of the former crops (as preceding crops in 2002 and as pre-preceding crops in 2003) and crop rotations on growth, grain yield and yield components.Unfavourable preceding crops significantly decreased yield of OSR, wheat and barley by 10% on average, however, with a large year-to-year variation. In addition, break-crop benefits in both crops, wheat and OSR, persisted to the second year. Wheat as preceding crop mainly decreased the thousand grain weight, and to a lesser extent, the ear density of the subsequent wheat crop. The amount of wheat yield decrease negatively correlated with the simple water balance (rainfall minus evapotranspiration) in May–July. In 2001/2002 and 2002/2003, the preceding crop superimposed the crop rotation effects, thus resulting in similar effects as observed in 1988–2001.Our results clearly reveal the importance of a favourable preceding crop for the yield performance of a crop, especially wheat and OSR. 相似文献
13.
In Northern Europe, cover crops are traditionally established before spring crops by undersowing, but some cover crops might also have an effect if preharvest sown before spring crops and even winter crops. The effects of cover crop sowing date, sowing technique and succeeding main crop on biomass production, N uptake, nitrate leaching and soil inorganic N were tested in lysimeters and in the field. Cruciferous cover crops (oil radish, white mustard) were sown preharvest by broadcasting into winter wheat in July and were allowed to grow until a following winter wheat was established in September. Other preharvest cover crops were left in place until late autumn. For comparison, the same cruciferous cover crops were established postharvest after light harrowing. Perennial ryegrass undersown in spring barley was also included. Aboveground N uptake in preharvest cover crops amounted to a maximum of 24 kg N/ha in September before sowing winter wheat. When left until late autumn, preharvest oil radish took up a maximum of 66 kg N/ha, and ryegrass and postharvest cover crops 35 kg N/ha. Preharvest establishment of cruciferous cover crops before a spring‐sown crop thus seems promising. The soil was depleted of inorganic N to the same extent in late autumn irrespective of cover crop type, sowing time and technique within winter wheat or spring barley. However, the reduction in nitrate leaching of preharvest cover crops incorporated after 2 months and followed by winter wheat was only half of that achieved by cover crops left until late autumn or spring. 相似文献
14.
Effects of cropping system and rates of nitrogen in animal slurry and mineral fertilizer on nitrate leaching from a sandy loam 总被引：3，自引：0，他引：3
Abstract. Leaching of nitrate from a sandy loam cropped with spring barley, winter wheat and grass was compared in a 4-year lysimeter study. Crops were grown continuously or in a sequence including sugarbeet. Lysimeters were unfertilized or supplied with equivalent amounts of inorganic nitrogen in calcium ammonium nitrate (CAN) or animal slurry according to recommended rates (1N) or 50% above recommended rates (1.5N).
Compared with unfertilized crops, leaching of nitrate increased only slightly when 1N (CAN) was added. Successive annual additions of 1.5N (CAN) or 1N and 1.5N (animal slurry) caused the cumulative loss of nitrate to increase significantly. More nitrate was leached after application of slurry because organic nitrogen in the slurry-was mineralized.
With 1N (CAN) the leaching losses of nitrate were in the following order: continuous spring barley undersown with Italian ryegrass < continuous ley of perennial ryegrass < spring barley in rotation and undersown with grass < perennial ryegrass grown in rotation = winter wheat grown in rotation < sugarbeet in rotation < continuous winter wheat < continuous barley < bare fallow.
At recommended levels of CAN (1N), cumulative nitrate losses over the four years were similar for the crops when grown in rotation or continuously. When crops received 1.5N (CAN) or animal slurry, nitrate losses from the crops grown continuously exceeded those from crops in rotation. Including a catch crop in the continuous cropping system eliminated the differences in nitrate leaching between the two cropping systems. 相似文献
Compared with unfertilized crops, leaching of nitrate increased only slightly when 1N (CAN) was added. Successive annual additions of 1.5N (CAN) or 1N and 1.5N (animal slurry) caused the cumulative loss of nitrate to increase significantly. More nitrate was leached after application of slurry because organic nitrogen in the slurry-was mineralized.
With 1N (CAN) the leaching losses of nitrate were in the following order: continuous spring barley undersown with Italian ryegrass < continuous ley of perennial ryegrass < spring barley in rotation and undersown with grass < perennial ryegrass grown in rotation = winter wheat grown in rotation < sugarbeet in rotation < continuous winter wheat < continuous barley < bare fallow.
At recommended levels of CAN (1N), cumulative nitrate losses over the four years were similar for the crops when grown in rotation or continuously. When crops received 1.5N (CAN) or animal slurry, nitrate losses from the crops grown continuously exceeded those from crops in rotation. Including a catch crop in the continuous cropping system eliminated the differences in nitrate leaching between the two cropping systems. 相似文献
15.
Anna Karina R. Schmidt 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(5):416-424
Seed crops of white clover (Trifolium repens L.) are usually established with a cover crop. Provided sufficient light, white clover may compensate for low plant density by stoloniferous growth. Our objectives were (1) to compare spring barley or spring wheat used as cover crops for white clover and (2) to find the optimal seeding rate/row distance for white clover. Seven field trials were conducted in Southeast Norway from 2000 to 2003. Barley was seeded at 360 and 240 seeds m?2 and wheat at 525 and 350 seeds m?2. White clover was seeded perpendicularly to the cover crop at 400 seeds m?2/13 cm row distance or 200 seeds m?2/26 cm. Results showed that light penetration in spring and early summer was better in wheat than in barley. On average for seven trials, this resulted in 11% higher seed yield after establishment in wheat than in barley. The 33% reduction in cover crop seeding rate had no effect on white clover seed yield for any of the cover crops. Reducing the seeding rate/doubling the row distance of white clover had no effect on seed yield but resulted in slightly earlier maturation of the seed crop. 相似文献
16.
不同竞争强度间作体系氮素利用和土壤剖面无机氮分布差异 总被引：6，自引：3，他引：3
田间小区试验,研究大麦/玉米间作、小麦/玉米间作和蚕豆/玉米间作及其对应单作体系,在不施氮和施氮225 kg/hm2情况下,对氮素吸收利用效率和土壤剖面无机氮变化的影响。结果表明,作物对养分的竞争能力与其根区土壤无机氮浓度和累积量密切相关。两作物共生期不施氮肥时,0—100 cm土层,土壤剖面无机氮残留量是间作大麦和间作小麦根区分别比间作蚕豆根区减少2032~82和10717~1 kg/hm2;与大麦和小麦间作的玉米根区分别比与蚕豆间作的玉米根区减少931~20和5687~kg/hm2。土壤无机氮累积量受作物类型、种间相互作用强度及实时土壤环境条件影响。种间相互作用提高了间作大麦和小麦的氮素当季回收率,但使与其间作的玉米氮素当季回收率降低。大麦/玉米和小麦/玉米竞争体系在不施氮肥时氮素利用效率最高。施用氮肥使大麦、小麦氮素收获指数降低,玉米氮素收获指数升高,对蚕豆无影响。在选择配对作物时,为获得间作优势要充分考虑作物竞争能力、土壤基础肥力条件、施肥水平及配套栽培措施等。低肥力土壤宜选择豆科/禾本科互惠体系,高肥力土壤宜选择禾本科/禾本科竞争体系。 相似文献
17.
Dry matter yield and water uptake by barley (Hordeum vulgare L., cv. ‘Gus') and wheat (Triticum aestivum L., cv. ‘Inia 66') grown in full strength Hoagland nutrient solution were compared under three NaCl salinity levels in a growth chamber. Total dry matter yield decreased with increasing salinity for both plants, but wheat was more severely affected than barley at the high salinity level. Reduction in dry matter weights of barley and wheat were 57% and 67%, respectively, at the 1.2 MPa stress. Salt stress substantially decreased the number of tillers in both crops, however, this reduction was more severe for wheat than barley. The numbers of tillers were 10 and 7 for barley plants at 0.6 and 1.2 MPa stress, respectively. The respective values were 6 and 4 for wheat plants. Water uptake in both plants was substantially decreased by increasing salinity stress. This reduction was essentially similar for both plants. Water uptake per gram dry weight was not significantly affected by salt stress for barley. For wheat, only 1.2 MPa stress increased the amount of water absorbed per g dry matter produced. 相似文献
18.
通过盐碱性防护林地播种大麦、小麦和大豆的试验,结果显示:夏季高温干旱期间,实施播种大豆防护林地土表(0~20 cm)层的可溶性盐分和PH值分别为0.65 g﹒kg-1和7.04,与实施播种大麦和小麦无明显差异,有机质(29.88 g﹒kg-1)、速磷(91.10 mg﹒kg-1)、速钾(23.10 mg﹒kg-1)和速氮(134.43 mg﹒kg-1)则分别比实施播种大麦和小麦有明显增高,并且存在极显著差异;3种作物播种后,防护林地没有出现“返盐碱”(发白)现象.表明:实施播种大豆对改善林地土壤条件的效果最好,其次是播种大麦和小麦. 相似文献
19.
Compacted subsoil may reduce plant root growth with resulting effects on plant uptake of water and nutrients. In organic farming systems subsoil loosening may therefore be considered an option to increase nutrient use. We investigated the effect of subsoil loosening with a paraplow to ca. 35 cm depth within a four-crop rotation in an organic farming experiment at Foulum (loamy sand) and Flakkebjerg (sandy loam) in Denmark. In each of the years 2000–2003, half of four plots per site were loosened in the autumn bearing a young grass-clover crop (mixture of Lolium perenne L., Trifolium repens L. and Trifolium pratense L.) established by undersowing in spring barley (Hordeum vulgare L.). The grass-clover was grown for another year as a green manure crop and was followed by winter wheat (Triticum aestivum L.), lupin (Lupinus angustifolius L.):barley and spring barley in the following 3 years. On-land ploughing was used for all cereal and pulse crops. Penetration resistance was recorded in all crops, and the results clearly showed that subsoil loosening had effectively reduced the plough pan and that the effect lasted at least for 3.5 years. Measurements of wheat root growth using minirhizotrons at Foulum in 2002/2003 did not show marked effects of subsoil loosening on root frequency in the subsoil. Subsoil loosening resulted in reduced growth and less N uptake of the grass-clover crop in which the subsoil loosening was carried out, probably due to a reduced biological nitrogen (N) fixation resulting from a smaller clover proportion. This had a marked effect on the growth of the succeeding winter wheat. Negative effect of subsoil loosening on yield of winter wheat and spring barley was observed without manure application, whereas small positive yield effect of subsoil loosening was observed in crops with a higher N supply from manure. Yield decrease in winter wheat was observed in years with high winter rainfall. There was no significant effect of subsoiling on grain yield of the lupin:barley crops, although subsoiling had a tendency to increase crop growth and yield during dry summers. Our results suggest that subsoil loosening should not be recommended in general under Danish conditions as a measure to ameliorate subsoil compaction. 相似文献