植物化学生态学中的克生作用在草业上的表现

为了解植物生化他感作用在草业（田间杂草）中的作用，１９８６－１９８８年通过查阅资料并对我国大部分牧区和农区实地考察，证明，在植间广泛存在着因植物次生代谢产物对微生态环境的改变所引起的植物种内和种间生长发育相互促进和抑制的生化他感作用，其中植物间的克生作用（抑制作用）表现的较为明显，而这种作用与草原退化和农田杂草的蔓延有着密切关系。     

卵叶青藓水提液对玉米种子萌发和幼苗生长的影响

为了解卵叶青藓可能具有的化感效应及其作用机制,以卵叶青藓配子体水提取液为处理液,以玉米种子为受试对象,通过测定不同浓度梯度卵叶青藓水提液对受试种子萌发及幼苗生长的影响,初步阐明卵叶青藓可能具有的化感潜能.结果表明:卵叶青藓配子体水提液对玉米种子发芽率有较大影响,且总体趋势表现为提取液浓度愈高,对其种子萌发率影响愈大,处理组玉米种子萌发率显著低于对照组(p＜0.05);卵叶青藓水提液对玉米幼苗生长的影响表现在对苗高与根长的抑制方面.随着水提液浓度的增高,玉米幼苗根长逐渐变短,在80 mg/mL处理下达到最短,且与对照间差异显著(p＜0.05);对玉米幼苗根部发育状况有较强的影响,即随着水提液浓度的提高,生根数目逐步减少,直至浓度为80 mg/mL时达到最少.实验中,玉米幼苗鲜重及干重均随着提取液浓度的升高而减小,尤其是幼苗于重,在提取液浓度达到40 mg/mL时达到最小.随卵叶青藓提取液浓度不断增高,玉米幼苗叶片总叶绿素含量和叶绿素a含量逐步下降,均在80 mg/mL时达到最低,而叶绿素b在5 mg/mL时反而略高于对照组,在10 mg/mL时达到最低.上述结果表明,卵叶青藓具有一定的化感潜能.     

苦瓜对8种蔬菜的化感作用

以8种海南主要栽培的蔬菜为受体,采用室内生测法研究苦瓜(Momordica charantiaL.)茎叶水浸提液对其化感作用。结果表明:苦瓜茎叶水浸提液对8种受体植物的种子萌发和幼苗生长均有一定的化感效应,且化感作用方式和强度在受体间及指标间存在显著差异;化感作用综合效应的平均值大小顺序为:辣椒黄瓜豇豆菜豆萝卜樱桃番茄胡萝卜番茄。试验结果为建立合理的栽培制度提供了理论和试验依据。     

Biology,impact, and management of Echinochloa colona (L.) Link

Echinochloa colona (L.) Link. is one of the most problematic weeds across the world. It is an annual C₄ summer grass, native to tropical and subtropical Asia, emerged as a serious and persistent threat in 35 cropping systems in more than 60 countries. E. colona is reported as an important associated weed species in transplanted and direct-seeded rice. Diverse ecotypes, high seed production, short seed dormancy, rapid growth, competitive potential, allelopathic interaction, and resistance against several herbicides makes it a more adaptable and persistent challenge in various agro-ecosystems. Development of resistance to recommended or higher doses of numerous herbicides, including ametryn, atrazine, bispyribac-sodium, clefoxidym, cyhalofop-butyl, fenoxaprop-p-ethyl, glyphosate, metribuzin, propanil, and triazine, is a serious concern for the farming and scientific community. Crop infestation with resistant E. colona biotypes may ultimately increase the weed control cost. Unfortunately, investigations on seed dormancy release, genetic diversity, allelopathic interference, and competitive ability of this weed are inadequate in accomplishing its appropriate control in different environments. Therefore, a comprehensive review is presented here to gather the existing information, to pin point key findings, and to highlight the research gaps in the biology, interference, and management of E. colona. Different management options have been discussed in relation with eco-biology of this noxious weed. The potential research endeavours have also been highlighted in order to provide an insight of its existing scenario and to facilitate the future management strategies.     

圆柏对几种农田杂草及作物的化感潜力分析

为探究圆柏（Sabina chinensis）的化感作用，本研究采用培养皿滤纸法研究圆柏叶片浸提液对地肤（Kochia scoparia）、稗草（Echinochloa crusgalli）、藜（Chenopodium album）、反枝苋（Amaranthus retroflexus）、马齿苋（Portulaca oleracea）5种杂草种子和向日葵（Helianthus annuus）、燕麦（Avena sativa）、油菜（Brassica campestris）、荞麦（Fagopyrum esculentum）4种作物萌发和生长的影响，并用圆柏叶片、树枝、树皮粉末和浸提液进行盆栽抑草效果检测。结果表明：圆柏叶片浸提液对5种杂草种子萌发和幼苗生长具有显著的抑制作用，对地肤、藜、反枝苋萌发及生长的化感效应指数均在-0.98以上；盆栽抑草结果表明，圆柏不同部位对5种杂草种子萌发和稗草及反枝苋株高生长均有较好的抑制作用，叶片化感强度大于树皮和树枝，叶片粉末拌土处理抑草效果好于浸提液叶面喷施；对作物的化感作用结果表明，圆柏叶片浸提液稀释1.5倍时，抑制荞麦种子萌发但不影响其株高及根生长，不影响燕麦种子萌发但降低其株高和根长生长，抑制油菜的发芽势和发芽指数但不影响其种子萌发率，促进油菜株高及根长生长，不影响向日葵种子萌发和生长。综上所述，圆柏具有良好的抑草活性，对作物影响较小。     

天仙子种子浸提液对黑麦草种子萌发和幼苗生长的化感作用

为了探究天仙子（Hyoscyamus niger L.）对禾本科牧草的化感作用,以天仙子和黑麦草（Lolium perenne L.）为材料,通过5个不同浓度天仙子种子浸提液（0,0.025,0.05,0.075,0.1 g·mL^-1）,对黑麦草种子萌发和幼苗生长进行处理,测定黑麦草种子萌发和幼苗生长情况。结果表明：不同浓度的天仙子种子浸提液对黑麦草种子萌发有极显著影响（P<0.01）,随浸提液浓度增加,黑麦草萌发率和发芽指数显著降低（P<0.05）;浸提液对黑麦草根长和地上、地下生物量有显著的影响（P<0.05）,对株高影响不显著;不同浓度的天仙子种子浸提液处理下,黑麦草幼苗丙二醛、脯氨酸含量、相对电导率均随浸提液浓度的增加而增加,叶片中叶绿素含量则随浸提液浓度的增大而减小。综上所述,天仙子种子浸提液对黑麦草幼苗细胞膜具有一定的损伤作用,黑麦草植株通过细胞膜的变化而影响内部生理生化过程,以适应不利的环境。     

Allelopathic potential of watermelon tissues and root exudates

Allelopathic potential of watermelon in hydroponic culture was investigated using the continuous root exudates trapping system (CRETS). Laboratory bioassays and high-performance liquid chromatography (HPLC) were used for quantification of phytotoxins in different plant tissues and root exudates collected using XAD-4 resin. Seedling growth of both watermelon and lettuce was significantly inhibited by watermelon root exudates and the degree of inhibition increased with increasing concentration of exudates. Root exudates had inhibitory effects throughout the experiment and these were most pronounced during the period 41–50 days after transplanting. Inhibitory effects of various plant tissues were demonstrated using the bioassay tests. Frulic acid was the dominant component found using HPLC and the amounts of allelochemicals found in the plant extracts were correlated with the bioassay results using the Petri dish test. The results indicate that the allelopathic potential of watermelon may play an important role in the phenomenon referred to as ‘soil sickness’.     

Weed Allelopathy,Its Ecological Impacts and Future Prospects

Summary

The importance, characteristics, positive and negative impacts, and future role of weeds as an integral part of the natural and agroecosystems are evaluated and discussed. Interference between plants in nature and the importance of differentiating between competition and allelopathy are interpreted. Allelopathy as one component of weed/crop interference, allelochemicals from weed species and their possible mechanism of action are listed and discussed. Weed species with inhibitory action against cultivated crops, other weed species, and plant pathogens, as well as self-inhibitory (autopathic) species are reviewed. Stimulatory or inhibitory allelopathic effects of different crop plants, trapping and catching species, and the potential of allelopathic weeds in inhibiting or stimulating certain parasitic weed species are discussed and evaluated. Allelopathy as a mechanism and future strategy for agricultural pest control and farm management and the potential use and development of some allelochemicals as natural pesticides or plant growth regulators are also considered and discussed.     

油松、辽东栎混交林中生化他感作用的研究

研究了油松（ＰｉｎｕｓｔａｂｕｌａｅｆｏｒｍｉｓＣａｒｒ．）、辽东栎（ＱｕｅｒｃｕｓｌｉａｏｔｕｎｇｅｎｓｉｓＫｏｉｄｚ．）混交林中的生化他感作用，结果表明：油松、辽东栎纯林及松栎混交林下的枯落叶、半分解枯落叶及表层土壤水浸液对油松及其它植物的种子发芽和幼苗胚根、幼茎生长有显著的影响，一般在高浓度下表现为强烈的抑制作用，低浓度下作用不显著或起促进作用。其中辽东栎枯落叶水浸液的抑制作用最为强烈，混交林中枯落叶的抑制作用有所下降。说明在某些条件（干旱、混交比例和混交方式不当）下，两树种混交可引起林地生化他感物质富积，从而导致油松生长不良，林地生产力下降。解释了实际林地的现象，为营造松栎混交林提供了依据。     

火炬树水浸液对地被植物种子萌发的化感效应

本研究用火炬树夏季叶片和秋季叶片水浸液,浓度为0.250g.Dw/mL、0.050g.Dw/mL、0.010g.Dw/mL、0.002g.Dw/mL对白花三叶草和草地早熟禾种子进行处理,结果表明：火炬树叶片水浸液对白花三叶草和草地早熟禾两种种子的发芽率、发芽指数和化感效应指数均表现为抑制作用,对草地早熟禾的抑制作用强于白花三叶草。秋季叶片水浸液抑制作用强于夏季的,火炬树叶片水浸液的浓度越高,对种子的抑制效果越强,当水浸液浓度为0.250g.Dw/mL时,白花三叶草发芽率为2%,而草地早熟禾的发芽率、发芽指数、发芽势均为0,化感效应指数为-1。