Effects of some pretreatments on germination of bladder-senna (Colutea armena Boiss. and Huet.) and smoke-tree (Cotinus coggygria Scop.) seeds

This study was carried out to determine effects of pre-treatments including floating in hot water(100 degrees C) followed by continual cooling for 24 hr in the same water floating in tap water for 24 hr submersion in concentrate (98%) sulphuric acid (H2SO4) and cold stratification for different durations (20, 40 and 60 days) and their combinations on seed germination and to investigate how to overcome dormancy of seeds of Colutea armena Boiss. and Huet. and Cotinus coggygria Scop. The seeds were sown in polyethylene pots in the greenhouse and on seedbeds under open field conditions. The statistical design was a randomized complete block design with three replications. The highest germination percentage (77.19%), the best germination rate (16 days) and the highest growth rate (69.01%) were obtained from Colutea armena seeds that were submersed in sulphuric acid for 30 min and sown in the greenhouse. The pre-treatment of submersion in sulphuric acid for 20 min with cold stratification for 60 days gave the highest germination percentage (82.77%) and the highest growth rate (79.37%) in the greenhouse for Cotinus coggygria seeds. On the other hand, the best germination rate (9 days) was obtained from smoketree seeds that were cold stratified 60 days and sown under open field conditions. It can be stated that there is an affirmative effect of the greenhouse condition on germination percentage and growth rate values of the seeds used in this study     

Effects of potassium humate solution and soaking periods on germination characteristics of undelinted cotton seeds (Gossypium hirsutum L.)

The present study was conducted to determine the effects of soaking in potassium humate (PH) solution (55% humic acid, 30% fulvic acid and 8% potassium hydroxide) and distilled water (DW) for different periods (0, 4, 8 and 16 hours) on germination characteristics of undelinted seeds of cotton cv Ersan-92. Radicle, hypocotyl and seedling length, radicle and hypocotyl elongation rate and vigor index increased by PH solution treatment and increasing soaking periods. The medium x soaking period interactions were significant except for germination percentage. Sixteen hour soaking period gave the highest values of investigated characteristics. It is suggested that pre-sowing PH solution treatment may be useful to provide a good stand establishment.     

Seed germination of three provenances of Pinus brutia (Ten.) as influenced by stratification, temperature and water stress

Seeds from three provenances of Pinus brutia were stratified for 0 or 45 d (days) at 4 +/- 1 degrees C and then germinated at 15 degrees C or 20 degrees C on filter paper saturated with polyethylene glycol solutions to provide water potentials of 0, -0.2 and -0.4 MPa (mega Pascal). Regardless of stratification, germination was lower at 15 degrees C than 20 degrees C for seeds of all provenances. Stratification significantly increased germination percentage at all water potentials regardless of the germination temperatures. Lowering the water potential to -0.4 MPa reduced germination for all three provenances in unstratified and stratified seeds when averaged for two temperatures, but reaction to the increased water stress was different among the provenances. Combined over two temperatures, stratified or unstratified seeds from the highest elevation (Cehennemdere) had the lowest germination performance at all water potentials, and stratified and nonstratified seeds from a coastal elevation (Silifke) had the highest germination parameters at the lowest water potential (-0.4 MPa). It might be concluded that seed germination and resistance to water stress vary according to provenance and stratification.     

塑料地膜对小麦种子萌发及幼苗抗氧化酶系统的影响

研究了中国北方地区常用的塑料地膜对小麦Triticum aestivum L.种子发芽率,芽长根长及幼苗抗氧化酶系的影响以探明塑料地膜的毒性。结果显示500~2 500 mg.kg-1两种质量分数的塑料地膜处理对小麦种子的发芽率几乎不产生影响,在高质量分数（≥5 000 mg.kg-1）处理下小麦的发芽率有所下降。500~5 000 mg.kg-1的塑料地膜能促进小麦叶和根的伸长,但在高质量分数情况下则显著抑制了根和芽的延伸,其中15 000 mg.kg-1添加量下,叶和根的抑制率分别达到了16.70%和15.07%。小麦根系抗氧化酶活性对两种塑料地膜的敏感程度大于叶片。在高质量分数条件下,根系中超氧化物歧化酶（SOD）活性随暴露时间的延长明显受到了抑制。在经地膜1和地膜2处理后,小麦叶片中过氧化物酶（POD）及过氧化氢酶（CAT）活性在不同暴露时间和不同质量分数下没有显著差异,但地膜1处理后的小麦根系中的POD随暴露时间的延长呈先降低后增加的趋势,而CAT活性变化不大。地膜2处理后的小麦根系中的POD和CAT活性随暴露时间的延长而降低。结果表明,高质量分数塑料地膜的处理会对小麦早期幼苗的抗氧化酶系统产生毒害作用。     

Influence of pretreatment and desiccation on the germination of Laurus nobilis L. seeds

The effects of moist stratification, gibberellic acid (GA3) in combination with cold-moist stratification and desiccation on the germination of bay laurel (Laurus nobilis L.) seeds were studied. It was found that the external fleshy pericarp caused dormancy. There was also embryo dormancy and it was broken in seeds lacking pericarp either warm-moist stratification (20 degrees C day/4 degrees C night) or cold-moist stratification (4 degrees C) for 8 and 10 weeks, respectively. Gibberellic acid had little effect on germination percent and germination value of seeds without pericarp when used alone but significantly increased overall germination performance when used with cold-moist stratification. The viability of seeds dropped when the moisture content of the seeds was reduced by desiccation, and the time required to reach the critical moisture levels in the seeds differed in the different desiccation temperatures. The critical minimum seed moisture content for bay laurel was around 15% and the seeds showed the typical behavior of recalcitrant seeds.     

Impacts of crude oil on the germination and growth of cress seeds (Lepidium sp.) after bioremediation of agricultural soil polluted with crude petroleum using "adapted" Pseudomonas putida

The impacts of crude oil on the germination, growth and morphology of cress seeds (Lepidium sp.) after bioremediation of agricultural soil polluted with crude petroleum using "adapted" Pseudomonas putida (PP) were examined for 15 days. At day 15 there was 100% germination in the untreated control samples, the mean height of the seedlings was 75.8 +/- 2.6 mm and all appeared to have grown morphologically normal. In the experimental samples treated with oil and PP inoculation, there was 98% germination and the seedlings reached a height of 63.8 +/- 6.9 mm; again, morphologically the seedlings appeared normal. However, in the control samples treated with oil but without PP inoculation, there was 31-38% germination and seedling heights of 34.2 +/- 11.4-42.3 +/- 8.5 mm with abnormal morphology. Treatment of oil-impacted agricultural soil with PP as a bioremediation agent does produce soil which is capable of growing larger and healthier plants than where bioremediation has not taken place.     

部分菊科入侵种种子(瘦果)的萌发能力和幼苗建群特性

对入侵种种子生物学各方面的了解有助于更好地预测入侵趋势和评估可持续管理的策略.研究通过对部分菊科入侵种种子(瘦果)进行的室内萌发实验和土壤埋藏实验,通过与相关研究的对比和分析,对这些入侵种的萌发能力和幼苗建群特性进行了研究.10个入侵种种子室内萌发实验的结果表明,在25℃、12h光照的情况下,除钻形紫菀和一年蓬以外,被研究的其它8个种的终萌发率超过了50%,而且都显示出早期快速萌发的特点.用SPSS的曲线拟合工具对10个种的累积萌发趋势进行了曲线回归分析,对应的最佳模型均为三次曲线方程.不同土壤埋藏深度下幼苗出苗实验的结果表明,菊科8个入侵种的种子在表土的出苗率均最高,随着覆土厚度的增加,种子的出苗率逐渐降低,当覆土厚度超过3 cm以上时,所有种子均不能出苗.种子在不同的埋藏深度的出苗情况与种子的大小有关,较大种子破土能力相对较强;种子在不同的埋藏深度的出苗情况与种子本身的萌发能力也相关.土壤埋藏期限的实验结果表明,随埋藏时期的增加,小蓬草、苏门白酒草和一年蓬3个人侵种种子的活力逐步降低,在土壤中埋藏12个月后,其活力分别为21.34%、18.15%和27.38%.这些入侵种较广的种子萌发温度适应范围和高萌发率为防除工作带来了困难.在生产上,可通过不同时期的翻耕、将种子深埋等措施减少这些入侵种的危害.     

不同温度处理对金钟藤种子萌发的影响

主要研究了恒温25、28、30℃不同处理下温度对金钟藤种子荫发的影响，并采用发芽率、发芽指数、活力指数、芽长和胚根长等指标对金钟藤种子发芽效果进行了评价。结果表明，随着温度的升高，金钟膝种子发芽率、发芽指数、活力指数均上升。此外，随着温度的升高，芽和胚根出现不同的生长趋势，芽生长增加而根生长减少，进一步显示其地上部分受温度影响会加快生长，预示其入侵危害可能加剧。鉴于金钟膝日前在广州的危害情况，文章提出应将金钟滕列为潜在的入侵植物，加强研究，尽早开展预防和控制措施。     

Effect of cadmium on germination, coleoptile and root growth of barley seeds in the presence of gibberellic acid and kinetin

Effect of cadmium on barley seeds treated with kinetin and gibberellic acid was investigated. As usual, cadmium has inhibited seed germination, and showed important inhibitory effects on roots and coleoptile growth after germination. In general, increase in cadmium concentration caused a greater inhibition of germination, root and coleoptile growth. The adverse effect of cadmium on root and coleoptile growth was more pronounced than that on germination. While testa was pierced by radicle (an indication of germination), no root or coleoptile development was observed above at concentration of 3-9.5 mM CdCl2xH2O. Low concentrations of cadmium have inhibited the root growth more than it did on coleoptile growth. Treatment of seeds with gibberellic acid and kinetin did not show any significant difference on the effect of cadmium in germination. However, inhibition of coleoptile elongation by cadmium has decreased a very much after kinetin application. The same result, although with lower rates when compared to kinetin, has been obtained for GA3 as well. In addition, the inhibitory effect of cadmium on root growth increased even more after kinetin application. The results have been found statistically significant through the least significant different (LSD) test at levels ofp < 0.05 and p < 0.01.     

The influence of growth regulators on shoot proliferation and rooting of in vitro propagated caper

The objectives of this study were to examine the effect of TDZ and BAP on shoot proliferation and to develop a satisfactory rooting procedure for in vitro propagation of caper (Capparis spinosa L). TDZ was found to be more effective than BAP in shoot production. The highest shoot number per explant (45.7) was achieved on the media that contained 4.54 microM TDZ in the absence of IAA. TDZ at 4.54 microM alone or in combination with 0.57 microM IAA did not inhibit shoot elongation, although they produced the most shoots. Dipping the caper shoots in the solution of IBA at 24.6 microM for 10 minutes before planting on MS media, improved the rooting percentage up to 80.5% under a 16 hr photoperiod.     

4,4'-二氨基二苯基甲烷对浮萍(Lemna minor L.)毒性作用

以浮萍(Lemna minor L.)为受试生物,通过研究不同浓度(0、0.6、1.8、5.4、16.2和48.6 mg·L-1)的4,4'-二氨基二苯基甲烷(4,4'-methylenedianiline,MDA)对浮萍生长、叶绿素含量、PSⅡ最大光化学效应(Fv/Fm)、质膜透性及超氧化物歧化酶(SOD)、过氧化物...     

Effects of secondary current and stratification on suspension concentration in an open channel flow

In this work, a mathematical model on concentration distribution is developed for a steady, uniform open channel turbulent flow laden with sediments by incorporating the effect of secondary current through velocity distribution together with the stratification effect due to presence of sediments. The effect of particle-particle interaction at reference level and the effect of incipient motion probability, non-ceasing probability and pick-up probability of the sediment particles at reference concentration are taken into account. The proposed model is compared with the Rouse equation as well as verified with existing experimental data. Good agreement between computed value and experimental data indicates that secondary current influences the suspension of particles significantly. The direction and magnitude (strength) of secondary current lead to different patterns of concentration distribution and theoretical analysis shows that type II profile (where maximum concentration appears at significant height above channel bed surface) always corresponds to upward direction and greater magnitude of secondary current.     

Effects of gamma rays irradiation on seed germination and growth of hard wheat

The effects of irradiation with low doses (0, 10, 20 and 30 Gy) of radioactive cobalt (⁶⁰Co) γ rays on seed germination, shoot and epicotyl growth of hard wheat (Triticum durum Desf.) were investigated under laboratory and glasshouse conditions. Irradiated wheat seeds kept their germination speed and capacity levels compared to the control. However, improvements of +18 and +32% were, respectively obtained in root number and root length at the 20-Gy dose. Moreover, the 20-Gy-irradiation dose generated an increase of +33% in epicotyl length. The 20-Gy-irradiation dose improved the root length by +32% and root number by +75% in plants grown on liquid medium. A lower root length increase of +23% was obtained with the same treatment under glasshouse growing conditions. These results show that the in depth development stimulation of hard wheat roots following gamma ray treatment may be used for drought control.     

Allelopathic effect of four weed species extracts on germination, growth and protein in different varieties of Glycine max (L.) Merrill

Allelopathic effect of Ageratum conyzoides L., Cynodon dactylon (L.) Pers., Parthenium hysterophorus L., and Solanum nigrum L. were examined on seed germination, seedling growth, total protein content and protein profile on Ankur, Bhatt, Bragg, PK -416, PS-1042 and Shilajeet varieties of soybean (Glycine max (L) Merill). Aqueous extracts of weeds (10% w/v) showed both inhibitory and stimulatory influence on percent seed germination and seedling growth in different varieties of soybean. On the basis of per cent reduction in different parameters, the variety Bragg and PS-1042, and Shilajeet were resistant and susceptible respectively to different weed extracts, and among weed extracts, S. nigrum was most effective followed by P. hysterophorus compared to others. The total protein content (mg/g f wt.) in different varieties was increased with all the weed extracts except Bragg with C. dactylon and P. hysterophorus, PS-1042 with A. conyzoides and Shilajeet with C. dactylon, in which it was decreased. The protein banding pattern in different varieties not only differ between control and treatments but also among treatments. The order of susceptibility of different varieties with different weed extracts followed the order: Ankur > PK-416 > Bhatt > Shilajeet > Bragg and > PS-1042.     

Effects of different pretreatments on germination of Prunus serotina seed sources

Establishing intensive plantations of fast growing hardwood tree species that have high market values in the forest industry can narrow the gap between Turkey's demand and the supply of quality hardwood products. Black cherry (P. serotina Ehrh.) is a fast growing hardwood species with a high market value. Introducing and intensively growing black cherry (BC) in Turkey may significantly reduce the country's quality wood shortage. Adequate seed germination constitutes the first essential step for successful establishments. In this paper effects of different pretreatments, including artificial and natural stratification, on the seeds of different BC seed sources (SSs) were studied. Pretreatments had substantial effects on the dormancy breaking and germination behaviours of the SSs. Consecutive periods of complex warm and cold artificial stratification regimes longer than 90 days or natural stratification (where seeds were assumed to be naturally exposed to this complexity) resulted in best dormancy breaking and, in turn, germination among all pretreatments. Deeper dormancy and reduced germination rates of some BC seeds as the altitude of the source increases might suggest an ecological adaptive strategy of the species. BC may have deeper morphophysiological dormancy than is commonly believed. Seed size may have a positive effect on seed germination.     

模拟氮沉降对大豆萌发和幼苗生长的影响

氮沉降是当今倍受关注的全球性环境问题.采用大田试验和室内培养的方法,研究大豆种子萌发和幼苗生长对氮沉降的响应.实验设4组处理(CK、T1、T2、T3),所施氮肥为NH4NO3,在室内培养实验中,4组处理的浓度分别为0、0.08、0.16、0.24mol/L.大田实验中,4组处理的氮施入量分别为0,50,100,150 kg·hm-2·a-1.结果表明:过量氮沉降对种子萌发有一定的抑制作用,降低了种子的发芽速度和发芽率;抑制了幼苗的生长速度,降低了植株的株高、叶面积和生物量,并减小了根冠比;随着氮施入量的增加幼苗的蒸腾速率逐渐降低,但叶片叶绿素含量逐渐增加.     

氮磷钾肥配施对腰果植株抗寒力的影响

2008年3月1日调查海南省昌江县受严重寒害的4龄腰果无性系FL30 L9(34)氮磷钾肥配施试验果园,观察受寒害植株的主干树皮和各级分枝树皮保持青绿色或变褐色状.根据植株受寒害程度,分析氮磷钾肥配施对植株抗寒力的影响.测定受寒害植株的株高、冠幅,分析植株受寒害程度与植株大小的相关性.结果表明,氮磷钾肥对腰果植株抗寒力的影响顺序是磷肥＞钾肥＞氮肥;高氮(N 650 g·a-1·株-1)、中磷(P2O5 200 g·a-1·株-1)、中钾(K2O 250 g·a-1·株-1)的施肥水平,有利于提高植株抗寒力,植株受寒害程度低;植株受寒害程度分别与植株的株高、冠幅呈直线极显著负相关和显著负相关.     

麝香酮和镉单一与复合污染对金鱼藻的生态毒理效应研究

为从生物化学角度探讨一种新型污染物———麝香酮与镉(Cd)单一和复合污染的生态毒理效应,以金鱼藻(Ceratophyllum demersum L.)为研究对象,分析了不同浓度麝香酮和Cd在水中单一与复合污染对金鱼藻叶片中抗氧化系统酶,包括超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT),脂质过氧化最终产物丙二醛(MDA),可溶性蛋白(SP)和叶绿素含量的影响.结果表明:在单一麝香酮和Cd暴露下,SOD活性第1天均显著降低,而第7天在低浓度污染物的胁迫下呈升高趋势;金鱼藻受麝香酮和Cd胁迫的第1天,POD酶活性分别呈升高和降低趋势;麝香酮浓度为0.05mg·L-1或Cd浓度为0.01mg·L-1时,金鱼藻叶片中的CAT活性变化表现为显著的毒物兴奋作用;用两种污染物单一或复合处理第7天,金鱼藻叶片中的MDA和叶绿素含量可以作为评价麝香酮或/和Cd污染水体环境的敏感指标;SP在这两种污染物胁迫下处于能量及脂蛋白的补偿和应激蛋白的合成两方面的得失平衡过程中,故其含量与处理浓度之间无显著相关关系;复合污染中低浓度的麝香酮和Cd复合对金鱼藻表现为拮抗作用,高浓度的复合表现为相加或协同作用.     

UV-B辐射对2个水稻品种幼苗稻瘟病的影响及机理初探

通过盆栽试验研究增强UV-B辐射和稻瘟病菌(Magnaporthe grisea)联合作用对水稻(Oryza sativa L.)幼苗生长和病害的影响.试验采用4个UV-B辐射强度(0、2/5 kJ·m-2、5.0 kJ·m-2和7.5 kJ·m-2)和两个稻瘟病菌生理小种(Y98-16T和Y99-63C)对2个水稻品种(黄壳糯和合系41)进行处理,以及4个UV-B辐射强度对2个稻瘟病菌生理小种处理.测定水稻的株高、生物量和病情指数,以及稻瘟病菌菌落生长速率的变化.结果表明:(1)增强UV-B辐射7 d再接种稻瘟病菌处理与只接种稻瘟病菌处理相比,导致2个水稻品种病情指数显著降低,最大降幅为2.5 kJ·m-2-Y98-16T处理后的合系41,达83.5%,病害明显减轻.这可能是UV-.B辐射诱导水稻形态结构和生理生化发生一定的变化,抵御病害的能力加强.(2)先接种稻瘟病菌Y98-16T再进行不同的UV-B辐射与只接种稻瘟病菌的处理相比,黄壳糯和合系41的病情指数均显著升高,最大增幅为Y98-16T-7.5 kJ·m-2处理后的合系41,达53.7%,病害加剧,且利用UV-B直接辐射稻瘟病菌Y98-16T,其生长速率总体上呈显著增加.(3)接种稻瘟病菌Y99-63C后进行不同的UV-B辐射与只接种稻瘟病的处理相比,2个水稻品种的病情指数均没有显著变化,总体上,UV-B辐射对稻瘟病菌Y99-63C的生长速率没有影响.     

阿维菌素对意大利蜜蜂(Apis mellifera L.)的毒性影响

通过单次饲喂高浓度阿维菌素药液以及连续饲喂亚致死浓度阿维菌素药液进行意大利蜜蜂的经口染毒,从而探讨阿维菌素对意大利蜜蜂的急性及慢性毒性影响。结果表明,阿维菌素对意大利蜜蜂急性经口毒性48 h半数致死剂量(48 h-LD50)为0.00700μg a.i.·蜂-1,慢性经口毒性240 h每日半数致死剂量(240 h-LDD50)为0.000308μg a.i.·蜂-1·天-1。在亚致死效应方面,0.0233 mg a.i.·L-1和0.0467 mg a.i.·L-1处理组在168 h后摄食量出现明显的减少,说明阿维菌素中毒已经严重影响意大利蜜蜂的觅食和摄食能力。同时,由于摄食量的下降以及阿维菌素的毒性作用,造成了0.0467 mg a.i.·L-1处理组意大利蜜蜂体重的大幅度下降,试验前后的体重变化率达到-54.84%。意大利蜜蜂爬行能力的测定结果显示,各处理组的爬行通过率均低于对照组,特别是0.0117 mg a.i.·L-1处理组、0.0233 mg a.i.·L-1处理组和0.0467 mg a.i.·L-1处理组(P0.05)。综上所述,阿维菌素对意大利蜜蜂的急性经口毒性为高毒,较高剂量染毒会引起意大利蜜蜂的直接死亡;此外,长期接触较低浓度的阿维菌素,一方面会损害意大利蜜蜂的运动能力,如爬行、飞行能力的减弱;另一方面意大利蜜蜂生理方面也会遭到威胁,表现为摄食量下降、体重减轻,甚至死亡。因此,在施用该农药时应尽量避开蜜蜂栖息地,同时避免在蜜源植株花期时施用。