云南甜龙竹和黄竹种子灭菌条件和萌发特性初步研究

目的]筛选云南甜龙竹和黄竹种子最佳表面灭菌条件,研究其萌发特性。[方法]筛选NaClO(2%、3%、4%)与HgCl_2(0.01%、0.1%)最佳消毒浓度组合;采用流水冲洗时间(6、12、18 h)、2%NaClO浸泡时间(5、10、15 min)和0.1%Hg Cl_2浸泡时间(5、10、15 min),设计正交试验实验,探讨2种竹种最佳表面灭菌处理的时间组合,并对竹种分别在滤纸、MS培养基以及经3 mg·L~(-1)GA_3浸泡后在MS培养基上的发芽率进行了探讨。[结果]NaClO、Hg Cl_2最佳消毒浓度组合为2%NaClO+0.1%HgCl_2;2种竹种最佳表面灭菌时间组合均为:流水冲洗6 h、2%Na Cl O浸泡10min、0.1%HgCl_2浸泡15 min,经此处理后云南甜龙竹和黄竹的发芽率分别为84.4%、72.2%,污染率分别为18.7%、29.6%。不同处理种子萌发率差异t检验结果显示:2种竹子种子是否经过3 mg·L~(-1)GA_3浸泡,对其在MS培养基上的发芽率无显著影响,但种子在MS培养基上的发芽率显著高于滤纸上的发芽率。经相同处理黄竹的发芽率均低于云南甜龙竹。[结论]云南甜龙竹、黄竹最佳表面灭菌组合均为:流水冲洗6 h、2%NaClO浸泡10 min、0.1%HgCl_2浸泡15 min;3 mg·L~(-1)GA_3浸泡处理对云南甜龙竹和黄竹种子在MS培养基上的发芽率无显著影响,但MS培养基上种子的发芽率显著高于其在滤纸上的发芽率。     

不同基质对三种樟科植物种子萌发及幼苗生长的影响

以河沙、草木灰、锯末配成的三种栽培基质为试验材料,以黑壳楠、楠木、闽楠为供试品种,采用露天播种育苗的方式,研究不同基质对三种樟科植物种子的萌发、幼苗生长情况的影响.结果表明:黑壳楠在河沙中的发芽率、发芽指数最高,幼苗生长情况最好;楠木和闽楠在河沙+草木灰的基质中萌发情况和幼苗生长情况最好.     

低温对油桐种子萌发和幼苗生长的影响

油桐种子和幼苗在低温下内部生理生化过程发生明显变化。随着温度的下降和胁迫时间的延长,其K+外渗率明显增加,细胞TTC还原率显著下降,超氧物歧化酶活性和抗坏血酸含量下降,膜脂过氧化产物丙二醛含量增加,过氧化氢酶、过氧化物酶和抗坏血酸氧化酶活性也发生明显变化。低温下,油桐幼苗叶片叶绿素含量下降,光合作用明显降低。冷害初期,幼苗呼吸即有增强的表现,特别是从低温转入暖温后呼吸速率大大增加,随着冷害的发展,呼吸又明显下降;冻害则使幼苗呼吸逐渐降低,但从低温转入暖温后仍出现呼吸高峰。不同品种或不同器官对低温的反应不同。外源脱落酸和抗坏血酸预处理能明显地提高油桐幼苗抗冷性。     

光照条件对旱冬瓜种子萌发和幼苗生长的影响

种子萌发及幼苗光合实验的结果表明，早冬瓜种子具有需光萌发的特性，黑暗中即使种子处在适于萌发的温度和水分条件下，种子仍保持休眠状态，需接受光照刺激才能解除休眠而萌发，故播种育苗时种子不宜盖土。早冬瓜幼苗生长的初期光补偿点为12μmo1／m^2s，光饱和点为1000μmo1／m^2s，具有一定的耐阴能力，适宜在50％遮荫条件下生长。随着月龄的增加，耐阴能力下降。6月龄苗光合补偿点上升到21μmo1／m^2s，光饱和点超过2000μmol/m^2s，只有在全光照的条件下才能生长良好，遮荫会降低幼苗高生长量和基径粗生长量。晴天，早冬瓜幼苗光合作用存在“午睡现象”，当植株处于缺水状态时，光合作用的“午睡现象”会更加强烈。表明早冬瓜适宜种植在次生裸地或撂荒地，种植后应及时除草进行透光抚育。     

储藏方式对五角枫种子萌发及幼苗生长的影响

为研究不同储藏条件下五角枫种子的活力,开展4种储藏方式对五角枫种子萌发影响的育苗试验,结果表明:储藏方式显著影响了五角枫种子的发芽率.常温混沙湿藏和低温混沙湿藏皆能有效地打破种子休眠,缩短种子的始萌发时间,其中低温湿沙储藏种子的发芽率最高,为53.2％.埋藏深度对五角枫种子的出苗率有显著影响,出苗率随埋藏深度的增加而下...     

不同浓度铅处理对草本种子萌发及幼苗生长影响

以紫花苜蓿、菊苣、黑麦草为试材,通过不同浓度铅处理,了解其对种子萌发、幼苗生长的影响。结果表明,随着铅浓度的增加,植物种子的发芽率、发芽势在低浓度时略有升高,高浓度时明显下降,平均发芽时间延长,幼苗胚根(根系)、胚轴(地上部分)的生长受到阻滞,生物量减少。     

大果沙棘种子萌发和幼苗生长实验

经测定,俄罗斯大果沙棘丘依斯克(Hippophae rhamnoides)种子的千粒重为17.75 g,与其它沙棘属的种子相比,其千粒重较大,为其2倍左右。在水、气适宜的条件下,主要研究了温度分别为15℃、20℃、25℃、30℃和光照强度分别为25%、50%、75%、100%状态下的不同处理对丘依斯克种子萌发的影响,并根据胚根生长量和全株生物量对沙棘种子发芽效果进行了评价,提出了沙棘种子发芽的最适温度和光强。结果表明,在25℃条件下,种子萌发最早,发芽势高达33.0±4.76%,发芽率高达95.5±1.5%,且主根生长量和生物量最大,分别为4.5±0.09 cm和0.137±0.002 g;75%光强最适合沙棘种子萌发,种子萌发最早,发芽势高达61.5±1.7%,发芽率高达86.0±1.1%,且主根生长量和生物量最大,分别为3.7±0.2 cm和0.108±0.004 g。因此,在直播营造大果沙棘防护林时,建议首选25℃的温度条件,同时,建议进行适度遮荫处理,在获得优质苗木的同时,降低蒸发量。     

培养基成分对梨花粉萌发和花粉管生长的影响

以黄冠梨花粉为试材,研究了不同蔗糖浓度,不同硼酸浓度和不同硝酸钙浓度对黄冠梨花粉萌发和花粉管生长的影响。结果表明：花粉萌发和花粉管生长的适宜蔗糖浓度为100g/L,硼酸浓度为100mg／L,硝酸钙浓度为300mg／L。     

香草醛对樟子松种子萌发与幼苗生长的影响

为了了解土壤中香草醛等酚类有毒化感物质对樟子松种子和幼苗的影响,文中采用不同浓度的香草醛溶液对樟子松种子进行发芽试验和樟子松幼苗生长试验。结果表明:不同浓度的香草醛溶液对樟子松种子萌发和幼苗生长都产生了影响,而且表现为低促高抑的效应,其中香草醛浓度为10mmol.L-1的溶液对樟子松胚根和幼茎生长的抑制作用达到了极显著水平。     

Effect of growing media on seed germination and vigor in biofuel tree species

To evaluate laboratory germination media, seed germi- nation rates and methodology for both Jatropha curcas and Pongamia pinnata were counted in different germination medium, such as river sand, quartz sand and vermiculite. The seeds of both species were sown at 2-cm depth of river sand, quartz sand and vermiculite. We evaluated methodologies of seeds of J. curcas and P. pinnata by ISTA （Interna- tional Seed Testing Association）. The results showed that river sand is the best medium for tree seeds planted at 2-cm depth of River sand. Vermiculite was second best. On paper media, there were many abnor- mal seedlings and this media were unsuitable for germination of the larger seeds.     

Improving seed germination and seedling growth of Omphalea oleifera (Euphorbiaceae) for restoration projects in tropical rain forests

To improve the restoration of tropical rain forests, we tested the germination of seeds of Omphalea oleifera collected from soil (S) and from trees (T) in the 2001 dry season (Spring), at the beginning of a dry season (2005a, winter) and in the rainy season (2005b, winter). All seeds had high water content (WC, 31–33%), and the lipid content varied from 14 to 46%. Seedlings from seeds collected in 2001 were subjected to moderate water stress as a preconditioning treatment for severe stress. T-seeds collected in the dry season had high WC, rapid and high germination percentage; S and T-seeds collected in winter (2005) had also high WC but were dormant. GA₃ (250 ppm) broke this dormancy. S-seeds collected in the dry season or at the beginning of it had relatively low WC and low and delayed germination. Some 2001 S-seeds produced albino seedlings. The critical water content for maintaining ecological longevity in these seeds was ∼15%. Seeds collected in 2005b that were dehydrated for 20 days in a moist and fresh atmosphere lost their viability, showing recalcitrant behavior. T-seeds with the lowest lipid content (2005a) after dehydration maintained low germination (15 ± 18%). In all samples the seed size varied widely and was not predictive of seed WC. Embryos taken from dehydrated seeds had two to four times higher WC than the seeds, but germination did not take place. Laboratory and field germination of dormant seeds showed that viability may be maintained for at least 2–3 months on a moist substrate (soil or agar). Moderate water stress at the seedling stage reduced the efficiency of biomass production. Response to this water stress was expressed more in physiological traits than in morphological characters, consequently biomass allocation was maintained and plants retained most of their morphological characteristics (root:shoot ratio, leaf area ratio, specific leaf area, leaf weight ratio). Moderate water stress did not increase the tolerance of seedlings to severe stress, causing leaf shedding and plant death. For restoration purposes we recommend that T-seeds be germinated immediately avoiding dehydration. The use of S-seeds could result in unhealthy seedlings. Seed recalcitrance and the response to moderate water stress restrict germination and establishment to small gaps, where this species naturally grows. We suggest that before introducing O. oleifera in restoration programs, a plant cover should be built to reduce soil water deficit. It is necessary to improve methods to increase potential seed longevity in storage.     

Differentiation of seed germination and early seedling growth in ten provenances ofEucalyptus microtheca

An investigation of seed germination and early seedling growth ofEucalyptus microtheca was based on seed collection from 10 widely separated provenances in Australia. Genetic variation of seed germination and early seedling growth was observed among a series of provenances whose natural habitats range from different climatic condition. In the ten provenances, both the model of seed relative germination percentage and the model of seed total germination percentage fitted Logistic regression [y=a/(1+exp(-ex+b))]. In comparison with provenances from four high temperature (mean annual maximum temperature >30.0 °C; mean annual minimum temperature >17.0 °C) areas, six low temperature (mean annual maximum temperature <30.0 °C; mean annual minimum temperature <17.0 °C) areas showed the fast germination rate and the high total germination percentage. For each provenance we have 45 seedlings equally divided into three watering levels (100%, 50%, and 25% of field capacity), and studies on relationship between early seedling growth and climatic factors of the natural habitat of provenance. In control treatment, height growth of the seedling has been associated with intrinsically the driest quarter precipitation in the seed collection areas of provenance. In all the treatments, length growth of the biggest leaf of the seedling was related to mean annual maximum temperature and mean annual minimum temperature in origin of provenance. In contrast, basal diameter growth of the seedling was related to mean annual minimum temperature of the seed collection areas in water stress treatment. From an ecological viewpoint, the fast germination rate and the high total germination percentage of the seed and rapid early growth of the seedling appear to be favourable adaptations to the climatic conditions prevailing in the natural habitat of provenance. Responsible Editor: Chai Ruihai     

植物延绿节水复壮剂对桑树种子发芽和育苗的影响

植物延绿节水复壮剂是由一种保持和改善植物营养、土壤物理、化学性质及生物活性的复合材料组成的产品。其具有吸水性、保湿性和促进植物生长的显著特点,具有包衣剂曲作用。用植物延绿节水复壮剂包衣桑树种子的试验结果表明,包衣桑树种子后提高了其萌发率和出苗率,改善了苗木出圃质量。     

植物激素对薄壳山核桃种子萌发及幼苗生长的影响

为给薄壳山核桃育苗技术及苗木生产提供理论依据,以薄壳山核桃种子为试材,GA3、IBA、IAA、NAA和6-BA分别设50、100、150、200、250 mg/L的5个质量浓度水平浸种7 d后播种于沙床中,50 d后对发芽数、虫害数、霉烂数和90 d后对地径、苗高、根径、根长、须根数、叶数进行调查和综合比较分析。5种外源植物激素处理中,发芽率最高的是IAA100 mg/L(98%),其次是IBA250 mg/L(93.3%),NAA250 mg/L、6-BA100 mg/L和GA3250 mg/L处理的发芽率均为90%。NAA 150 mg/L处理的幼苗最高,达15.1 cm;地径生长值最大的处理是GA350 mg/L,达0.31 cm;GA3150 mg/L根径最大,达0.49 cm;NAA 100 mg/L处理主根最长,达25.5 cm;6-BA 50 mg/L处理须根数最多,为53根;IAA 250 mg/L、6-BA 50 mg/L叶片数最多,有6片。薄壳山核桃种子经外源植物激素浸泡后出芽率有明显的提高,各处理发芽率均高于对照。GA3影响幼苗地上部和地下部的粗生长,中低质量浓度的NAA有利于主根的长生长,6-BA有利于侧根的分生。IBA对幼苗苗高的影响较大。     

不同基质和覆盖处理对杜鹃种子萌芽及成苗的影响

为获得高效的杜鹃育苗方法,以杜鹃花‘紫鹤’和‘粉鹤’自交种子为试材,研究了不同基质和覆盖处理对杜鹃花种子萌发、成苗和实生苗形态建成的影响。研究结果表明:以未发酵的玉米秸秆粉末作为播种基质不能使杜鹃花种子发芽和形成实生苗;以园土与干苔藓混合物和园土与棉籽壳混合物作为播种基质仅有少量种子发芽,不利于实生苗的生长;以蛭石和蛭石与干苔藓混合物作为播种基质的杜鹃发芽率和成苗率分别可达到65.33%~81.33%和62.67%~78.67%,但不利于杜鹃花实生苗的形态建成;以草炭和草炭与干苔藓的混合物作为播种基质能显著促进杜鹃花种子的萌发和成苗形成,且杜鹃花实生苗生长发育健壮;覆盖处理则降低了杜鹃花种子的发芽率。     

Effect of salt stress on germination and seedling growth of Prosopis juliflora (Sw.)

The present study was conducted to evaluate the effect of different concentrations of salts on seed germination and seedling growth of Prosopis juliflora. The experiment was carried out in Forestry Laboratory at Sari Agricultural Sciences and Natural Resources University, Iran. The collected seeds were treated with boiling water and H₂SO₄ then left to germinate in controlled growth chamber. Seed were grown under salinity levels 100, 200 and 300 mM of CaCl₂, NaH₂PO₄, KNO₃ and KH₂PO₄. Germination parameters and various seedling growth variables such as root and stem length, seedlings fresh and dry weight were measured after 56 days. Results showed that germination percentage significantly decreased as the salinity level of medium increased. Salinity treatments at 100 mM enhanced the percentage of seeds germination and significantly improved the germination index and seeds stamina. In this study, the best treatment was 100 mM salinity for biomass production of seedlings. For Prosopis juliflora, 100 mM salinity significantly enhanced both germination and biomass production.     

Seed germination of Albizia procera (Roxb.) Benth. in Bangladesh: a basis for seed source variation and pre-sowing treatment effect

An experiment in seed morphology and seed germination techniques of Albizia procera was carried out in the nursery of the Forestry and Wood Technology Discipline,Khulna University,Bangladesh in order to discover the source variation in seeds and pre-sowing treatment effects on seed germination.Mature seeds of A.procera were collected from healthy trees in home garden plantations from five different districts in Bangladesh and treated with four pre-sowing treatments,i.e.,control,immersion in cold water (4°C for 24 h)and immersion in hot water(80°C for 10 min and 100°C for 1 min).The average length,width and thickness of seeds were calculated as 0.502±0.485,0.420±0.060 and 0.191±0.118 cm,respectively.Germination was conducted in poly-bags with a mixture of topsoil and cow dung in a ratio of 3:1.The results revealed that pre-sowing treatments affected the rate of germination of seeds,which significantly increased the germination percentages of seeds in hot water treatments compared with those in control (60.60%)and the cold water treatment(4°C for 24 h,63.53%).The highest germination success was 82.07%in the treatment of immersion in hot water(80°C)for 10 min,followed by 79.00%in immersion in hot water(100°C)for 1 min.Germination started 4 to 6 days after seed sowing and completed in a period of 22 to 25 days in all treatments.ANOVAs showed statistically significant differences(p0.05)in seed germination starting dates,closing dates,germination percentages and rates of germination among treatments,but no significant differences in seed germination starting dates,closing dates,germination period,germination percentages and rates of germination among the seed sources.The study also revealed that the interaction between seed source variation and treatment effect significantly differed in seed germination starting dates,closing dates,germination percentages and rates of germination. The hot water(100°C for 1 min)treatment is recommended for seed germination of A.procera in rural Bangladesh.     

不同处理对菘蓝种子萌发及幼苗生长的影响

试验采用室内培养法,研究了不同浓度的硝酸钾(KNO3)、高锰酸钾(KMnO4)、赤霉素(GA3)、聚乙二醇(PEG)对菘蓝种子萌发及幼苗生长的影响,以探讨促进其种子萌发及幼苗生长的有效途径,为菘蓝的规模化栽培及生产提供理论依据。结果表明:与对照相比,2g/L KNO3处理的幼苗根长提高61.35%,10g/L KMnO4处理的幼苗保水力提高81.58%,3种浓度GA3处理幼苗根系活力分别提高17.88%、21.85%、13.82%,0.2g/L GA3处理使种子发芽势和发芽率分别提高38.90%、79.18%,幼苗鲜重和苗长分别提高84.38%、24.24%;3种浓度PEG处理的幼苗根系活力分别提高14.08%、19.32%、13.57%,鲜重分别提高75.00%、106.25%、87.50%,200g/L PEG、300g/L PEG处理的种子发芽率分别提高68.15%、46.93%。综上所述,以GA3溶液处理效果最好,其中,以0.2g/L GA3处理效果最佳,能显著提高种子发芽率及发芽势,促进幼苗生长。