PEG处理对连香树种子萌发与芽苗生长的影响

以连香树种子为试验材料,研究不同质量浓度PEG对种子萌发的影响.结果表明:适宜质量浓度(140～301 g·L-1)的PEG预处理连香树种子,能促进种子萌发和芽苗生长,增加渗透凋节物质如可溶性蛋白、可溶性糖和脯氨酸的含量,提高保护性酶SOD,POD和CAT的活性,降低MDA含量,修复膜系统损伤,提高其抗旱性.在干旱胁迫下,伴随PEG质量浓度的增加,连香树种子萌发和幼苗生长受到抑制,可溶性蛋白含量先升高后降低,可溶性糖、脯氨酸和MDA含量升高,保护性酶SOD和CAT的活性升高及POD活性下降.连香树对干旱胁迫较为敏感,PEG质量浓度≥95 g·L-1对种子萌发、芽苗胚轴和胚根生长产生抑制作用.     

山合欢种子超干燥贮藏的生理生化效应

采用正交设计从种子含水量、包装方法、保存温度和预回湿方法4个因素来探索山合欢种子超干燥保存的可行性。用硅胶将种子脱水至1.42%～6.35%6个含水量梯度,结合不同处理密封保存1年,随后测定发芽率和一些生理生化指标,包括相对电导率(RC)、脯氨酸(Pro)、丙二醛(MDA)、超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、可溶性总糖含量和脂肪酸组分。结果表明:种子含水量和预回湿方法对发芽率有显著影响,超干种子与未经超干处理的种子相比,发芽率有明显提高;超干种子发芽率与相对电导率和丙二醛含量呈显著负相关,与脯氨酸含量和3种抗氧化酶活性呈显著正相关;超干种子的油酸和α-亚麻酸含量比对照提高。适宜的超干处理能使抗氧化酶活性增强,使不饱和脂肪酸和可溶性总糖的含量增加,从而减缓种子生活力下降。     

Nursery practice on seed germination and seedling growth of <Emphasis Type="Italic">Dalbergia sissoo</Emphasis> using beneficial microbial inoculants

Nursery practice using microbial inoculants was performed to find out the efficacy of the inoculants on seed germination and seedling growth of sissoo (Dalbergia sissoo Roxb.). Microbial inoculants or effective microorganisms (EM) are a mixture of many different beneficial microorganisms in a solution. The seedlings were grown in a mixture of sandy soil and cowdung (3:1) kept in polybags with pouring EM solution at different concentrations (0.1%, 0.5%, 1%, 2%, 5% and 10%) before and after a week of sowing the seeds. Seed germination rate and growth parameters of seedlings were measured, such as, shoot and root length, vigor index, fresh and dry weight of shoot and root and total biomass increment. The nodulation status influenced by EM was also observed along with the measurement of pigment contents in leaves. The highest germination rate (69%) was observed in 2% EM treatment, followed by 67% and 65% in 1% and 5% EM. The highest shoot length (33.2 cm) was in 2% EM, whereas highest root length (26.3 cm) was in 1% EM. Both fresh and dry weights from shoot and root, were maximum (4.16 g and 1.57 g; 2.12 g and 0.83 g respectively) in 2% EM and were significantly (p ≤ 0.05) different from control. Vigor index was highest (4071) in 2% EM, which was significantly (p ≤ 0.05) different from control. Total dry weight increment was highest in 2% EM treatment, followed by 1% and 5% concentrations of EM. Nodulation number was higher at very low (0.1%) concentration of EM solution but it normally decreased with the increase of EM concentrations. The contents of chlorophyll a, chlorophyll b and carotenoid were highest (60.11, 17.05 and 42.48 mg·L⁻¹ respectively) in 2% EM treatment and lowest (39.35, 13.55 and 27.29 mg·L⁻¹ respectively) in control treatment. Therefore, low concentration of EM (up to 2%) can be used for getting maximum seed germination rate and seedling development of Dalbergia sissoo Roxb.     

毛豹皮樟苗木耐涝性评价指标筛选

对毛豹皮樟4个品种在人为水涝胁迫下测定其叶片的可溶性蛋白、丙二醛(MDA)、可溶性糖、SOD、叶绿素含量,结果表明:涝害处理对SOD有显著影响,对叶绿素有极显著影响;品种对SOD有显著影响,对MDA有极显著影响;涝害和品种对可溶性糖与可溶性蛋白均没有显著影响,而对SOD则有显著影响。经主成分分析SOD与耐涝性有较好的相关性(R2=0.99563),SOD对毛豹皮樟耐涝性评价经检验精度都在98%以上。因此SOD可以作为毛豹皮樟耐涝性评价指标。     

微量元素对油松苗生长的影响

于年间在哈尔滨园林研究所苗圃,用不同的微量元素和不同浓度浸泡种子和喷洒苗木进行了微量元素对油松苗木生长刺激作用的实验。实验结果表明,用1%和02%浓度的Mn浸泡的种子发芽效果最好,与对照组相比,1%浓度Mn处理的种子发芽率提高了9%~19%,0.2%浓度Mn处理的种子发芽率提高了12%-14%。用硼处理的种子的发芽率最低。对用微量元素施表肥(叶部喷洒)而言,Mn和Mo微量元素效果较好,且低浓度处理效果更好。用低浓度Mn和Mo喷洒的苗木的高度和叶绿素含量均比未处理的苗木高。与种子浸泡法相比,叶部喷洒的效果更好。表7参7。     

外源IAA对油茶芽苗砧嵌合体愈合的效应

以油茶芽苗砧嵌合体为试验材料,用IAA 100、200、300 mg.L-1浸泡接穗20 min,以清水浸泡为对照(CK),研究外源IAA对油茶芽苗砧嵌合体死亡率、叶绿素相对含量(SPAD值)、可溶性糖、可溶性蛋白和保护性酶等生理指标的影响。结果表明:经外源IAA处理的嫁接苗死亡率低于对照,其中以IAA 300 mg.L-1处理效果最好。在愈合过程中,叶片的叶绿素相对含量呈增长的趋势,IAA 200、300 mg.L-1处理的叶绿素相对含量增加的速度比对照快。经外源IAA处理后,油茶嫁接苗叶片的可溶性糖和可溶性蛋白含量变幅比对照大;超氧化物歧化酶(SOD)活性高于对照;超氧化物酶(POD)活性比对照提前出现双峰;愈合前期多酚氧化酶(PPO)活性小于对照,愈合后期高浓度外源IAA处理的则大于对照。相关分析表明,可溶性糖含量、SPAD值、PPO和SOD活性是通过影响可溶性蛋白含量而影响嫁接苗的愈合。采用外源IAA处理油茶芽苗砧嵌合体的接穗,操作简单,效果良好,丰富了油茶苗木繁殖技术。     

铅(Pb2+)和镉(Cd2+)对火炬树种子萌发及幼苗生长的影响

【目的】研究不同浓度重金属铅(Pb^2+)和镉(Cd^2+)对火炬树Rhus typhina种子萌发及幼苗生长的影响,探索火炬树对重金属铅、镉胁迫的耐受程度及机理。【方法】采用培养皿滤纸发芽法,分别用不同浓度Pb^2+(300、600、900、1200、1500 mmol/L)、Cd^2+(140、280、420、560、700 mmol/L)溶液处理火炬树种子,测定种子发芽率、发芽指数、幼苗胚根长和茎长、硫代巴比妥酸(TBARS)含量、可溶性蛋白含量、超氧化物歧化酶(SOD)活性及过氧化物酶(POD)活性。【结果】与对照相比,不同浓度Pb^2+、Cd^2+均对火炬树种子的发芽率、发芽指数和幼苗生长有抑制作用,但低浓度Pb^2+可促进根长和芽长的伸长。随着Pb^2+和Cd^2+溶液浓度的增加,幼苗叶片中SOD活性和可溶性蛋白含量表现为先增加后降低,POD活性和TBARS含量均逐渐升高。其中,Cd^2+浓度为700 mmol/L时,发芽率、发芽指数、芽长和SOD活性达到最低值,而TBARS含量最高;Pb^2+浓度为1500 mmol/L时,根长达到最低值,POD活性达到最高值;Pb^2+浓度为600 mmol/L时,可溶性蛋白含量最高。【结论】Pb^2+浓度为300 mmol/L时会抑制火炬树种子萌发,但会促进幼苗生长,其余浓度Pb^2+、Cd^2+胁迫下,火炬树种子与幼苗受到一定影响,但是均较好完成了萌发与幼苗生长,并表现出多种积极的适应性特征,未出现无根苗现象,火炬树较其他木本植物对铅、镉2种重金属表现出更强的耐性。本试验结果可为今后选用火炬树作为重金属污染土壤的植物修复材料提供理论参考。     

Culling phenotypically inferior trees in seed production area enhances seed and seedling quality of <Emphasis Type="Italic">Acacia auriculiformis</Emphasis>

Improvement in seed and seedling quality of Acacia auriculiformis after culling phenotypically inferior trees was studied in a 6-year old seed production area (SPA). A 5-ha plantation was identified, of which 2.3 ha was converted into SPA. The initial stocking, 1 612 trees·ha⁻¹, was thinned down to 982 trees·ha⁻¹ based on growth characteristics. The following fruiting season, seeds were collected from 10 randomly selected trees in culled and non-culled stands, and seed physical characters, germination and seedling traits were assessed. Seed weight, seed thickness and percentage germination increased by 32.1%, 4.43% and 22.37%, respectively in the culled stand compared to the non-culled stand. Culling also increased the speed of germination, seedling dry weight and seedling vigor index. Heritability values were high for seed weight (0.974) and seed thickness (0.948) while medium values were observed for percentage germination (0.577) and total dry weight (0.534). Predicted genetic gain was 11.13% and 11.22% for seed weight and percentage germination, respectively. The actual gain was 32.1, 51.9 and 22.9% for seed weight, percentage germination and total dry matter, respectively. In conclusion, SPAs established by culling inferior trees could serve as sources of good quality seeds for reforestation programs until genetically improved seeds are made available.     

野生欧洲李种子萌发特性

为了掌握野生欧洲李种子萌发特性,探讨野生欧洲李实生繁殖规律,以新疆野生欧洲李为研究对象,观察种子形态,测定种子千粒质量、种皮透水性、种子含水量、种子活力,测定种子浸提液对白菜种子发芽和胚根生长抑制活性的影响。结果表明:新疆野生欧洲李种子的种皮透水性比较差;种子含水量为30.57%;TTC法检测种子活力为81.67%;4℃低温沙藏层积的野生欧洲李种子,在处理后90 d种子出现萌发,持续层积200 d后总萌发率为47%;种子各部分浸提液对白菜种子发芽率作用不明显,但对胚根生长有明显的抑制作用,随着浸提液浓度增长,对白菜种子发芽抑制活性越强,其胚根长度越短;随着野生欧洲李层积天数的增加,浸提液处理的白菜种子胚根长度增加;野生欧洲李种子各部分浸提物对白菜种子发芽抑制活性顺序为:种胚最强,种皮次之,种壳最弱。     

遮阴处理对华北落叶松幼苗生长的影响

对2年生落叶松幼苗进行不同的遮阴处理,测定华北落叶松叶片内可溶性糖、蛋白质、叶绿素的含量,结果表明：伴随着遮阴程度的增加,可溶性糖与蛋白质含量相应减少。与此同时,为了保护光合作用的正常进行,叶绿素b的含量逐渐增多。华北落叶松幼苗在生长过程中需要充足的光照,但适度的遮阴可促进光合作用的高效进行。     

不同处理对神黄豆种子发芽的影响

用剪刀剪、锉子锉、与瓜子石混搓等机械处理法以及用5%氢氧化钾、98%浓硫酸等化学处理法对神黄豆种子进行预处理,3倍种子体积沸水浸泡并自然冷却浸种48 h,观察并统计种子吸胀粒数、种皮破裂数后置床进行发芽测定。结果表明,除与瓜子石混搓处理外,其余处理均能促进种子吸水膨胀,显著提高神黄豆种子发芽率。其中以98%浓硫酸浸泡2 h处理效果最好,其吸胀率达98.0%、发芽率最高,达88.3%,吸胀破皮率、不正常发芽率均为0%;其次是锉子锉处理效果好,其吸胀率达99.0%,发芽率可达84.7%,吸胀破皮率、不正常发芽率均为0%;用5%氢氧化钾进行浸泡处理,对种子发芽有一定的促进作用,但发芽不整齐,发芽速度慢,处理14 d吸胀率为59.7%、发芽率最高为48.0%;与瓜子石混搓处理效果相对较差,对神黄豆种子发芽的促进作用不明显,吸胀率为5.0%、发芽率为5.0%。     

Effect of different pre-sowing seed treatments on the germination of <Emphasis Type="Italic">Leucaena leucocephala</Emphasis> (Lam.) and <Emphasis Type="Italic">Acacia farnesiana</Emphasis> (L.)

Leucaena leucocephala and Acacia farnesiana are tree species used for several agricultural purposes in the Mediterranean region. The seeds of these species exhibit dormancy, causing delayed germination. Two experiments were conducted to investigate the effect of pre-sowing treatments (scarification, hot water, or soaking) on seed germination of L. leucocephala and A. farnesiana. In one experiment, seeds were exposed to three pre-sowing treatments: control, sandpaper scarification, or soaking in 70°C water for 4, 8, 12, 16, 20, or 24 min. In another experiment, seeds were soaked in 70°C water for 20 min, and then soaked in water at room temperature for an additional 24, 48, or 72 h or blade scarified. In general, soaking the seeds of the two species in hot water was more effective in breaking seed dormancy than scarification. Sandpaper scarification was not effective for either species. Blade scarification increased A. farnesiana seed germination to 56%, indicating that seed dormancy was mainly a consequence of hardseededness. L. leucocephala seeds collected from Jordan University of Science and Technology (JUST) site and soaked in 70°C water for 20 min and then soaked for 24, 48, or 72 h had germination rates above 97%. Our results suggest that blade scarification of A. farnesiana seeds and soaking of L. leucocephala seeds in 70°C water for 20 min are effective treatments to break seed dormancy and enhance seed germination of these vital species.     

Optimal germination condition by sulfuric acid pretreatment to improve seed germination of Sabina vulgaris Ant.

Understanding the germination traits of plants is important not only for understanding natural regeneration processes but also for developing seedling production techniques for planting. Sabina vulgaris Ant. is a common species used for reforestation in semi-arid areas of the Mu-Us Desert, in Inner Mongolia, China, but its extremely low germination rate, both in situ and in vivo, is a bottleneck for seedling production. Sulfuric acid pretreatment was applied to improve germination, and the germination rate was compared for different soaking time (10, 30, 60, 90, and 120 min), different temperatures (10, 15, 20, 30, and 35°C) and under different lighting conditions (dark and light). Sulfuric acid treatment gave a high germination rate, reaching 60% at 30 days after sowing. However, the non-treated seeds produced no germination. The optimal treatment time in sulfuric acid was 120 min. Germination after sulfuric acid treatment increased at incubation temperatures from 10 to 30°C, but decreased at 35°C. Incubation at 25–30°C gave maximum germination of more than 50%. Light treatment had little effect on germination. Pretreatment with sulfuric acid improved water absorption by the embryo by creating cracks and cavities in the seed coat tissue. These results indicated that S. vulgaris seeds have physical dormancy caused by their hard seed coats, which prevents absorption of water into the embryo. A combination of pretreatment with sulfuric acid and incubation at 25–30°C was most effective in improving the germination of S. vulgaris seeds.     

Variation in seed traits and seedling vigour of <Emphasis Type="Italic">Cordia africana</Emphasis> Lam. provenances in Ethiopia

Cordia africana is a very important indigenous tree species for timber and other products and services in Ethiopia. Seed traits and seedling vigour of seeds from 12 provenances of the species were compared. Mean seed mass for each provenance was assessed for 1000 seeds in 10 replications, and seed length and width were measured for 100 seeds in four replications per provenance. Germination was assessed in a glasshouse taking 400 seeds from each provenance. Root collar diameter and height of 440 seedlings grown in a nursery for 290 days in Addis Ababa were measured. Seed length, seed width, seed mass, and shoot height and root collar diameter of seedlings showed significant differences (P < 0.001) among provenances. Correlation analysis between seed and seedling traits and environmental variables revealed significant positive correlations between seed width and germination percentage, seed width and altitude, seed width and longitude and seed length and latitude. Negative correlations were obtained between seed width and temperature, seed width and rainfall, seed mass and temperature, and germination and temperature of the seed source. As expected, differences in seed trait did not explain the variability in seedling vigour. Determining quantitative variations in seed traits and seedling vigour among provenances and the patterns along environmental gradients are essential for informing decisions on the tree improvement programme of the species.     

Effects of tallowtree seed coat on seed germination

We measured physiological parameters including water uptake, in-vitro embryo germination ratio, and seed coat structure observed by scanning electron microscopy (SEM) to explore the influence of seed coat on the germination of seeds of tallow tree (Sapium sebiferum (Linn) Roxb.). Tallow tree seeds had good water permeability. We found that germination of cabbage seeds was inhibited when cabbage seeds were soaked in extracted solutions from tallow tree seed coat. Seed coat structure at the side of the radicle appeared to be a barrier to seed germination. We tested methods to break tallow tree seed dormancy. Dormancy of tallow tree seeds was overcome by soaking the seeds in 500 mg·L-1 or 1000 mg·L-1 GA3, followed by 100 days of cold stratification.     

自然脱水过程中七叶树种子生理特性的变化

于 2003 年研究了自然脱水过程中七叶树种子生理特性的变化。结果表明:七叶树种子对脱水高度敏感,为顽拗性种子。种子成熟采收时含水量高达 60.3%,种子在室温下自然干燥 30 天后,含水量下降到 30.2%,此时种子生活力完全丧失。在脱水初期,种子发芽率有所上升,但随后种子发芽率迅速降低。随着含水量的下降,种子浸出液相对电导率上升,但当含水量在 53.7% 到 50.9%之间时,种子浸出液相对电导率出现异常升高。同时种子超氧化物歧化酶(SOD)的活性随脱水时间的延长而下降,只有种子含水量在 53.7% 到 50.9%之间时出现例外。丙二醛(MDA)含量在脱水初期缓慢上升,在含水量下降到低于 50.9%时,丙二醛(MDA)含量快速上升。可溶性糖含量随脱水时间的延长缓慢上升。当种子含水量为 47%–60%时,种子发芽率较高,说明这一含水量区间有利于种子生活力的保持。图 6 参 13。     

6号ABT生根粉在云南松育苗上应用的试验

应用６号ＡＢＴ生根粉进行云南松育苗试验。用浓度２０ｍｇ／Ｌ的６号ＡＢＴ生根粉浸种３ｈ后播种,出苗后分别用浓度为２０ｍｇ／Ｌ和３０ｍｇ／Ｌ的该溶液喷叶。结果显示,浸种处理后能提高云南松种子的出苗率,缩短育苗时间;在浸种处理的基础上喷叶能使苗木根系生长量显著增加,苗高生长量也有一定程度的提高。其中,以用２０ｍｇ／Ｌ浓度的６号ＡＢＴ生根粉溶液浸种３ｈ,出苗后再用浓度为３０ｍｇ／Ｌ的该溶液喷叶效果最佳,与对照相比,苗根生长量提高３４４％,侧根条数增加４０２％,苗高生长量提高１５２％。     

盐胁迫对木瓜种子萌发和幼苗生长的影响

以MS培养基培养木瓜种子,观察研究在不同的NaCl浓度胁迫下,木瓜种子萌发和幼苗生长的状况.结果表明:随着NaCl浓度的增加,木瓜种子萌发率逐渐降低,幼苗根系活力下降;叶绿素含量、SOD酶活性以及POD酶活性逐渐升高,但当培养基中NaCl浓度过高时,以上3个指标开始下降;MDA含量与NaCl浓度有关,随着NaCl浓度的增加,MDA含量逐渐增加,但均小于对照.     

花梨木引种试验播种育苗技术研究

对花梨木进行播种育苗试验,研究播种时不同的种子处理方法、不同的播种时间对花梨木发芽、成活及苗木生长量的影响,结果表明,采用温水浸种和冬季播种可提高种子发芽率,冬播种子的平均发芽率达32%;花梨木冬播苗1年生平均苗高120 cm,平均地径0.5 cm,分别是春播苗的1.33倍和1.43倍。因此,花梨木进行播种育苗采用温水浸种和冬季播种,苗木的生长要好于春播苗。为今后花梨木的播种育苗提供参考。     

胡枝子属种子萌发特性试验

以8个种子样品(种、种源)的胡枝子种子进行热水处理、浓硫酸酸蚀处理,探索破除种子硬实促进萌发的适合方法。结果表明:胡枝子种子千粒质量越小则硬实率越高,浓硫酸酸蚀处理较热水浸泡处理能显著提高胡枝子种子发芽率与发芽整齐度。应根据种子大小确定种子酸蚀处理时间,分别为小粒种子(截叶胡枝子)适合处理时间为10 min以下、中粒种子(中华胡枝子、达乌里胡枝子、多花胡枝子)为10～15 min、大粒种子(二色胡枝子、美丽胡枝子)15～20 min。