片段化生境中木本植物种子大小对幼苗存活的影响

以千岛湖29个样岛木本植物的种子与幼苗为研究对象,分析了种子大小与种子数量的相关性,以及岛屿参数、地形因素和土壤养分含量如何影响种子大小并作用于幼苗早期存活。结果显示:(1)物种间种子大小与种子数量存在权衡关系;(2)种子大小对幼苗半年存活率无显著正效应,但坡向朝东、土壤碳含量低增加了种子大小对幼苗存活率的正效应,而夏季对大种子幼苗的不利影响大于小种子幼苗;(3)幼苗高度和土壤磷含量对幼苗半年存活率有正效应,而幼苗所在岛屿与最近岛屿的距离对幼苗存活率有负效应。本研究结果表明,千岛湖片段化生境中种子大小和生境因素共同影响幼苗早期存活,小尺度的生境异质性增强种子大小的作用,从而影响森林更新和群落构建。     

土壤质地和种子成熟度对水翁种子发芽和幼苗生长的影响

文章研究了不同土壤质地、种子成熟度和果肉对水翁Syzygium nervosum种子发芽和幼苗生长的影响,结果表明:不同质地的土壤对水翁种子的最终发芽率影响不大,但对种子发芽的速度和幼苗的株高有显著影响,种子发芽速度为砂土壤土砂壤土,幼苗株高为砂土砂壤土壤土;种子的成熟度对种子的发芽率和幼苗的株高有显著影响,幼苗株高为成熟种子未成熟种子过熟种子;果肉对种子的发芽率和幼苗的株高影响不大,但对早期发芽的速度有影响。     

丝葵种子和胚萌发特性的研究

通过对丝葵种子和胚的人工培养,揭示了其萌发特征。结果表明:丝葵是正常型种子,干燥后可长期低温保存,种子和胚的发芽率高达95%和93%,真菌感染并未影响种子的萌发。胚萌发早于种子萌发,二者平均萌发时间(MGT)分别为6.8天和8.7天。胚和胚幼苗的含水量大于种子和种子幼苗,但是种子幼苗无论在质量、长度还是侧根数等方面均优于胚幼苗,说明种子幼苗生命活力更强,环境适应性更好。     

紫茎泽兰植株不同部位及浓度的水提液对蓝桉种子萌发和幼苗生长的化感效应

为探讨紫茎泽兰不同部位水提液对蓝桉的化感作用,用紫茎泽兰植株的鲜叶、花、枯叶、茎和根的不同浓度水提液对蓝桉种子进行处理.结果表明,花和鲜叶水提液对蓝桉种子的萌发和幼苗生长的抑制作用远大于枯叶、茎和根的水提液.浓度为0.067 g/mL时,对花和鲜叶的水提液来说,几乎是蓝桉种子萌发和幼苗生长的致死浓度,此浓度的枯叶、茎和根水提液对蓝桉种子萌发和幼苗生长有很强的抑制作用,导致发芽量明显下降及幼苗在形态上发生明显变形;浓度为0.020 g/mL时,花和鲜叶水提液对蓝桉种子萌发及幼苗生长仍有很强的抑制作用,表现在发芽量明显下降及幼苗明显变形,而枯叶、茎和根水提液对蓝桉种子萌发和幼苗生长的抑制作用明显下降,甚至有促进作用,幼苗变形已大为减轻.浓度为0.005 g/mL时,不同部位的水提液对蓝桉种子萌发及幼苗生长的抑制作用进一步下降,而促进作用增强,幼苗已能正常生长.     

不同剂量~(60)Co-γ射线对凤丹种子生根、出苗及幼苗生长的影响

以凤丹(油用牡丹)的干种子、湿沙层积的湿种子为辐射诱变材料,通过不同剂量60Co-γ射线照射处理,研究对种子生根、幼苗生长及幼苗变异情况的影响。结果表明:凤丹干、湿种子的生根率、主根长度≥4 cm种子的百分率、须根的比率均表现为低剂量促进、高剂量抑制的趋势。低剂量辐射处理干、湿种子,均表现为初萌期提前,出苗指数和出苗率提高;随着剂量增加,初萌期延迟,出苗指数和出苗率降低。根据出苗率计算出凤丹干、湿种子的半致死辐射剂量分别为18.94 Gy和9.51 Gy。干种子中低辐射剂量(10 Gy)处理的苗高与对照无显著差异;当辐射剂量超过20 Gy时,苗高随辐射剂量的增大而降低。各处理幼苗的茎粗与对照均无显著差异。辐射对湿种子幼苗高度的影响与干种子相似,但湿种子耐辐射能力稍差,辐射超过6 Gy,苗高即显著低于对照;而较高辐射处理(10—20Gy)的湿种子幼苗茎粗显著低于对照。干、湿种子的幼苗变异率均表现为随辐射剂量加大逐渐增大的趋势。60Co-γ射线对凤丹幼苗的诱变效应主要表现为小叶退化和叶色变化,且随辐射剂量增大,幼苗也会出现叶片畸形、叶尖枯萎、茎徒长等畸变。     

沙区樟子松幼苗培育技术

文章通过对樟子松种子、幼苗生物学特性的大量观测实践和研究,总结出樟子松种子处理、幼苗培育和病虫害防治的育苗技术。     

华山姜浸提液对杉木种子萌发及幼苗生长的影响

为探讨杉木林下种植华山姜潜在的化感作用，采用水浸提法，用华山姜不同器官、不同浓度浸提液进行杉木种子发芽试验，比较不同处理对杉木种子萌发和幼苗生长指标的影响。结果表明：华山姜果实浸提液对杉木种子萌发和幼苗生长指标均表现出低促高抑的规律；干叶片浸提液对杉木种子萌发和幼苗生长指标均表现出抑制作用；新鲜叶片浸提液对杉木种子萌发和幼苗生长指标均无显著影响；根浸提液对杉木种子发芽率和发芽指数及幼苗叶片生长有促进作用，对幼苗茎生长有抑制作用，对幼苗根生长影响不显著。表明华山姜不同器官浸提液中具有化感活性物质，杉木林下种植华山姜时，需及时清理枯落叶、防止果实过度脱落并及时采摘。     

油茶水浸液对桔梗种子的化感效应

以蕲春出产的桔梗种子为材料,研究了不同浓度油茶水浸液对桔梗种子萌发和幼苗生长的影响.结果表明:油茶水浸液可以在一定程度上促进桔梗种子的萌发和幼苗的生长.油茶水浸液对桔梗种子萌发的化感促进作用随着浓度的增加逐渐减弱,甚至表现为抑制作用.在较低浓度范围内油茶水浸液对桔梗幼苗根、茎生长均表现为促进作用,最适于桔梗种子萌发和幼苗生长的油茶水浸液浓度为0.010 g/mL.     

沙棘种子检验幼苗率与质量分级试验初步研究

对沙棘种子进行幼苗率检验试验,将结果通过一元线性回归分析得出:Ⅰ级沙棘种子发芽率与幼苗率对比差平均为5%,幼苗率≥75%;Ⅱ级沙棘种子发芽率与幼苗率对比差为6.4%,幼苗率65%～74%;Ⅲ级沙棘种子发芽率与幼苗率对比差为7.35%,幼苗率54%～63%.     

不同处理对蒙古扁桃种子吸水及幼苗生长影响

通过对蒙古扁桃种子吸水过程、幼苗生长的观测,拟合了种子的吸水模型,分析了幼苗生物量的差异.结果表明:蒙古扁桃种子吸水过程适合对数函数曲线模型,吸水率分别适合幂函数、对数函数曲线模型;50℃温水处理水平可以有效地提高带内果皮种子的吸水量和吸水速度,不带内果皮种子经过温水处理后9 h、吸水量为6.3%时种子吸水量即基本达到饱和;种子在1 h内能够大量吸水,适应荒漠强降雨环境;内果皮能够吸收一定的水分,在环境干旱时可以减轻环境干旱造成的种子失水;幼苗地上部分生物量大于地下部分,带内果皮种子育苗能够有效地增加幼苗高度和根系长度.     

Temporal allocation of (14)C to extramatrical hyphae of ectomycorrhizal ponderosa pine seedlings

Ponderosa pine seedlings were inoculated with Hebeloma crustuliniforme either in growth pouches before they were transplanted to root-mycocosms (P seedlings), or at the time of transfer to root-mycocosms (V seedlings). Uninoculated seedlings served as controls (U seedlings). The use of root-mycocosms allowed examination of portions of hyphae separate from roots and rooting substrate but still in symbiosis with the host. The results thus provided a quantitative basis for estimating hyphal mass and carbon allocation to extramatrical hyphae. The amount of (14)CO(2) fixed after a 2-h exposure was greatest for P seedlings and least for uninoculated seedlings. Four and nine days after exposure, (14)C content was greatest in uninoculated seedlings and least in inoculated seedlings. In isotope distribution and dry mass accumulation, V seedlings were more similar to U than to P seedlings. Calculated on a dry weight basis, the allocation of isotope to mycelium suggested that extramatrical hyphae of P seedlings were a stronger sink for carbon than extramatrical hyphae of V seedlings. Differences in inoculation methods resulted in differences in carbon allocation and physiology of extramatrical hyphae that could affect seedling establishment and survival. Seedlings inoculated by one method cannot serve as surrogates for mycorrhizal seedlings produced by other inoculation techniques.     

Stock-type patterns of phosphorus uptake,retranslocation, net photosynthesis and morphological development in interior spruce seedlings

One-year-old interior spruce (Picea glauca (Moench) Voss × Picea engelmannii Parry) spring-stock and summer-stock were grown under two phosphorus (P) fertility regimes, with (+P) or without (–P), followed by a simulated winter, and a second growing period under an adequate fertility regime in a controlled environment room. The two stock-types differed in their response to low P availability. For spring-stock, morphological development, phosphorus-use efficiency (PUE) and P specific absorption rate (SAR) were similar between –P and +P seedlings. For summer-stock, –P seedlings compared to +P seedlings had lower (p 0.05) morphological development, but greater PUE and SAR. For both stock-types, P content increased in +P seedlings, remained low in –P seedlings, and P concentration decreased in nursery-needles (i.e., formed in the nursery) of –P seedlings. The difference in stock-type response to low phosphorus availability (–P) was attributed to internal supply of P and it's retranslocation. Assimilation (A) of CO₂ in nursery-needles was similar between –P and +P seedlings for both stock-types. For spring-stock, +P seedlings had greater A in new-needles (i.e., needles formed during the trial) than –P seedlings. It was recommended that the spring-stock be selected over summer-stock for sites low in P availability.     

沙地海岸松在山东和浙江引种试验研究

通过对引种沙地海岸松的育苗和造林试验研究,结果表明:在沙地海岸松第一年幼苗期生长中,播种密度对其影响不大,而适度遮荫(80%透光率)有利于海岸松幼苗的生长。沙地海岸松在养分含量高、偏酸性土壤中生长占优势,且在温州地区育苗及造林后的高与地径生长均显著高于蓬莱地区。海岸松容器苗的造林成活率显著高于裸根苗;不同海岸带造林后,其生长速度在海阳市最快,其次是莱州市和烟台市。     

铝对马尾松菌根苗生长及营养元素吸收的影响

以接种褐环乳牛肝菌和未接种的马尾松幼苗为试验材料,采用水培法研究不同浓度铝(Al^3+)处理(0、0.2、0.4、0.8和1.2 mmol·L^-1)对菌根化和非菌根化马尾松幼苗生长、营养元素吸收的影响,揭示菌根化马尾松苗木对Al^3+的适应机制,为减轻马尾松苗木铝毒害现象提供理论和技术依据。结果表明,在相同浓度Al^3+胁迫下,接种褐环乳牛肝菌的马尾松幼苗苗高、生物量、根系形态以及对氮(N)、磷(P)、钾(K)的吸收能力均优于不接种的马尾松苗。马尾松幼苗苗高、干物质量积累以及根系生长随着Al^3+浓度的增大均呈现先升后降再升的趋势,随着Al^3+浓度的逐渐增大,马尾松幼苗根、茎、叶中的N、P、K含量呈现出低促高抑的趋势,根、茎、叶中Al^3+含量的分配为根>茎>叶。Al^3+胁迫下,接种褐环乳牛肝菌的马尾松幼苗,通过改变马尾松幼苗根系结构,促进了幼苗的生长,特别是根系的生长,以及对N、P、K等营养元素的吸收,抑制了根系吸收Al^3+,提高了马尾松幼苗的耐铝能力。     

Growth and nutrition of nonmycorrhizal and mycorrhizal pitch pine (Pinus rigida) seedlings under phosphorus limitation

The association of ectomycorrhizal fungi with tree roots enhances the acquisition of phosphorus (P) from the soil. In addition to increasing the uptake of H(2)PO(4) (-) (P(i)), mycorrhizal fungi may increase the spectrum of P sources utilized by tree roots by mediating the dissolution of insoluble metallophosphate salts or the hydrolysis of organic P compounds. To investigate the role of ectomycorrhizal fungi in enhancing P acquisition by tree roots, pitch pine (Pinus rigida Mill.) seedlings were grown in sand culture with or without the ectomycorrhizal symbiont Pisolithus tinctorius Coker and Couch under various conditions of P limitation. Compared with nonmycorrhizal seedlings, seedlings inoculated with P. tinctorius exhibited a greater capacity to function under P limitation as evidenced by superior growth and the maintenance of normal foliar ion composition at low P(i) concentrations. Nonmycorrhizal seedlings subjected to P-limiting conditions exhibited depressed K and P and elevated Na concentrations in foliage. The association of P. tinctorius with pitch pine seedling roots maintained foliar K concentrations and prevented the accumulation of Na under P limitation. Nonmycorrhizal seedlings were unable to obtain P from either solid AlPO(4) or inositol hexaphosphate (IHP), whereas seedlings inoculated with P. tinctorius utilized AlPO(4), but not IHP as a P source. Root surface acid phosphatase (APase) activity was depressed in roots infected with the mycorrhizal symbiont and was negatively correlated with seedling growth on all P sources. Root APase activity was negatively correlated with foliar P concentrations in seedlings grown on P(i), but was not correlated with foliar P concentrations in seedlings cultured with AlPO(4) or IHP.     

云南松不同部位氮、磷、钾储量分配及异速生长研究

为更好进行云南松苗木培育,提升云南松苗木质量,通过对2年生云南松苗木生长性状及不同部位氮（N）、磷（P）、钾（K）储量进行统计以及相关性、异速生长分析,研究云南松氮、磷、钾储量。结果表明,云南松幼苗生长2年后,其地下部位氮、磷、钾分配大小依次为钾储量＞氮储量＞磷储量;氮、磷、钾在土壤中的分配比例为氮储量＞磷储量＞钾储量;地上部位氮、磷、钾储量占单株氮、磷、钾储量的比例为钾储量＞磷储量＞氮储量;磷和钾在地下部位的累积速率大于地上部位的累积速率。以期为云南松苗木培育提供理论参考,为实际生产提供一定理论依据。     

Synergistic effects between Suilllus luteus and Trichoderma virens on growth of Korean spruce seedlings and drought resistance of Scotch pine seedlings

Korean spruce(Picea koraiensis Sieb. El Zucc.)is one of the main afforestation species in northern China.Seedling quality is a critical factor at planting time. To test whether the synergistic growth enhancement of Scotch pine(P. sylvestris var. mongolica) seedlings brought by the plant beneficial fungus Trichoderma virens(J.H. Mill., Giddens and A.A. Foster) Arx and ectomycorrhizal fungus(Suillus luteus(L.) Roussel.) can also benefit Korean spruce seedlings, we examined the effects of S. luteus and T. virens on the growth of P. koraiensis seedlings and drought resistance of P. sylvestris var. mongolica in peat soils. The two fungi were added to sterilized peat soil in pots, and the plants were grown for 4 months. Seedling growth and physiological variables, including mycorrhizal colonization rate of roots,biomass, and chlorophyll content, were examined. The colonization rate of the mycorrhizal fungus on P. koraiensis exceeded 65 %, and the synergism between S. luteus and T.virens enhanced most of the variables for P. koraiensis seedlings after inoculation with S. luteus then 30 days later with T. virens as in our published results for seedlings of P.sylvestris var. mongolica. When seedlings of P. sylvestris var. mongolica were inoculated with this sequence, they became more drought tolerant. T. virens also induced S.luteus to produce-1,3-glucanase and chitinase. This inoculation sequence at planting can thus improve the quality of P. sylvestris var. mongolica and P. koraiensis seedlings and substantiates our previous results.     

赤松幼苗接种菌根真菌生长效应的初步研究

以赤松幼苗接种松茸菌进行盆栽和圃地栽培试验,研究菌根菌感染数量和菌根菌对苗木生长效应的影响。结果表明:在盆栽条件下,三种处理根系菌根真菌的感染指数分别为80、50、3,截根接种和不截根接种分别为对照的26.7倍和16.7倍,且截根处理是不截根的1.6倍;幼苗苗高、地径生长量显著提高,干重比对照分别增加33.3%和18.5%。在圃地条件下,截根接种与不截根接种的幼苗苗高、地径生长量比对照分别提高5.4%、4.2%和14.9%、6.9%。     

Early developmental responses of mountain birch (Betula pubescens subsp. czerepanovii) seedlings to different concentrations of phosphorus

Phenolic compounds, identified by high performance liquid chromatography (HPLC), and growth were investigated in the first true leaves, cotyledons, stems and roots of 2.5-week-old seedlings of mountain birch (Betula pubescens subsp. czerepanovii (Orlova) H?metahti) grown with 1.5, 15 and 50 ppm phosphorus (P). Phenolic compounds in seeds and unfertilized 6-day-old seedlings were also studied. Seeds contained few phenolics, but had an abundance of condensed tannins. There were fewer HPLC phenolic compounds in 6-day-old seedlings than in 2.5-week-old seedlings. In 2.5-week-old seedlings, growth of the first true leaves, but not of other plant parts, was affected by P regime. In the first true leaves and stems, the concentration of condensed tannins was significantly affected by P, being higher at 1.5 ppm than at higher concentrations. The concentration of total HPLC phenolics was significantly affected by P only in stems.