油橄榄实生苗与扦插苗生长特性比较

为了掌握不同育苗方式下1年生油橄榄苗木间的生长差异,对以油橄榄品种佛奥同一株成龄树的种子及枝条育成的1年生实生苗和扦插苗的生长特性进行了试验研究。结果表明:1)佛奥实生苗根(地下部)、茎、叶生物量的分配较为平均;佛奥扦插苗叶片生物量的积累最多,占其总生物量的36.45%,其根(地下部)的生物量次之,占其总生物量的34.73%,其茎的生物量最少,占其总生物量的28.82%,且其叶的生物量比其茎的生物量高出7.63%。2)实生苗的苗高同地径、根生物量均呈显著正相关,其地径同根生物量呈显著正相关;扦插苗的苗高和茎生物量、根生物量均呈显著正相关,其地径同茎生物量、根生物量亦均呈显著正相关。3)实生苗和扦插苗的地上部干质量、茎干质量、叶干质量,根干质量、根直径均呈极显著差异,其根总长、根体积、根表面积、根尖数均呈极显著差异,表明实生苗地上部长势旺盛,根系发达。4)实生苗和扦插苗的地上部生物量、叶生物量、茎生物量同其根(地下部)生物量间均呈正相关。     

荨麻叶龙头草花期器官生物量分配研究

选取处于花期的荨麻叶龙头草30株,对其根、茎、叶及花等器官生物量及其分配相关关系进行研究。结果表明:花期各器官生物量表现为根茎叶花,变异系数分别表现为19.38%、17.20%、31.34%;花生物量分配变异系数相对较大,说明其调节生殖分配能力较强。植株高度与各器官生物量呈正相关性,但不显著;根生物量分配与总生物量呈极显著正相关,茎叶及花生物量分配与总生物量均呈负相关,但花器官生物量分配不显著。花期各器官物质分配规律是:由营养器官(根)、支持器官(茎)、光合器官(叶)向生殖器官(花)转移,在林分郁闭后,其茎直接转换成茎状根,为下一年繁殖做好准备。说明其具有自我调节各器官生产力分配能力,对外界有较强适应性。     

盐胁迫对香菇草克隆生长及其钠、钾离子平衡的影响

选取长势一致的香菇草(Hydrocotyle vulgaris)为实验材料,在人工气候箱内,研究了盐胁迫下香菇草克隆生长及体内Na+、K+积累的特性,结果表明,当NaCl浓度3.0 g/L时,香菇草的生长显著受到抑制,在NaCl浓度为5.0 g/L时,香菇草各生长指标降低的百分率分别为花序数(87.06%)花序生物量(82.61%)叶生物量(59.26%)整株生物量(58.60%)叶片数(58.27%)根生物量(58.33%)匍匐茎生物量(51.22%)节间数(27.10%);在盐度为1.0~5.0 g/L,除了叶比重有显著波动以外,茎重比、根重比和花重比并没有明显变化,表明香菇草可以通过内在调节机制适应盐度的变化;根、茎和叶中的Na+、K+随着盐度的增加,分别表现上升和下降趋势,相关分析表明,根、茎和叶中的Na+、K+间分别呈现极显著负相关。     

盛花期一年蓬构件生物量分配特征

用统计分析方法,从构件水平研究了盛花期一年蓬种群各构件生物量结构特征、一些构件生物量之间的关系模型和各构件生物量与其他所测相关指标的关系模型,并进行定量分析。结果表明,一年蓬各构件生物量之间关系为茎>花序>叶>根。各构件生物量在个体生物量中所占的比率表现同样的关系。一年蓬花构件生物量与茎构件生物量之间显著地呈线性正相关,一年蓬比叶面积变异系数在各构件生物量变异系数中最小(24.45%)。一年蓬各构件生物量与其他所测指标在非线性模型中表现显著正相关。     

云南松幼苗生物量分配的家系效应

以云南松2年生幼苗为研究对象,对各组分生物量进行测定,研究不同家系云南松幼苗生物量分配规律。结果表明:不同家系云南松幼苗生物量分配比例均表现为叶茎根,叶生物量积累高于根、茎;不同家系间云南松幼苗各组分和单株生物量均存在极显著差异;地径与生物量之间呈极显著正相关,苗高与生物量之间成显著正相关,主根长与生物量正相关部分不显著。除叶含水率外,不同家系云南松幼苗各组分及单株的含水率存在显著差异。由此表明,不同家系云南松幼苗生物量分配模式差异明显。     

云南松苗木构件生物量的分配及其预估模型构建

为分析云南松苗木各构件生物量的分配及构建生物量模型,以3年生的云南松为材料,通过对其生物量的测定,分析了云南松苗木构件水平上生物量的分配情况,并基于生长量与生物量的关系构建了云南松苗木各构件生物量的预估模型。结果表明,3年生云南松苗木将较多的生物量分配到叶(40.631%)和茎(41.389%)上,而分配给根的生物量较少,其生长主要侧重于地上部分生长;各构件生物量间均存在极显著的线性正相关关系(P0.001);经相关分析发现,各构件生物量与地径、苗高均呈极显著的正向相关;并以D~2H为变量结合异速生长理论,拟合了云南松苗木根、茎、叶及全株生物量的预估模型:y_根=0.139(D~2H)~(0.755)、y_叶=0.209(D~2H)~(0.873)、y_茎=0.239(D~2H)~(0.849)和y_(全株)=0.631(D~2H)~(0.831)。     

栓皮栎不同种源苗期变异与初步选择

收集了栓皮栎分布区内25个种源种子,在肥西县花岗镇蔡冲村进行播种育苗试验,对其苗期生长性状、生物量进行测定分析。结果表明,栓皮栎苗高、地径生长均表现"S"形曲线,7—9月中旬为速生期;不同种源栓皮栎除根长存在显著差异外,苗高、地径、高径比、生物量均存在极显著差异;苗高与地径、茎、叶、总生物量呈极显著正相关,地径与根、茎、叶、总生物量也呈极显著正相关,根与茎、叶、总生物量同样呈极显著正相关。主成分分析表明,种源间的差异主要是由生物量和地径决定的。初步筛选出云南勐海、安徽东至、河南信阳、重庆酉阳、浙江杭州、安徽金寨2号、安徽绩溪7个优良种源。     

黧蒴栲芽苗截根移栽育苗及造林成效研究

为了提高黧蒴栲苗木质量和造林成活率,利用随机区组设计开展了黧蒴栲芽苗截根移栽、截根苗造林对比试验.结果表明：黧蒴栲芽苗截根处理对苗高、主根长、一级侧根数、叶干重、茎枝干重、根器官干重有极显著影响,对苗木地径、一级侧根长度有显著影响.芽苗截根处理后苗木高度增加17.51％、地径增加13.72％.不同剪叶处理方式对黧蒴栲苗木造林成活率有极显著影响,芽苗截根苗造林以剪叶75％效果最好,造林成活率达95.86％,而未剪叶苗造林成活率为57.69％;应用芽苗截根苗造林可提高造林成活率17.0％～24.0％,增加当年树高、地径生长量分别为18.22％、15.44％.     

2年生云南松实生苗生物量家系间变异研究

以20个云南松半同胞家系的2 a生实生苗为研究对象,对其生物量的累积与分配在家系层次的变异规律进行研究,以期为科学评价云南松苗木质量和提高遗传改良的潜在增益提供依据.结果表明,20个云南松半同胞家系2a生实生苗的生物量累积与分配指标,在家系间均达到显著或极显著水平的差异.根干重、茎干重、叶干重、地上干重、全株干重、根分...     

淡水培养对桐花树幼苗生长发育的影响

在广东梅州实验地全光照条件下用恒定淹水位淡水培养处理红树植物桐花树幼苗1年,以人工海水(盐度8 g·kg^-1)为对照,研究了淡水培养对桐花树幼苗生长发育的影响。结果表明:淡水组幼苗的茎高、基径、胚轴直径等指标显著低于人工海水组,而叶片数则极显著低于人工海水组,在胚轴高、分枝数、叶长、叶宽、叶长/叶宽、根长、根径、根数等指标上差异不显著;淡水组的叶面积比人工海水组大18.11%,差异显著。180天时,淡水组植株的根、茎、叶的生物量及总生物量与人工海水组的相比没有显著差异,但分别比人工海水组低12.50%、18.40%、16.48%、16.32%,两组植株的根、茎、叶生物量的大小均为:茎＞叶＞根;360天时,2组植株的根、茎、叶的生物量及总生物量间差异不显著,但淡水组比人工海水组分别低33.88%、17.48%、28.30%、26.51%,两组植株的根、茎、叶生物量的大小均为:叶＞茎＞根。种植1年后,两组桐花树幼苗的存活率都达90%以上,部分植株有花蕾出现且开花,其中,人工海水组植株先出现花蕾,而淡水组植株相对迟25 天出现花蕾,但淡水组出现花蕾的株数比人工海水组多33.82%。由此可见,淡水对桐花树幼苗大部分形态指标均有显著影响,但桐花树幼苗可以正常生长,且能够开花,表明桐花树对淡水环境具有较强的适应性。     

盐胁迫对楝树6个家系实生苗生长的影响

对楝树6个家系幼苗在0,2‰,4‰,6‰和8‰Na Cl单盐胁迫下的苗高、地径、根幅、主根长、根鲜质量、茎鲜质量、叶鲜质量、根干质量、茎干质量、叶干质量和总生物量等11个性状进行测定和分析表明,楝树6个供试家系之间耐盐能力存在差异,不同质量分数Na Cl单盐胁迫对同一家系的多个性状影响显著。上述11个性状有随Na Cl胁迫质量分数增大而降低的趋势,但各家系之间差异较大。根冠比则基本呈现出随Na Cl胁迫质量分数增大而增大的趋势。     

圆齿野鸦椿种子预处理和苗木生长规律及育苗技术研究

通过2年以上对圆齿野鸦椿的种子预处理、种子主要播种品质参数测定和对苗木的苗高、地径、主根长、大于5cmI级侧根数、根幅、冠幅、鲜叶重、鲜干枝重、鲜根重的测定,以及对苗木物候、苗木生长规律进行研究,从而得出圆齿野鸦椿的较为系统的育苗技术。     

Quantitative Genetic Variability in Picralima nitida (Stapf) from Seven Sources in Nigeria

Intraspecific variation in useful tree species is a requirement for any improvement program. Fruits of P. nitida were collected from seven different sources along its geographic range in Nigeria; metrical traits of seeds and resulting seedlings were assessed as well as the biomass. There were significant (p ≤ .05) differences in seed metrical traits of length, width, and weight. Seeds from J4 had the highest germination percentage of 95%, while Ore had the lowest percentage of 70. Highest mean values of 2.22 g, 3.11 cm, and 95 for weight, length, and number of seeds per pod, respectively, were obtained from Edo seeds. There were significant (p ≤ .05) differences in seedlings height, collar diameter, number of leaves, internodes, stem dry weight, root dry weight, leaf dry weight, total dry weight, and leaf area among the sources. The highest mean values of 4.33 cm (collar diameter), 2.31 cm (internodes length), were obtained from Edo collection. Other seedling traits and biomass indices were highest in J4 provenance. J4 seedlings had the highest average relative growth rate (RGR) values of 0.0450 gg^?1 wk^?1 while Etemi seedlings had the highest average net assimilation rate (NAR) value of 0.0063 g² wk^?1. J4 propagule had the best overall performance and is therefore recommended as a seed source for the improvement and conservation of Picralima nitida.     

黄皮树种源苗木性状遗传参数及其相关选择效率研究

对湖南省黄皮树１１个种源１年生苗木４个性状组２０个性状的遗传参数及其相关选择效率作了测定和分析。其结果表明：（１）４个性状组中，１７个性状在种源间存在显著差异，其中，生产力性状组的性状表型及遗传变异系数较大，而幼苗、复叶和地上生长性状组的表型及遗传变异较小；（２）地上生长性状间、生产力性状间及其相互间具有显著的表型相关和遗传相关，这为黄皮树地上与地下、生长与生产力性状间的相关选择提供了理论依据；（３）幼苗、生长及复叶性状组的性状遗传力较高，多在０．５以上，而生产力性状的遗传力相对较低，一般在０．４以下；（４）用苗高、柄高及地径３个性状，对苗皮质量和根总质量的间接选择效率高于直接选择。其中，用苗高选择苗皮质量和根总质量的选择效率分别提高１６．１％和６２．９％；用地径选择苗皮质量和根总质量的选择效率则分别提高２４．５％和１０３．８％。苗高和地径可作为黄皮树生产力性状苗期选择的主要指标。     

The Effects of Seed Mass on Germination, Seedling Emergence, and Early Seedling Growth of Eastern White Pine (Pinus strobus L.)

Half-sib seed of several eastern white pine (Pinus strobus L.) families was used to examine seed mass effects on laboratory germination, and seedling emergence and growth under moderate and low light (47 and 13% full sunlight) in a greenhouse. Percent germination and speed of germination under laboratory conditions were not related to seed mass among half-sib families or multi-family seedlots bulked by seed mass. Percent seedling emergence in the greenhouse was not related to seed mass, but families with heavier seeds exhibited faster emergence. Both rate and percent emergence were significantly increased under low light. Family differences in leaf, stem, root, and total seedling dry mass, primary root length, and the number of first-order-lateral-roots were positively related to seed mass in both light environments. Low light diminished the absolute biomass increment per unit seed mass, but the proportional change in biomass with seed mass was similar between light environments. Rate of emergence also influenced seedling size within families, with earlier emergence increasing seedling dry mass from 7 to 58%, dependent on light environment. Biomass partitioning coefficients were influenced by light environment but largely independent of seed mass.     

黄皮树种源苗木性状遗传参数及其相关选择效率研究

对湖南省黄皮树１１个种源１年生苗木４个性状组２０个性状的遗传参数及其相关选择效率作了测定和分析。其结果表明：（１）４个性状组中,１７个性状在种源间存在显著差异,其中,生产力性状组的性状表型及遗传变异系数较大,而幼苗、复叶和地上生长性状组的表型及遗传变异较小;（２）地上生长性状间、生产力性状间及其相互间具有显著的表型相关和遗传相关,这为黄皮树地上与地下、生长与生产力性状间的相关选择提供了理论依据;（     

不同播种密度对楸树砧木梓树幼苗的生长影响研究

对梓树3个种源当年生幼苗进行砧木培育,通过不同密度的播种和移栽,选出在天水地区以种源A最为适宜培育,播种移栽密度以19株/m2为宜,当年生苗木平均地径可达8.85 mm;苗木地径与平均侧根长、地上部鲜质量、地下部鲜质量、地上部干质量、地下部干质量呈正相关性,与苗高、叶数、根数、主根长无显著相关性;各种源苗木生物量与平均侧根长呈正相关,与主根长无显著相关性。     

Interacting effects of irradiance and water stress on dry weight and biomass partitioning in Fagus sylvatica seedlings

Abstract

Actual climate models for central Europe predict prolonged summer droughts. Knowledge on how the interaction between light and water availability affects regeneration will hence be of major importance. In an experiment carried out under controlled conditions, newly emerged beech seedlings were grown in pots with sand during 54 days. Three treatments applying three different light levels (2, 9 and 43% relative light intensity) were combined with two soil water treatments (control and drought). At the end of the experiment, seedlings were separated into leaves, stem and root and the seedlings’ dry mass, leaf area and stem length was determined. Low irradiance (2%) had a strong negative effect on dry weights of seedling components, leaf area and specific leaf mass. Drought clearly affected biomass partitioning for seedlings at high irradiance levels (43%). An interaction between irradiance and drought on biomass partitioning in beech seedlings was observed at medium irradiance level (9%). Within a wide range of light levels in the forests, both light and drought may affect biomass partitioning in young seedlings.     

Biomass distribution in 40-year-old trees of Japanese black pine

Measurements were carried out to survey the quantity of above- and below-ground biomass and its distribution of five Japanese black pines (Pinus thunbergii Parl.) growing on a sandy soil. The roots, divided into diameter groups, were surveyed using two methods—soil coring and excavation. Average dry weight of total biomass of the trees was 176,185 g. Roots represented 13.2%, below-ground stump 6.5%, stem 70.4% and branches with needles 9.9% of total biomass. Roots made up about two thirds and stump one third of below-ground biomass. Total length of below-ground biomass (except roots with diameter < 0.1 cm) was 479.1 m/tree. Roots with diameter of 0.1–0.2 cm represented only 0.7% of below-ground biomass, however as much as 49.9% of their total length. Roots with diameter over 10.0 cm constituted as much as 21.6% of below-ground biomass, however were only 0.3% of its total length. Root systems had well developed tap roots to maximal depth of 231 cm. The results indicated that mass and length of roots with diameter 0.5–2.0 cm had a close correlation with branch mass. Mass and length of roots with diameter 2.0–10.0 cm closely correlated to stem mass. Stem mass, root mass and root length closely correlated to DBH. A rather low correlation was found between DBH and mass of branches and below-ground stump. DBH was a suitable variable for predicting total biomass.