杉木种子园子代林测试结果

<正> 树木良种选育是按表型进行选择,而表型是受遗传和环境因素共同作用的结果,因此,仅根据表型的优劣来评定其遗传的好坏是困难的。为了确定表型的性状是遗传基础的作用,还是环境因素的影响及这种作用的强度就必须进行子代测定,这是选择育种的中心环节。现将我省第二批杉木初级种子园自由授粉子代多点测试结果初报如下。一、材料和方法参试的种子来自临安横畈林场、丽水地区林科所、景宁林业总场、庆元县林场和龙泉县林科所等5个单位的杉木初级种子园,共59个家系,分别以当地混杂商品种子为对照。供试种子由省林科所统一进行播种品质检验。1981年在龙泉、丽水、开化、昌化、景宁     

红豆树优树子代遗传多样性及与生长相关性分析

[目的]研究红豆树优树自由授粉子代遗传多样性及其对生长的影响,比较天然居群子代和孤立木子代遗传多样性差异,揭示子代遗传多样性的变化规律及天然居群在子代遗传多样性维持中的作用,为红豆树遗传保育和优异种质挖掘提供科学依据。[方法]以来自浙、闽、赣、川等26个红豆树优树自由授粉家系为研究对象,利用11对SSR引物对765个子代群体进行遗传多样性评价,同时分析子代遗传多样性参数与种子、生长性状的相关性。[结果](1)红豆树优树子代群体具有较高的遗传多样性,有效等位基因数为7.766个,观测杂合度(H_O)和期望杂合度(H_E)分别为0.469和0.865。(2)除SSR8外,其余位点的观测杂合度均小于期望杂合度,表明子代群体绝大多数位点处于杂合子缺失状态。(3)红豆树不同家系的遗传多样性存在明显差异,12号家系的遗传多样性水平最高,8号家系则最低。(4)比较发现,天然居群子代的遗传多样性显著或极显著地高于孤立木子代。(5)F统计量和分子方差分析(AMOVA)均表明,红豆树优树子代群体的遗传变异主要存在于家系内,家系间的遗传分化相对较小。(6)相关性分析发现,子代遗传多样性参数与种子性状、子代年高生长量呈显著正相关(r=0.378~0.527)。[结论]较大的红豆树天然居群在维持其子代较高遗传多样性中发挥了重要作用,子代遗传多样性显著影响苗木生长,这为红豆树遗传保育和优良家系选择提供了理论依据。     

首批杉木种子园生产的自由授粉种子的子代鉴定

<正> 杉木优树表型性状是遗传和环境因素共同作用的结果,要评定其遗传品质的优劣,并估算主要性状的遗传力和遗传相关,达到优中选优目的,必须进行优树子代鉴定。我们从1980年开始,分批进行了子代鉴定工作。现将第一批5个种子园中的48个自由授粉子代苗期及3年生幼林鉴定结果简介如下:     

杉木优树后代测验初报

杉木优树是按表现型进行选择的。表现型是遗传基础和环境条件互相作用的结果。因此,必须进行后代测定,籍以鉴定其遗传品质,以选出一般配合力高的优良个体。后代测定我们用优树自由授粉种子和人工控制授粉的种子。现将几年来工作情况汇报如下。     

小粒林木种子检验方法

林木种子品质检验又叫品质鉴定。种子品质包括遗传品质和播种品质两个方面。遗传品质不能从种子的外部形状来判断,我们通常所说的种子品质检验,就是指播种品质的检验。     

“土贡松”母树林种子品质与遗传多样性初步分析

种子品质及遗传多样性是评价良种生产群体优劣的重要指标。本研究对广西55a生"土贡松"母树林种子表型及生活力、性状间相关性、子代遗传多样性等进行了分析研究,表明:不同采种母树在种子表型性状(种子长、种子宽、种翅长、种翅宽、种子长宽比、种翅长宽比、千粒重)及种子生活力(萌发率、胚根长度)上均存在极显著差异(P0.0001);不同母树种子的萌发率在47%~95%之间;种子表型性状与种子生活力性状无显著相关性;母树林具有较广泛的遗传基础,基因期望杂合度、Nei期望杂合度分别为0.602、0.588;林内个体间存在明显的授粉不随机现象(观察杂合度0.381期望杂合度0.602),可能存在一定程度近交或自交。     

马尾松自由授粉子代测定的研究

对 8 0个马尾松自由授粉子代进行了连续 13年的测定。其结果表明 ,马尾松自由授粉子代在树高、胸径、材积 3个主要生长性状上存在极显著的差异 ,差异主要由遗传因素引起。参试的自由授粉子代材积生长表现十分突出 ,所有的子代生长都好于对照 ;生长最好的子代单株材积高达 0 .0 584 1m3 ,为生长最差子代的 340 .8%。利用 13年生的材积、树高和胸径指标对参试的 80个马尾松自由授粉子代进行综合分析、评价 ,从中选出表现最好的 12个。其单株树高平均值 7.0 7m、遗传增益平均值为 10 .3% ;单株胸径平均值 12 .7cm、遗传增益平均值 16 .7% ;单株材积平均值 0 .0 4 6 9m3 遗传增益平均值 4 6 .5% ,增产效果十分显著     

日本落叶松种子园自由授粉种子发芽性状的测定与评价

以柳河五道沟林木种子园2014年采集的日本落叶松自由授粉种子为材料,对不同方法处理的种子发芽性状进行测定与评价,结果表明:种子发芽率、发芽势、平均发芽时间、发芽指数分别为65%、19%、7.1 d和10.8。种子发芽率分别高出国家标准和吉林省地方标准20个和15个百分点,种子活力实际使用价值分别提高了44%和30%,发芽性状遗传品质显著高于一般商品种子。     

林分状况、丰歉年和贮存对云南松种子品质的影响

种子的品质包括遗传品质和播种品质两方面,但通常所说的种子品质是指的后者,本文所说的种子品质也只包含播种品质。影响种子品质最重要的是纯度和发芽率两项指标,其次为千粒重。纯度全受人为因素的影响,发芽率及千粒重却与自然因素有关。     

木麻黄嫁接种子园种子活力比较研究初报

种子活力,据Woodstock(1965)认为,是指种子能否适应各种环境条件而迅速、整齐地萌发的能力。由于林木生产周期性长,因此,应用种子活力的大小来早期鉴定种子品质;预测种子在田间条件下生产能力,在国内外愈来愈被人们所重视。本试验采用活力指数、发芽值等生理指标,对木麻黄嫁接种子园内30个家系及对照的自由授粉     

Browsing Damage on Pine (Pinus sylvestris and P. contorta) by a migrating moose (Alces alces) Population in Winter: Relation to Habitat Composition and Road Barriers

In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads.     

Effects of Root Freezing on the Physiology and Growth of Picea glauca,Picea mariana and Pinus banksiana Seedlings Under Different Soil Moisture Regimes

The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage.     

Stand Structure in Pine,Spruce and Deciduous Forests: A Comparison Between Finnish and Russian Karelia

This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland.     

Growth and Terminal Bud Formation in Picea abies Seedlings Grown with Alternating Diurnal Temperature and Different Light Qualities

The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions.     

CAD与建筑设计的关系

本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。     

Natural Regeneration in Clear-cuts: Effects of Scarification,Slash Removal and Clear-cut Age

The effects of soil scarification (mounding), slash removal and clear-cut age on the natural regeneration in clear-cuts was evaluated using data from four sites in southern Sweden. The treatments were carried out during a good seed and establishment year for birch ( Betula pubescens Ehrh. and B. pendula Roth). Scarification had the strongest positive effect on the density of naturally regenerated seedlings, especially in birch, but also in pine ( Pinus sylvestris L.) and spruce [ Picea abies (L.) Karst]. Slash removal had a positive effect on birch density. No statistically significant effect of clear-cut age was found. In addition, no statistically significant interactions between clear-cut age and scarification or slash removal were found. The ingrowth of field vegetation was the fastest in areas that were not scarified, less rapid in areas scarified on old clear-cuts, and the slowest after scarification in fresh clear-cuts. In conclusion, it may be possible to control the density of birch during a good establishment year for birch. If birch is desired, the best combination of treatments is to remove the slash and scarify; otherwise, these treatments should be avoided.     

Risk Perception Among Non-industrial Private Forest Owners

Based on an enquiry, risk perception among non-industrial private forest owners is described in relation to climate change and forestry hazards. Of the respondents, 11% took action to remedy the effects of climate change. Out of a given set, hazards were ranked according to each respondent's experience of recent substantial financial loss to the estate and in relation to his or her willingness to make investments aimed at risk reduction. For each hazard, the respondent assessed the risk in four classes ranging from very high to negligible risk. Six hazards were considered most problematic in all three aspects: browsing damage, falling timber prices, damage by wind, spruce bark beetle, root rot and pine weevil. A majority of the respondents claimed to take action to reduce the risk associated with at least one hazard, while 35% did not know whether they did. Excluding climate change, the need for decision support was the largest in relation to damage by wind owing to a combination of perceived high risk and a high level of ignorance in relation to whether risk-reducing measures were taken.     

Interactions in decomposition and N mineralization between tropical legume residue components

In situ produced plant residues contain a mixture of different plant components of varying quality. To assess synergistic or antagonistic interactions occurring during the decomposition and mineralization of such mixtures, individual plant parts (stems, leaves, leaf litter and roots) or the mixture of stems, leaves and leaf litter of the agroforestry species pigeonpea (Cajanus cajan) or of crop residues of peanut (Arachis hypogaea) or of the weed hairy indigo (Indigofera hirsuta) were incubated in pots for 19 weeks. Periodically, remaining plant residues were sieved out (>2 mm), weighed and N content as well as soil mineral N determined. Above- and below-ground residues of peanut decomposed fastest and showed the largest N release in agreement with their high N concentration and low-acid detergent fibre (ADF) : N ratio. Hairy indigo was hypothesized to be of lower quality than pigeonpea because of its high-polyphenol content. However, it decomposed faster than pigeonpea, largely because of the higher N and lower lignin concentration of its components. Ranking of individual plant components for N mineralization resulted in the following pattern, leaves > leaf litter > roots > stems. In mixtures of the different plant components a similar species order in decomposition was obtained, e.g. peanut > hairy indigo > pigeonpea. The amount of N released from the mixture was dominated by stem material that comprised 46–61% of the mixture. The interactions in mixtures were relatively small for peanut (generally high-quality components) as well as for pigeonpea (low proportion of high-quality components, i.e. N rich leaf material). However, a positive interaction occurred during later stages of N mineralization in the mixture of hairy indigo as it had a significant proportion of N rich components and absence of highly reactive polyphenols. Thus, for plants with low to intermediate chemical quality attributes, manipulating plant composition (e.g. by varying harvest age, affecting stem and leaf proportions) will be important to obtain significant interactions during decomposition when its components are mixed.     

Pasture production and tree growth in a young pine plantation fertilized with inorganic fertilizers and milk sewage in northwestern Spain

The use of organic waste materials such as milk sewage as an organic fertilizer could have the dual advantages of organic-waste disposal and reduced dependence on inorganic fertilizers. The effects of fertilization with (1) conventional mineral fertilization, (2) milk sewage sludge at 40 kg N ha⁻¹ target rate and (3) no fertilization on pasture production and tree growth were examined in an experiment consisting of two pasture mixtures under a one-year-old Pinus radiata plantation with a density of 2500 trees ha⁻¹. The two pasture mixtures were: (1) Dactylis glomerata L. var. saborto (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹); (2) Lolium perenne L. var. Tove (25 kg ha⁻¹) + Trifolium repens L. group Ladino (4 kg ha⁻¹) + Trifolium pratense L. var. Marino (1 kg ha⁻¹). The experiment began in the spring of 1995 using a randomized block design with three replicates in Castro Riberas de Lea (Lugo, Galicia, north-western Spain). Plot size was 12 × 8 m², with a 1 m buffer strip between plots. Two-year data showed that fertilization with either material had a positive effect on pasture production, with no significant difference between the two fertilization treatments. Tree growth in the milk sewage sludge plot was significantly higher than in the control plots. Inorganic fertilization increased pasture production, but affected tree growth negatively. The results show that milk sewage sludge could be used as a fertilizer in silvo-pastoral systems. This revised version was published online in June 2006 with corrections to the Cover Date.