不同软枣猕猴桃雄株花粉离体培养条件及花粉性状的比较

【目的】为初步筛选授粉性状优良的软枣猕猴桃雄株提供依据，进而促进授粉雄株的合理配置及育种效率的提高。【方法】对15份雄株的花粉离体培养条件、萌发特性和花粉量进行了测定与比较。【结果】1）软枣猕猴桃花粉萌发和花粉管生长所需的适宜离体培养条件略有不同，总体来看，适宜花粉培养的蔗糖浓度为5.0%～10.0%，硼酸浓度为25～50 mg/L，培养温度为30℃，最佳观察时间为4.5～6.0 h。2）不同雄株的花粉量及花粉萌发特性存在明显的株间差异。单花花药数的变幅为32.67～47.88枚，单药花粉量为3 267～26 000粒。单花花粉量，S3和S13的均较多，均超过1 000 000粒；S4、S6的均较少，均低于150 000粒。15份雄株的花粉萌发率均较高，其中，Z1与S8的萌发率达到90%以上，Z2、S4、S9的萌发率虽均较低，但也都在65%以上；花粉管长度，Z1、S2与S8的均相对较高，均极显著高于其余雄株的。3）依据单花花粉量、萌发率与花粉管长度进行聚类分析，15份雄株可分为4个类群：类群1的萌发率、花粉管长度最高，单花花粉量也较高但其变幅大，筛选结果表明，Z1的综合表现较好；类群2...     

不同苞片色地涌金莲杂交亲和性研究

从花粉育性检测、不同授粉处理结实调查,以及4种人工授粉组合花粉萌发和花粉管生长情况的荧光显微观察等方面,对不同花(苞片)色地涌金莲杂交亲和性进行研究.结果表明:地涌金莲花粉活力可高达95%,萌发率最高时可达23%.套袋不授粉处理下,结实率为0.开放授粉处理下,黄花植株结实率为93%,红花植株为90%.4种人工授粉组合,花粉萌发和花粉管生长正常,结实率为95%～97%,单果种子数19～35粒,与开放授粉相当.由此推断红、黄花植株间杂交亲和.     

锥栗开花授粉生物学特性

通过田间调查、花粉离体萌发、石蜡切片和人工授粉等试验手段对锥栗的开花动态、花粉活力、柱头可授性、风媒传粉特性和授粉特性等进行研究。结果表明：锥栗雌花群体分化时间约40天,单花分化时间约22天,柱头可授性持续期为7天;雄花序4—5月开花,群体花期23～26天,群体盛花期13～15天,单花序花期10～12天,开花后6天内花粉保持较高活力。风媒传粉是锥栗传粉的主要途径,风速和风向是影响锥栗传粉的主要气象因素,顺风方向上花粉的传播距离及花粉通量显著高于其他3个方向。锥栗在去雄套袋且不进行人工授粉的处理下未坐果,表明锥栗不存在无融合生殖;异交授粉坐果率均显著高于自交,表明异交能显著提高锥栗坐果率,生产上需配置授粉树。     

柳兰引种试验

在长春进行柳兰引种试验,结果表明：柳兰在长春能够安全越冬,生长发育正常,具有良好的适应性。新芽萌发出土、展叶、现蕾、初花期、盛花期和末花期时间较原产地分别提前了4d、6d、17d、23d、31d和30d,各物候相起始时≥10°的有效积温分别为78℃、84℃、410℃、590℃、679℃和1104℃。始花时整个花序轴平均长度12．2cm,平均着生花54．3枚,花序最长者达32．4cm,着生花76枚;花开放时植株平均高57．1cm,最高达到104．0cm;植株高生长定型时,平均高128．0cm,花序平均长度为46．8cm,每个花序平均着生花87．8枚。     

濒危植物天台鹅耳枥开花特性与花粉生活力测定

2014年对浙江省天台县天台鹅耳枥(Carpinus tientaiensis)的花期物候、花形态特征进行观测,并测定其花粉生活力和雌蕊柱头可授性。结果表明,天台鹅耳枥雄花始花期早于雌花,雄花散粉与雌花柱头可授期重叠时间为15 d,较大的空气湿度和阴雨天气可能会对授粉产生不利影响;天台鹅耳枥初花期花粉萌发率最高,达到10.83%,是人工采集花粉的最佳时期;0.6%琼脂粉+0.005%和0.01%的硼酸+1%的蔗糖最有利于花粉的萌发;雌蕊柱头可授性在开花1 d后达到最佳状态,可授期为5 d。     

蒙古扁桃和长柄扁桃对栽培环境的传粉适应性研究

通过测定花粉和花柱头可授粉性活力,探讨了呼和浩特市树木园人工栽培17年的蒙古扁桃和长柄扁桃的生殖适应性。结果表明,栽培蒙古扁桃花粉活力维持时间大致为12 d,开花当天花粉活力最强,从开花前1 d至花后第4 d均保持较高的活力。其花柱头授粉能力维持时间为9~12 d,其中短花柱的为12 d、中花柱的为9 d、长花柱的为10 d,花后第2~4 d授粉能力最强,与花粉活力最强时间基本相重合;栽培长柄扁桃花粉活力维持时间大致为15 d,维持花柱头授粉能力时间为13 d左右,其中从开花前1 d至花后第4 d保持较高的花粉活力,从开花前1 d至花后第5 d保持较高的柱头授粉活力,两者重叠时间可达6 d,更有利于授粉。说明,该栽培环境对蒙古扁桃和长柄扁桃的花粉活力和花柱头可授性未产生不良影响。     

'赣州油'系列油茶品种配置筛选

【目的】油茶为自交不亲和树种,选择‘赣州油’系列油茶品种间花期相遇及授粉亲和性高的品种,为‘赣州油’系列油茶品种配置提供参考依据。【方法】以赣南主栽的‘赣州油’系列油茶品种为试验材料,在开展油茶开花物候期观测、花粉量和花粉活力测定的基础上,通过品种间异交亲和性调查,初步建立‘赣州油’系列油茶授粉品种配置模式。【结果】根据开花时间,‘赣州油’系列油茶品种被分为早花、中花、晚花品种。不同油茶品种单花花粉量和花粉活力存在较大差异,单花花药数最多的品种为‘赣州油17号’,单花花粉量最多的是‘GLS赣州油2号’,单花有效花粉数最多的为‘赣州油18号’。人工自花授粉试验结果显示,油茶并非完全自交不亲和,‘GLS赣州油2号’和‘GLS赣州油4’号可以实现自花授粉结实,但其结实率较低,分别为10.00%和11.11%;‘GLS赣州油4号’的同品种异株间人工授粉结实率达到42.86%。异花杂交试验结果显示,‘GLS赣州油1号’ב赣州油6号’杂交坐果率达到88.89%,综合考虑父本和母本的性状、稳定性、配合力等情况,从32个组合中筛选出6个最佳组配,分别为‘GLS赣州油1号’ב赣州油6号’、‘GLS赣州油5号’בGLS赣州油2号’、‘GLS赣州油5号’ב赣州油10号’、‘赣州油9号’ב赣州油10号’、‘GLS赣州油4号’בGLS赣州油2号’、‘GLS赣州油4号’ב赣州油6号’。【结论】‘赣州油’系列油茶品种的花药数和花粉量不能作为品种间亲和力的判断依据,油茶的品种配置应综合考虑花期、花粉活力、亲和性等各方面的因素。     

东北山梅花株间开花生物学特性的观测与研究

以磐石市江南林场施业区内生长的东北山梅花为对象,观测其开花生物学特性,结果表明:在2016年气候条件下,群体花期为31 d,平均单株花期为27 d,平均盛花期为14 d;单花序着生小花4~19枚,以8~10枚者居多,单花序开放时间为12~14 d,单花开放时间为8~9 d;花白色纯正,散发淡雅花香。花期前≥10℃的有效积温为631℃,开花期间为586℃;开花期间共有雨天24 d。     

锈叶杜鹃的开花特性及繁育系统研究

2012年对锈叶杜鹃自然居群进行了开花物候及访花昆虫的调查,分析了其开花特性;并运用杂交指数、花粉-胚珠比和人工控制授粉方法,对其繁育系统进行了研究。结果表明,锈叶杜鹃开花时间为2月初至7月,其单花花期、单花序花期及单株花期分别为7.06±2.74 d,12.33±2.37 d和16.17±4.24 d。锈叶杜鹃的雌、雄性器官具有同熟性,但两者的最佳活性时间不同,花粉活力在开花第1天的活力最高,而柱头可授性在开花第4～6天最好。锈叶杜鹃的繁育系统为异交型,自交亲和,需要传粉者;同株异花授粉是其主要的授粉方式。锈叶杜鹃的有效传粉昆虫主要为蜂类,而象甲类、蚁类、叶蜂类昆虫是侵害性昆虫,严重影响其传粉;传粉昆虫访花频率低,可能是导致锈叶杜鹃自然杂交结实率低的主要原因。     

银杏人工授粉试验

于2009—2011年期间,连续3 a在福建省宁化县开展银杏人工授粉试验,结果表明:银杏花粉的保存方法、雌树不同花期和时间(1 d内)授粉、授粉方法均对坐果率具有极显著影响。花粉保存方法以放入干燥器置于冰箱(3～5℃)保存的授粉坐果率最高,平均达67.8%;雌树以盛花期的晴天,10∶00—16∶00授粉坐果率最高,平均达67.7%;授粉方法以花粉与清水1∶5000水溶液喷雾最适宜,坐果率达67.8%,平均单粒果核重达2.6 g·粒-1,可在生产中大面积推广应用。     

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.