湖南不同板栗品种结实性研究初报

为了加快板栗良种的选育进程,了解湖南各地选育板栗良种的结实特性,将湖南省各地区选育出的板栗品种1~11号与湖南本地推广板栗良种铁粒头(作为对照CK)进行了品比试验,并就树体冠幅面积、单株果实个数、单位冠幅面积果实个数、单株产量、单株栗苞产量、单株坚果产量、出实率及板栗果实各项生长指标间的相关性进行了调查、观测与分析。结果表明:板栗品种5、7、9、11号在单位冠幅面积果实个数、单株果实产量及结实性等方面的表现均比CK突出,尤其是板栗品种7号,可作为下一步良种选育的研究对象;在板栗果实各项生长指标中,栗果长与栗果宽存在显著正相关,与栗果高存在极显著正相关,而栗果宽与坚果皮厚存在负相关;坚果长与坚果宽和坚果高均存在极显著的正相关,坚果宽与坚果皮厚存在负相关;平均单株产量与单株栗苞质量和单株坚果质量均存在极显著的正相关,而板栗果实的出实率与树体冠幅面积存在极显著的相关性。文中因此认为,合理控制冠幅,不仅可以提高单株产量,还可以提高板栗果实的出实率。     

不同倍性广东桑的花粉形态

【目的】针对桑树形态倍性鉴定及品种间鉴别问题,研究广东桑不同倍性及品种之间孢粉学上的异同,为桑树多倍体育种提供科学依据。【方法】利用扫描电镜对广东桑10个不同倍性品种花粉的形态、大小、萌发孔、外壁纹饰等孢粉学特性进行观察,并运用图片分析结合数理统计的方法对其花粉形态进行研究。【结果】供试广东桑不同品种的花粉微观形态相近,均为小型花粉,近球形,花粉粒极轴长16.98～24.46μm,赤道轴长15.37～23.86μm,极轴长与赤道轴长的比值为1.01～1.12;供试不同品种花粉粒萌发孔1～3个,圆形,直径为2.11～3.51μm,部分花粉粒萌发孔外壁内陷形成漏斗形,按照额尔特曼 G 的 NPC(萌发器官的数目、位置及特征)分类系统属N3P3C4类型;不同倍性间广东桑花粉的赤道轴长、极轴长和萌发孔大小存在显著性差异(P ＜0.05),均表现为四倍体＞二倍体,但花粉粒的极轴/赤轴比值差异不显著(P＞0.05);广东桑花粉外壁为分布不均的刺状突起－脑条纹复合纹饰,不同品种间花粉的表面纹饰有明显差别,根据外壁纹饰可将供试10个品种花粉分为细刺颗粒状突起－细条纹纹饰、细刺颗粒状突起－粗条纹纹饰、粗刺颗粒状突起－细条纹纹饰和粗刺颗粒状突起－粗条纹纹饰4种类型,花粉外壁纹饰体现了不同品种的遗传多样性和遗传分化;不同倍性间广东桑花粉表面的刺状突起密度及大小差异不显著(P＞0.05);供试四倍体广东桑品种花粉存在少数败育花粉粒,表现为干瘪而不充实,外形异常。【结论】供试广东桑不同倍性及品种间花粉形态特征具有差异,不同倍性间花粉粒和萌发孔大小存在差异,不同品种间花粉的表面纹饰存在明显差别,初步认为花粉的亚显微结构特征可作为广东桑倍性鉴定及品种间鉴别的重要标准之一。     

云南板栗花粉形态、萌发率和果实特性的研究

以4个云南板栗品种为试验材料,从其花粉形态特性,萌发率和通过相互授粉试验来研究果实直感效应.本次试验结果表明板栗花粉粒的形态大小在不同品种间具有一定的差异,云栗15号的花粉粒比云栗42号大,其在同一品种雌株上授粉所结果实亦比云栗42号的大;从板栗花粉萌发率上的结果上看.云栗42号的萌发率比云粟15号的要高,其球苞内坚果数亦比云栗15号多.板栗果实大小的直感效应受到授粉组合的亲和力、花粉粒大小和萌发率的影响.     

白龙江干热河谷地带油橄榄花期物候及花性特征研究

试验观察油橄榄7个品种花朵的物候期,研究油橄榄2个不同品种完全花与雄花的花粉粒的大小及形态、花粉生活力的变化及花粉畸形率。结果显示:(1)在油橄榄7个品种中,"莱星"花期时间最长达20天,"皮削利"花期最短仅为16天;(2)油橄榄花粉粒形态相近均为长球形,但大小略有差异,赤道面为近椭圆形,具3个萌发沟,外壁纹饰清晰且呈穴网状;(3)"城固32号"和"鄂植8号"2种品种完全花花粉大小为263.16~245.06μm×181.96~173.86μm、雄花花粉大小为267.32~244.09μm×180.41~161.55μm,花粉形状指数(P/E)的变幅范围为1.44~1.52;(4)"城固32号"和"鄂植8号"2种品种的完全花与雄花的花粉畸形率均低于16.00%;(5)在4h内"鄂植8号"完全花的花粉生活力最高可达93.38%,"鄂植8号"雄花的花粉活力较为稳定,4~36h时段花粉生活力为73.94%~62.08%,在36h时段"城固32号"完全花的花粉生活力最低仅为49.84%。     

鹅耳枥属部分植物花粉形态扫描电镜观察

为了明确鹅耳枥属部分植物的花粉形态特征,验证花粉形态在鹅耳枥属植物种间鉴定应用中的可行性,从而为该属植物的分类鉴定、遗传变异及系统演化等方面的研究提供科学依据,采用扫描电镜技术(SEM)对7种鹅耳枥属的植物花粉形态进行了研究与分析。结果表明:7种鹅耳枥属植物花粉为单粒花粉,等极,近球形;花粉的极面观为近圆状,赤道面观为椭圆状;几种鹅耳枥的极轴长和赤道轴长差异显著,极轴长度为22.600~30.884μm,赤道轴长度为21.269~30.001μm,"帚状"欧洲鹅耳枥为花粉体积相对最大的种,而鹅耳枥为花粉体积相对最小的种;7个树种的花粉萌发孔形状为椭圆形,孔长为1.494~2.002μm,孔宽为1.146~1.618μm,不同种之间差异显著;萌发孔排列在赤道上,花粉表面纹饰较为相似,呈皱波状,但不同种之间表面突起和颗粒分布存在差别;研究发现鹅耳枥属植物属于较为进化的植物类群。     

结实与不结实紫薇花粉的萌发特性

【目的】明确紫薇花粉形态特征,探究蔗糖、硼酸以及植物生长调节剂对紫薇花粉萌发的影响,以期为紫薇属花粉活力研究和杂交育种提供理论基础。【方法】本试验以新鲜紫薇花粉为试验材料,通过电子扫描显微镜观察紫薇花药和花粉形态特征,通过荧光显微镜判断花粉是否具有活力,通过离体萌发法和完全随机二因素试验讨论蔗糖和硼酸对紫薇花粉萌发的影响,采用单因素试验法探究萘乙酸（NAA）、吲哚乙酸（IAA）以及赤霉素（GA3）对紫薇花粉萌发的影响。【结果】结实紫薇花药较干燥,表面粗糙厚实,花粉数量多,长雄蕊花粉饱满,极轴长与赤道轴长比值（P/E）1.70,短雄蕊P/E值为1.50。不结实紫薇花药较湿润,表面较光滑,开裂少,长雄蕊花粉平均极轴长（P）30.13μm,赤道轴长（E）21.21μm;短雄蕊平均极轴长（P）22.42μm,赤道轴长（E）20.12μm,P/E比值为1.11,花粉均为长球形。结实紫薇花粉在柱头上有明显的花粉管萌发,而不结实紫薇花粉在柱头上未发现花粉管。蔗糖与硼酸组合试验对花粉萌发有显著影响,蔗糖浓度在100～200 g/L间时,花粉萌发率随硼酸浓度的增加而增加,蔗糖浓度为250 g/L时,随着...     

不同板栗品种(单株)果实重要农艺性状的模糊综合评价

为了研究不同板栗品种(单株)果实重要农艺性状的遗传变异规律,对34个板栗品种(单株)的果实外观特征和种仁营养物质进行了观测,并应用模糊数学法对不同品种(单株)果实品质进行了隶属函数模糊评价。研究结果表明:不同品种(单株)板栗球果的质量、横径、纵径和果实的质量、果形指数、出仁率间均存在极显著差异,其中,实生树(011号)的果形指数(1.82)最大,桂花香(298号)品种的单果平均质量和种仁平均质量均最大,特早(182号)品种的出仁率最高;不同品种(单株)板栗种实的可溶性糖、淀粉、可溶性蛋白含量间均存在极显著差异。通过分析板栗品种(系)栗实的单粒质量、干物质、淀粉、可溶性糖等指标的测试数据,建立了各指标的线性隶属函数,在对各隶属度进行加权平均的基础上,根据最大隶属原则对各品质指标进行了排序,综合权重比较得出,尖顶油栗(358号)、汪字头7号(283号)、岑口大栗(374号)、桂花香(25号)及双合大红袍(216号)等品种的果实品质均最佳。     

不同品种梨花粉亚显微形态观察及比较

应用扫描电子显微镜观察胶东半岛6个主栽梨品种的花粉形态,比较极轴、赤道轴、P/E值以及外壁特征,旨在拓展花粉亚显微结构在种质鉴定方面的应用范围。试验结果表明:梨属植物花粉形态相似,呈长球形,萌发孔均为3条拟孔沟,沿极轴方向延伸至两极;花粉表面为条纹纹饰,有网状和平行两种类型,不同品种间存在较大差异。条脊交叉与平行排列程度,穿孔大小、形态与数量也有所不同;‘红香酥’和‘巴梨’花粉外壁为网状条纹纹饰,而其他4个品种呈现平行型条纹状纹饰,推断梨花粉孢粉学信息呈现趋母本遗传特性。     

不同品种梨花粉亚显微形态观察及比较

应用扫描电子显微镜观察胶东半岛6个主栽梨品种的花粉形态,比较极轴、赤道轴、P/E值以及外壁特征,旨在拓展花粉亚显微结构在种质鉴定方面的应用范围.试验结果表明:梨属植物花粉形态相似,呈长球形,萌发孔均为3条拟孔沟,沿极轴方向延伸至两极;花粉表面为条纹纹饰,有网状和平行两种类型,不同品种间存在较大差异.条脊交叉与平行排列程度,穿孔大小、形态与数量也有所不同;‘红香酥’和‘巴梨’花粉外壁为网状条纹纹饰,而其他4个品种呈现平行型条纹状纹饰,推断梨花粉孢粉学信息呈现趋母本遗传特性.     

白花树花粉生活力检测方法与贮藏特性研究

以江西吉水种源的白花树花粉为研究材料,进行了扫描电子显微镜下的花粉形态结构观察以及采用离体培养基法、I2-KI和TTC染色等花粉生活力测定方法的比较研究,探讨了不同贮藏条件对花粉萌发的影响。研究结果表明:白花树花粉粒为长球型,具3孔沟,外壁面具细网状纹饰;花粉平均极轴长52.33±0.577μm,平均赤道轴长26.89±0.502μm;3种花粉生活力测定方法中以离体培养基法最有效,花粉萌发的最佳组合为:10%蔗糖+0.05 g·L-1硼酸+100 mg·L-1GA3+3 h;花粉最佳贮藏条件为-80℃密封保存,贮藏180 d后花粉的萌发率仍可达40.97%。     

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.