Effects of artificial environmental conditions on anatomical and physiological ripening of Pinus sylvestris L. seeds

To determine suitable conditions for artificial ripening of Scots pine seeds, cones collected on seven occasions between August 6 and November 26, 1990, in northern Sweden, were subjected to artificial ripening at different temperatures (+5°–+15°C) and cone moisture contents for 3–9 weeks. Complete physiological ripening and improved seed vigour were attained after artificial ripening if collection occurred no earlier than the beginning of September. The highest germination percentage after artificial ripening, ca 90%, was achieved for seeds collected after the anatomical ripening in nature had ceased and was at least as high as for seeds ripened in nature. Temperature did not influence ripening, whereas a low cone moisture content impaired ripening of those seeds collected earliest. The germination percentage was not influenced by 2–6 months of cone storage subsequent to artificial ripening, but seed vigour was impaired. Anatomical ripening during artificial ripening was very limited.     

自然脱水过程中七叶树种子生理特性的变化

于 2003 年研究了自然脱水过程中七叶树种子生理特性的变化。结果表明:七叶树种子对脱水高度敏感,为顽拗性种子。种子成熟采收时含水量高达 60.3%,种子在室温下自然干燥 30 天后,含水量下降到 30.2%,此时种子生活力完全丧失。在脱水初期,种子发芽率有所上升,但随后种子发芽率迅速降低。随着含水量的下降,种子浸出液相对电导率上升,但当含水量在 53.7% 到 50.9%之间时,种子浸出液相对电导率出现异常升高。同时种子超氧化物歧化酶(SOD)的活性随脱水时间的延长而下降,只有种子含水量在 53.7% 到 50.9%之间时出现例外。丙二醛(MDA)含量在脱水初期缓慢上升,在含水量下降到低于 50.9%时,丙二醛(MDA)含量快速上升。可溶性糖含量随脱水时间的延长缓慢上升。当种子含水量为 47%–60%时,种子发芽率较高,说明这一含水量区间有利于种子生活力的保持。图 6 参 13。     

Effects of priming treatments on germination and biochemical characteristics of Pinus bungeana seeds

This experiment was conducted to evaluate the effect of seed priming on the germination and physiology of Pinus bungeana seeds.Seeds were treated by hydropriming with distilled water,halopriming with potassium nitrate (KNO 3) at 0.3,0.6,1.2 MPa respectively (untreated dry seeds were taken as control).Properties of seed germination and physiology were determined and the effect of hydro-and halopriming on germination and physiology of P.bungeana seeds were investigated.The results showed that,compared with control,each priming treatment had increased the germination percentage (GP) and germination index (GI),shortened the mean germination time (MGT) and the time required for 50% of the seeds to germinate (G 50).Primed P.bungeana seeds significantly decreased the relative conductivity and the amount of malondialdehyde (MDA).Of all the treatments applied to seeds of P.bungeana,halopriming at 0.3 MPa KNO 3 produced the highest GP (65.0%) and the shortest MGT (18.8 d) and G 50 (18.2 d).     

华山松种子发芽影响因素和生活力检验方法研究

以泾源县沙塘林场提供的华山松种子为试材,对华山松种子发芽的影响因素和生活力检验方法进行了研究.结果表明:纸床培养的华山松种子的发芽率要高于沙床培养的,两者之间存在显著差异;45℃清水浸种72 h的种子比用细纱1～5℃低温层积过的种子萌芽时间和萌芽高峰期明显滞后;染色时间20h、四唑浓度0.5％、染色温度20℃为检验华山...     

不同杨树品种越冬时期含水率的测定

通过测定不同杨树品种越冬时期的含水率,分析越冬时期苗木体内的含水率变化情况,结果得出:从12月1日至翌年4月10日各品种杨树的含水率处于连续波动、缓慢下降的过程,12月1日为最高,翌年4月10为最低,从翌年4月10日起,各样本的平均含水率开始恢复且迅速上升,其中3016杨的平均含水率最高,中阳九杨的平均含水率最低,它们的排序从高到低为3016杨、辽育3号杨、108杨、小胡杨、沙兰杨、辽宁杨、小美旱、中阳九杨。     

不同基质对短序润楠种子发芽及生长节律的影响

比较分析了河沙、草炭土、园土及三者的混合土对短序润楠种子发芽和幼苗生长的影响。结果表明:不同基质处理下短序润楠种子发芽及生长具有显著差异,混合土和黄心土的发芽率、发芽势和发芽指数等均明显高于河沙和草炭土,但草炭土的叶片展开时的苗高最大。不同基质处理下的短序润楠幼苗的生长特性表明,幼苗早期生长规律符合Logistic曲线特征,其方程拟合模型的决定系数(R~2)均大于0.998,达到显著相关水平。根据Logistic曲线方程上两个生长拐点可以将短序润楠的生长过程划分为渐增期、速生期、缓增期,其中处于速生期幼苗的苗高生长量均超过总量的50%。     

杉木、马尾松种子贮藏过程中生理生化变化研究

杉木(Cunninghamia lanceolata)、马尾松(Pinus massoniana)是我国南方主要造林树种,每年造林用种量很大.由于杉木、马尾松结实都存在大小年现象,大年结实量多,播种品质好,采种成本低; 小年结实量少,播种品质差,采种成本高.因此,生产上常常贮藏杉木、马尾松种子,以达到以丰补歉的目的.近年来,随着生物遗传多样性的日益被重视,作为种质资源保存措施之一,杉木、马尾松种子的长期贮藏也被提上议事日程.     

Morphological and biochemical changes of Aesculus chinensis seeds in the process of maturation

Morphological and biochemical changes of Chinese horse chestnut (Aesculus chinensis Bge.) seeds were studied during the process of maturation. Fruit and seed diameter increased linearly from DPA (Days Post Anthesis) 60 to DPA 150 and were stable thereafter. The weight of fruit and seed increased sigmoidally between DPA 100 and DPA 160. The water contents of whole seeds, axes and cotyledons had a sharp reduction from DPA 110 to DPA 130 but changed little after DPA 130. The water contents of whole seeds, axes and cotyledons were 1.42, 1.93 and 1.30?g?g^?1DW, respectively at the end of maturation. The starch content of cotyledons from mature seeds was high on a dry weight basis (31.4%) while the total soluble sugar content varied between 12 and 20%. In both axes and cotyledons, the total soluble sugar content decreased during the process of maturation, as did all five soluble sugar components measured (glucose, sucrose, trehalose, raffinose and stachyose). Sucrose and stachyose contents remained relatively high at the time of seed maturation, followed by glucose and a trace level of trehalose. The oligosaccharide/disaccharide (O/D) ratio in the axes was 3.1 at DPA 140. The high level of sucrose and stachyose might contribute to the greater desiccation tolerance of Aesculus chinensis seeds relative to typical recalcitrant tropical seeds. High levels of ABA content in seed coats and a low GA₃/ABA ratio in both seed coats and axes might also influence the desiccation tolerance and shallow dormancy of mature Aesculus chinensis seeds.     

Fine root electrolyte leakage and moisture content: indices of Sitka spruce and Douglas-fir seedling performance after desiccation

In spring 1992, 2-year-old bare-rooted seedlings of Sitka spruce (Picea sitchensis (Bong.) Carr.) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were exposed for 0, 0.5, 1.0, 1.5, or 3 h in a controlled environment room at 20°C. Plants were desiccated in batches during February and March; 100 seedlings of each species were planted in 5 20-plant plots at each of 6 planting sites using the normal planting times and methods of each area. The effect of exposure was assessed within 24 h of desiccation on a subsample of plants by measuring fine root moisture content and electrolyte leakage and, in a limited number of cases, needle water potential. These measures were related to survival and growth after the first and second growing seasons.There were significant interactions between the effect of desiccation and site. The measurements following desiccation were significantly related to survival and growth on some but not all sites; in general, the effect of condition was more pronounced on sites with low spring rainfall than on sites with greater than 100 mm rainfall per month during the spring of planting. Root electrolyte leakage was significantly related to performance in slightly more cases than needle water potential or root moisture content.     

稻草覆盖对果园土壤温度与含水量的影响

在洮南市北部半山区的果树试验场,按果树树冠垂直投影筑树盘,对树盘进行稻草覆盖处理,研究其对土壤温度与含水量的影响。结果表明：覆草处理能够有效地提高土壤含水量,年平均含水量比清耕地高出16．0％;经覆草处理的土壤,生长前期土温上升缓慢,后期土温下降缓慢,越冬前,土温高于清耕地2．00℃,可减少低温对根系的危害。     

Effect of sowing date on seedling emergence of species with seeds enclosed in a stony endocarp

The aim of the present study was to investigate the effect of the natural sequence of temperature conditions between the time of seed sowing and their germination on dormancy release of Prunus avium, P. mahaleb, P. divaricata, P. laurocerasus, P. spinosa, Cornus mas, C. sanguinea, and Celtis australis seeds which are enclosed in a hard stony endocarp. According to their collection date, the seeds (with the endocarp) of the above species were sown outdoor in summer, autumn, and winter and the number of emerged seedlings was counted during the following two springs. For all species, the first sowing date was immediately after seed collection and cleaning. In all species, seedling emergence occurred in early spring and dormancy was released only after the exposure of seeds to specific season conditions. The exposure of seeds of all studied species, except C. australis, to a period of warm temperatures prior to winter was necessary for dormancy breaking and germination. Autumn sowing of P. laurocerasus and C. sanguinea seeds, which were collected in summer, and the sowing immediately after seed collection of the rest species, resulted in a maximum percentage of seedling emergence in the following spring.     

磁化浸种促进林木种子发芽生长的初步研究

用不同磁场和不同磁场强度处理的水对林木种子浸种培育，观察种子发芽率、发芽势、胚根和下胚轴的变化。实验结果表明，磁化水能提高林木种子的发芽率、发芽势，促进幼苗的生长；匀场比梯度场好，磁场强度为0.4T的比0.2T的好。但对不同的树种其影响程度有所不同。     

川中浅丘农区坡地林农复合系统的水文效应

本文对坡地林农复合系统水文效应进行的研究结果表明，复合系统中林地土壤非毛管孔隙对降水的有效调蓄能力比荒草坡强；全年除了３月，５月外，复合系统农地土壤含水量均比对应的纯农地略高；采用横坡聚土垄作或土石护坎工程可有效地减少复合系统农地水土养分的流失量。     

Effect of natural brassinolide on germination of Ailanthus altissima seeds

The germination capacity of Ailanthus altissima seeds improved after the seeds were soaked with different concentrations of natural brassinolide (NBR). The germination rate and germination energy of the seeds increased by 17.6% and 18.8%, and the mean germination speed (i.e., germination time) of the seeds was shortened by 1.4 d under the optimal concentration (0.4 mg.L⁻¹) treatment, compared with the control. After hypocotyls of A. altissima were treated with NBR, the elongation of the hypocotyls increased. Among different concentrations of the NBR, 0.4 mg·L⁻¹ NBR appeared to be the optimal concentration for the elongation of A. altissima hypocotyls.     

水分胁迫对短梗大参生理生化特征的影响

为了探索短梗大参对水分胁迫的适应性,提供其引种驯化和园林栽培依据,以2年生短梗大参苗木为试验材料,采用盆栽试验和称重控水法进行土壤水分胁迫(设置土壤相对含水量分别为田间最大持水量的80%、70%、60%和50%,以田间最大持水量100%为对照),研究不同水分胁迫对短梗大参生理生化特征的影响。结果表明:短梗大参叶片相对含水量随着土壤水分胁迫程度加强而降低,最大降幅达34.50%;质膜在水分胁迫下易遭受破坏,在严重水分胁迫下相对质膜透性高达79.85%,丙二醛(MDA)含量增幅达121.07%;渗透调节物质脯氨酸和可溶性糖的含量在水分胁迫下增加,至土壤相对含水量70%时达到最高,分别比对照升高34.73%和40.39%,而可溶性蛋白质含量下降;总叶绿素、叶绿素a和叶绿素b含量在水分胁迫下降低,而叶绿素a与叶绿素b的比值升高。     

油松等常用林木种子贮藏有效年限的试验

选择辽宁省林业厅草河口林子种子库,结合生产需要,对油松等１０种常用造林、绿化树种的种子,在特定的环境条件下进行了贮藏试验。经多年试验观测,得出各树种种子保持生活力的有效年限;总结出种子含水量、环境温度、密封贮藏与种子贮藏寿命的关系。文中所得数据对种子贮藏时,确定最优技术组合、降低成本、提高效益具有一定参考价值。     

鱼鳞坑整地改善土壤水分状况与造林效果分析

通过引入土壤储水量、树冠覆盖率等指标,对鱼鳞坑整地改善土壤水分状况及其在侧柏造林中的应用效果进行分析,结果表明：采用鱼鳞坑整地可显著提高土壤含水率和土壤储水量;随着林地土壤水分状况的改善,造林保存率、林木生长量、林地生产力、郁闭成林的速度随之提高;在不同的土壤水分状况下,种群通过生物量投资与分配格局调节形成与之相适应的种群行为及个体形态特征,从而提高种群的稳定性或持久性。     

Effect of steam pretreatment on wood moisture content and characteristics of vacuum drying

The effects of high temperature steam pretreatment on the change in wood moisture content (MC) and characteristics of vacuum drying were investigated in this study. Poplar and manchurian walnut woods were pretreated with high temperature steam at 100°C and 140°C, prior to vacuum drying. A comparison of the characteristics of vacuum drying between steam pretreated wood and untreated wood was carried out. The results show that during steam pretreatment, the MC of wood decreased within a few hours. The reduction of MC varied with the temperature; the higher the temperature, the faster the MC dropped. During the vacuum drying stage, the rates of drying of pretreated samples were higher than those of untreated samples when MC was below the fiber saturation point. Furthermore, the total drying time of samples treated at a steam temperature of 140°C was lower than that of untreated samples. Therefore, a vacuum procedure after steam pretreatment can effectively shorten the drying time when drying wood.     

天山樱桃种子萌发特性研究

为了探讨天山樱桃在新疆伊犁西天山野果林内其种群自然更新困难的原因及其种子在萌发阶段对环境的特殊要求,以期提高种子的萌发率,以天山樱桃种子为试验材料,以中井樱桃种子为对照,对带壳与去壳的两类种子采用不同浓度的GA3和不同时间的低温层积处理,并对种子发芽率与胚根生长量进行了统计。结果表明:(1)天山樱桃种子的发芽率随着层积时间的延长而提高,去壳种子的发芽率最高为90.0%;在相同的层积和浸种条件下,去壳种子的胚根生长量最长为28.59 mm。(2)天山樱桃去壳种子的发芽率随GA3浓度的升高而降低,低温层积70 d以上的天山樱桃去壳种子,以GA3浸种24 h的胚根生长量最长为53.40 mm。     

东革阿里种子生物学特性研究

为研究药用植物东革阿里(Eurycoma longifolia)种子的生物学特性,通过形态学观察、种子发芽试验等方法对5个东革阿里种源的种子形态、千粒重、种子含水量、种子发芽率等指标进行测定.结果表明:5个东革阿里种源的种子外观形态差异不大,其千粒重和含水量从大到小排列均为:海岸带种源＞海岛种源＞低地种源＞大陆种源＞山地种源.5个种源中以海岸带种源发芽率最高,为52％;低地种源和海岛种源发芽率低,仅为28％和34％.初步筛选出海岸带种源东革阿里种子可作为优良种质资源.