极度濒危植物--崖柏种群空间格局与动态的初步研究

通过对开县境内4个典型崖柏种群空间分布格局进行初步研究,表明崖柏种群为明显的集群分布,在取样尺度较小时（群落Ⅰ、Ⅲ、Ⅳ为4m^2;群落Ⅱ为6m^2）集群强度最大,且随着取样尺度的扩大聚集强度逐渐减小。在各群落中集群强度以多齿长尾槭一崖柏群落（Ⅰ）最大,依次为崖柏一铁杉群落（Ⅱ）,崖柏-巴东栎群落（Ⅲ）,崖柏-黄杨群落（Ⅳ）最小。在对崖柏初步研究的基础上还提出了进一步研究的方向。     

Seed germination ofThuja orientalis under PEG osmose treatment

Abstrct Thuja orientalis seeds was treated by different molecular weight, different concentration and different lasting time in the Seedling Laboratory of Northeast Forestry University. The results are as follows:(1) it shows significant promoting effects on the germination viability of seeds by different molecular weight of PEG(-6000, -10000 and -20000), and PEG-10000 is the best. (2)Different effects on germination viability, germination rate and simple vigor index are made by different concentration of the same weight molecular(PEG-10000), the promoting effects are shown when the concentration is below 30%, and from 20% to 30% is the best range, but inhibitions will be shown if the concentration is more than 35%. (3)The most suitable lasting time of osmose treatment of PEG-10000 with 20% concentration is from 2 to 4 days, not more than 6 days, but it will show significant inhibition if the treated time is more than 8 days. (4)The treatments of PEG-10000 and PEG-20000 with higher molecular weight can increase the germination rate and seed vigor, and decrease the electric conductivity of the seed soaking liquid after the natural air-dry treatment. The suitable time of natural air-dry is about 6 to 8 hours. It is also concluded that the PEG osmose treatment is an effective method to increase the germination rate by the field simulation in the laboratroy.     

北美香柏插穗生根过程中营养物质的变化

以北美香柏嫩枝插穗为材料,用ABT2和GGR6处理插穗,以清水处理为对照,研究扦插生根过程中营养物质的变化。结果表明:各处理的插穗,在其生根过程中可溶性总糖含量变化趋势较为相似,在根诱导期和伸长期出现峰值。ABT2处理的插穗可溶性总糖含量较高,对照的含量相对较低,推测可溶性总糖对生根起促进作用。插穗氮含量在生根过程中整体呈下降趋势,对照的氮含量高于其他处理,可能是低氮的条件更有利于生根。C/N值的变化趋势与可溶性总糖一致。可溶性总糖、C/N值与生根率的灰色关联度分析表明,可溶性总糖和C/N值可能是调控插穗生根的主要因子,且在根诱导期和伸长期作用明显。     

不同光环境下濒危植物崖柏的光合日动态

崖柏(Thuja sutchuenensis Franch.)为柏科(Cupressaceae)崖柏属常绿乔木,是我国特有的珍稀濒危植物[1].该植物目前多见于重庆城口县和开县交界的石灰岩山地,喜光,生长缓慢,耐瘠薄.目前有关崖柏的研究有遗传多样性[2-3]、群落生态学[4]、无性繁殖[5]和低温适应机制[6]等,但是崖柏光合特征参数与环境因子的相关性及其对光环境响应方面的研究尚未见报道.光是影响植物生存和生长发育最重要的环境因子之一,植物与光环境的关系一直是植物生理生态学研究的热点问题.随着生长光强的变化,植物能够在形态及生理方面产生可塑性响应,以适应变化的光环境[7].     

朝鲜崖柏种子形态质量及萌发特性的初步研究

以吉林省长白县十五道沟采集的朝鲜崖柏种子为试验材料,利用超景深三维显微系统对其种子形态、千粒重进行了观察、描述和测定,探讨不同温度对种子萌发的影响,结果表明:朝鲜崖柏种子长2. 20~3. 80 mm、宽0. 96~1. 31 mm、厚0. 15~0. 84 mm,种翅长3. 63~5. 25 mm、宽0. 49~0. 90 mm,千粒重1. 174 1 g,朝鲜崖柏种子在相对湿度75%、温度25℃下萌发效果最好。     

崖柏组织培养初探

以崖柏茎段为外植体,MS为基本培养基,探讨0.1%升汞不同消毒时间对外植体消毒效果;不同盐浓度的培养基对外植体生长的影响。结果表明:0.1%升汞消毒12 min污染率最低,杀伤率低,表面灭菌效果最好;1/2MS培养基上培养愈伤组织长势效果最好。     

北美香柏全光喷雾扦插繁殖技术研究

在全光喷雾条件下,研究了基质、蔗糖处理、激素处理和插穗年龄对北美香柏插穗生根的影响。结果表明:以蛭石为基质扦插香柏的生根效果最好。蔗糖处理可以显著提高生根率,浓度为5%的蔗糖处理效果最佳。激素对促进生根也有显著效果,以2000 mg/L ABT2速蘸30 s处理效果最好,生根率达到92.9%。随着插穗年龄的增加,生根率下降,1 a生枝条扦插生根效果最好。     

温度、光照和水分对珍稀濒危树种崖柏种子萌发的影响

以崖柏种子为试验材料,研究不同温度条件、光照和持续黑暗、不同浸种时间等对种子萌发的影响,探讨适宜崖柏种子萌发的环境条件。结果表明:适宜崖柏种子萌发的温度为25℃,种子发芽率为88%,20℃和30℃条件下的种子发芽率分别为77%和33%。种子萌发进程在20℃和30℃条件下比在25℃条件下开始的时间晚,萌发持续的时间长。高温会显著提高种子霉变率,30℃条件下的种子霉变率高达40%;光照不是崖柏种子萌发的必要条件。在连续黑暗条件下种子仍可萌发,且种子发芽率、发芽指数、发芽势、霉变率等无明显差别。但在光照下种子持续发芽的时间短,种子霉变率低;浸种72 h、96 h和120 h对崖柏的种子萌发没有显著影响,但浸种120 h的种子发芽率低,霉变率高。浸种72 h即可以满足崖柏种子萌发对水分的基本需求。     

Root development of Thuja plicata in peat-substitute rooting media

In this study we investigated the potential usefulness of different substrates produced from gorse (Ulex europaeus L.) for propagating cuttings of Thuja plicata ‘Atrovirens’. The gorse was composted by different methods, to produce four types of compost. These composts were then used as such (100% compost) or in mixes with coarse sand and pine bark compost (25% compost, 25% coarse sand and 50% pine bark compost, v/v/v) to prepare eight different substrates. The substrates were compared in cutting propagation trials carried out in a greenhouse, with a standard rooting medium consisting of 25% Sphagnum peat moss, 25% coarse sand and 50% pine bark compost (v/v/v). Cuttings were taken from a garden hedge in March 2003, and comprised shoots of the previous year's growth. The bases of the cuttings were treated with a 0.4% solution of IBA rooting hormone, then inserted into cells filled with the corresponding substrate and placed on a propagation bench. Rooting percentage and visual rooting score were determined in July. The quality of roots was evaluated, as total root length and number of root tips, in July, September and November 2003, by use of a Delta-T Scan system. The rooting success of the cuttings ranged from 75% to 90%, except when the substrate comprised the pure composted gorse, obtained after the shorter period in an enclosed composting system with addition of fertilizer and reuse of leachates. Most of the cuttings in this substrate died and only 4% of the cuttings rooted successfully. Physicochemical characteristics of this rooting medium included very high electrical conductivity, low C/N ratio and high water retention. Addition of coarse sand and pine bark compost to the composted gorse significantly increased the rooting success. The root quality variables differed depending on the substrate considered and date of harvest. The results showed that substrates made from gorse compost are of potential use as a peat substitute for propagating cuttings of T. plicata ‘Atrovirens’. The physicochemical properties of the composted gorse should be determined before its use to establish whether it can be used pure as a substrate for rooting or whether it should be mixed with other substances.     

长白侧柏资源及其生长规律的调查

本文采用标准地调查法对长白侧柏资源状况进行了研究,通过调查掌握了该种在高寒、高海拔山区的生长规律及生态环境。