The effects of Douglas-fir on tree-specific arthropod communities in mixed species stands with European beech and Norway spruce

The ecological effects of planting exotic Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] in Central Europe are still poorly understood. The aim of this study was to answer the question of whether Douglas-fir affects tree specific arthropod communities in different mature forest types (Douglas-fir, spruce and beech dominated) in Southern Germany. Therefore, arthropod communities of stem and tree crown strata of Douglas-fir and spruce (Picea abies L.) were sampled in the years 1999–2001 using arboreal photo-eclectors and flight interception traps. Statistical analysis was conducted for all species and focused on conifer specialists at three levels: (1) species diversity, (2) guild structure and (3) community structure. Within the stem stratum, species diversity was significantly higher on spruce than on Douglas-fir independent of year and stand composition. This could not be explained by a single feeding guild, rather by species changing strata during the vegetation period. In contrast, species diversity in tree crowns was approximately the same for both conifer species. However, communities in Douglas-fir crowns were conspicuously different from those in spruce crowns, especially in the Douglas-fir dominated stand type. While zoophagous insects exhibited higher activity on Douglas-fir in 2000, xylophagous beetles were more abundant on spruce in 2001. In European beech stands with widely spaced Douglas-fir trees, the site specific and broad-leaved tree related fauna might be maintained. In addition, Douglas-fir with its resource of Adelges cooleyi and crowns that overtop the broad-leaved tree canopy, offer additional resources for several aphidophagous and thermophile species.     

天然红松种群遗传多样性和遗传分化的研究

ISSR是一种特异性较强、稳定性较高的分子标记方法。本研究采用ISSR-PCR技术,检测了红松(PinuskoraiensisSieb.etZucc)在伊春市汤旺河高峰林场、长白山二道白河、黑河胜山林场和俄罗斯海参崴市郊的四个种群的遗传多样性和遗传分化。15个引物的扩增结果表明:红松群体的多态位点比率是60.70%,平均每个引物3.6个多态位点,多样性水平在松科植物中是较高的;红松分布中心区的遗传多样性要高于边界区;和大多数木本植物一致,红松群体的基因多样性主要来自种群内部,占总基因多样性的73%;红松四个种群的遗传距离和地理距离之间无正相关性。根据研究结果推测,天然红松分布区逐渐缩小的原因不是由于遗传多样性水平过低引起的,而是由于人类的破坏作用,再加上火灾和风倒等因素造成的。     

Variation in Heterobasidion annosum detected by Random Amplified Polymorphic DNAs

The production of Random Amplified Polymorphic DNAs (RAPDs) by Polymerase Chain Reaction (PCR) was used to detect variation in the isolates of Heterobasidion annosum with various geographical origins. Specific RAPD products were detected for each of the intersterility groups: the European S, F, P and the North American S group. There was considerably more polymorphism found among European S than P isolates. The analysis of RAPDs was shown to be a simple and a fast way to generate DNA markers specific to the previously established intersterility groups and thus useful for diagnostic purposes.     

国外云杉遗传改良现状和粗枝云杉育种策略

综述国外云杉遗传改良现状和育种策略。讨论“种子园危机”缘由。介绍德国、瑞典、丹麦、挪威和芬兰等国欧洲云杉无性系林业研究方法、技术路线、生产规模、应用前景及可能障碍。世界云杉遗传改良正沿着高效益、低成本的方向快速发展。提出粗枝云杉近期改良策略。     

植物生物技术:苏云金杆菌抗虫基因的研究和它对未来树木遗传工程的影响

许多不同的技术可以促进农业生产力的持续增长，生物技术是其中最重要和最有前途的方法。因为生物技术不仅可以增加生产力。而且在环境和自然资源的保护中起重要作用，应用生物技术可以生产高产、优质、高抗性和无病植物，同时也可以提高育种效率和促进食品的工业化生产。苏云金杆菌抗虫基因是目前生物技术领域中应用最广泛的例子之一。由此而产生的抗虫植物正在广泛应用于世界各地的商业化生产。本文综述了苏云金杆菌抗虫基因的研究进展和它在未来林木遗传工程中的应用。表4参68。     

利用RAPD分析大青杨天然群体的遗传结构

本文利用ＲＡＰＤ分子标记技术从ＤＮＡ分子水平上探测了大青场（ｐｌｐｕｌｕｓｕｓｓｕｒｉｅｎｓｉｓＫｏｍ．）天然群体的遗传结构和分化程度。结果得出：用１４个随机寡核苷酸引物共产生１８０个扩增片段，扩增片断在２１１ｂｐ至１６３６ｂｐ之间。Ｓｈａｎｎｏｎ表型多样度（ＨＯ）估测值在群体间变动范围为０．２７１至０．３９２，平均为０．３１０。对分子水平变异分为群体间和群体内两部分进行分析，群体间分量占总变异的６２．３％，群体内只占３７．７％。不同引物在群体内探测能力也各不相同，ＣＨｌ－ｌ引物探测多样度（ＨＯ）最高（０．５４０），而２１１６引物最低（０．１５１）。     

发根农杆菌(Agrobacterium rhizogenes) Ri T-DNA遗传转化丝石竹(Gypsophila paniculata)的研究

近年来,已发展出遗传转化高等植物的一些新技术,其中有些技术如脂质体融合,微注射技术和电击导入都是基于动物细胞培养方面的工作,而另一些技术是来自于植物界独特的天然转化系统,其中包括已知能遗传转化高等植物的农杆菌(Agrobacterium)的二个种,即致瘤农杆菌(A.tumefaciens)和发根农杆菌(A.rhizogenes),这二个种都能够将其致病质粒Ti或Ri所携带的DNA序列(T-DNA)插入到双子叶植物细胞核基因组中。pTi诱发寄主产生根基肿瘤,pRi诱发寄主产生毛状根。二者的差别可能是毛状根可以从毛状根培养物获得具有完整的T-DNA序列的有生育能力的再生植株,而从致病农杆菌(A.tumefaciens)菌株所诱发的肿瘤很难获得再生植株。因此,利用发根农杆菌(A.rhizogenes)pRi作为遗传转化高等植物的基因克隆载体的研究和应用日益受到重视。     

蓝桉、直干桉重要材性性状的遗传参数和预期增益

在种子园育种区4个区组内,从蓝按和直干按中各抽30个家系对它们的纤维长度、木材密度的遗传力、遗传相关和遗传增益作了估算.蓝按纤维长度和木材密度的单株遗传力分别为,0.6745±0.0746和0.3546±0.1010;直干按两性状的遗传力分别为0.3416±0.1011和0.0670±0.0850.两树种的纤维长度与木材密度、树高和胸径的遗传相关系数均为正值,而木材密度与树高和胸径的遗传相关系数都是负数.为这两树种提出了选择的主要性状、选择方法和标准,还为高世代育种应注意的事项作了建议.     

利用ISSR标记对12种五针松亲缘关系的研究

采用ISSR 标记技术,对12 种五针松的亲缘关系进行分析。利用筛选出的12 个ISSR 引物共检测到117 个位点,多态条带比率(PPB)在9.40%～33.33 %之间,遗传分化最高的是偃松,最低的是柔枝松。12 种五针松的基因多样性(Ht)为26.21%,其中种内基因多样性(Hs)为7.66%,种间基因多样性(Dst)为18.55%,五针松种间变异占总变异的70.78%。遗传距离聚类,将12 种五针松分为2 个类群,第一类群包括乔松、华山松、海南五针松、华南五针松、北美乔松、山白松和云南五针松;第二类群包括美国白皮松、偃松、、柔枝松、西伯利亚红松和红松。图1 表3 参6。     

Genetic parameter estimates for growth and form traits in common ash (Fraxinus excelsior, L.) in a breeding seedling orchard at Little Wittenham in England

Data from a trial of 36 families at Little Wittenham, North Oxford was used to assess growth traits and stem form in common ash (Fraxinus excelsior, L.). The trial followed a design described by Barnes (Silv Genet 44(2–3):81–88, 1995) as the Breeding Seedling Orchard (BSO). The objectives of the study were to determine variation in growth and form traits and estimate genetic parameters of families. Assessments conducted at 3–8 years for height, diameter at breast height (dbh), straightness and forking showed significant differences (P < 0.05) among families with Guys (19), Settrington (34), Overbury (23) and Grimthorpe (36) being the best performers while Coleford (3 and 5) Gwynedd (27) and Bacheiddon (32) were the least performers. At the overall level, the additive genetic coefficient of variation (CV_A) ranged between 10.2 and 12.7% for height and 1.5 and 2.1% for dbh. Height had a high genetic correlation (r_g = 0.85) with dbh whilst forking had low correlation (r_g = 0.25) with height. Estimates of heritability decreased with age from  = 0.62 at 3 years to  = 0.30 at 8 years for height while values for dbh decreased from  = 0.48 at 4 years to  = 0.27 at 8 years. Some genetic gains are possible despite the low genetic variation among families; height had the greatest potential of genetic gain (12.5% at 8 years). Results suggest that early selection of superior families of Fraxinus excelsior appears to be feasible and it could be possible to achieve simultaneous improvement in both growth and form.