Comparing genetic diversity in agroforestry systems with natural forest: a case study of the important timber tree Vitex fischeri in central Kenya

It is possible that current tree domestication practices undertaken by farmers reduce the genetic base of tree resources on farms, raising concerns regarding the productivity, sustainability and conservation value of agroforestry ecosystems. Here, we assessed possible changes in genetic variation during domestication in the important and heavily utilised timber species, Vitex fischeri Gürke (syn. Vitex keniensis), by comparing geographically proximate forest and farm material in central Kenya. Employing RAPD analysis, a total of 104 polymorphic markers revealed by five arbitrary primers were scored in a total of 65 individuals, 32 from forest and 33 from farmland. Despite concerns of possible genetic erosion, forest and farm stands did not differ significantly in levels of genetic variation, with H values of 0.278 and 0.269, respectively. However, Mantel tests did reveal greater geographically related associative genetic structure among individuals in farm rather than forest material, with r _M values of 0.217 and 0.114, respectively. A more detailed analysis of structure suggested this could be due to local variation in origin of some on-farm trees. Implications of data for the genetic management of V. fischeri stands during farmer-led tree domestication activities are discussed. At present, there appears little reason to reject on-farm V. fischeri as a source of germplasm for future on-farm planting or for conservation purposes, although this situation may change and will require monitoring.     

欧洲赤松引种试验初报

树木引种驯化在林业发展中,始终具有较强的魅力。这是由于一个优良的树种,理性地引入一个地区后,所带来的良性变化决定的。欧洲赤松生长快、抗性强、耐干旱瘠薄、耐高寒。我们从80代即开始了国内外松属植物的引种工作,其中欧洲赤松(pinusdensiflorasieb·etzucc)是较为成功的一例。本文实录了20余年赤松引种驯化情况,以供同行们参考。     

树木引种驯化的生态限制条件探索

在昆明树木园的树木引种驯化工作中 ,探讨了引种树木的生存、生长、发育受引种地常年性和偶发性生态条件影响的程度以及引种树种对新环境条件的适应能力。一定的生态环境 ,对一些树种是适生条件 ,对另一些树种则是生存、生长发育的限制条件。这决定于树木的遗传变异性。由于各树种的遗传变异性不同 ,因而在受引种地生态条件影响的程度上存在种间差异 ,相同树种个体间也存在一定的遗传差异 ,种内在受引种地生态条件影响的程度上也存在着个体差异。引种树木对引种地的新环境的适应能力可分为相似生态适应能力、潜在适应能力和可塑性适应能力。这种适应能力也存在种间和种内个体差异 ;适应能力的大小是该引种树木在新环境中能否存活以致正常生长发育的关键。研究引种地常年性和偶发性生态条件对引种树木的影响和引种树木的适应能力 ,可以开扩树木引种驯化视野 ,使树木的引种驯化工作取得显著成效     

广玉兰在北方地区引种驯化与嫁接繁育技术

对广玉兰由南方引入北方过程中的技术要求做了阐述，并利用北方资源嫁接繁育，通过砧穗之间的相互影响及栽培措施，培育出了抗寒性强的群体类型，使其成为北方风景园林的优良树种。     

观光木人工林驯化栽培试验和系统生产力研究

本文对观光木驯化栽培环节中的采种、育苗、造林、管抚等摸索了一定的经验,并用分层切割法测定10年生样本地上部分各器官的生物量,用壕沟法测定地下部分根系的生物量。结果表明:10年生林分生物量为55.03t/hm~2,其中乔木层为53.035t/hm~2(占96.37%),乔木层中树干、枝、叶和根系分别为37.91t/hm~2、6.17t/hm~2、2.21t/hm~2和6.75t/hm~2。18年生解析木数据表明:胸径、树高和材积速生期分别出现在4—12年、5—7年和第14年。     

野生盾叶秋海棠引种驯化及应用研究

1997～2001年，采集西畴、麻栗坡野生盾叶秋海棠，引种至昆明市植物园温室区，通过物候观察，繁殖，生态适应性试验，证明引种的盾叶秋海棠生长健壮，正常开花结实，繁殖后代，可用于室内观赏或作为林下地被。     

白马鸡人工驯养初步研究

通过人工饲养的方式探索出白马鸡驯养的经验,即:在野生白马鸡适宜生境下建立饲养场,从育雏阶段开始进行人工投食饲养和本地土鸡带领相结合的驯养方式。目前已经完成从子一代到子二代的完整驯养、饲养流程,取得了云南省林业厅的驯养繁殖许可证。对育雏、亚成体、成体阶段的喂食量、存活情况等作了分析,认为接近原始生境的环境及本地带雏母鸡是成功的重要条件。     

牡丹在拉萨的引种驯化初探

牡丹是中国传统名花,观赏价值较高,深受广大人民喜爱。在拉萨从未有过大规模引种栽培牡丹的历史,为了提高本地区园林绿化水平和景观质量,满足人们观赏牡丹的需要,西藏农牧科学院蔬菜所从2009年起开始进行牡丹引种栽培试验,通过多年尝试,发现紫斑牡丹可以适应拉萨气候条件,并能露地安全越冬,已建成紫斑牡丹园。中原牡丹和西南牡丹适应性较差,不适合在拉萨气候条件。文中详细阐述了牡丹在拉萨市栽培和养护管理的技术要点和经验教训,可为在拉萨以及其他高寒地区园林绿化中推广及应用牡丹提供借鉴。     

Comparison of larval performance between Thai and Vietnamese freshwater giant prawn, Macrobrachium rosenbergii (de Man): a preliminary study

This study compared the performance of larvae of giant freshwater prawn (Macrobrachium rosenbergii) from Thailand and Vietnam. Thai broods were collected from a farm and Vietnamese broods were collected from a river. Larvae from these two sources were raised in identical environments, and their rates of development and survival as well as their ability to withstand environmental stresses were assessed. The first postlarval stage was observed in both strains on day 22. All larvae (100%) from Thai broods completed metamorphosis by day 36, but only 89% of the Vietnam strain completed metamorphosis by day 45. The stages of development were more uniform in larvae from the Thai stock than the Vietnamese stock. Survival differences were observed within the first week (92% in the Thai group vs. 55% in the Vietnamese group). These differences were most pronounced beginning in week 5 (52% and 16% respectively) and week 7 (33% and 2% respectively). No clear difference was found in brood size and fecundity between the two groups. No difference in survival was observed between the two groups of larvae challenged with salinity, oxygen or formalin. Differential development rates of larvae in the same batch would naturally create conditions favourable for cannibalism and impaired ability to capture food. The earlier and more uniform rate of development, and subsequent higher rate of survival of Thai stock compared with the Vietnamese wild stock is suggested to be due to inadvertent selection in the domesticated stock.     

樟子松引种驯化和遗传改良研究现状

樟子松为中国北方特有的珍贵树种,具有生长快、适应性、耐干旱瘠薄的优良特性,经济、社会和生态价值显著。因此,樟子松这一珍贵资源的引种驯化与遗传改良极为重要,在汲取国内外相关研究成果和学术观点的基础上,系统阐述了樟子松的种源试验、引种驯化、遗传改良、良种选育、种质保存及可持续利用等领域的研究现状和进展,指出了种质资源保存方面存在的不足,展望了种质资源可持续经营的广阔前景,提出了优异种质创新利用的具体思路和对策,以期为拯救并保护障子松资源提供理论参考。