用RAPD标记进行鹅掌楸杂种识别和亲本选配

杂种马褂木是以鹅掌楸属 (Ｌｉｒｉｏｄｅｎｄｒｏｎ)现存两个种中国马褂木 (Ｌ .ｃｈｉｎｅｎｓｅ(Ｈｅｍｓｌ.)Ｓａｒｇ .)和北美鹅掌楸 (Ｌ .ｔｕｌｉｐｉｆｅｒａＬ .)为亲本所创造的种间杂种 ,由叶培忠教授于 1 963年首次育成。 30多年的栽培试验表明 ,该杂种不仅在生长和     

落羽杉属树木种间杂交选育研究进展

对落羽杉属树木种间杂交育种研究及杂交后代优良无性系的特性作了综述,并对该属树木种间持续育种和优良杂种的推广应用前景进行展望。     

榆树杂交育种研究报告

我国榆属树种约有25种,其中以白榆分布最广,栽培利用最多,是华北平原四旁绿化和小片林的主要树种,但生长较慢,侧枝粗大,主干低矮,迫切需要选育生长快、干形好的良种。榆属各种,长期适应不同地理区域的土壤气候条件的结果,形成了各不相同的生物学特性,具有不同的经济价值,这就给杂交育种工作提供了丰富的原始材料。 我们从1972年进行榆属种间杂交育种,十年来先后利用十几个种进行了近30个杂交组合的试验,后期还利用杂种做亲本进行了复交,先后获得杂种苗5000余株,选     

杂种马褂木杂种优势的遗传分析

在叶培忠先生的鹅掌楸属种间杂交育种研究基础上按遗传设计与环境设计开展了扩大北美鹅掌楸遗传基础条件下的正反交以及前人从未做过的回交和F1 间杂交 ,并进行了杂种马褂木杂种优势的遗传分析。结果表明 :(1)正反交F1 、BC1 和F2 4种交配系统杂种的 1a生幼苗普遍存在显著正向生长杂种优势 ;幼苗生长性状在家系间存在极显著差异而在家系内具有很大变异性 ;回交家系表现特别优良 ,因而家系选择、单株选择以及BC1 和F2 利用潜力很大。 (2 )初步提出“光合优势假说”(Photosyntheticsuperiorityhypothesis)作为杂种马褂木和其它杂种树木杂种优势机理的理论解释。 (3)简单估算了一些重要遗传参数     

柳树杂种木材基本密度的遗传变异

利用柳属和钻天柳属种间、属间杂交１５个杂种３９个杂交组合１５１个无性系材料，对木材基本密度的遗传变异情况进行了研究。结果表明，杂种间和无性系间，在木材基本密度上存在极显著（α＝０．０１）差异，其中属间杂种（旱柳×钻天柳）×旱柳平均木材基本密度达到０．４８８，显著（α＝０．０５）超过各杂种平均值；柳树杂种及无性系木材基本密度是受强遗传控制的，被研究群体的广义遗传力达到０．９２￣０．９８，遗传变异系数     

国外针叶树种间杂交研究进展

杂种在工业用材林中的作用越来越受到世界各国重视。数十年来不少国家都开展过广泛的针叶树种间杂交研究,为选出各自适用的种间杂种,在理论、方法和实用性方面取得重大进展。通过种间杂交创造新的、对特殊生境更有适应力的杂种对引入树种更有效果。若干外域树种引入我国后表现良好,并成为主要造林树种,探索它们的杂种利用,对开展边沿低质土地的造林有重大实用性。通过推行“杂种林业”,提高我国工业人工林的经营效益,今后将成为遗传改良的一个重要领域。本文概述世界一些国家在这一领域的经验,供实施中借鉴。     

中国柳属次级区分的探讨(一)

中国柳属约有200个种（以及大量的杂种和一些外来种）.本文中,该属被区分为38个组,以种为一整体的概念编制了分组检索表,详细记述了每一个组,同时列出了全部的种类（含杂种和外来种）,包括它们的名称（正名、异名）、地理分布等.     

咖啡种间杂种的不育性

本文研究了咖啡属六个二倍体种的六个种间杂种Ｆ１后代姊妹株之间生殖障碍的各种因素。提出花粉和柱头组织的原生质渗透浓度和杂种群体自花不孕等位基因遗传变异性的降低，就是可能的生殖障碍，因而也是这些杂种不育性的原因。     

君子兰莳养管理技术

君子兰属石蒜科，原产非洲南部温暖干旱森林地区，有大花、垂笑、杂种君子兰3种。     

中国柳属次级区分的探讨(二)

中国柳属约有200个种（以及大量的杂种和一些外来种）。本文中，该属被区分为38个组。以种为一整体的概念编制了分组检索表，详细记述了每一个组，同时列出了全部的种类（舍杂种和外来种），包括它们的名称（正名、异名）、地理分布等。     

Interspecific hybridization of Eucalyptus: key issues for breeders and geneticists

Eucalypt hybrids are significant in forestry, particularly in sub-tropic and tropical regions, where cost efficient, clonal propagation is the key to their exploitation. However, the outstanding success of selected hybrid clones has given a biased impression of the vigor of eucalypt hybrids and the strength of reproductive barriers in the genus. When full account is made of losses through the life cycle, a picture of high incompatibility and inviability often emerges. Hybrid inviability tends to increase with increasing taxonomic distance between parents, but there are exceptions. Hybrids also seem more susceptible to pests than their pure species. Intense selection may still result in elite hybrid clones, but such inviability and susceptibility adds a significant cost to their development. Breeders must carefully evaluate the costs of hybrid development and deployment compared with pure species options. A key to hybrid selection is the rapid development and testing of large populations and application of high selection intensities. However, eventually this approach must be linked with more formal breeding strategies. As most traits are intermediate in F₁ hybrids there is increasing interest in advanced generation hybrids to provide desirable trait combinations. In such cases, there is a clear role for marker assisted selection to speed introgression.     

广州市园林木本植物原产区分析

对广州市园林木本植物进行了调查,调查结果为:该市园林木本植物共有339种以上,其中原产于广州市的有54种,占总种数的15.9%,其它均为引种,主要引自于亚洲、中美洲、南美洲、非洲和大洋洲的热带和亚热带地区.对该市园林木本植物所属的科、种及其分布进行了详细分析,分析结果为:原产区分为12类,根据原产区的类型,我国自然分布的有150种,占总种数的44.2%;从国外引进的种(我国不产)有163种,占总种数的48.1%;杂交种和栽培变种有26种,占总种数的7.7%.在分析原产地的基础上,就今后的引种栽培工作提出了4点建议.     

落叶松种间及其杂种管胞特征及微纤丝角的变异

对落叶松属4个种及其以日本落叶松为母本的种间杂交组合的早晚材管胞形态和微纤丝角进行了测定分析,研究结果表明:落叶松各管胞特征值及微纤丝角基本符合甚至远超过较优纸浆材筛选要求;落叶松种间及其杂种早晚材管胞形态特征值差异显著或极显著,早、晚材管胞长变幅分别为3164.45～3 865.26、3 318.51～4 200.8...     

Vegetative Propagation of Leucaena Hybrids by Cuttings

Many interspecific hybrids have been produced among Leucaena species, some with great potential for high-value wood and forage production. Superior hybrids are often highly sterile, and vegetative propagation would be essential for their exploitation. Four experiments were conducted to investigate factors affecting the rooting of cuttings of Leucaena hybrids. Nine hybrids were studied that represented different ploidy levels (2x, 3x, and 4x), different levels of seedlessness, different ages (5–16 years) and varying leaflet sizes. Rooting ability basically depended on genotype, with only a few hybrids failing to root. Cuttings required leaflets to root, and half or more of a leaf led to higher frequencies of better roots. One-node cuttings had the same rooting ability as two-node cuttings. Rooting ability decreased dramatically in the cooler, low-light winter seasons of lowland Hawaii. Etiolation treatments increased rooting ability significantly for two difficult-to-root hybrids.     

落叶松种间及其杂种生长与形质性状评价研究

[目的]通过对落叶松种间及其杂种生长与形质性状评价来定向选育优良落叶松建筑材。[方法]以辽宁省大孤家林场32年生的落叶松试验林为实验材料,对落叶松属日本、兴安、长白及华北4个落叶松种,及以日本落叶松为母本的日本×兴安、日本×华北、日本×长白、日本×日本杂种的生长和形质性状进行变异规律分析,并采用模糊数学隶属函数对其差异显著指标进行综合评价。[结果]表明:落叶松种和杂种间生长差异显著(p<0.01),杂种胸径、树高和材积总生长量与母本差异不显著,却显著高于相应父本;杂种之间的生长差异体现在林分的前10年,随着林龄的增大优势逐渐减退;树冠特征因子中的枝下高、冠长、枝条直径、长度、角度和干形特征因子中的高径比、树干圆满度、节子直径、长度、角度在落叶松种和杂种间差异显著。基于上述指标进行了生长和形质性状综合评价,排名前三位的分别为日本×兴安、日本×长白和日本落叶松。32年生时日本×兴安的胸径、树高和材积分别为18.69 cm、21.62 m和0.339 2 m³;日本×长白的为18.44 cm、23.85 m和0.339 6 m³;日本落叶松的为19.36 cm、21.31 m和0.335 7 m³;而且它们在适应性上也具有明显优势。[结论]日本×兴安、日本×长白和日本落叶松适合作为定向培育建筑材的优良品种在东北地区重点推广。     

柳树花粉生活力分析

花粉生活力是植物杂交育种成败的现柳树种间、杂种间及亲本与杂种之间的花粉生活力差异较大.用花粉生活力较高的绵毛柳P716做花粉贮藏实验,结果表明花粉生活力与贮藏时间呈负相关,低温干燥对花粉贮藏是有利的.     

落叶松种间及种内和种间杂种家系间的物候变异与早期选择

对造林后1～3年生7种(变种)落叶松和7个种内和种间杂种家系的9个物候期进行连续定株观察及生长量调查,利用方差分析方法研究落叶松种间、家系间物候期的变异,利用主成分分析方法划分落叶松种(家系)的物候群,利用典型相关分析方法确定物候期与幼林生长量之间的关系.结果表明:除侧枝芽膨大外,落叶松种间、家系间各物候期的变异均达极显著水平.同样,种内个体间、家系内个体间也存在一定的物候期变异,但同种家系内个体间的变异明显小于杂种家系内个体间的变异.兴安落叶松顶芽展叶、抽新梢时间明显早于其他种,封顶也最早;其次是长白落叶松和华北落叶松;朝鲜落叶松和欧洲落叶松的封顶时间比长白和华北落叶松还要迟半个月;日本落叶松顶芽膨大和展叶时间最晚,封顶时间也明显迟于其他种.以日本落叶松为母本的各种间杂种,在物候上多数表现出中间偏母本的特性,而在抗病能力方面较父本有所改善,在抗寒性方面却明显优于母本.日本落叶松生长最快,其次是长白和朝鲜落叶松,而日×长、日×兴杂种生长量超过母本,表现出超亲杂种优势,表明在东北地区落叶松杂种利用潜力巨大.根据主成分聚类结果,可将14份遗传材料分为4个物候型.除侧枝芽开始展叶、完全展叶和抽新梢以外的其他物候因子与生长量之间相关紧密.物候因子对生长量有相当好的预测能力,即顶芽萌动、展叶越早,封顶越迟,生长期越长,对树木的生长越有利.     

Stomatal characteristics of riparian poplar species in a semi-arid environment

Several native poplar species meet at the margins of their natural distributions in southern Alberta, Canada. In this semi-arid area, poplars are obligate riparian species but they occupy several intergrading ecoregions. Populus deltoides Bartr. ex Marsh predominates in the warmest and driest eastern prairie ecoregions; P. balsamifera L. occupies the cooler and wetter western parkland and montane ecoregions; and P. angustifolia James and hybrids between the species occur in the intermediate grassland ecoregions. We investigated stomatal characteristics of these poplars in 51 genotypes collected across the range of ecoregions and grown in a semi-arid common garden. Stomatal length differed among genotypes within species but did not differ among species, ranging from 19 to 22 microm. Total stomatal densities (adaxial plus abaxial) differed among genotypes within species but were similar among species (290-420 stomata mm(-2)). Single-surface stomatal densities differed among species and consequently, the ratio of adaxial:abaxial stomatal density also differed, ranging from 0.94 for P. deltoides to 0.27 for P. balsamifera, with intermediate stomatal density ratios in P. angustifolia and hybrids. In a subsequent study of a subset of the same genotypes, stomatal density was correlated with stomatal conductance (r2 = 0.75) and the conductance ratios differed among species in the same manner as the stomatal density ratios. We conclude that: (1) diverse poplar genotypes respond similarly to a semi-arid environment by producing comparatively small and dense stomata; (2) differences in stomatal density underlie differences in stomatal conductance and differences among species in stomatal density ratio or conductance ratio may reflect adaptation to climatic differences among ecoregions; and (3) there is substantial variation in stomatal characteristics within and among species and hybrids in this area that could be useful for the selection and breeding of poplars adapted to different climatic conditions.