Morphology and rooting of shoots developing in response to decapitation and pruning of Caribbean pine

The effects of decapitation at various levels, combined with heavy pruning of remaining branches, were examined for Caribbean pine. This treatment stimulated the development of shoots with long primary needles at all levels in the crown of trees aged one, four and eight years. Although a significant positive relationship between primary needle length and rooting was demonstrated, the very juvenile appearance of these shoots was not a reliable guide to rooting. There was an over-riding effect on rooting of the ortet age × level in crown × decapitation height treatment. Decapitated trees provided shoots of higher rooting capacity than intact trees for the one and four, but not the eight year old trees. Shoots developing in the lower crown in response to decapitation and heavy pruning of four year old trees displayed a high level of rooting-equivalent to that of shoots from the decapitated and pruned one year old trees.     

福建山樱花扦插繁殖及其影响因子研究

在塑料拱棚下进行福建山樱花半木质化枝条扦插繁殖试验,分别进行了不同扦插繁殖时间、不同浓度的ABT1号和IBA处理、不同扦插基质和添加钙镁磷对生根促进剂提高福建山樱花扦插生根的影响试验及综合试验。结果表明,福建山樱花半木质化枝条扦插繁殖以冬末春初为适宜时期,以2份素沙+1份粘性黄土为扦插基质,插穗经IBA 2 500 mg.L-1+钙镁磷沾根I、BA 3 750 mg.L-1+钙镁磷沾根或IBA 5 000 mg.L-1浸泡处理均有良好的促进生根效果,平均插穗生根率和平均一级不定根数最高分别可达86.67%和4.68条。     

红叶石楠组培苗瓶外生根技术研究

以苗龄为40 d的红叶石楠组培继代芽苗为瓶外生根试验材料,采用多因素正交试验设计研究不同栽培基质、不同激素、不同激素浓度处理及处理时间对红叶石楠继代芽苗瓶外生根诱导的影响,继代芽苗扦插前的不同炼苗方式及扦插后施肥方式对芽苗瓶外生根率的影响。结果表明:A3B1C3D2组合(珍珠岩、生根粉ABT 200 mg.L-1浸泡处理30 min)获得59%瓶外生根率,而A3B1C1D2(珍珠岩、ABT 50 mg.L-1浸泡处理30 min)为最理想的组合;芽苗在自然散射光下炼苗15~20 d,生根率可提高到81%;栽后适时追施营养液有利于芽苗的高生长。继代芽苗瓶外生根技术的应用减少组培苗培养工序,促进红叶石楠的组培快繁效率,降低组培苗的生产成本。     

Observations on the rooting patterns of some agroforestry trees in an arid region of north-western India

The present study deals with root architecture of 6-year-old trees of 9 indigenous and 3 exotic species growing in arid climate of north-western India. Observations, made on excavated root systems (3 tree replicates of each species) showed large variation in horizontal and vertical spread of roots. In Morus alba, Melia azedarach and Populus deltoides, the roots were confined to 80 cm, while in Prosopis cineraria, Acacia nilotica and Eucalyptus tereticornis, roots penetrated more deeply to 233 cm. The number of total roots ranged from 103 in Acacia catechu to 1932 in Eucalyptus tereticornis, and 62 to 80% of the roots were less than 2 mm in diameter. The primary roots were more horizontal than the secondary roots. The total root biomass varied from 2.2 kg in Acacia catechu to 30.6 kg^–1 tree in Populus deltoides, and top 30 cm soil contained 42 to 78% of the total biomass. The implications of the results are discussed in the context of the ecological niche of the species, and its usefulness in agroforestry systems.     

四倍体刺槐组培瓶苗生根培养及生根苗移栽研究

四倍体刺槐是从韩国和匈牙利引进的大叶速生刺槐人工诱变的四倍体树种，具有速生、叶大、条粗、枝密、抗性强等特点，生长速度是普通刺槐的2倍以上。利用不同质量的组培瓶苗为材料，选取最佳生根状态的组培瓶苗进行生根培养和生根苗移栽试验，成功地筛选出生根培养基激素和生根苗移栽基质的最佳组合，建立了四倍体刺槐的再生系统。     

粉枝莓的组织培养与植株再生研究

利用粉枝莓的茎段和幼嫩叶片作为外植体，研究了不同激素水平对诱导产生愈伤组织，芽和根，完成植株再生的影响。试验结果表明：MS 6-BA0.5 NAA0.2培养基对诱导愈伤组织和芽的分化效果最佳。1/2MS IBA0.3对促进生根效果较好，在两步移栽法中，移栽存活率分别为94%和98%。     

Vegetative propagation of Colutea istria Mill. from leafy stem cuttings

This study investigates the optimal conditions for the vegetative propagation of the multipurpose leguminous shrub Colutea istria from leafy stem cuttings. The conditions examined included 1) the origin of the cutting (apical, medial or basal), 2) indole-3-butyric acid (IBA) treatment (0, 50, 200 or 400 mg/l), 3) the relative humidity of the propagation environment (high or low), 4) wounding base of cutting, and 5) the season in which the cutting was taken. The rooting ability of the cuttings was significantly influenced by all these factors. Winter cuttings obtained from the middle and base of the branch showed a greater rooting capacity than those harvested from the apical area, while autumn cuttings harvested from the middle and apical areas of the branch showed a greater rooting capacity than those harvested from the base. Winter cuttings showed the best rooting capacity than autumn cuttings. IBA treatment (200 mg/l), high humidity (98-100%), and wounding increased the rooting capacity of the cuttings. The sprout of new leaves was higher in basal cuttings, while IBA and wounding also significantly enhanced the root number of rooted cuttings. A method for vegetatively propagating C. istria plants is given.     

台湾杉木幼树侧枝扦插试验初报

从５年生台湾杉木幼林中选择优良单株，利用树冠中上部枝条进行扦插试验。结果表明：台湾杉木扦插生根与愈伤组织的形成关系不大，属皮部生根型；用不具顶芽的１年生二级侧枝作插穗，穗长８ｃｍ，去除插穗下部２／３的针叶，用１００×１０￣（－６）ＡＢＴ＿１生根粉处理４小时，插于粘性黄心土上效果最好。     

The use of isozyme genetic markers to estimate the rate of outcrossing in a Sitka spruce (Picea sitchensis (Bong.) Carr.) seed orchard in Scotland

Effects of genotype, collection date, auxin treatment, crown position and artificial chilling on rooting and subsequent vegetative growth of Cupressus sempervirens L. softwood cuttings taken from 13-year-old plants were evaluated. Three different clones (318, 296 and 22) previously selected for resistance to cypress cortical cancer caused by Seiridium cardinale were used. In all these clones, both the IBA treated and the untreated cuttings showed seasonal periodicity of rooting. Untreated cuttings rooted best when collected in April (up to 49% for the best clone, i.e. 296) and rooted very poorly in July and October. Auxin treatments appeared unable to overcome this periodicity, as the cuttings taken in July and October did not respond to IBA stimulation. However, in January and April, IBA treatments enhanced adventitious root formation of poorly rooting clones (318 and 22), as well as of clone 296, which performed best (89%) when cuttings were treated in April with 1.5% IBA. Cuttings of each clone collected in the lower third of the crown of the donor trees showed a significantly higher rooting percentage, when compared with those from the upper third. A 4-week post-severance chilling treatment (4°C) significantly enhanced the rooting capacity of cuttings taken in January, while a longer chilling treatment (8 weeks) had a negative effect. The subsequent growth of the rooted cuttings was not affected by either the crown position of the severed cuttings, or the genotype.     

尾叶桉的组织培养及植株再生

研究了以尾叶桉(Eucalyptusurophylla)优树(U6无性系)无菌苗的叶子和茎段作为外植体诱导愈伤组织、丛生芽发生以及植株再生的过程。通过多种生长调节剂不同浓度组合的对比试验,确定了U6快繁体系的最适宜培养条件:(1)愈伤组织诱导培养基:MS 1-2mg/L2,4-D;(2)芽增殖培养基:MS 0.5mg/L6-BA;(3)生根培养基:1/2MS 2.0mg/LNAA。