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。     

四川乡土和引进丛生竹的生长表现及竹丛营养空间拓展分析

围绕四川竹业资源培植需求,对8个丛生竹竹(品)种引种栽培3 a的生长性状变化和适应性进行分析.从立竹胸高断面积、竹丛篼幅及冠幅的变异系数变化,探讨了竹丛生长的营养空间拓展及其立地适应性表现.结果表明,丛生竹造林3 a的生长增殖已正常地表现出丛生竹无性系种群增长及结构动态,竹林已具备资源生态经济价值.     

Rooting of juvenile succulent cuttings from haif‐sib families of Picea abies

Leader shoots from juvenile succulent Norway spruce seedlings were used as cuttings 11 weeks after sowing. The seedlings were grown for 6 additional weeks and then apically dominant and lateral shoots were also used as cuttings. These three cutting categories, leaders, dominants and laterals, rooted 99.4, 99.0 and 97.5 % respectively and performed differently with respect to rooting development, number of roots per cutting and response to IBA and PIBA treatments (synthetic auxins). A large individual variation in number of roots per cutting, which auxin treatments did not reduce, was present within each cutting categoty. Laterals from the three different families included in the study showed a different variation than did leaders and dominants. Generally, the juvenile succulent cuttings were easy to root. Seedlings grown at a rather high light intensity (62 W/m²) had the potential to give good rooting even without hormonal treatments.     

Restoration of the mangrove vegetation in the Mahanadi delta,Orissa, India

In India, mangroves occupy 6740 km² of which the Mahanadi delta andBhitarkanika mangrove forests of Orissa cover 191.44 km², most of whichhas been severely overexploited. World wide concern to conserve mangrovesnecessitated propagation of mangroves to re-establish them on barren andswampy land along tidal creeks around Paradeep port of Orissa. Avicenniaofficinalis, Aegiceras corniculatum, Bruguiera parviflora, B. sexangula,Ceriops decandra, Excoecaria agallocha, Heritiera fomes, Kandelia candel,Rhizophora mucronata, Sonneratia apetala were vegetatively propagated andplanted over 10 ha of degraded salt-marshy wetlands of Mahanadi delta inpure and mixed stands depending on the intensity and the frequency of tidalinundation at the experimental site. Survival was significantly higher(80%) in S. apetala followed by A. officinalis, R. mucronata, K.candel and H. fomes (70–75%). S. apetala recorded the maximumgrowth in height (3.0 m after 2 years) whereas C. decandra showed theminimum growth (0.5 m). Growth performance was better with plants in mixedstands than the plantation with single species. This gives us hope topropagate and re-establish mangroves for conservation in scientificallymanaged plantations in a physiologically arid environment.     

尾叶桉等植物叶提取液对几种植物插条生根和种子萌发的影响

尾叶桉等植物叶提取液对几种植物插条生根和种子萌发的影响＊黄卓烈林韶湘谭绍满林松煜杨国清莫晓勇关键词尾叶桉落地生根紫竹梅水竹草插条生根种子萌发桉树是相当难生根的植物。当用桉树的成熟枝条扦插时成功率极低［１］，甚至成活率为零［２］。柳树和杨树则是较容易生...     

杉木无性系在不同条件下扦插生根及生长的研究

对杉木无性系扦插繁殖的生根及生长能力与扦插基质、原株年龄、采穗部位、穗条长度、扦插深度和时间等相关因素进行研究,结果表明,在不同杉木无性系之间,扦插生根及生长能力存在极显著差异．扦插基质、原株年龄、采穗部位和穗长、扦插深度和时间,对杉木扦插成活有显著或极显著的影响：①蛭石插床有利于插穗生根,但苗高生长以混合土为基质的插床为好;②无性系的生根能力、苗高和根径的生长量与原株年龄的关系表现为1年生＞3～5年生＞15～20年生;③根径处插穗的生根率、侧根生长量及苗高,分别比苗高1／3处的插穗大11．8％～18．6％,3．4％～9．8％和14．7％～25．7％;④穗长以10～12cm为宜,扦插深度为穗长1／2为好,扦插时间选择在12月份为佳．     

Rooting of baldcypress cuttings

A test of the rooting performance and growth of cuttings from 1-year-old and 25-to 50-year old baldcypress (Taxodium distichum L.) branch tips is reported. Rooting of cuttings from one-year-old trees averaged 75% (0.1% IBA treatment) and 88% (control), cuttings from 25 to 50-year-old trees averaged 12% in both the IBA treatment and the control treatment. Indole-3-butyric acid at a 0.1% concentration did not enhance rooting, but resulted in a significant increase in shoot dry weight on cuttings from one-year-old trees. The results of this experiment suggest that cuttings from mature baldcypres trees have the potential to root, thereby, additional rooting techniques such as girdling and stump sprouts is worthy of pursuing.     

Stem respiration in leafy cuttings of Prosopis juliflora during the rooting process

An oxygen electrode was used to estimate the respiration rate of basal 1 cm sections of Prosopis juliflora cuttings. The respiration rate per unit dry mass decreased linearly with increasing diameter at a rate of 0.42 nmol0₂g^–1s^–1mm^–1 between the range of 1–3 mm diameter. However, as a result of increased mass, total respiration for the whole 1 cm section of tissue increased linearly with increasing diameter. The average respiration rate of the basal 1 cm of stem tissue, measured 14 days after insertion in the propagator, was almost double that of the 1 cm section of tissue above it (1.01 nmol0₂g^–1s^–1 compared to 0.57 nmol0₂g^–1s^–1). The value of this technique as an aid to our understanding of the development of adventitious roots is discussed.     

油松嫩枝扦插育苗试验

用油松嫩枝作插穗，在粗河沙中扦插育苗，插后先形成愈合组织，后从愈合组织处生根，皮部不生根．以浓度１０００μｇ／ｇ萘乙酸处理生根率最高，为５７．７％，移栽成活率为９４．９％。     

Browse yield and nutritive value of two Salix species and Dorycnium rectum in New Zealand

The willows Salix matsudana x alba and S. kinuyanagi, and the leguminous shrub Dorycnium rectum, are used for soil conservation in New Zealand and have potential value as browse plants. Two experiments were conducted in the lower North Island to ascertain the effect of selected establishment and cutting practices on their browse yield and nutritive value. A hill site experiment determined the effect of rooted and unrooted stem cuttings on establishment and initial production of the Salix species. A flat site experiment determined the effect of cutting height (0.10–0.30 m, 0.80 m, and 1.20 m above ground) and cutting frequency (once or twice per year) on yield of the Salix species and D. rectum. The establishment and dry matter (DM) yields of the Salix species were unaffected by the type of stem cutting. S. matsudana x alba (1.2 kg DM/tree) plants yielded more edible DM than S. kinuyanagi (0.9 kg DM/tree) and D. rectum (0.4 kg DM/tree). Cutting height had no effect on edible DM yield but affected total DM yield of the Salix species. Nitrogen concentration in edible DM, of all species, was 18–22 g/kg DM. In vitro organic matter digestibility of S. matsudana x alba (648–691 g/kg DM) and D. rectum (664–666 g/kg DM) was greater than S. kinuyanagi (611–615 g/kg DM). The condensed tannin concentration in edible DM of S. kinuyanagi was four-fold higher than in S. matsudana x alba (255 vs. 59 g/kg DM). It was concluded that S. matsudana x alba had the greatest potential as a browse species and D. rectum the least.This revised version was published online in November 2005 with corrections to the Cover Date.