土壤水分对杜仲剥皮再生的影响

分别对12和25年生杜仲进行Ⅰ、Ⅱ、Ⅲ、Ⅳ级供水处理,研究不同水分条件对杜仲愈伤组织和再生皮生长的影响.结果表明:供水改善了林地水分条件,土壤平均含水量和贮水量增大,25年生杜仲消耗土壤水分较多,土壤含水量较12年生杜仲林地的低.杜仲剥皮后,供水能加快愈伤组织的形成,剥皮后第5 d,处理Ⅰ、Ⅱ、Ⅲ均有微绿色的愈伤组织出现,较对照提前5 d左右;剥皮后25 d,12和25年生的愈伤组织厚度分别达到1.00和0.94mm,生长速度分别为0.040和0.037 mm·d-1,分别较对照增加47.1%和80.8%.供水能显著促进杜仲再生皮的生长,剥皮后5个月,12和25年生杜仲Ⅰ、Ⅱ、Ⅲ、Ⅳ级供水处理的再生皮厚度分别较对照增加5.0%、22.5%、75.8%、71.7%和18.5%、29.3%、80.7%、95.0%.6月份是杜仲再生皮生长的关键期,供水对再生皮生长最有利.杜仲水分利用效率在Ⅲ级供水处理时最大,12和25年生分别较对照提高39.3%和37.4%.生长季中,土壤含水量应保持在160～170 g·kg-1.     

The characteristics of oleoresin exudation amount from the trunks of pine trees

The amounts of oleoresin exudation from artificially-marked wounds on the trunks of pine trees were measured, and several characteristics of the oleoresin exudation amount (OEA) were elucidated. OEA showed no regular diurnal change and had no relation to both heights and directions of the wounds marked on the trunks, but differed between individual trees and between locations on the same tree. The exudation of oleoresin from each wound stopped after several hours. Mean OEA per wound decreased with increase in the number of wounds per given area. When the exudation of oleoresin from a wound was exhausted, further oleoresin was scarcely exuded even from a new wound made close to the initial one. In response to wounding, therefore, primary oleoresin exudation seems to occur by releasing the resin stocked in the resin canal.     

Promotion of seed production in Douglas-fir grafts by girdling + gibberellin A4/7 stem injection,and effect of retreatment

Twelve- to 17-year-old Douglas-fir grafts, which in 1985 received no treatment, stem girdles only (G), or girdles plus stem injection of gibberellin A_4/7 (G + GA) at vegetative bud burst, were in 1987 retreated with G + GA or left untreated. Tree were untreated in 1986 and cone production the following year was very sparse. G + GA treatment in 1987 increased the 1988 production of seed cones from 465 to 1600 per tree, with a comparable increase in frequency of grafts producing a heavy crop of pollen cones. However, induction treatments applied in 1985 adversely affected seed- and pollen-cone production in 1988, independent of treatment in 1987. Cone size, total and filled seed per cone, and seed germination were little affected by treatment either year. Treatment with G + GA in 1987 only maximized the production of filled seeds (48 100/tree), although G + GA in both 1985 and 1987 (31 200/tree) was still highly effective relative to no treatment in either year (14 700/tree). The G + GA treatment adversely affected tree condition more severely than previously (or since) experienced, probably as a consequence of grafts also being subjected to prolonged late-summer droughts during each of the treatment years.     

3种针叶树种树皮抗火性研究

通过测定和分析云南油杉、云南松、华山松3种针叶树种树皮的厚度、导热系数、外界热辐射作用下的失重过程和树皮内表面温度4个因子，结合3个树种在火烧迹地上的死亡率数据，得出如下结论：树皮的结构、导热系数是决定这3种树种耐火性差异的主要因素，3种针叶树种树皮的抗火性由强到弱的顺序为云南油杉〉云南松〉华山松，与这3个树种的死亡率由小到大的顺序相同。     

降香黄檀树皮率、心材率及木材密度研究

对降香黄檀（Dalbergia odorifera）的树皮率、心材率，木材密度进行了研究。结果表明：降香黄檀树皮体积百分率及质量百分率平均值分别为20．14％、13．77％；心材百分率平均值为30．53％，心材形成的年龄为9～15a；生材密度平均值为1．064g／cm^3；基本密度平均值为0．715g／cm^3；生材含水率平均值为49．21％。降香黄檀树皮体积百分率及质量百分率均随着树高的增加而增加；生材密度及心材率随着树高的增加而减少；基本密度随着树高增加，呈大-小-大-小的趋势变化；生材含水率随着树高的增加，呈小-大-小-大的趋势变化。     

Genotypic Difference in Resistance to Internal Bark Necrosis in Apple Trees Is Related to Manganese Uptake,the Distribution of Manganese,and Antioxidant Activity

Field investigations and pot culture experiments were performed to elucidate the genotypic differences of two apple cultivars that vary in resistance to internal bark necrosis (IBN). Factors examined were manganese (Mn) uptake, antioxidant activity, as well as the accumulation and distribution of Mn in apple branches. Lesser Mn concentrations were found in the bark and branches of an IBN‐tolerant cultivar (‘Jonagold’) than in those of the sensitive cultivar (‘Fuji’) from both field investigations and pot culture, which is correlated with a reduction in Mn uptake from soil. Histochemical tests and x‐ray microanalyses indicated that Mn is localized in the bark and coincided with the occurrence of necrosis in ‘Fuji,’ whereas a more homogenous distribution of Mn was found in ‘Jonagold,’ possibly resulting in an alleviation of Mn toxicity. Physiological parameters indicated that the occurrence of IBN in apple was related to oxidative stress. Under field conditions, ascorbic acid concentration in the bark or leaves of ‘Fuji,’ which were severely affected by IBN, was less than that of ‘Jonagold.’ Because of greater Mn uptake from soil, an uneven distribution of Mn among tissues, and less reduction activity in the sensitive apple tree, oxidized Mn precipitation occurred in the bark, which ultimately exhibited IBN.     

思茅松树皮低聚原花青素提取工艺研究

[目的]研究思茅松树皮低聚原花青素的最适提取条件,为开发思茅松树皮低聚原花青素提供有利参数。[方法]在单因素试验和正交试验的基础上,采用溶剂回流提取法,用70%乙醇作提取溶剂从思茅松树皮中提取有效成分低聚原花青素。[结果]影响提取工艺各因素的主次顺序依次为:提取时间提取温度料液比。确定最佳的超声提取条件为:提取温度为55℃,料液比1∶20,提取时间为2 h,提取3次。[结论]按此条件制备得到的低聚原花青素提取率达到2.30%。     

2008年河口地区橡胶树寒害后小蠹虫严重危害及防治

2008年,云南河口植胶区继严重寒害后首次发生橡胶树小蠹虫严重为害,经调查证实橡胶树遭严重寒害是诱发小蠹虫大发生的直接原因;通过生产性防治试验,提出新的、有效实用的防治措施。     

Variations in bark thickness and sapwood density of <Emphasis Type="Italic">Calophyllum inophyllum</Emphasis> provenances in Australia and in Sri Lanka

Sapwood density and bark thickness of Calophyllum inophyllum L. (a multipurpose durable timber species) were studied in various locations in Northern Australia and in Sri Lanka. Measurements were taken non-destructively by using core sampling and bark gauge. From each provenance, 4-15 mature trees having girth at breast height over bark (GBHOB) at 100-150 cm were selected on the basis of the population size. Significant (p<0.05) hemispheric and provenance variations in bark thickness were found. Variations in the bark thickness are influenced by environmental variables. Variations in sapwood density were less pronounced compared to that of bark thickness. Variations in sapwood density are likely to be governed by genotypic variations.