松毛虫DpKettin基因片段的克隆与初步定位研究

对于ZW型鳞翅目昆虫, 雄性为ZZ, 雌性为ZW; 细胞内Z染色体数与常染色体组数之比在雌雄间存在差异, 雄性为2Z∶2A=1.0, 雌性为Z∶2A=0.5, 如果某物种一个基因(假如K基因)位于Z染色体上, 另一个基因(假如N基因)位于常染色体上, 则雄体中2K∶2N=1.0, 雌体中K∶2N=0.5。研究利用家蚕、棉铃虫等昆虫Kettin基因序列, 克隆了松毛虫的同源基因(DpKettin)片段, 并采用荧光定量PCR技术, 以松毛虫的ANT基因为参照基因, 检测松毛虫雌雄不同个体间DpKettin基因与腺苷酸转移酶基因(ANT)的拷贝数之比, 结果表明: 雄体DpKettin∶ANT=1.0, 雌体DpKettin∶ANT=0.5, 说明DpKettin基因位于松毛虫Z染色体上。     

Wood properties and ring width responses to long-term atmospheric CO2 enrichment in field-grown loblolly pine (Pinus taeda L.)

Loblolly pine (Pinus taeda L.) were grown in the field, under non-limiting nutrient conditions, in open-top chambers for 4 years at ambient CO₂ partial pressures (pCO₂) and with a CO₂-enriched atmosphere (+ 30 Pa pCO₂ compared to ambient concentration). A third replicate of trees were grown without chambers at ambient pCO₂. Wood anatomy, wood density and tree ring width were analysed using stem wood samples. No significant differences were observed in the cell wall to cell lumen ratio within the latewood of the third growth ring formed in 1994. No significant differences were observed in the density of resin canals or in the ratio of resin canal cross-sectional area to xylem area within the same growth ring. Ring widths were significantly wider in the CO₂-enrichment treatment for 3 of 4 years compared to the ambient chamber control treatment. Latewood in the 1995 growth ring was significantly wider than that in the ambient control and represented a larger percentage of the total growth-ring width. Carbon dioxide enrichment also significantly increased the total wood specific gravity (determined by displacement). However, when determined as total sample wood density by X-ray densitometry, the density of enriched samples was not significantly higher than that of the ambient chamber controls. Only the 1993 growth ring of enriched trees had a significantly higher maximum latewood density than that of trees grown on non-chambered plots or ambient chambered controls. No significant differences were observed in the minimum earlywood density of individual growth rings between chambered treatments. These results show that the most significant effect of CO₂ enrichment on wood production in loblolly pine is its influence on radial growth, measured as annual tree ring widths. This influence is most pronounced in the first year of growth and decreases with age.     

Assessing fine-root biomass and production in a Scots pine stand – comparison of soil core and root ingrowth core methods

Soil core and root ingrowth core methods for assessing fine-root (< 2 mm) biomass and production were compared in a 38-year-old Scots pine (Pinus sylvestris L) stand in eastern Finland. 140 soil cores and 114 ingrowth cores were taken from two mineral soil layers (0–10 cm and 10–30 cm) during 1985–1988. Seasonal changes in root biomass (including both Scots pine and understorey roots) and necromass were used for calculating fine-root production. The Scots pine fine-root biomass averaged annually 143 g/m² and 217 g/m² in the upper mineral soil layer, and 118 g/m² and 66 g/m² in the lower layer of soil cores and ingrowth cores, respectively. The fine-root necromass averaged annually 601 g/m² and 311 g/m² in the upper mineral soil layer, and 196 g/m² and 159 g/m² in the lower layer of soil cores and ingrowth cores, respectively. The annual fine-root production in a Scots pine stand in the 30 cm thick mineral soil layer, varied between 370–1630 g/m² in soil cores and between 210 – 490 g/m² in ingrowth cores during three years. The annual production calculated for Scots pine fine roots, varied between 330–950 g/m² in soil cores and between 110 – 610 g/m² in ingrowth cores. The horizontal and vertical variation in fine-root biomass was smaller in soil cores than in ingrowth cores. Roots in soil cores were in the natural dynamic state, while the roots in the ingrowth cores were still expanding both horizontally and vertically. The annual production of fine-root biomass in the Scots pine stand was less in root ingrowth cores than in soil cores. During the third year, the fine-root biomass production of Scots pine, when calculated by the ingrowth core method, was similar to that calculated by the soil core method. Both techniques have sources of error. In this research the sampling interval in the soil core method was 6–8 weeks, and thus root growth and death between sampling dates could not be accurately estimated. In the ingrowth core method, fine roots were still growing into the mesh bags. In Finnish conditions, after more than three growing seasons, roots in the ingrowth cores can be compared with those in the surrounding soil. The soil core method can be used for studying both the annual and seasonal biomass variations. For estimation of production, sampling should be done at short intervals. The ingrowth core method is more suitable for estimating the potential of annual fine-root production between different site types.     

Somatic embryogenic tissue establishment from mature Pinus nigra Arn. ssp. salzmannii embryos

Summary Somatic embryogenesis from mature zygotic embryos of salgare?o pine (Pinus nigra Arn. ssp. salzmannii) was induced after 2 wk of culture in L₁ medium [Murashige and Skoog mineral solution with 10.7 μM naphthaleneacetic acid (NAA) and 8.8 μM 6-benzyladenine (BA)] or L₂ medium [Gupta and Durzan mineral solution (DCR)] supplemented with the phytohormone combination as above. Four different combinations of growth regulators, NAA (2.6–10.7 μM) and BA (6.6–8.8 μM), were tried for subsequent passage. The best percentage of embryo induction and manifestation was obtained on DCR medium with 2.6 μM NAA and 6.6–8.8 μM BA. Transfer of isolated somatic embryos from the basal media to L₃ medium (Quoirin and Le Poivre modified mineral solution without hormones and supplemented with 0.3% activated charcoal), facilitated random embryo maturation and some development into plantlets.     

Rearing of the colydiid beetle predator, Dastarcus helophoroides, on artificial diet

Artificial diets for the colydiid beetle, Dastarcus helophoroides, a predator of cerambycid beetles and xylocopid bees, were evaluated. Hatched larvae were reared on artificial diets composed of silkworm pupa-powder, dry yeasts, yeast extract, sucrose, peptone, squid liver oil, preservatives and distilled water, but their emergence rate was very low. If larvae were fed paralyzed cerambycid larvae till they became approximately 8 mm in body length and then reared on artificial diet, emergence rates were high. Using the latter method, mass-production of this colydiid beetle is feasible.     

Seasonality of Glutathione Dynamics in Scots Pine and Bilberry

Abstract: Seasonal changes in the glutathione status of Scots pine ( Pinus sylvestris L .) needles and bilberry ( Vaccinium myrtillus L.) stems and leaves were investigated during 1995 and 1997–1998, respectively. The glutathione concentration, the proportion of reduced glutathione (GSH%) and glutathione reductase (GR) activity were measured at monthly intervals throughout one year. The glutathione concentration and GSH% in current year's Scots pine needles were highest during late summer, but decreased during autumn. It is suggested that exchange reactions between free and protein-bound glutathione may be involved in this reduction. Both metabolites decreased towards summer in the previous year's needles. GR activity exhibited the lowest values in summer and the highest values in winter in both needle generations. In bilberry stems, glutathione peaked during midwinter, while GSH% remained high and relatively constant throughout the year. GR activity was highest in August, after which it gradually declined. In bilberry leaves, the total glutathione concentration was high in early summer. This peak was followed by a sharp decrease during midsummer. GR activity in the leaves was very low, but showed a clear increase towards autumn. Obviously, glutathione metabolism showed considerable seasonal variation in Scots pine needles and in bilberry leaves and stems, but the pattern of variation differed between the studied species and organs.     

蒙古栎红松林物种组成和结构动态的研究

 通过对蒙古栎红松林3个年龄阶段物种和结构动态的研究,结果表明,该类型森林的更新状况良好,早期阶段红松(Pinus koraiensis)和阔叶树的更新数量相同,后期更新树种以红松为主;在森林发育早期阶段蒙古栎(Quercus mongolica)等阳性树种占优势,中期为红松和阔叶树占优势的混交林,后期形成红松占优势的林分;随着森林的发育,灌木和草本层动态呈现复杂的变化。通过对该类型森林直径分布变化的研究得出,在林分发育的早期,阔叶树中大径级木较多,针叶树中小径级木多,在林分发育的后期呈相反的规律。用理论概率模型拟合直径分布表明,韦布尔概率分布模型是描述蒙古栎红松林直径分布的最适模型。     

Western white pine (Pinus monticola Dougl.) reproduction: II. Fertilisation and cytoplasmic inheritance

Fertilisation and proembryo development are described from transmission electron micrographs emphasising the origin and fate of the maternal and paternal mitochondria and plastids. During central cell and egg development mitochondria migrate toward the nuclei, forming a perinuclear zone consisting predominantly of maternal mitochondria and polysomes. At the same time, maternal plastids transformed and at fertilisation are excluded from the neocytoplasm. The pollen tube releases two sperm nuclei into the egg with cytoplasm from the generative cell and the tube cell. The leading sperm nucleus fuses with the egg nucleus and a small number of paternal mitochondria and plastids are taken into the perinuclear zone. The second sperm nucleus degenerates. As the zygote nucleus undergoes mitosis followed by free nuclear division and nuclear migration to the chalazal end of the archegonium, maternal and paternal organelles intermingle within the neocytoplasm. The result is paternal inheritance of plastids and biparental, but predominantly maternal, inheritance of mitochondria. This pattern is consistent within the Pinaceae but differs from some other conifer families. Received: 9 December 1999 / Revision accepted: 30 April 2000     

长白山阔叶红松林太阳辐射分光谱特征

根据对林冠上方和林下太阳辐射的观测及气象站资料,分析了长白山阔叶红松林太阳辐射分光谱特征。结果表明,长白山阔叶红松林区太阳总辐射、直接辐射、散射辐射的光合有效辐射系数有一定的日变化和年变化,年平均值分别为０．４６、０．４３、０．５６。阔叶红松林中不同树种的单叶对于太阳总辐射的反射率、透射率、吸收率的平均值分别为２７．０％、２３．４％、４９．６％。单叶的分光谱反射、透射和吸收的特点是,单叶对紫外辐射