Effect of an ectomycorrhizal fungus,Laccaria laccata,on Fusarium damping-off in Pinus banksiana seedlings

Damping-off caused by Fusarium oxysporum Schlecht in Pinus banksiana Lamb, was reduced significantly when inoculated with an ectomycorrhizal fungus, Laccaria laccata (Scop. ex Fr.) Berk. and Br. In paired culture, growth of F. oxysporum was significantly reduced by L. laccata. The number of colony forming units of F. oxysporum was reduced significantly in the rhizosphere of P. banksiana seedlings when inoculated with L. laccata. Spore germination and germ tube length of F. oxysporum was inhibited strongly by culture filtrate of L. laccata and root exudate of P. banksiana inoculated with L. laccata. Mycorrhizal seedlings had significantly higher amount of total soluble phenols than nonmycorrhizal ones.     

Fungal auxin overproduction affects the anatomy of Hebeloma cylindrosporum-Pinus pinaster ectomycorrhizas

We studied the effect of fungal auxin overproduction on the growth polarity of cortical cells in pine mycorrhizas by comparing the anatomy of Pinus pinaster (Ait.) Sol. mycorrhizas formed by an IAA-overproducing mutant of Hebeloma cylindrosporum Romagnesi or by the corresponding wild type with non-mycorrhizal short roots. Both wild- type and mutant strains induced an increase in root diameter that was mostly a result of the influence of the fungus on root cortical development. Both strains affected growth polarity of P. pinaster cortical cells and induced a change in their shape. The main modifications were a large reduction in axial diameter and an increase in the radial diameter of the cortical cells. The modifications were more marked with the mutant than with the wild type. The mutant induced a 43% reduction in cortical cell elongation and a 35% increase in radial diameter, whereas the corresponding changes induced by the wild type were 30 and 10%, respectively. The volume of cortical cells in mature mycorrhizas was generally lower than in uninoculated short roots indicating that wild-type and mutant strains induced a reorientation of cortical cell growth but did not induce an increase in turgor pressure of the cells. Immunolocalization allowed visualization of alpha-tubulin in root cortical cells, but no obvious modification in alpha-tubulin distribution was detected as a consequence of symbiosis establishment. Likewise, cytochemical localization of polysaccharides in cortical cell walls did not show significant modification following symbiosis establishment and Hartig net formation. The only noticeable modification was a reduction in cortical cell wall thickness in mycorrhizas compared with uninoculated short roots. The possible involvement of fungal auxin in the observed modifications is discussed.     

Effects of an ectomycorrhizal fungus on the growth and physiology of Pinus sylvestris var. mongolica seedlings subjected to saline-alkali stress

This research investigates the mechanism of increased salinity tolerance of ectomycorrhizal fungiinoculated P. sylvestris var. mongolica to provide a theoretical basis for the application of the fungus in saline soils.Growth effects due to inoculation of seedlings with Suillus luteus(a symbiotic ectomycorrhizal fungus), were determined in four kinds of saline–alkali soils. Growth and physiological indicators, including photosynthetic characteristics, plant height, biomass, photosynthetic pigments,catalase(CAT) and superoxide dismutase(SOD) enzyme levels, and malondialdehyde(MDA), an organic marker for oxidative stress, and soluble protein levels were determined. Mycorrhizal colonization rate decreased with increasing saline–alkalinity and growth of inoculated seedlings was significantly enhanced. Biomass and chlorophyll contents also increased significantly. SOD and CAT activities were higher than in non-inoculated seedlings. However, MDA content decreased in inoculatedseedlings. Soluble protein content did not increase significantly. Inoculation with a symbiotic ectomycorrhizal fungus could enhance the saline–alkali tolerance of P. sylvestris var. mongolica. Growth and physiological performance of inoculated seedlings were significantly better than that of uninoculated seedlings. The results indicate that inoculated P. sylvestris var. mongolica seedlings may be useful in the improvement of saline–alkali lands.     

希腊海岸松叶中聚戊烯醇含量与化学结构分析

利用HPLC与聚戊烯醇对照品保留时间对照的定性方法,确定海岸松叶中聚戊烯醇的异戊烯基单元数为14~20;利用1H NMR和13C NMR确定海岸松聚戊烯醇化学结构为ω-trans2-cisn-OH构型。采用Kromasil C18 ODS-1(150 mm×4.6 mm,5μm)色谱柱,以甲醇-异丙醇(体积比9∶16)为流动相,流速为0.50 mL/min,检测波长为210 nm,柱温为25℃,PDA检测器等色谱条件,测定海岸松叶聚戊烯醇在1.10~12.10μg范围内线性良好(r=0.996 3),平均回收率为98.21%,RSD为2.27%(n=6),海岸松干叶中聚戊烯醇含量为0.33%。     

Variability of stem and branch maintenance respiration in a Pinus pinaster tree

The relationship between maintenance respiration (Rm) of woody organs and their structural characteristics was explored in adult Pinus pinaster Ait. trees. We measured Rm on 75 stem and branch segments of different ages (from 3 to 24 years) and diameters (from 1 to 35 cm). The temperature response of Rm was derived from field measurements based on a classical exponential function with Q10 = 2.13. Relationships between Rm and the dimensions of the woody organs were analyzed under controlled conditions in the laboratory. The surface area of a woody organ was a better predictor of Rm than volume, but surface area failed to account for the observed within-tree variability of Rm among stems, branches and twigs. Two simple models were proposed to predict the variability of Rm at 15 degrees C in an adult tree. Model 1, a linear function model based on the dry mass and nitrogen concentration of sapwood and phloem tissues, explained most of the variability of Rm in branches and stems (R2 = 0.97). We concluded that the respective contributions of the phloem and sapwood depend on the location and diameter of the woody organ. Model 2, a power-law function model based on the length, diameter and age of the sample, explained the same variance of Rm as Model 1 and is appropriate for scaling Rm to the stand level. Models 1 and 2 appear to explain a larger variability of Rm than models based on stem area or sapwood mass.     

Modelling the site index of Pinus pinaster plantations in Turkey using ecological variables

The determination of site productivity in forest ecosystems plays a crucial role in resource management.This study was carried out to identify relationships between site characteristics and height growth of Corsican maritime pine(Pinus pinaster Ait.) plantations in Turkey.Sixty-nine sample plots 20 years of age were selected from locations with different inclinations,aspects,elevations,slope positions and site class.Soil samples were taken at various depths.Height and age were measured on a dominant tree after felling in each plot.Physical and chemical properties of the soil were determined.Relationships between site index(SI_(25)) and physiographic factors,climatic attributes as well as soil properties were evaluated using correlation analysis and multiple regression analysis.Site index was significantly related with annual precipitation,mean spring rainfall,rainfall June to September,rainfall of the driest month,length of the dry period,mean maximum temperature,mean temperature of the warmest month,stoniness of the soil,sand,silt,clay,pH,electrical conductivity,and available water capacity.Multiple regression accounted for 57.9% of variations in height growth.The models obtained can be used to determine the site index of potential areas in Turkey for maritime pine.It can be said that the productivity of maritime pine may decline in the future due to global climate change.     

Kinetics and mechanism of acetic acid pulping of detannined Pinus pinaster bark

Summary The observed kinetics of Pinus pinaster bark with acetic acid after alkali treatment, with or without intervening acid prehydrolysis, are satisfactorily explained by a model involving both solubilization and condensation reactions.This study was subsidised by the Xunta de Galicia. J. González is grateful to DGICYT for a research grant     

Influence of copper on root growth and morphology of Pinus pinea L. and Pinus pinaster Ait. seedlings

We assessed the effects of Cu on root growth and morphology of stone pine (Pinus pinea L.) and maritime pine (Pinus pinaster Ait.) seedlings grown in culture solutions supplied with 0.012 (control), 0.1, 1 or 5 micro M CuSO(4). The presence of 5 micro M Cu in the nutrient solution completely inhibited root growth of both species within 3 days. In both species, taproot elongation was reduced in the presence of 1 micro M Cu, although partial growth recovery occurred after 7 days of treatment. The presence of 0.1 micro M Cu in the culture solution slightly enhanced root elongation in P. pinaster, but did not significantly influence root elongation in P. pinea. In both species, root weight per unit length increased in response to Cu exposure, and in P. pinaster, root diameter was significantly increased. The Cu treatments also affected lateral root number and length. In the presence of 1 micro M Cu, both species formed only short lateral primordia. The 1 micro M Cu treatment increased the lateral root index (number of roots per cm of root length) of P. pinaster, but decreased that of P. pinea, compared with control values. Neither the 0.1 nor 1 micro M Cu treatment had a significant effect on the mitotic index of either species. We conclude that cell elongation is more sensitive to Cu than cell division. Cell membrane damage, as indicated by Trypan blue staining, occurred after 10 days of exposure to 1 micro M Cu.     

沙地海岸松在山东和浙江引种试验研究

通过对引种沙地海岸松的育苗和造林试验研究,结果表明:在沙地海岸松第一年幼苗期生长中,播种密度对其影响不大,而适度遮荫(80%透光率)有利于海岸松幼苗的生长。沙地海岸松在养分含量高、偏酸性土壤中生长占优势,且在温州地区育苗及造林后的高与地径生长均显著高于蓬莱地区。海岸松容器苗的造林成活率显著高于裸根苗;不同海岸带造林后,其生长速度在海阳市最快,其次是莱州市和烟台市。     

Hydraulic efficiency and safety of vascular and non-vascular components in Pinus pinaster leaves

Leaves, the distal section of the soil-plant-atmosphere continuum, exhibit the lowest water potentials in a plant. In contrast to angiosperm leaves, knowledge of the hydraulic architecture of conifer needles is scant. We investigated the hydraulic efficiency and safety of Pinus pinaster needles, comparing different techniques. The xylem hydraulic conductivity (k(s)) and embolism vulnerability (P(50)) of both needle and stem were measured using the cavitron technique. The conductance and vulnerability of whole needles were measured via rehydration kinetics, and Cryo-SEM and 3D X-ray microtomographic observations were used as reference tools to validate physical measurements. The needle xylem of P. pinaster had lower hydraulic efficiency (k(s)?=?2.0?×?10(-4) m(2) MPa(-1) s(-1)) and safety (P(50)?=?-?1.5 MPa) than stem xylem (k(s)?=?7.7?×?10(-4) m(2) MPa(-1) s(-1); P(50)?=?-?3.6 to?-?3.2 MPa). P(50) of whole needles (both extra-vascular and vascular pathways) was?-?0.5 MPa, suggesting that non-vascular tissues were more vulnerable than the xylem. During dehydration to?-?3.5 MPa, collapse and embolism in xylem tracheids, and gap formation in surrounding tissues were observed. However, a discrepancy in hydraulic and acoustic results appeared compared with visualizations, arguing for greater caution with these techniques when applied to needles. Our results indicate that the most distal parts of the water transport pathway are limiting for hydraulics of P. pinaster. Needle tissues exhibit a low hydraulic efficiency and low hydraulic safety, but may also act to buffer short-term water deficits, thus preventing xylem embolism.     

Optimization of seasonality and mother plant nutrition for vegetative propagation of Pinus pinaster Ait

Due to the high economic importance of Pinus pinaster Ait., there is considerable interest in developing, improving and extending the use of its families for mass clonal propagation and in breeding programmes. In the current study, we evaluated shoot growth, rooting ability and mini-cuttings production of P. pinaster in response to nitrogen fertilization and seasons. We compared eight half-sib families of P. pinaster from Asturias and Galicia (Northern Iberian Peninsula), searching for useful parameters and growing conditions to be included in a mass propagation program for clonal family forestry. We fertilized P. pinaster seedling mother plants kept in a greenhouse with three levels of nitrogen: high (HN), medium (MN) and low (LN) to evaluate rooting ability of mini-cuttings. In addition, we evaluated the maximal potential production of rooted mini-cuttings considering nine cycles of propagation over 1?year, also using three levels of nitrogen. The HN treatment significantly influenced the rooting process, with length, area and volume of roots all being positively affected. Spring was the most favourable season for mini-cuttings in the HN treatment. This study provides valuable new information to optimize the clonal propagation protocol for P. pinaster and shows that the mini-cuttings technique has great potential in mass scale cloning, providing high quality sprout production and well-formed new plants.     

The relationship between seed weight, germination and biochemical reserves of maritime pine (Pinus pinaster Ait.) in Morocco

Seed germination and biochemical reserves of maritime pine (Pinus pinaster Ait.) were studied with the aim of providing germination information for reforestation and conservation programs. Ten natural populations were used to assess variation in seed weight, germination characteristics and biochemical reserves and to examine the relationship between these characteristics. The analysis of variance showed highly significant population effects for seed weight, germination characteristics and protein content in both seeds and the female gametophyte. The mobilization of protein content in female gametophyte during seed germination differed more among populations than sugar content, suggesting that protein content was more sensitive to environment effects than sugar content. A strong positive correlation between germination capacity and the protein content in both seeds and female gametophyte indicated that the best populations in term of germination capacity may also be the richest in protein content. Seeds that were heavier and had a lower speed of protein content mobilization in the female gametophyte appeared to be better adapted to drought conditions. The results also suggested that as much as possible of the potentially valuable genetic variation among populations of this species should be preserved for reforestation and conservation purposes.     

Associations between Tomicus destruens and Leptographium spp. in Pinus pinea and P. pinaster stands in Tuscany,central Italy

The association between Tomicus destruens and fungi of the genus Leptographium was studied in Pinus pinea and P. pinaster forests in Tuscany, central Italy. Fungi were isolated from adult beetles and from pine tissues from infested trees. On average, Leptographium spp. were associated with 18% of beetles in breeding galleries, 35% of emergent brood beetles and 18% of beetles undergoing maturation feeding in pine twigs. The fungal species most frequently identified were Leptographium wingfieldii and L. lundbergii while L. guttulatum and L. serpens were also found.     

红松坚果园(林)营建方法的探讨

根据红松坚果园(林)营建存在的问题和已有遗传改良基础上总结出原有红松种子园改建、原有红松人工林的疏伐改建、原有樟子松人工林的改建等现有人工林改建坚果园方法,并提出利用原有红松种子园无性系测定资料、新选坚果型优树、坚果型采穗圃的营建和管理等新建坚果园营建及管理方法,建议持续进行红松高世代改良研究。     

Growth and soluble proteins of cell cultures derived from explants and protoplasts of Pinus pinaster cotyledons

Pinus pinaster Ait. cell suspension cultures were derived from chopped cotyledons and from cotyledon protoplasts. When transferred after 12 weeks in culture, growth of both cell types showed a lag of 5 days followed by an exponential phase of 14 days for the protoplast-derived cells and 23 days for the organ-derived cells. During the exponential growth phase, packed cell volume of protoplast-derived cultures increased 7-fold and that of organ-derived cultures 13-fold. During the stationary phase, the diameters of protoplast-derived cells averaged 80 microm and those of organ-derived cells 100 microm. After 30 days, the media containing protoplast-derived and organ-derived cells decreased in osmolarity by 50 and 120 mOs per kg water, respectively, and in pH by 1.4 and 2.0 units, respectively. Throughout the growth cycle, protein content per unit of packed cell volume was always at least 35% higher in the protoplast-derived cultures than in the organ-derived cultures. Two-dimensional electrophoretic separation of soluble proteins revealed three peptides present in protoplast-derived cells that were absent from organ-derived cells and two peptides present in organ-derived cells that were absent from protoplast-derived cells. Other peptides differed quantitatively between the cell types.     

Variability of the photosynthetic characteristics of mature needles within the crown of a 25-year-old Pinus pinaster

Photosynthetic characteristics of 1- and 2-year-old needles were determined in excised shoots of maritime pine (Pinus pinaster Ait.) with an open gas exchange system. We used the nonlinear least mean squares method to derive values for quantum yield of electron transport (alpha), maximum carboxylation velocity (V(cmax)), and maximum electron transport rate (J(max)), from photosynthetic response curves to light and CO(2). Crown height had no significant effect on any of the parameters; however, V(cmax) and J(max), as well as alpha were 43, 26 and 35% higher, respectively, in 1-year-old needles than in 2-year-old needles. The main effect of irradiance on needles was a small decline in leaf concentrations of nitrogen and phosphorus from the top to the bottom of the canopy. Only J(max) demonstrated a linear relationship with both nitrogen content (R(2) = 0.42) and irradiance at the shoot level. Because needle age accounted for most of the variability in photosynthesis, we incorporated needle age into the photosynthesis model of Farquhar et al. (1980). The modified model underestimated the daily assimilation rate of 1-year-old needles in the field, especially when assimilation rates were high.