Fumigant toxicity of Eucalyptus intertexta, Eucalyptus sargentii and Eucalyptus camaldulensis against stored-product beetles

Abstract:  Three essential oils extracted from the species of the family Myrtaceae found in Kashan (centre regions of Iran) were shown to have potent fumigant toxicity against three major stored-product insects: Callosobruchus maculatus (Fab.), Sitophilus oryzae (L.) and Tribolium castaneum (Herbst). These were the essential oils from Eucalyptus intertexta R.T. Baker, Eucalyptus sargentii Maiden and Eucalyptus camaldulensis Dehnh. The mortality of 1- to 7-day-old adults of the insect pests increased with concentration from 37 to 926  μ l/l air and with exposure time from 3 to 24 h. The LC₅₀ values to the selected essential oils were between 2.55 and 3.97  μ l/l air for C. maculatus , 6.93 and 12.91  μ l/l for S. oryzae and 11.59 and 33.50  μ l/l air for T. castaneum . Fumigant effects of these essential oils were considered to warrant further research into their potential for commercial use.     

Effects of flooding on Eucalyptus camaldulensis and Eucalyptus globulus seedlings

Summary Flooding for up to 40 days induced morphological changes and reduced growth of 6-week-old Eucalyptus camaldulensis and Eucalyptus globulus seedlings. However, the specific responses to flooding varied markedly between these species and with duration of flooding. Both species produced abundant adventitious roots that originated near the tap root and original lateral roots, but only E. camaldulensis produced adventitious roots on submerged portions of the stem. Flooding induced leaf epinasty and reduced total dry weight increment of seedling of both species but growth of E. globulus was reduced more. In both species dry weight increment of shoots was reduced more than dry weight increment of roots, reflecting compensatory growth of adventitious roots. Adaptation to flooding appeared to be greater in E. camaldulensis than in E. globulus. the importance of formation of adventitious roots in flooding tolerance is emphasized.Research supported by the College of Agricultural and Life Sciences, University of Wisconsin, Madison; CEPEC (Cacao Research Center), Bahia, Brazil; and BMBRAPA (Brazilian Research Institute), Brasilia, Brazil     

Genetic mapping in Eucalyptus urophylla and Eucalyptus grandis using RAPD markers.

Two single-tree linkage maps were constructed for Eucalyptus urophylla and Eucalyptus grandis, based on the segregation of 480 random amplified polymorphic DNA (RAPD) markers in a F1 interspecific progeny. A mixture of three types of single-locus segregations were observed: 244 1:1 female, 211 1:1 male, and 25 markers common to both, segregating 3:1. Markers segregating in the 1:1 ratio (testcross loci) were used to establish separate maternal and paternal maps, while markers segregating in the 3:1 ratio were used to identify homology between linkage groups of the two species maps. An average of 2.8 polymorphic loci were mapped for each arbitrary decamer primer used in the polymerase chain reaction. The mean interval size beween framework markers on the maps was 14 cM. The maps comprised 269 markers covering 1331 cM and 236 markers covering 1415 cM, in 11 linkage groups, for E. urophylla (2n = 2x = 22) and E. grandis (2n = 2x = 22), respectively. A comparative mapping analysis with two other E. urophylla and E. grandis linkage maps showed that RAPDs could be reliable markers for establishing a consensus species map. RAPD markers were automatically and quantitatively scored with an imaging analyzer. They were classified into four categories based on their optical density. A fragment intensity threshold is proposed to optimize the selection of reliable RAPD markers for future mapping experiments. Key words : genetic linkage map, Eucalyptus urophylla, Eucalyptus grandis, random amplified polymorphic DNA, RAPD, automated data collection.     

桉树基因组和功能基因组

本文就桉树基因组和功能基因组的研究进展作介绍。     

Crown structure and vertical foliage distribution in 4-year-old plantation-grown Eucalyptus pilularis and Eucalyptus cloeziana

Tree growth and form are both influenced by crown architecture and how it effects leaf distribution and light interception. This study examined the vertical distribution of foliage in 4-year-old plantation-grown Eucalyptus pilularis Sm. and E. cloeziana F. Muell. trees. Leaf area (LA) distribution was determined at two different sites using allometric approaches to determine LA in crown sections and for whole trees. Leaf area was distributed more towards the upper crowns when canopies had been closed for longer. Leaf area was also skewed more towards the upper crowns for Eucalyptus pilularis than E. cloeziana. These species differences were consistent with differences in vertical light availability gradients as determined by point quantum sensors. Leaf area of individual branches was highly correlated with branch cross-sectional area (CSA) and whole-tree LA was closely related to stem CSA. Branch-level allometric relationships were influenced by site and crown position. However, the general allometric equations between stem size and whole-tree leaf area could be applied across sites. Results from this study suggest that pruning of live branches in these species should follow species-specific guides for the timing and height of pruning to optimise the effects on stem growth and form.     

Regeneration and transformation of Eucalyptus camaldulensis

Reliable regeneration protocols for Eucalyptus camaldulensis using leaf explants from in vitro-grown plants have been developed. Out of the 24 clones tested 13 were regenerated and of these, 6 showed regeneration from more than 60% of the explants. Identical protocols were also successful in the regeneration of some clones of E. microtheca, E. ochrophloia, E. grandis and E. marginata, but at lower frequencies. Co-cultivation of E. camaldulensis leaf explants with Agrobacterium tumefaciens strains carrying a kanamycin resistance gene and the reporter gene β-glucuronidase (GUS), followed by selection on kanamycin at 9 mg l^–1, allowed the selection of transformed shoots that could be rooted on selective media. Transformation of the plants was verified by staining for the GUS enzyme in various plant tissues, NptII assays and by Southern blotting on isolated DNA using specific probes for both the GUS and selectable marker genes. Transformed tissue was obtained with 5 clones of E. camaldulensis tested and a number of A. tumefaciens strains. However, only 1 clone regenerated transformed whole plants reliably. Received: 14 October 1996 / Revision received: 18 February 1997 / Accepted: 1 April 1997     

Hydrothermal and pulp processing of Eucalyptus

Hydrothermal processing of Eucalyptus wood was performed at operation temperature of 181 degrees C, processing time or 37.5 min and solid water ratio of 1/6 to ensure a maximum loss of xylan recuperation with minimum cellulose fibre degradation. Under those conditions, the loss of xylan was 22% less than that achieved with the conditions 196 degrees C, 50.6 min and 1/8 (solid/water). IN In addition, an experimental design was used to study the influence of process variables: temperature (145-175 degrees C), pulping time (40-120 min) and ethanol concentration (40-70% weight concentration), on the properties of pulps (yield, kappa number, viscosity, cellulose, xylan, lignin acetyl groups contents and brightness) and paper sheets (stretch index, burst index and tear index) obtained from the solid fraction after hydrothermal treatment of Eucalyptus globulus. Pulps with acceptably high physical and chemical properties can be obtained operating at 175 degrees C for 90 min with 55% ethanol concentration.     

Revisiting the stem proteome of Eucalyptus grandis and Eucalyptus globulus: Identification of temperature-induced changes

Eucalyptus grandis and Eucalyptus globulus are important species for the Brazilian forestry industry. E. grandis plantations are mainly found in tropical regions, yet E. globulus plants are usually cultivated under moderate to low temperature conditions. As temperature seems to be a key factor for the planting of these species, we revisited our previously generated shotgun proteomics dataset to identify the main patterns of proteome regulation induced by thermal stimulus and to pinpoint specific proteins involved in the environmental response. Large-scale analysis has pointed out the different proteomic responses of E. grandis and E. globulus under temperature stimulus, with 296 proteins considered to be differentially regulated in the stems of Eucalyptus spp. grown at different temperatures. A stringent filtering approach was used to identify the most differentially regulated proteins. Through the stringent criteria, 66 proteins were found to be enriched in the plant species. Cultivation of E. globulus plants in low-temperature conditions induced the highest number of differentially regulated proteins. Additionally, metabolic proteins were mostly down-regulated, while stress-related proteins were majorly up-regulated in both species. Finally, the subset of the most differentially regulated proteins comprised new candidates of protein markers of temperature stress.     

Species discrimination, population structure and linkage disequilibrium in Eucalyptus camaldulensis and Eucalyptus tereticornis using SSR markers

Eucalyptus camaldulensis and E. tereticornis are closely related species commonly cultivated for pulp wood in many tropical countries including India. Understanding the genetic structure and linkage disequilibrium (LD) existing in these species is essential for the improvement of industrially important traits. Our goal was to evaluate the use of simple sequence repeat (SSR) loci for species discrimination, population structure and LD analysis in these species. Investigations were carried out with the most common alleles in 93 accessions belonging to these two species using 62 SSR markers through cross amplification. The polymorphic information content (PIC) ranged from 0.44 to 0.93 and 0.36 to 0.93 in E. camaldulensis and E. tereticornis respectively. A clear delineation between the two species was evident based on the analysis of population structure and species-specific alleles. Significant genotypic LD was found in E. camaldulensis, wherein out of 135 significant pairs, 17 pairs showed r(2)≥0.1. Similarly, in E. tereticornis, out of 136 significant pairs, 18 pairs showed r(2)≥0.1. The extent of LD decayed rapidly showing the significance of association analyses in eucalypts with higher resolution markers. The availability of whole genome sequence for E. grandis and the synteny and co-linearity in the genome of eucalypts, will allow genome-wide genotyping using microsatellites or single nucleotide polymorphims.     

Eucalyptus und ihre Eigenschaften

Ohne Zusammenfassung     

Root and shoot elongation of rhizotron-grown seedlings of Eucalyptus nitens and Eucalyptus globulus in relation to temperature

Information on the growth response of a crop plant in relation to temperature can be helpful in selecting genotypes to suit local environments, scheduling favourable time of planting and forecasting growth and yield. To determine the effects of varying temperature on root and shoot elongation of eucalypt seedlings, elongation rates of roots and shoots were measured in rhizotrons for two species (Eucalyptus nitens (Deane and Maiden) Maiden, and Eucalyptus globulus Labill.) at a temperature range of 5–23 °C. Within this range of temperatures, elongation rates of roots and shoots of both species increased with an increase in temperature. Roots of E. globulus were more sensitive and shoots less sensitive to temperature than those of E. nitens. However, the threshold temperature corresponding with zero elongation rate predicted from the regression of elongation rate against temperature was similar for the roots (∼5 °C) and shoots (∼0 °C) of both species. Hysteresis did not appear to have a significant influence on root or shoot elongation of both species during warming compared with cooling. Results are discussed highlighting the importance of the interaction between development and growth of plant components.     

Cold-induced photoinhibition affects establishment of Eucalyptus nitens (Deane and Maiden) Maiden and Eucalyptus globulus Labill

The effects of cold-induced photoinhibition on Eucalyptus globulus and Eucalyptus nitens seedlings were assessed between planting and age 23 weeks. The seedlings were subjected to four treatments before planting: non-hardened (NH) E. globulus and E. nitens, cold-hardened (CH) E. nitens, and nutrient-starved (NS) E. nitens. Seedlings were planted alongside established 1-year-old E. nitens saplings. The experimental site was at 350 m above sea level, which is considered marginal for the establishment of E. globulus plantations due to low mean minimum temperatures. Cold and sunny conditions after frost increased photoinhibition in the order: NH E. globulus > NH and CH E. nitens > NS and established E. nitens. As a result there was 20% mortality of NH E. globulus seedlings. NS E. nitens seedlings were severely photoinhibited and had high anthocyanin levels at planting; levels of photoinhibition decreased after planting, anthocyanin levels remained high and there was no mortality. Carotenoid levels were low in E. globulus compared to E. nitens treatments. It was concluded that cold-induced photoinhibition is a factor determining the range of environments where E. globulus can be successfully planted, and not frost tolerance alone. Anthocyanin was synthesised in response to increased photoinhibition. Anthocyanin levels were correlated to the severity of the photoinhibition. Thus, E. nitens seedlings nutrient starved in the nursery are pre-conditioned to photoinhibitory conditions experienced soon after planting. This treatment is a useful risk-management tool where cold-induced photoinhibition is likely to occur during seedling establishment.     

Tannins from Bendo Eucalyptus

The gallic acid, (+)-catechin and myricetin glucoside have been isolated and indentified from Bendo Eucalyptus, and two kinds of dimeric flavan-3-ol B1 and B3 were isolated as their peracetates and identified by chromatography on TLC and 1H NMR spectroscopic cha- racteristics. It is showed that condensed tannin is a procyanidin with (+)-catechin as terminal units and (–)-epicatechin as extension units by hydrolyzation anthocyanidin reaction, phloroglucinol degradation and polarimetry, UV and IR spectrometry, HPLC, 3C NMR. Linkage is C4–C8. Degree of polymerization is about 4–5.     

Genetic Linkage Maps of Eucalyptus Grandis and Eucalyptus Urophylla Using a Pseudo-Testcross: Mapping Strategy and Rapd Markers

We have used a ``two-way pseudo-testcross' mapping strategy in combination with the random amplified polymorhic DNA (RAPD) assay to construct two moderate density genetic linkage maps for species of Eucalyptus. In the cross between two heterozygous individuals many single-dose RAPD markers will be heterozygous in one parent, null in the other and therefore segregate 1:1 in their F(1) progeny following a testcross configuration. Meiosis and gametic segregation in each individual can be directly and efficiently analyzed using RAPD markers. We screened 305 primers of arbitrary sequence, and selected 151 to amplify a total of 558 markers. These markers were grouped at LOD 5.0, θ = 0.25, resulting in the maternal Eucalyptus grandis map having a total of 240 markers into 14 linkage groups (1552 cM) and the paternal Eucalyptus urophylla map with 251 markers in 11 linkage groups (1101 cM) (n = 11 in Eucalyptus). Framework maps ordered with a likelihood support >/=1000:1 were assembled covering 95% of the estimated genome size in both individuals. Characterization of genome complexity of a sample of 48 mapped random amplified polymorphic DNA (RAPD) markers indicate that 53% amplify from low copy regions. These are the first reported high coverage linkage maps for any species of Eucalyptus and among the first for any hardwood tree species. We propose the combined use of RAPD markers and the pseudo-testcross configuration as a general strategy for the construction of single individual genetic linkage maps in outbred forest trees as well as in any highly heterozygous sexually reproducing living organism. A survey of the occurrence of RAPD markers in different individuals suggests that the pseudo-testcross/RAPD mapping strategy should also be efficient at the intraspecific level and increasingly so with crosses of genetically divergent individuals. The ability to quickly construct single-tree genetic linkage maps in any forest species opens the way for a shift from the paradigm of a species index map to the heterodox proposal of constructing several maps for individual trees of a population, therefore mitigating the problem of linkage equilibrium between marker and trait loci for the application of marker assisted strategies in tree breeding.