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.     

Eucalyptus und ihre Eigenschaften

Ohne Zusammenfassung     

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.     

Somatic embryogenesis in Eucalyptus globulus

Somatic embryos were obtained from 1% of cotyledon pieces and hypocotyls of mature embryos of Eucalyptus globulus Labill. cultured on media containing a high concentration of picloram or IBA. 2,4-D and other synthetic auxins did not yield somatic embryos or embryogenic callus. Somatic embryos arose indirectly via callus, being visible after four months, and directly, where little callus or adventitious root initiation occurred. Somatic embryos, formed directly from explants, were visible within five weeks. Various structural abnormalities of somatic embryos were observed, especially after induction on media containing picloram. Only two out of fifteen somatic embryos showed hypocotyl and radical elongation, but plantlets did not develop further.     

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。     

Integrating genomics into Eucalyptus breeding

The advent of high throughput genomic technologies has opened new perspectives in the speed, scale and detail with which one can investigate genes, genomes and complex traits in Eucalyptus species. A genomic approach to a more detailed understanding of important metabolic and physiological processes, which affect tree growth and stress resistance, and the identification of genes and their allelic variants, which determine the major chemical and physical features of wood properties, should eventually lead to new opportunities for directed genetic modifications of far-reaching economic impact in forest industry. It should be kept in mind, however, that basic breeding strategies, coupled with sophisticated quantitative methods, breeder's experience and breeder's intuition, will continue to generate significant genetic gains and have a clear measurable impact on production forestry. Even with a much more global view of genetic processes, genomics will only succeed in contributing to the development of improved industrial forests if it is strongly interconnected with intensive fieldwork and creative breeding. Integrated genomic projects involving multi-species expressed sequence tag sequencing and quantitative trait locus detection, single nucleotide polymorphism discovery for association mapping, and the development of a gene-rich physical map for the Eucalyptus genome will quickly move toward linking phenotypes to genes that control the wood formation processes that define industrial-level traits. Exploiting the full power of the superior natural phenotypic variation in wood properties found in Eucalyptus genetic resources will undoubtedly be a key factor to reach this goal.     

Chocolate spot disease of Eucalyptus

Chocolate Spot leaf disease of Eucalyptus is associated with several Heteroconium-like species of hyphomycetes that resemble Heteroconium s.str. in morphology. They differ, however, in their ecology, with the former being plant pathogenic, while Heteroconium s.str. is a genus of sooty moulds. Results of molecular analyses, inferred from DNA sequences of the large subunit (LSU) and internal transcribed spacers (ITS) region of nrDNA, delineated four Heteroconium-like species on Eucalyptus, namely H. eucalypti, H. kleinziense, Alysidiella parasitica, and one isolate resembling a novel species in a clade separate from the holotype of Heteroconium, H. citharexyli. Based on molecular phylogeny, morphology and ecology, the Heteroconium-like species associated with Chocolate Spot disease are reclassified in the genus Alysidiella, which is shown to have mycelium that is immersed in and superficial on the host tissue and conidiogenous cells that can have loci that are either inconspicuous or proliferating percurrently. Furthermore, conidiogenous cells can either occur solitary on hyphae, or be sporodochial, arranged on a weakly developed stroma, which further distinguishes Alysidiella from Heteroconium.     

Histocytological characteristics of Eucalyptus urophylla?��?Eucalyptus grandis shoot apical meristems of different physiological ages

Histocytological characteristics of Eucalyptus urophylla × Eucalyptus grandis shoot apical meristems (SAMs) were described, comparing five outdoor and in vitro sources of akin genotypes differing in their physiological age. The size and the number of cells of the five zones identified within each SAM, i.e. the two tunica layers (L1 and L2), the central mother cells (CMC), the peripheral zone (PZ) and the combination of these four zones (4CZ) varied according to physiological age and plastochron phase. These five zones were significantly larger with higher numbers of cells for SAMs from mature and juvenile trees than for those from physiologically rejuvenated, in vitro mature and in vitro juvenile plants. However, these origin-related differences were not significant for SAMs in their early plastochron phase, to become obvious in a more advanced plastochron stage. Individual cell and nuclear measurements confirmed the rationale of distinguishing within SAM zones, characterized by specific cell and nuclear sizes liable to vary according to physiological age. The various histocytological investigations carried out established that SAM cell characteristics appeared to be the more reliable indicators of phase change. This was particularly true for the nucleoplasmic ratio and for more qualitative differences observed also at the nuclear level. SAM nuclei of the two in vitro origins were more evenly stained by naphtol blue-black, uniformly light for the juvenile source, whereas the mature source showed also darker nuclei. In contrast, SAM nuclei from outdoor origins had more chromocenters, darker and diffusely spread for the mature source than for the rejuvenated and the juvenile origins, where they were more peripherally distributed and where the nucleoli appeared more clearly. These results were discussed with respect to physiological ageing and in vitro culture influence, and suggest a determining influence of SAM cell nuclei on phase change phenomenon of arborescent species.     

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.     

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.