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11.
Gabriela Claudia Cangahuala-Inocente Lírio Luiz Dal Vesco Douglas Steinmacher Antonio Carlos Torres Miguel Pedro Guerra 《Scientia Horticulturae》2007
Pineapple guava (Acca sellowiana) syn. Feijoa sellowiana, a Brazilian indigenous Myrtaceae is under domestication in South Brazil. Previous works showed that this species is responsive to somatic embryogenesis and recalcitrant to conventional methods of clonal propagation. In the present work it was evaluated the role of components of culture medium in the induction and development of somatic embryos. The technology of synthetic seeds was also evaluated. Zygotic embryos were inoculated in LPm medium supplemented with 8 mM glutamic acid and 8 mM l-glutamine, 2,4-dichlophenoxiacetic acid (20 μM) and myo-inositol. For conversion of somatic embryos and synthetic seeds it was tested the effect of 6-benzylaminopurine and gibberellic acid combined or not with activated charcoal. The highest values for embryogenetic induction (100%) and number of somatic embryos/explant (113) were observed in the LPm medium supplemented with Glu (8 mM), and 2,4-D. The culture medium supplemented with BA (0.5 μM) and GA3 (1 μM) and activated charcoal (1.5 g L−1) enhanced the conversion of somatic embryos to plantlets. Pre-germinated somatic embryos encapsulated in sodium alginate with BA (0.5 μM) and GA3 (1 μM) developed radicles. The use of synthetic seed was a requisite for the survival of plantlets. 相似文献
12.
Zusammenfassung Mit Hilfe elektronischer Meßmethoden sowie durch verschiedene weitere Versuchsanordnungen konnte gezeigt werden, daß der Buchdrucker in seinem Anflugverhalten an Pheromonquellen maßgeblich durch die jeweils herrschenden Lichtverhältnisse beeinflußt wird. Es bestand eine deutliche Präferenz von besonnten Standorten. In sonnigen Zeitabschnitten, auch innerhalb von nur wenigen Minuten, waren signifikant höhere Anflugzahlen zu vereichnen als in Phasen mit Bewölkung. Für den Kupferstecher gilt dies nur in eingeschränktem Maße.Diese Zusammenhänge konnten auch anhand von nord-bzw. südexponierten Fallen aufgezeigt werden. Die besonnte Fallenseite fing 4,2mal mehr Buchdrucker als die der Sonne abgewandte Seite. Beim Kupferstecher betrug der Faktor nur 1,66. Die beschriebenen Ergebnisse fanden ihre Bestätigung auch in der Befallssituation im Kalamitätsgebiet. Bei beginnendem Stehendbefall wurden vom Buchdrucker zunächst südexponierte Bestandesränder und hier die zur tageszeitlichen Hauptschwärmzeit besonnten Stämme besetzt.
Mit 2 Abbildungen und 1 Table. 相似文献
Influencing the flight behaviour of bark beetles by light conditions
With the aid of eletronic registration equipment and other experimental methods, it could be shown that the flight behaviour of spruce bark beetles to pheromone sources is strongly influenced by the prevailing light conditions. There is a definite preference for sunny conditions. Even during sunny periods of only a few minutes, significantly more beetles were flying than during overcast periods.A similar pattern of behaviour was observed for P.chalcographus, but there was no statistical evidence. This preference was also seen when pheromone baited traps were set up in a northerly direction with low sunlight levels and a southerly direction with strong sunlight. In the traps facing south 4,2 times more lps typographus were caught than in the north facing traps. P. chalcographus preferred the sunnier traps at a radio of 1,66.These results confirm the fact that at the beginning of an infestation of forest the southerly regions were first to be attacked by spruce bark beetles. Even there trees were first affected where they were exposed to sun during the daily main period of flight activity.
Mit 2 Abbildungen und 1 Table. 相似文献
13.
Pastur Guillermo Martínez Peri Pablo Luis Fernández María Cecilia Staffieri Gabriela Lencinas Mará Vanessa 《Journal of Forest Research》2002,7(3):165-174
Human commercial activities must be compatible with sustainable management to achieve species conservation in the natural
environment. After harvesting, diversity and abundance of understory species differ substantially from the pre-harvest situation.
Have knowledge of the changes that logging produces in all components of the system allows us to develop management alternatives
with reduced impacts. The objective of this work was to evaluate changes in density, biomass and diversity of understory species
along a forest shelterwood cut system management cycle in aNothofagus pumilio forest. Six forest management situations (postharvesting stands and different phases of forest development) were sampled
in a pureN. pumilio forest of Tierra del Fuego (Argentina) of middle-high site class (fromclass I toIII). Species number, density and biomass were modified substantially after a shelterwood cut. These were being greatest after
cutting and falling substantially when the forest canopy closes during theinitial growth phase, returning to values similar to this virgin forest when themature phase was reached. The impact of the forest management on understory species diversity is analyzed and discussed. The silvicultural
practices applied toN. pumilio forest in Tierra del Fuego permit the introduction of alien flora to the system, and produce great changes during the forest
management cycle.
To Celina Matteri, Itatí Ferraro, and Rosa Kofalt for their aid in taxonomical identification. To Juan Manuel Cellini, Ricardo
Vukasovic and Gregorio Martínez Pastur for their participation in the field work; and to the sawmillLos Castores, Universidad Nacional de la Patagonia Austral, Centro Austral de Investigaciones Científicas and Instituto Nacional de Tecnología
Agropecuaria for the institutional and financial support. 相似文献
14.
Dr. Gabriela Lobinger 《Journal of pest science》1994,67(1):14-17
Single catches of bark beetles in pheromone baited traps were registered by the aid of a new instrument. It consists of an electronical weather station in connection with a pheromone trap with infrared sensors as additional equipment. So it was possible also to register weather data at the moment of every catching event. It could be shown that the flight behaviour of both species of bark beetles was influenced by air temperature.I. typographus did not fly beneath a minimum temperature of 16.5°C. There was also an upper limit of 30°C for flight activity of this species.P. chalcographus has a threshold of temperatures about 16.8–17°C, for activity. No upper limit of temperature could be observed up to 35°C. Both of them,I.typ. andP. chalc., reacted very sensitive and spontaneous to these temperature thresholds. 相似文献
15.
Carlos O. Schild Fabiana M. Boabaid Luiz G.S. Olivera Mizael Machado Ana Vildoza Anderson Saravia Alejandra Custodio Carolina Command Agustín Martinez Martín Jaurena Rob Dixon Franklin Riet-Correa 《Journal of veterinary diagnostic investigation》2021,33(5):1018
We investigated 2 outbreaks of osteomalacia as a result of phosphorus (P) deficiency in herds of lactating beef cows grazing subtropical native pastures in Uruguay. Cows exhibited pica, difficulty to stand and walk, rib fractures, and body weight loss even with adequate forage availability. Osteopenia and severe osteomalacia were observed on gross and histologic examination. The concentrations of bicarbonate-extractable P in soil (4.0, 4.1 mg P/kg), total P in pasture (0.9, 1.1 g P/kg), inorganic P in serum (1.0, 0.71 mmol P/L), and P in bone (73 mg P/mL) were all low. Although injectable and mineral salt supplements provided additional P in both outbreaks, these supplementary amounts were insufficient to prevent P deficiency. The P ingested by the cows from the pasture and supplements would have provided 20–55% of their daily P requirements of ~21 g P/d. Osteomalacia occurred in cattle at the 2 ranches as a result of severe P deficiency in the soil and forage, and inadequate P supplementation. Following diagnosis, control of P deficiency in beef cattle requires estimation of the amount of pasture P ingested and provision of sufficient additional supplementary P to meet the animals’ requirements. 相似文献
16.
Soliani Carolina Mattera Ma. Gabriela Marchelli Paula Azpilicueta Ma. Marta Dalla-Salda Guillermina 《European Journal of Forest Research》2021,140(5):1147-1161
European Journal of Forest Research - The resistance of different genotypes to abiotic stress may be due to genetic effects and/or to phenotypic plasticity allowing them to acclimate to variable... 相似文献
17.
18.
Cristina Pascual Leticia Arena Gerard Cuzon Gabriela Gaxiola Gabriel Taboada Manuel Valenzuela Carlos Rosas 《Aquaculture (Amsterdam, Netherlands)》2004,230(1-4):405-416
Blood metabolites in wild and seventh-generation cultivated shrimp were measured to determine how size-based selection could alter the nutritional and immunological conditions of Litopenaeus vannamei. Wild L. vannamei juveniles and a sample of seventh-generation cultured shrimp were acclimated under identical conditions. During 55 days, shrimp were fed a high (HCHO: 44%) or a low (LCHO: 3%) carbohydrate diet for 55 days. Wild shrimp showed a direct relation between dietary CHO and lactate, protein and hemocyte levels indicating that dietary CHO was used for protein synthesis via transamination pathways. In seventh-generation cultured shrimp these parameters were inversely proportional to dietary CHO level, indicating the capacity to synthesize protein from dietary CHO was repressed in cultured shrimp. Farmed shrimp showed a limited capacity to respond to LCHO diets demonstrating high protein dependence in their metabolism and immune response. These results demonstrate that during size-based breeding programs other metabolic process than CHO catabolism can be selected. The incapacity of shrimp to use dietary CHO could limit protein reduction of diets and limit the efforts of the shrimp industry to be ecologically and environmentally profitable. 相似文献
19.
Enrique Maldonado-Cervantes José A. Huerta-Ocampo Gabriela M. Montero-Morán Alberto Barrera-Pacheco Eduardo Espitia-Rangel Ana P. Barba de la Rosa 《Journal of Cereal Science》2014
Amaranth is taking great attention as an important cereal crop that could fulfill food requirements for the growing population, especially in developing countries. However, the protein composition of these seeds is not well known yet. We have used the proteomics tools to characterize amaranth seed proteome. About 400 proteins spots were resolved on two-dimensional gel electrophoresis (2-DE) and protein spots were analyzed by LC-MS/MS (liquid chromatography tandem mass spectrometry). Identified proteins were related to stress and defense responses, metabolic, respiratory, and oxide-reduction processes. One abundant spot was identified as a Late Embryogenesis Abundant (LEA) protein and the gene was cloned and characterized. The AcLEA cDNA contains a 418 bp open reading frame (ORF) encoding a polypeptide of 139 amino acids. Bioinformatics analysis showed that AcLEA belongs to LEAs Group 5. Proteomics is a powerful technique that could be used even in non-sequenced organisms such as amaranth. The obtained information reveals that amaranth seed, beyond the classical seed storage proteins, contains proteins related to protection against stress. The identification of these proteins opens the door to the application of new strategies to improve the quality of amaranth production. 相似文献
20.
We compared the abundance, species richness and diversity of saprobic filamentous microfungi in the forest and in coffee plantation systems (with different biophysical structures of the vegetation and agricultural management) and evaluated the degree of similarity in species composition among these sites. Soil washing was used to isolate the saprobic filamentous microfungi. Emerging colonies were quantified and transferred to tubes with culture medium and then mounted on semi-permanent slides for identification under the microscope. From 90 samples and 4,500 inoculated soils particles, 415 species were distinguished. The genera Trichoderma, Penicillium, Fusarium, Chaetomium and Humicola were the most frequent in all study sites. The transformation of the tropical montane cloud forest in coffee plantation had no significant effect on the abundance, species richness and diversity of the saprobic filamentous microfungi. Effects of the biophysical structures of the vegetation and the agricultural management of the sites were only detected at the level of dominant genera (Fusarium, Trichoderma and Penicillium) and on the evenness. The low degree of similarity among the six sites suggests the existence of a high exchange of species. 相似文献