193 resultados para Host Lattice
Resumo:
The native tree Schinus molle (Anacardiacae) is reported for the first time as a host plant for larvae of the little known geometrid moth Eupithecia yubitzae Vargas & Parra (Lepidoptera, Geometridae) in the Atacama Desert of northern Chile, based on morphology and DNA barcodes. This discovery importantly expands the host range of E. yubitzae, as previous records were restricted to Fabaceae trees. Larvae were previously known as florivorous, while these were found to be folivorous on S. molle. Furthermore, host-associated cryptic larval polychromatism was detected, as larvae collected on S. molle were found to be mostly pale green, contrasting with the dark yellow ground color of the larvae typically collected on fabaceous host plants.
Resumo:
ABSTRACT This work has the objective to catalogue the information of Chrysodeixis includens (Walker, [1858]) (Lepidoptera: Noctuidae: Plusiinae) host plants. The list of plants comprehends new reports of host plants in Brazil and information from literature review around the world. It is listed 174 plants which are from 39 botanic families. The higher number of host plants of C. includens are in Asteraceae (29), Solanaceae (21), Fabaceae (18) and Lamiaceae (12).
Resumo:
Ni(II)-Fe(II)-Fe(III) layered double hydroxides (LDH) or Ni-containing sulfate green rust (GR2) samples were prepared from Ni(II), Fe(II) and Fe(III) sulfate salts and analyzed with X ray diffraction. Nickel is readily incorporated in the GR2 structure and forms a solid solution between GR2 and a Ni(II)-Fe(III) LDH. There is a correlation between the unit cell a-value and the fraction of Ni(II) incorporated into the Ni(II)-GR2 structure. Since there is strong evidence that the divalent/trivalent cation ratio in GR2 is fixed at 2, it is possible in principle to determine the extent of divalent cation substitution for Fe(II) in GR2 from the unit cell a-value. Oxidation forms a mixture of minerals but the LDH structure is retained if at least 20 % of the divalent cations in the initial solution are Ni(II). It appears that Ni(II) is incorporated in a stable LDH structure. This may be important for two reasons, first for understanding the formation of LDHs, which are anion exchangers, in the natural environment. Secondly, this is important for understanding the fate of transition metals in the environment, particularly in the presence of reduced Fe compounds.
Resumo:
A resistência a diversas moléstias fúngicas do trigo tem sido transferida de espécies perenes da tribo Triticeae, mas o híbrido produzido pelo cruzamento intergenérico apresenta embrião abortivo. Embora a técnica de resgate e cultivo in vitro destes embriões já seja amplamente utilizada, sua eficiência ainda é muito baixa. Este trabalho objetivou a obtenção de progênies de retrocruzamentos em híbrido F1 (2n=56), proveniente do cruzamento de trigo (Triticum aestivum) (2n=42) com Agropyron elongatum (2n=70), utilizando-se a técnica de cultivo in vitro dos embriões imaturos. Partindo-se do material perene na geração F1, utilizou-se o trigo como parental recorrente nos retrocruzamentos. A eficiência da polinização foi de 6% no primeiro retrocruzamento (RC1) e de 12,4% no segundo (RC2). As plantas do RC1 foram viabilizadas pelo resgate e cultivo in vitro dos embriões imaturos utilizando- se o meio batata-regeneração, com adição de vitaminas. De 22 sementes, 18 embriões foram resgatados e cultivados in vitro, originando 12 plântulas. Desses embriões, 50% foram normais, 27,8% apresentaram tamanho reduzido, 16,7% foram deformados e 5,5% apresentaram desenvolvimento retardado. A eficiência do cultivo dos embriões na regeneração de plântulas foi de 66,6%. Tal resultado indica que a técnica de resgate e o meio de cultura utilizados foram eficientes para o cultivo e regeneração dos embriões híbridos, obtendo progênies viáveis de retrocruzamentos a partir de híbridos intergenéricos, nas condições realizadas.
Resumo:
This paper focused on four alternatives of analysis of experiments in square lattice as far as the estimation of variance components and some genetic parameters are concerned: 1) intra-block analysis with adjusted treatment and blocks within unadjusted repetitions; 2) lattice analysis as complete randomized blocks; 3) intrablock analysis with unadjusted treatment and blocks within adjusted repetitions; 4) lattice analysis as complete randomized blocks, by utilizing the adjusted means of treatments, obtained from the analysis with recovery of interblock information, having as mean square of the error the mean effective variance of this same analysis with recovery of inter-block information. For the four alternatives of analysis, the estimators and estimates were obtained for the variance components and heritability coefficients. The classification of material was also studied. The present study suggests that for each experiment and depending of the objectives of the analysis, one should observe which alternative of analysis is preferable, mainly in cases where a negative estimate is obtained for the variance component due to effects of blocks within adjusted repetitions.
Resumo:
A bioassay-guided fractionation of culture filtrates of the fungus Alternaria euphorbiicola, a pathogen of the weed Euphorbia heterophylla, led to the isolation of anhydromevalonolactone (1), tyrosol (2), (R)-( - )-mevalonolactone (3), and cycloglycylproline (4). When tested on the punctured leaves of the host plant, these compounds produced bleached lesions with dark brown margins at concentrations as low as 80 µM. When tested on the leaves of other relevant weeds, only cycloglycylproline showed selective activity against E. heterophylla. This is the first report on the isolation of phytotoxins from A. euphorbiicola and on the phytotoxicity of anhydromevalonolactone, (R)-( - )-mevalonolactone, and cycloglycylproline.
Resumo:
Mango branch blight disease, caused by Ceratocystis fimbriata, is endemic to the municipality of São Fidelis in northern Rio de Janeiro State. In addition to mango, C. fimbriata was found associated with sugar apple trees (Annona squamosa) showing symptoms of branch blight in São Fidelis. Sugar apple and mango isolates from the same region had the same morphology and showed similar ITS-rDNA sequences. These sequences were also similar to other Brazilian isolates of C. fimbriata sensu stricto. Cross inoculation of such isolates obtained from diseased sugar apple and mango resulted in diseased symptoms on both plant species. This is the first record of A. squamosa as a host for C. fimbriata.
Resumo:
Two Lettuce mosaic virus isolates capable of overcoming the resistance afforded by the resistance gene mo1² in lettuce, LMV-AF199 from Brazil, and LMV-E, an European isolate, were evaluated for the rapidity and severity of symptoms induced on the lettuce variety Salinas 88 (mo1²). The mosaic symptoms on Salinas 88 plants inoculated with LMV-AF199 appeared 7 days post-inoculation (dpi) and 15 dpi for LMV-E. The symptoms induced by LMV-AF199 in this cultivar were also more severe than those induced by LMV-E. In order to identify the region of the viral genome responsible for this phenotype, recombinant viruses were constructed between these isolates and the phenotype of each recombinant was analysed. The region encoding proteins P1 and HcPro from LMV-AF199 was associated with the increased virulence in Salinas 88.
Resumo:
ABSTRACTThe composition and structure of the low-trunk epiphytic herb assembly as well as its vertical distribution were studied. DBH of host tree and bark type influence species richness and abundance in a nonlooded lowland tropical rainforest in Eastern Amazonia (1º57’36"S 51º36’55"W). A total of 37 epiphytic herb species were identified, among which 60% were Araceae. Species richness and abundance of epiphytic herbs showed tendency of positive correlation with host tree size and no relationships with bark type. Low positive correlation may be a by-product of the predominance of trees with smaller diameter in our sample rather than a reflection of neutral relationship. The absence of relationships with bark type may be partially explained by the large number of secondary, generalist, hemi-epiphytes and also may reflect the absence of suitable substrate in trees with smaller diameter.
Resumo:
The irrigated rice production can be limited by various phytopathogenic agents, including root-knot nematodes (Meloidogyne spp.). Thus, the aim of this research was to check the host suitability of plant species most often found off-season and during rice cultivation, to root-knot nematode Meloidogyne graminicola, under two irrigation managements. Two experiments were conducted in a completely randomized design. In the first experiment seven plant species that occur in an area of rice cultivation, in fallow, off-season were evaluated. For the second experiment nine weed species infesting the irrigated rice culture were tested in rainfed and flooding conditions. The sixteen species, kept individually in pots with sterilized substrate, were inoculated with 5,000 eggs and second stage juveniles (J2) of nematode. BRS 410 IRGA rice plants inoculated with M.graminicola were used as control. Two months after inoculation, the root system of each plant was evaluated for number of galls and nematode reproduction factor. It was verified that the species of off-season of rice cultivation Sida rhombifolia, Raphanus raphanistrum, Spergula arvensis, Lotus corniculatus and Trifolium repens, and, during the cycle of rice cultivation, Aeschynomene denticulata, Leersia hexandra, are immune to nematode. The plant species off-season, Avena strigosa and Lolium multiflorum and of cultivation, Alternanthera philoxeroides, red rice, Echinochloa crusgalli, Cyperus difformis, Cyperus esculentus, Cyperus iria and Fimbristylis miliacea would behave as hosts of M.graminicola, mostly under rainfed conditions.