222 research outputs found

    Selection among and within half-sib families in "Dentado Composto" maize variety for resistance to S. frugiperda and H. zea. ll cycle.

    Get PDF
    Estudou-se a obtenção de parâmetros genéticos para alguns caracteres de planta e espiga de milho (Zea mays L.) cv. Composto Dentado. O material é do segundo ciclo de seleção entre e dentro de famílias de meios-irmãos. Avaliaram-se 400 progénies num delineamento de látice simples 10 x 10 com uma repetição por local: Caruaru e S. Bento do Una, PE. Os experimentos não receberam tratamentos fitossanitários, e foram isolados das áreas que receberam tratamentos com inseticidas, utilizando-se infestações naturais. Foram coletados os dados para: altura da planta (AP) e da espiga (AE), número de espigas por planta (NE) e de espigas mal empalhadas (NEME), danos causados por H. zea (HZ) e S. frugiperda (SF), e produção de grãos (PG). As estimativas de variância genética aditiva foram altas (P < 0,05) para AP, AE e PG, e baixas para os demais caracteres. Tendo em vista os baixos valores encontrados para a variabilidade genética concernentes aos caracteres HZ e SF, é necessário um controle ambiental mais eficiente nas avaliações das progénies.The obtention of genetic parameters was studied for some characters of plant and ear of maize (Zea mays L.) cv. Composto Dentado. The material came from the second cicle of selection inter and intra families of half-sibs. Four hundred progenies were evaluated in a 10 x 10 simple lattice design, with one replicate for each place: Caruaru and São Bento do Una, PE, Brazil. The experiments did not receive phytosanitary treatments. They were isolated from the areas that received insecticide applications and lhe natural infestation was used. Data were colected for: plant height (PH), ear height (EH), number of ears per plant (NE), number of ear with loosed husk (NELH), S.frugiperda damage (SFD), H. Zea damage (HZD) and grain yield (GY). The variance analysis showed significance (P < 0.01) for all characters studied except for SFD. The estimate values for the additive genetic variance were high for PH, EH and GY and low for Lhe other characters. Considering the low values found for genetic variability concerning the characters HZ and SF, an environmental control more efficient ia the progenie evaluations is needed

    Masters of the manipulator: two new hypocrealean genera, Niveomyces (Cordycipitaceae) and Torrubiellomyces (Ophiocordycipitaceae), parasitic on the zombie ant fungus Ophiocordyceps camponoti-floridani

    Get PDF
    During surveys in central Florida of the zombie-ant fungus Ophiocordyceps camponoti-floridani, which manipulates the behavior of the carpenter ant Camponotus floridanus, two distinct fungal morphotypes were discovered associated with and purportedly parasitic on O. camponoti-floridani. Based on a combination of unique morphology, ecology and phylogenetic placement, we discovered that these morphotypes comprise two novel lineages of fungi. Here, we propose two new genera, Niveomyces and Torrubiellomyces, each including a single species within the families Cordycipitaceae and Ophiocordycipitaceae, respectively. We generated de novo draft genomes for both new species and performed morphological and multi-loci phylogenetic analyses. The macromorphology and incidence of both new species, Niveomyces coronatus and Torrubiellomyces zombiae, suggest that these fungi are mycoparasites since their growth is observed exclusively on O. camponoti-floridani mycelium, stalks and ascomata, causing evident degradation of their fungal hosts. This work provides a starting point for more studies into fungal interactions between mycopathogens and entomopathogens, which have the potential to contribute towards efforts to battle the global rise of plant and animal mycoses

    Specific heat of quasi-2D antiferromagnetic Heisenberg models with varying inter-planar couplings

    Full text link
    We have used the stochastic series expansion (SSE) quantum Monte Carlo (QMC) method to study the three-dimensional (3D) antiferromagnetic Heisenberg model on cubic lattices with in-plane coupling J and varying inter-plane coupling J_perp < J. The specific heat curves exhibit a 3D ordering peak as well as a broad maximum arising from short-range 2D order. For J_perp << J, there is a clear separation of the two peaks. In the simulations, the contributions to the total specific heat from the ordering across and within the layers can be separated, and this enables us to study in detail the 3D peak around T_c (which otherwise typically is dominated by statistical noise). We find that the peak height decreases with decreasing J_perp, becoming nearly linear below J_perp = 0.2J. The relevance of these results to the lack of observed specific heat anomaly at the ordering transition of some quasi-2D antiferromagnets is discussed.Comment: 7 pages, 8 figure
    corecore