Influencia de virus y similares en el desarrollo de yemas de cítricos cultivadas “in vitro”

Se estudio el efecto de seis agentes patógenos en el desarrollo de yemas de citricos cultivadas in vitro y la obtención de plantas a partir de las mismas. Las enfermedades estudiadas fueron la tristeza causada por un closterovirus (CTV), el infectious variegation causado por un virus ilar (CIVV), el vein enation y la psoriasis que son enfermedades de etiologia desconocida transmisibles por injerto, y la exocortis y la cachexia producidos por un complejo de viroides

Influence of Virus and Virus-Like Agents on the Development of Citrus Buds Cultured Invitro

Tissue culture in vitro was used to determine the effect of six major citrus virus and virus-like agents. Nodal stem segments from inoculated Pineapple sweet orange (Citrus sinensis (L.) Osb.), Mexican lime (C. aurantifolia (Christm.) Swing.) and Arizona Etrog citron 861-Sl (C. medica L.) were cultured in vitro to induce shoots. Some virus and virus-like agents had a marked effect on bud development and further recovery of plantlets. The number and size of the shoots that developed from each bud were affected as a result of infection. The effect depended on the specific virus, the isolate and the host-disease combination. The possible implications of these results are discussed

Effects of carbides on fatigue characteristics of austempered ductile iron

Crack initiation and growth behavior of an austempered ductile iron (ADI) austenitized at 800 °C and austempered at 260 °C have been assessed under three-point bend fatigue conditions. Initiation sites have been identified as carbides remaining from the as-cast ductile iron due to insufficient austenization. The number of carbides cracking on loading to stresses greater than 275 MPa is critical in determining the failure mechanism. In general, high carbide area fractions promote coalescence-dominated fatigue crack failure, while low area fractions promote propagation-dominated fatigue crack failure. Individual carbides have been characterized using finite body tessellation (FBT) and adaptive numerical modeling (SUpport vector Parsimonious ANalysis Of VAriance (SUPANOVA)) techniques in an attempt to quantify the factors promoting carbide fracture. This indicated that large or long and thin carbides on the whole appear to be susceptible to fracture, and carbides that are locally clustered and aligned perpendicular to the tensile axis are particularly susceptible to fracture