Genetic transformation: a short review of methods and their applications, results and perspectives for forest trees

This report reviews the state-of-the-art in plant genetic engineering, covering both direct and indirect gene transfer methods. The application of these techniques to forest trees has been discussed and a summary of the published results given. An overview of the possibilities of introducing genes of agronomic interest to improve some characteristics such as resistance to pests and modifications of phenotypic traits has been examined.La transformation génétique : résultats et perspectives pour les arbres forestiers. Cet article fait le point sur les techniques directes et indirectes de transformation génétique des plantes. Leur application pour la transformation des arbres forestiers est discutée et une liste des résultats déjà publiés est établie. Les différents gènes d'intérêt agronomique qui peuvent être introduits afin d'améliorer des caractères comme la résistance aux pathogènes et des modifications du phénotype sont détaillés

The effect of tetraploidization of wild Arachis on leaf morphology and other drought-related traits

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Cultivated peanut is an allotetraploid (genome type AABB) with a very narrow genetic base, therefore wild species are an attractive source of new variability and traits. Because most wild species are diploid, the first step of introgression usually involves hybridization of wild species and polyploidization to produce a synthetic allotetraploid (AABB) that is sexually compatible with peanut. This study investigates drought-related traits such as leaf morphology, transpiration profile, chlorophyll meter readings (SCMR), specific leaf area (SLA) and transpiration rate per leaf area for two wild diploids (Arachis duranensis and Arachis ipaensis) that could be of interest for improvement of the peanut crop. Furthermore, the inheritance of the traits from the diploid to the tetraploid state was investigated. Results showed that whilst some diploid traits such as SCMR, are maintained through hybridization and polyploidization, most characters, such as the leaf area, stomata size, trichome density and transpiration profile, are substantially modified. The study concludes that direct evaluations of drought-related traits in wild diploids may be useful for evaluation of wild species to be used in introgression. However, evaluations on wild-derived synthetic tetraploids are likely to be more informative. Published by Elsevier B.V.841724Generation Challenge Programme TL1FAP-DFConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)EMBRAPAConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Sucrose synthase molecular marker associated with sugar content in elite sugarcane progeny

We describe the development and application of an expressed sequence tag (EST)-derived restriction fragment length polymorphism (RFLP) marker for sugarcane elite genotypes which can be used for quantitative trait loci (QTL) tagging for sugar content. EST-derived RFLP markers for proteins involved in sucrose metabolism have been used in Southern analysis for mapping and gene tagging in elite sugarcane clones. A single dose marker, obtained from a sucrose synthase EST associated with sugar content at the alpha = 0.01 probability level, is presented for sugarcane breeding. Utilization of EST homologues to known genes for generation of molecular markers accelerated the identification of a QTL controlling an important trait-sugar content. Sugarcane bacterial artificial chromosome (BAC) clones hybridizing to the sucrose synthase EST were identified