Genetic diversity in Algerian maize (Zea mays L) landraces using SSR markers

In the Sahara, maize (Zea mays L) has been adapted to extreme environmental conditions during the last five centuries; therefore, this germplasm has a potential value as source of tolerance to stress. No previous report of the genetic diversity of Saharan maize has been published so far. The objective of this study was to determine the genetic diversity of a collection of Saharan maize. Fifteen accessions representing the geographic diversity of Algeria were characterized with 18 SSR. Most loci (93%) were polymorphic; the total amount of alleles was 87 and the average of alleles per locus was 5.8. The total genetic diversity (He) was 0.57, being 69% intra-accessions and 31% inter-accession. Eight of the alleles were accession-specific and belonged to six populations. Genetic distance among the 15 accessions resulted in the definition of three main clusters related to the geographic origin. Maize germplasm from the Algerian Sahara can be classified at least in three groups and the most variable accessions are in the southern oasis. Some accessions were highly variable and can be sources of favorable alleles for breeding for tolerance to extreme stress conditions.This research was supported by the Spanish Agency for International Cooperation and Development (AECID project A/023430/09), the École Nationale Supérieure Agronomique (ENSA) Algiers,Algeria,the Spanish Council for Scientific Research (CSIC) and the Algerian Ministry of high Education and scientific research (MESRS).Peer reviewe

Genetic diversity in Algerian maize (Zea mays L) landraces using SSR markers

In the Sahara, maize (Zea mays L) has been adapted to extreme environmental conditions during the last five centuries; therefore, this germplasm has a potential value as source of tolerance to stress. No previous report of the genetic diversity of Saharan maize has been published so far. The objective of this study was to determine the genetic diversity of a collection of Saharan maize. Fifteen accessions representing the geographic diversity of Algeria were characterized with 18 SSR. Most loci (93%) were polymorphic; the total amount of alleles was 87 and the average of alleles per locus was 5.8. The total genetic diversity (He) was 0.57, being 69% intra-accessions and 31% inter-accession. Eight of the alleles were accession-specific and belonged to six populations. Genetic distance among the 15 accessions resulted in the definition of three main clusters related to the geographic origin. Maize germplasm from the Algerian Sahara can be classified at least in three groups and the most variable acces¬sions are in the southern oasis. Some accessions were highly variable and can be sources of favorable alleles for breeding for tolerance to extreme stress conditions

A Pruning Algorithm Based on Relevancy Index of Hidden Neurons Outputs

Choosing the training algorithm and determining the architecture of artificial neural networks are very important issues with large application. There are no general methods which permit the estimation of the adequate neural networks size. In order to achieve this goal, a pruning algorithm based on the relevancy index of hidden neurons outputs is developed in this paper. The relevancy index depends on the output amplitude of each hidden neuron and estimates his contribution on the learning process. This method is validated with an academic example and it is tested on a wind turbine modeling problem. Compared with two modified versions of Optimal Brain Surgeon (OBS) algorithm, the developed approach gives interesting results

PbS Infrared Detectors: Experiment and Simulation

The present work deals with the characterization and simulation of lead sulfide (PbS) photoconductors infrared detectors growth by Chemical Bath Deposition (CBD) method. Three different solutions bath are used in order to explore the doping effect and oxidant agent on detection capabilities. Photoelectrical characterization indicates that detectors performances depend strongly on oxidant and doping agents. A simulation study with surface state model is also presented. The physical parameters are deduced and are found to be in agreement with those published in the literature

Linkage disequilibrium between fitness QTLs and the sugary1 allele of maize

Understanding how biological systems evolve across changing conditions has been a crucial focus of research. Mutations change the genetic context in which genes are expressed and yet the mechanisms underlying mutation fitness are still unclear. We use the sweet corn mutant sugary1 (su1) as a model for understanding the genetic regulation of mutant fitness, focusing on the mutant × genotype interaction across diverse environments. In a previous work, we identified quantitative trait loci (QTLs) affecting fitness in a mapping population of recombinant inbred lines (RILs) derived from a cross between field corn (B73) × sweet corn (P39 or IL14h) parents; however, the epistatic effects of these QTLs on su1 fitness were not investigated. In the present study, we estimated fitness for two seed production environments. Viability of su1 is under genetic and environmental controls, regulated by multiple genes with minor contributions, and these genes depend on the genotype into which the mutation is introduced and on the environment. Some QTLs were in linkage disequilibrium with the maize gene Su1 and had epistatic effects on su1 fitness. These QTLs could be used by sweet corn breeders by combining the most favorable alleles associated with su1 viability in breeding new genotypes from field × sweet corn crosses. These results also have implications for mutagenesis breeding or genome editing because the epistatic effects of the target genome on the new alleles generated by these techniques could affect the success of the breeding program.This work was supported by the Spanish Plan for Research and Development (grant number AGL2016-77628-R); FEDER (grant number AGL2016-77628-R); and the College of Agricultural and Life Sciences (University of WisconsinMadison)

Influence of indium on the dissociation of dislocations in GaAs at high temperature

Dislocations have been introduced in GaAs doped with indium, by plastic deformation between 773 K and 1 373 K. Transmission electron microscope observations have shown that indium increases the width of dissociation. This can explain the reduction of as-grown dislocations in In doped GaAs.Des dislocations ont été introduites dans GaAs dopé à l'indium par déformation plastique entre 773 K et 1 373 K. Des observations en microscopie électronique en transmission ont montré que l'indium augmente la largeur de dissociation. Cela permet d'expliquer la réduction de densité de dislocations de croissance dans GaAs dopé à l'indium

Evaluation of algerian maize for drought tolerance

2 páginas y 1 tabla.-Trabajo presentado en el VIII Congreso de Mejora genética de plantas, celebrado en Vitoria-Gasteiz entre el 12 y el 14 de julio de 2016.Maize (Zea mays L.) is currently among the three most widely grown crops produced in the world. However, its production and yield stability is greatly affected by an array of abiotic and biotic stresses. 18 maize populations from the Algerian Saharan oasis were evaIuated under well water and water stress conditions. Water stress was started two weeks before flowering by withdrawing irrigation. Under water stress, Algerian populations exhibited a great variability and their ability to sustain yield production was superior to European and American maize. TAO was the best population followed by LOM and BTM vía the adjustment of various yield related traits. We suggested that Algerian populations can be considered as a novel source of favorable alleles for drought tolerance. However, their yield still low compared to improved populations, reason why breeding for yield will be necessary.Peer reviewe