Study of root para-nodules formation in wheat (Triticum durum) inoculated with Frankia strain CcI3 and treated with 2, 4-dichlorophenoxyacetate (2, 4-D)

Frankia strains can induce N2-fixing root nodules on certain non-leguminous plants. It is known that exogenous application of 2,4-dichlorophenoxyacetate (2,4-D) affects root morphology. In this work, wheat roots were treated with 2,4-D and inoculated with the actinomycete Frankia. Wheat plants grew in a growth chamber with hydroponic medium. Binocular observation revealed that para-nodules were formed when wheat roots were inoculated with Frankia and the root length was enhanced. When the inoculation with Frankia was combined to 2,4-D treatment, the para-nodules formed were bigger and more numerous, while the root length was shortened.Keywords: Frankia, wheat, roots, para-nodules, 2,4-dichlorophenoxyacetateAfrican Journal of Biotechnology Vol. 12(35), pp. 5427-543

Dislocation multiplication in GaAs : inhibition by doping

The crystal quality improvement by electrical or isoelectronic doping of L.E.C. grown GaAs crystals is related to the thermoelastic modelling of stresses during growth. The dislocation structure in as-grown and annealed crystals is deduced, in particular with the help of the results of plastic deformation. The addition of various elements of the columns II-III-IV-V-VI in GaAs is considered and its influence on the establishment of the dislocation substructure is discussed.L'amélioration de la qualité cristalline par dopage électrique ou isoélectronique des cristaux de GaAs obtenus par la méthode L.E.C. est reliée aux modèles thermoélastiques donnant les contraintes en cours de croissance. On en déduit les structures de dislocations dans les cristaux bruts de croissance et recuits, en particulier A la lumière des r6sultats de d6formation plastique. L'addition de diff6rents éléments des colonnes II-III-IV-V-VI dans GaAs est envisagée et son influence sur les mécanismes d'établissement de la sousstructure de dislocations est discutée

Algerian maize populations from the Sahara desert as potential sources of drought tolerance

Drought affects maize (Zea mays L.) performance from seedling to grain filling. Sources of drought tolerance at multi-scale growth are crucial for maize breeders. The objectives of this work were to identify new sources and mechanisms of drought tolerance and to study the traits controlling plant growth under drought and their associations with yield. We evaluated a collection of 18 maize populations from the Algerian Saharan oases under simulated drought conditions using Polyethylene glycol 6000, and in the field. The genotype × treatment interactions were more significant under field than under control conditions. Under field conditions, based on general agronomic performance, PI527476, PI542678 and PI527474 were the most drought-tolerant populations. PI527476 was the most tolerant population for germination-related traits, PI542678 exhibited high final germination, high number of secondary roots and positive water use efficiency (WUE), while PI527474 presented high number of secondary roots number and WUE. PI542685 was drought tolerant at seedling stage, characterized by high germination, long roots, heavy root, high number of secondary roots, and stable shoot/root weight ratio. Germination, shoot/root weight, root dry weight at seedling stage, and dry weight of secondary roots were the most significant seedling growth-related traits affecting WUE and yield under drought. Differences were detected among populations under stress conditions at multi-scale growth phases with some common genetic dependency of yield on seedling-related traits. Therefore, these Saharan populations could provide favorable alleles for drought tolerance for breeding programs, and the use of seedling-related traits, especially root performance, as secondary yield-related traits could lead to increased gain yield selection under drought conditions.Research was supported by the Spanish Plan for Research and Development (Project codes AGL2013-48852-C3-1-R, AGL2016-77628-R and FEDER) and the École Nationale Supérieure Agronomique. Seed from Algerian populations was provided by the North Central Regional Plant Introduction Station of the USA. The Instituto de Ordenación Rural de Ourense (INORDE) has hosted one trial

Développement et composition de la graine de Medicago truncatula

National audienc

Développement et composition de la graine de Medicago truncatula

National audienc

Development and composition of the seeds of nine genotypes of the Medicago truncatula species complex

International audienc