Mise Au Point Des Techniques De Micropropagation Pour Une Multiplication Massive De Gladiolus Segetum Et Gladiolus Dubius

Apical buds of corms of gladiolus (Gladiolus segetum and Gladiolus dubius) were cultivated on Murashige and Skoog (1962) medium supplemented with IBA 0.1 mg.l-1 and BA 2 mg.l-1. The number of newly formed buds was 3,8 and 4,13 buds per explants for respectively Gladiolus segetum and Gladiolus dubius. The in vitro Rooting need a supplement with auxin and sucrose. Rooting is not present in the control medium. The rate of rooting varied from 10 to 36%, depending on the species and the concentration of IBA in the medium. The Important rooting (36%) is observed for Gladiolus segetum in the presence of IBA 1 mg.l -1. Finally, the acclimatization is possible, these shoots rooted have formed many corms after 6 weeks of culture

MORPHOLOGICAL AND KARYOLOGICAL STUDIES IN TWO WILD IRIS SPECIES (IRIDACEAE) OF TUNISIA

Morphological and cytological variation among two wild iris species (iris juncea (poir) and iris sisyrinchium. (l)) from tunisia was studied. Initially, morphological traits analyzed concern floral and vegetative characters. Analysis of variance showed significant differences. Higher variation coefficient belongs to flower height, flower diameter, filament length, seed diameter, and level number. Pearson coefficients correlations between different characters were positive and highly significant (p< 0.0001) for flower diameter and flower heigth. Factor analysis showed that only two axes define 100% of variance among characters. Secondly, in cytological variation each species had different karyotypic formula such as 2n = 32 = 30sm + 2st for iris juncea with a satellite in pair number 2; 2n= 24 = 18 st + 6 sm for iris sisyrinchium beja‘s population and 2n=26=18 st + 8sm for iris sisyrinchium hammamet population

Morphometric variation and taxonomic identification of thirteen wild rose populations from Tunisia

Thirteen populations of wild roses (Rosa L.) growing in northern and central Tunisia have been used for studies on the discrimination between accessions and populations. Thirty-eight morphological characters related to the branches, prickles, leaves and corymbs were measured on the collected accessions to study the phenotypic diversity among and within species. Principal component and hierarchical cluster analyses (PCA and HCA) separated rose accessions into two distinctive groups and eight subgroups. A taxonomic interpretation of the morphological variability has shown that Tunisian rose populations belong to two sections (Synstylae and Caninae) of the genus Rosa. Moreover, they have been identified as seven separated taxa: R. sempervirens L., R. sempervirens var. submoshata Rouy., R. sempervirens var. prostrata Lindl. belonging to Synstylae section and R. canina L., R. agrestis Savi., R. micrantha Smith. and R. dumetorum Thuill. belonging to Caninae section. PCA and HCA proved that morphological characters used in taxonomic identification such as styles form, leaf and leaflets length, number of flowers by corymb, leaflet serration, presence of glands in leaflet, peduncle, receptacle and sepal have a high value of discrimination, and have been very successful in morphological identification

Use of nurse endosperm for the culture of haploid embryos produced by durum wheat x maize crosses

The use of doubled-haploids in plant breeding programs enables accelerating the release of new varieties adapted to climate change. The durum wheat x maize crosses technique is a method of choice for producing durum wheat haploid plants. The haploid embryos produced by this method develop without albumen and their survival is ensured by post-pollination hormonal treatments. In this study, nine post-pollination treatments with 2,4-Dichlorophenoxyacetic acid (2,4-D), Picloram and Dicamba at the concentrations of 10, 50 and 100 mg.L-1 were applied to 7 durum wheat genotypes. The effects of genotype and post-pollination treatment on durum wheat haploid embryos produced by durum wheat x maize crosses and the use of the endosperm nursing technique for haploid plantlets regeneration were investigated. The haploid induction parameters varied with the durum wheat genotypes as well as the post-pollination treatments. The phenomenon of polyembryony resulting from durum wheat x maize crosses is reported for the first time in this article. The durum wheat genotypes showed different abilities to produce monoembryo and polyembryos. The post-pollination treatments with 2,4-D (10 mg.L-1) and Picloram (10 and 100 mg.L-1) gave a higher embryo formation frequency than the treatments with Dicamba. The embryo conversion to plantlet was greatly improved, especially in recalcitrant genotypes using the durum wheat endosperm as supplemental nourishment in combination with the Gamborg B5 regeneration medium.Keywords: Durum wheat; Haploid embryo; Maize; Nurse Endosperm Technique; Polyembryony

Use of nurse endosperm for the culture of haploid embryos produced by durum wheat x maize crosses

The use of doubled-haploids in plant breeding programs enables accelerating the release of new varieties adapted to climate change. The durum wheat x maize crosses technique is a method of choice for producing durum wheat haploid plants. The haploid embryos produced by this method develop without albumen and their survival is ensured by post-pollination hormonal treatments. In this study, nine post-pollination treatments with 2,4-Dichlorophenoxyacetic acid (2,4-D), Picloram and Dicamba at the concentrations of 10, 50 and 100 mg.L-1 were applied to 7 durum wheat genotypes. The effects of genotype and post-pollination treatment on durum wheat haploid embryos produced by durum wheat x maize crosses and the use of the endosperm nursing technique for haploid plantlets regeneration were investigated. The haploid induction parameters varied with the durum wheat genotypes as well as the post-pollination treatments. The phenomenon of polyembryony resulting from durum wheat x maize crosses is reported for the first time in this article. The durum wheat genotypes showed different abilities to produce monoembryo and polyembryos. The post-pollination treatments with 2,4-D (10 mg.L-1) and Picloram (10 and 100 mg.L-1) gave a higher embryo formation frequency than the treatments with Dicamba. The embryo conversion to plantlet was greatly improved, especially in recalcitrant genotypes using the durum wheat endosperm as supplemental nourishment in combination with the Gamborg B5 regeneration medium.Keywords: Durum wheat; Haploid embryo; Maize; Nurse Endosperm Technique; Polyembryony

Effet de la salinité sur la répartition des cations (Na+, K+ et Ca2+) et du chlore (Cl-) dans les parties aériennes et les racines du ray-grass anglais et du chiendent

Salinity effect on the assessment of cations (Na+, K+ and Ca2+) and chlorine (Cl-) in the aerial parts and roots of perennial ryegrass and bermudagrass. Seedling plants of bermudagrass, var. Tifway, and perennial ryegrass, var. Perfect, were cultivated in growth plate and sprinkled with running water added with different contents of NaCl (50 to 150 mM). One cultivation is led during summer time and another one during winter time. The ionic characteristics of vegetative organs of plants (leaves, roots) depend of the species and the season of cultivation. The plants of perennial ryegrass and bermudagrass accumulated Na+ and Cl- in their tissues but leaf contents for these ions were generally higher in perennial ryegrass especially at the highest concentration of NaCl. Salinity led to modifications in K+ and Ca2+ contents according to the species, kind of organ and season

Volatile Oil Components of Laurel (Laurus nobilis L.) Leaves Obtained from Plants Cultivated under Salinity Stress Conditions

Laurel (Laurus nobilis L.) is a strict endemic species of natural vegetation of the Mediterranean region, which is known for its medicinal, aromatic, forestry, ornamental and culinary properties. This species produces valuable essential oil (EO). The content of EO and its composition depend on different factors, e.g., genetic, cultural practices and environmental conditions. Among these, salt stress is a major limiting factor, which affects almost all plant functions. Similar to essential oils (EOs), biotic and abiotic stresses may stimulate or inhibit the emission of volatile compounds (VCs) in plant materials, suggesting that these substances can be responsible on stress defense strategies. Therefore, an experiment was conducted to assess the effect of different NaCl concentrations (0, 50, 100 and 150 mM) of the irrigation water on VCs of laurel leaves. Our results showed that salt stress affected the volatile metabolites compounds, mainly the major ones. For instance, 1,8-cineole and linalool were negatively affected by high salinity levels, while the opposite was observed for -terpenyl acetate and methyl eugenol. The proportion of grouped compounds of laurel VCs also differed among the studied treatments. The relative content of oxygenated monoterpenes and monoterpene hydrocarbons, respectively the first and the second largest groups, decreased with increasing NaCl concentration. Differently, the relative amount of sesquiterpene hydrocarbon group increased, especially at 100 mM NaCl. These findings indicate that the cultivation of laurel in marginal lands, characterized by high salinity or low-quality water, must be carefully evaluated because it significantly varies the quality of its products