Effect of ABA,arginine and sucrose on protein content of date palm somatic embryos

Abscisic acid (ABA), arginine and sucrose were evaluated for their effects on the morphology, germination rates and protein content of date palm somatic embryos (SE). Different concentrations of these supplements in the culture medium were used. The comparative study of SE length and thickness between treated and untreated SE revealed no differences, except for ABA (20 μM), which increased thickness. A decrease of water content (WC) in favor of an increase in dry weight (DW) was observed in all treated SE, especially with sucrose (90 g l⁻¹) and ABA (20 μM). Only ABA (20 and 4 μM) caused a proliferation rate of the cultures higher than those in the control. Although all the tested compounds increased protein content, ABA (20 μM) was more effective in protein enrichment than arginine and sucrose treatments. The SDS-PAGE protein profiles showed a significant difference between treated and untreated SE. A protein band of 22 kDa, identified as glutelin in a previous work, was accumulated after treatment with 20 μM ABA or 3 mM arginine. These findings may contribute to further understanding of the mechanisms involved in the accumulation of specific storage proteins in several plants.     

The effect of some watershed,soil characteristics and morphometric factors on the relationship between the gully volume and length in Fars Province,Iran

A survey consisting of 146 first order gullies selected from five sites with different land use, soil and watershed properties was carried out to estimate the parameters of the empirical power function in order to describe the relationship between the gully volume and length in Fars province, Iran. Subsequently, the gullies were clustered into seven groups (“A” to “G”) based on nine morphometric factors. The linearized functions were fitted to the natural logarithms of the volume and length in each group and the parameters “a” and “b” were determined. The obtained “a” and “b” parameters are in the ranges of 1.0–10.8 and 0.8–1.4, respectively. Comparison of “a” and “b” parameters in each group with the mean of nine factors and the mean soil, watershed and land use characteristics in each group showed that the gully volume and average cross section are correlated with the gully depths in different sections and the gully head slopes. Also it was shown that the parameters of fitted functions to the plots of gully volumes versus gully lengths are proportional to width at the gully heads. The gully widths at the top and bottom of the five meter sections are correlated with the average upstream watershed area of the gullies.     

Latent infection of asymptomatic Hawaiian sugarcane cultivars with 16SrI and 16SrXI phytoplasmas

Leaves from sugarcane were collected at the Hawaiian sugarcane breeding station and from recent and previous Hawaiian plantation fields and tested for phytoplasma by nested PCR, quantitative PCR and partly by the 16S/23S internal spacer sequence. Phytoplasmas were found in samples of 10 of the 11 tested cultivars from the station and identified as strains 16SrI phytoplasma (aster yellows phytoplasma) and 16SrXI phytoplasma (rice yellow dwarf phytoplasma). Hot water treatment could partially eliminate the phytoplasmas, but sugarcane plants in the Hawaiian plantations, which routinely use hot-water-treated seed cane cuttings, were nevertheless infected by 16SrXI phytoplasma. Samples from abandoned sugarcane plantations contained 16SrI phytoplasma or 16SrXI phytoplasma. The titre of phytoplasma was very low in all cases, i.e., at or below the detection threshold of quantitative PCR, and no difference in phytoplasma infection was observed between healthy-looking, green plants and plants that had YLS symptoms. Apparently the Hawaiian sugarcane cultivars have some kind of phytoplasma resistance under the growth conditions in Hawaii. The latent presence of phytoplasma strains calls for awareness and rigorous treatment of sugarcane setts even in cases, where YLS was so far exclusively related to the presence of Sugarcane yellow leaf virus.     

Les mauvaises herbes de Syrie

L'analyse de la littérature a permis de relever 610 espèces de mauvaises herbes en Syrie; elles se répartissent en 251 genres et 48 familles. La flore complète comporte 3460 espèces, 867 genres et 130 familles. The weeds of Syria An analysis of the literature shows there are 610 species of weeds in Syria. They are grouped in 251 genera and 48 families. The complete flora contains 3460 species, 867 genera and 130 families. Die Unkräuter von Syrien Eine Analyse der vorhandenen Literatur hat ergeben, dass 610 in Syrien vorkommende Arten als Unkräuter bezeichnet werden können; sie verteilen sich auf 251 Gattungen und 48 Familien. Die komplette Flora umfasst 3460 Arten, 867 Gattungen und 130 Familien. Le dernier volume de la flore de Mouterde (1962–1985) sur la Syrie vient de paraître, édités par Charpin. Pour chaque taxon cité, l'auteur indique dans quel type de milieu il peut être trouvé. C'est à partir de cet ouvrage, quand il était encore inachevé, qu'ont été préparé divers documents sur les mauvaises herbes de Syrie (Ann., s.d.). Nous avons repris l'exploitation complète des indications stationnelles de Mouterde pour établir cinq listes (Soufi 1985), à savoir: (i) listes des mauvaises herbes, comportant les espèces localisées dans les cultures: les stations indiquées sont ‘terres de culture’, ‘champs de blé’, ‘céréales’, ‘vignes’, ‘vergers’, etc.; (ii) liste des espèces de mauvaises herbes potentielles, localisées dans les ‘abords de cultures’, ‘champs pierreux’ (136 espèces); (iii) liste des espèces se trouvant dans les ‘terrains à l'abandon’, ‘lieux incultes’, ‘jachères’ (71 espèces); (iv) liste des plantes parasites; (v) liste des espèces des ‘terrains à l'abandon’ et ‘lieux incultes’, mais ne pouvant devenir des mauvaises herbes; par exemple parce qu'elles sont ligneuses (20 espèces). Pour chacune de ces catégories, des listes alphabétiques ou taxinomiques ont été publiées (Soufi 1985) et peuvent être obtenues, ensemble ou séparément, sur simple demande. Seule la première liste, qui rassemble les mauvaises herbes à proprement parler, sera analysée ici. Elle compate 610 espèces ou sous-espèces, en 251 genres et 48 familles. À titre de comparaison, l'ensemble de la flore syrienne, analysé par Daget et Al Hakim (s.p.), comporte 3460 espèces ou sous-espèces, en 867 genres et 131 familles. Pour les mauvaises herbes, il y a donc: 12.7 espèces par famille concernée, 2.4 espèces par genre concerne et 5.3 genres par famille concernée. Pour l'ensemble de la flore, ces ratios sont respectivement de 26.6, 4 et 6.7. La flore des mauvaises herbes est donc taxonomiquement moins riche, mais plus variée que la flore dans son ensemble. Le tableau I donne le détail de la répartition des taxons. Les familles comportant plus de 10 genres sont dans l'ordre adoptées par Hutchinson (1959): Papillonaceae (21), Cruciferacees (32), Ombeliferacees (24), Compositae (39), Labiatae (13), Liliaceae (12), Gramineae (19). Les 24 familles monogénériques sont suivant le même ordre: Urticacaea, Rutaceae, Valerianaceae, Violaceae, Aristolochiaceae, Convolvulaceae, Polygalaceae, Resedaceae, Aconthaceae, Linaceae, Portulacaceae, Orobanchaceae, Zygophylaceae, Chenopodiaceae, Oxalidaceae, Clusiaceae, Amaronthaceae, Cuscutaceae, Loranthaceae, Gentianaceae, Orchidiaceae, Santalaceae, Plantaginaceae, Cyperaceae. Les 7 genres comportant plus de 10 espèces sont: Astragalus (16), Medicago (10), Trifolium (10), Euphorbia (17), Silene (11), Veronica (15), Salvia(12). Les 15 familles comportant plus de 10 espèces sont: Papilionaceae (179), Malvaceae (13), Euphorbiaceae (20), Rubiaceae (10), Papaveraceae (16), Cruciferaceae (53), Caryophylaceae (23), Ombeliferaceae (40), Dipsacaceae (11), Compositae (78), Scrofulariacae (34), Boraginae (12), Labiatae (37), Lilaceae (38), Graminae (32). Enfin les 10 familles mono spécifiques sont: Urticaceae, Polygalaceae, Zygophyllaceae, Clusiaceae, Loranthaceae, Portulacaceae, Gentianaceae, Acanthaceae, Orchidiaceae, Cyperaceae. Les travaux en cours portent sur l'étude du comportement biogéographique des mauvaises herbes et sur celle de leur répartition dans le territoire syrien. Une prochaine note en donnera les premiers résultats.     

Development of zygotic and somatic embryos of Phoenix dactylifera L. cv. Deglet Nour: Comparative study

In order to improve somatic embryogenesis production in date palm Phoenix dactilyfera L. cv. Deglet Nour (DN), a comparative study between somatic (SE) and zygotic (ZE) embryos developments was carried out. The data showed that ZE maturation occurred from 10 to 19 weeks after pollination (WAP). During this period, the fresh weight (FW) and the dry weight (DW) of ZE increased progressively to reach a maximum level at 19 WAP. SE development occurred in three distinct stages. The DW remained constant during the two first stages, and declined slightly during the third and final stage. Embryo protein analysis revealed significant differences between ZE and SE. The ZE total protein level was initially low and increased to the maximum at mature stage. However, no significant change in total protein was detected during SE development. SDS-PAGE analysis showed a poor protein profile for SE, compared to that of ZE. In the latter, a 22 kDa protein was identified by N-terminal sequencing as a glutelin. This protein was accumulated rapidly during early development and remained at a relatively constant level during ZE development, and then declined progressively 12 days after embryo germination (DG). This protein seems to be absent in SE.     

Genetic analysis of live weight of local kids to promote genetic evaluations in the arid areas of Tunisia

Tropical Animal Health and Production - Goat meat production, a widely extended activity in the more arid areas of Tunisia, relies on local breeds. These breeds are well adapted to produce under...     

Plant selection method for urban landscapes of semi-arid cities (a case study of Tehran)

Choosing appropriate plants for urban landscapes is vital to avoid potential financial and environmental losses that may occur if all selection parameters are not taken into account. A methodology has been developed to assist landscape architects, planting designers, and urban horticulturists in the plant selection process. Tehran has been picked as a case study due to its arid and semi-arid climate which poses more challenges in front of an expert. After grouping plants, selection parameters have been defined for each plant group. Plant species were comparatively graded for each parameter by a group of eight specialists. Analytical hierarchy process (AHP) technique and hierarchical cluster analysis have been utilized to find the most adaptable plant species for the area according to the main selection parameters of zone tolerance, urban conditions, esthetics, maintenance, growth characteristics, and specific features. Several new plants were ranked high in the final tables suggesting that the urban landscape of Tehran has a great potential to become more attractive, less allergic, and less costly, as well as consuming less water. Before introducing new plants to the urban environment, they should be experimented on in small numbers for several years to confirm that they will not change the ecology of the whole region through invasion or posing a threat to any local plant species.     

Spatial distribution and habitat selection of culicoides imicola: The potential vector of bluetongue virus in Tunisia

The increasing threat of vector-borne diseases (VBDs) represents a great challenge to those who manage public and animal health. Determining the spatial distribution of arthropod vector species is an essential step in studying the risk of transmission of a vector-borne pathogen (VBP) and in estimating risk levels of VBD. Risk maps allow better targeting surveillance and help in designing control measures. We aimed to study the geographical distribution of Culicoides imicola, the main competent vector of Bluetongue virus (BTV) in sheep in Tunisia. Fifty-three records covering the whole distribution range of C.imicola in Tunisia were obtained during a 2-year field entomological survey (August 2017 – January 2018 and August 2018 – January 2019). The ecological niche of C. imicola is described using ecological-niche factor analysis (ENFA) and Mahalanobis distances factor analysis (MADIFA). An environmental suitability map (ESM) was developed by MaxEnt software to map the optimal habitat under the current climate background. The MaxEnt model was highly accurate with a statistically significant area under curve (AUC) value of 0.941. The location of the potential distribution of C. imicola is predicted in specified regions of Tunisia. Our findings can be applied in various ways such as surveillance and control program of BTV in Tunisia.