The State of the Art of the Tunisian Apidae Fauna (Hymenoptera: Anthophila)

Based on a review of the available literature, the state of the art and a checklist of the fauna of the Apidae family of Tunisia is presented. The first list of the species of the family is given. 184 species and subspecies belonging to 19 genera, 12 tribes and three subfamilies were listed. Distribution of recorded taxa from Tunisia and from the world is provided. Apinae is the subfamily with the highest species richness with 89 species. Nomada has the highest number of species represented by 62 taxa. The Tunisian East center is the least species-diversified regions with only 16 species and subspecies reported so far. Five species are endemic to Tunisian fauna. Eight Nomada and one Anthophora species were collected from Tunisia, but their identity should be re-confirmed. The presence of Thyreomelecta sibirica (Radoszkowski, 1893) in Tunisia is doubtful and a re-examination and confirmation are needed

Un listado de la familia Bembicidae (Hymenoptera: Apoidea) de Túnez

A checklist of family Bembicidae from Tunisia is compiled based on data available in the literature, new material collected from different localities in Tunisia between 2017 and 2019, and some specimens hosted in the Muséum National d’Histoire Naturelle, Paris, France. As a result, 49 species and two subspecies in 16 genera of the family Bembicidae are recorded. Two genera: Psammaecius Lepeletier de Saint Fargeau, 1832, and Brachystegus A. Costa, 1859, are reported in this study for the first time. This is in addition to nine species and subspecies: Alysson ratzeburgi Dahlbom, 1843, Psammaecius eremorum de Beaumont, 1952, Stizoides klugii (F. Smith, 1856), Stizus fuscatus Morice, 1897, Stizus niloticus saharae Roth, 1934, Stizus pubescens arenarum Handlirsch, 1892, Stizus ruficornis strigatus Mochi, 1939, Stizus vespoides (Walker, 1871) and Brachystegus braueri (Handlirsch, 1887) that are new for the Tunisian fauna. New localities are also reported for several species and subspecies that had already been reported from Tunisia. Identified taxa are illustrated by digital photographs and their global and Tunisian distribution is presented.Se recopila una lista de la familia Bembicidae en Túnez basada en los datos disponibles en la literatura, en nuevo material recolectado de diferentes localidades de Túnez entre 2017 y 2019, y algunos especímenes conservados en el Muséum National d’Histoire Naturelle, París, Francia. Como resultado, se registraron 49 especies y dos subespecies en 16 géneros de la familia Bembicidae. Dos géneros: Psammaecius Lepeletier de Saint Fargeau, 1832 y Brachystegus A. Costa, 1859 se reportan en este estudio por primera vez. Esto se suma a nueve especies y subespecies: Alysson ratzeburgi Dahlbom, 1843, Psammaecius eremorum de Beaumont, 1952, Stizoides klugii (F. Smith, 1856), Stizus fuscatus Morice, 1897, Stizus niloticus saharae Roth, 1934, Stizus pubescens arenarum Handlirsch, 1892, Stizus ruficornis strigatus Mochi, 1939, Stizus vespoides (Walker, 1871) y Brachystegus braueri (Handlirsch, 1887) que son nuevas para la fauna tunecina. También se han encontrado nuevas localidades para varis especies y subespecies, que ya habían sido reportadadas de Túnez. Los taxones identificados se ilustran mediante fotografías digitales y se presenta su distribución global y en Túnez

Effect of Water Stress on Photosynthetic Assimilation and Biomass Accumulation in Olive Tree

The climate change that we are attending in recent years requires a revision of the water resources management in order to en sure a sustainable supply. For this reason, in order to test the plants ability to face water stress, three water stress intensities (100% (T0), 50 (T1) and 25% (T2) field capacity (fc)), for 42 days in a greenhouse under semi-controlled conditions, were applied on 18 olive plants (Olea europaea L. cv 'Meski') of one year old. An evaluation of the response of the olive tree at different water supplies was conducted by monitoring the photosynthetic assimilation, chlorophyll index measured by SPAD, plant growth and dry matter accumulation. The results showed that photosynthesis has increased after 42 days for T0 plants while it increased during the first two weeks before dropping to the 42th day of the application of water restriction (AWR) for T1 plants; a decrease of 26% compared to control treatment. The photosynthetic assimilation of T2 plants has increased at a rate slower until the 28th day AWR then it has dropped after 42 days a decrease of 46% from the witness thus increasing the irrigation dose results in improved photosynthesis. The chlorophyll index fell 2, and 7% compared to the control treatment for T1 and T2, respectively, after 42 days AWR showing that fluid restriction affects the integrity of chlorophylls. Plant growth was shown by the development of a longer root for T2 plants ex plained by the search for minimum quantities of water available. The results showed that the control plants have accumulated more dry matter than stressed plants in the roots and the stem while the underground part/aerial part report seems indifferent to water stress. Water restriction has affected thereby biomass of roots and stems in favor of the leaves, the first operator of the photosyn thetic activit

The Effects of Ripening Stage and Mode of Culture of Chemlali, Arbequina and Koroneiki on the Capacities of Oils to Scavenge ABTS Free Radicals

The aim of this study is to evaluate the antioxidant power of the olive oil against the cation radical ABTS•+, according to cultivars: Chemlali, Arbequina and Koroneiki; culture modes: extensive and intensive; ripening stages: November and December corresponding stages and study year: 2017 and 2018. Radical percentage inhibition (PI), Trolox equivalent antioxidant capacity (TEAC), inhibitory concentration required to scavenge 50% of radicals (IC50) and principal component analysis (ACP) were determined.  The oil of the Tunisian main cultivar Chemlali, cultivated in extensive mode, has the best scavenging power with the lowest IC50 values of 9.3, 10.8, 9.65 and 10.4 µg/ml respectively in all the ripening stages. Also, at the lowest tested concentration of 20 µg/ml, this oil has the highest TEAC values, respectively 2.28 and 2.20 in November of 2017 and 2018. For the introduced cultivars, Koroneiki presents better performance than Arbequina, in intensive mode, with IC50 ranged from 9.6 to 13.8 against 12.40 to 22.35 for Arbequina. Furthermore, the principal component analysis proves that the oils of Chemlali in extensive mode and Koroneiki in intensive have the best scavenging capacity of ABTS•+. This study proves that the extensive mode is the best culture mode and the ripening stage of November is the best stage in order to get oils with a height antioxidant capacity

Climate change effects on phytochemical compounds and antioxidant activity of Olea europaea L.

To tolerate water shortage and high temperature, olive cv. ‘Meski’, the main variety of table olives in Tunisia, developed several biochemical changes. The hereby study focused on the adaptation of the olive tree to the climatic conditions, considering the evaluation of phenolic compounds, chlorophylls, carotenoids, saponin and steroid synthesis, as well as the evaluation of the antioxidant activity. The analyses were made upon fresh leaves collected from three coastal areas of Tunisia (North (sub-humid), center (higher semi-arid) and South (lower arid)) and using different leaves’ extracts. The results emphasized that Southern ‘Meski’ trees had leaves with more polyphenols, flavonoids, o-diphenols and tannins compared with the Northern ones. From the North to the South, ‘Meski’ leaves showed an increase of carotenoids and a decrease of chlorophyll a and b contents. The highest level of antioxidant compounds of Southern leaves could be contributed to reduce the oxidative stress of the olive tree. The spectrophotometric analysis of the antioxidant capacity of leaves collected from central and Southern areas, based on DPPH and ABTS radical-scavenging activity, showed a higher value of antioxidant activity than the Northern ones, at different extract concentrations. Therefore, the increase of the analyzed bioactive compounds can be considered as a response of the tree to surround aggressions and to oppose the oxidative stress that results from the severity of climatic conditions, characteristic of the Southern area

The Effects of Ripening Stage and Mode of Culture of Chemlali, Arbequina, and Koroneiki on the Capacities of Oils to Scavenge ABTS Free Radicals

This paper focuses on evaluating the antioxidant power of olive oil against the cation radical ABTS•+ according to cultivars (Chemlali, Arbequina and Koroneiki), culture modes (extensive and intensive), ripening stages (November and December corresponding stages), and study year (2017 and 2018). Radical percentage inhibition (PI), Trolox equivalent antioxidant capacity (TEAC), inhibitory concentration required to scavenge 50% of radicals (IC50), and principal component analysis (PCA) were determined. The oil of the Tunisian main cultivar, Chemlali, cultivated in extensive mode, has the best scavenging power with the lowest IC50 values of 9.3, 10.8, 9.65 and 10.4 µg/ml respectively in all the ripening stages. Also, at the lowest tested concentration of 20 µg/ml, this oil has the highest TEAC values, respectively 2.28 and 2.20 in November of 2017 and 2018. For the introduced cultivars, Koroneiki presents better performance than Arbequina, in intensive mode, with IC50 ranged from 9.6 to 13.8 against 12.40 to 22.35 for Arbequina. Furthermore, the principal component analysis proves that the oils of Chemlali in extensive mode and Koroneiki in intensive mode have the best scavenging capacity of ABTS•+. This study proves that the extensive mode is the best culture mode and the ripening stage of November is the best stage in order to get oils with the highest antioxidant capacity

The Effects of Ripening Stage and Mode of Culture of Chemlali, Arbequina and Koroneiki on the Capacities of Oils to Scavenge ABTS Free Radicals

The aim of this study is to evaluate the antioxidant power of the olive oil against the cation radical ABTS•+, according to cultivars: Chemlali, Arbequina and Koroneiki; culture modes: extensive and intensive; ripening stages: November and December corresponding stages and study year: 2017 and 2018. Radical percentage inhibition (PI), Trolox equivalent antioxidant capacity (TEAC), inhibitory concentration required to scavenge 50% of radicals (IC50) and principal component analysis (ACP) were determined.  The oil of the Tunisian main cultivar Chemlali, cultivated in extensive mode, has the best scavenging power with the lowest IC50 values of 9.3, 10.8, 9.65 and 10.4 µg/ml respectively in all the ripening stages. Also, at the lowest tested concentration of 20 µg/ml, this oil has the highest TEAC values, respectively 2.28 and 2.20 in November of 2017 and 2018. For the introduced cultivars, Koroneiki presents better performance than Arbequina, in intensive mode, with IC50 ranged from 9.6 to 13.8 against 12.40 to 22.35 for Arbequina. Furthermore, the principal component analysis proves that the oils of Chemlali in extensive mode and Koroneiki in intensive have the best scavenging capacity of ABTS•+. This study proves that the extensive mode is the best culture mode and the ripening stage of November is the best stage in order to get oils with a height antioxidant capacity

Ecophysiological Responses of Two Olive Tree Cultivars (Olea europaea L. CV Koroneiki and Chemlali) Under Three Water Treatments

In this paper, our objective is to assess and compare the effects of three levels of irrigation application on the ecophysiological behavior and plant dry matter accumulation of two young olive tree cultivars Koroneiki, a promising greek cultivar, and Chemlali, the best local cultivar. According to this assessment, we can determine the most efficient water treatment that could be suitable for Mediterranean environments subjected to water shortage conditions. Measurements were made in the green house of the Tunisian Olive tree Institute under normal day-light conditions from March, 16th to April, 21st 2015. Three water treatments were applied which are T100% (control treatment: Daily irrigation at 100% of Available Water Content (AWC)), T50% (Daily irrigation at 50% of AWC) and T0% (Without watering). The results showed that the two olive tree cultivars possess important mechanisms to overtake limited water resources. However, some striking variations existed between the two cultivars studied. Indeed, as water stress increased (T0%), Chemlali maintained longer a high midday leaf water potential compared (- 4.54 MPa) to Koroneiki (- 5.8 MPa). T50% treatment seems to be sufficient for both cultivars. Measurements of total Osmotic Adjustment (OA) showed that olive trees use this mechanism to create very negative leaf water potentials in order to be able to extract water from a dry root environment. The root/shoot ratio of Chemlali plants at T50% treatment was the highest (1.08) comparatively with the other two treatments (0.70 and 0.79 for T100% and T0% AWC water treatments, respectively). This result shows that Chemlali plants valorize low quantities of water (T50%) rather than high quantities (T100%) and Koroneiki plants behave better when it is irrigated at 100% AWC. To conclude, Chemlali plants irrigated at 50% AWC, compared to Koroneiki plants, are the most suitable to tolerate water restriction conditions

WATER USE IN OLIVE ORCHARDS ESTIMATED BY PHYSIOLOGIC AND CLIMATIC METHODS IN TUNISIA

This experimental study conducted on irrigated olive trees (cv. Meski) in arid climate in Enfidha-Tunisia. This study aims to estimate the water needs of the Olive Trees for a possible optimization of irrigation.To do this, a calculation of water requirements was performed by physiologic and climatic methods and compared to traditional irrigation practiced by farmer (T0). The physiologic method is based on the xylem sap flow (T1) and the climatic method is based on the reference evapotranspiration (T2).Results showed that the values of the highest transpiration are recorded under 60% ET0 (T2).Under this treatment, the average of transpiration was about 50% of the applied irrigation dose, with soil evaporation average about 15%. These results allowed us to conclude that the physiological method (T1) allows a better estimate of water needs. This method also improves the profitability of the olive tree with a better optimization of water use (save 35% of water)