Fluidite de l’huile produite par des arbres du second cycle de selection reccurente reciproque chez le palmier a huile (Elaeis guineensis Jacq)

L’étude de la fluidité de l’huile du Palmier à huile (Elaeis guineensis) présente de nombreux intérêts, en particulier pour l’identification des arbres élites qui seront utilisés dans le programme d’amélioration soit par clonage, soit par croisement en vue d’augmenter la fraction d’huile fluide dans le fruit. Dans cette perspective, les indices d’iode des huiles extraites à partir des régimes produits par des arbres du second cycle de sélection récurrente réciproque ont été évalués et comparés à ceux des huiles extraites à partir d’arbres du premier cycle. Les résultats obtenus indiquent que le matériel végétal Deli x La Mé issu du premier cycle de sélection récurrente réciproque possède un indice d’iode moyen de 55. Les indices d’iode des matériels issus du second cycle de sélection récurrente réciproque, laissent apparaître globalement une amélioration de 2 points pour les arbres des croisements réalisés avec des parents femelles DA5D x DA3D et DA 115D AF (Indice d’Iode moyen = 57) et de 3 points pour ceux issus des croisements ayant pour parent femelle DA3D AF (Indice d’Iode moyen = 58). La fluidité de l’huile des arbres témoins ayant pour parent femelle DA115D AF pris comme référence dans les essais comparatifs, demeure stable du premier au second cycle de sélection récurrente réciproque avec un indice d’iode moyen de 54. L’amélioration sensible obtenue au niveau de la fluidité de l’huile du matériel de second cycle, serait essentiellement due aux meilleures recombinaisons des génotypes du premier cycle de sélection récurrente réciproque.Mots clés : Fluidité, huile, indice d’iode, palmier à huile, Elaeis guineensisFUIDITY OF OIL PRODUCED BY TREES FROM THE SECOND CYCLE OF RECIPROCAL RECURRENT BREEDING (RRS) OF OIL PALM (Elaeis guineensis JACQ)Research on Palm oil’s fluidity has several interests, especially for the identification of elite trees used in breeding program for the improvement of the quantity of fluid oil in the fruit. In this prospective, iodine indices of oil produced by bunches of palm trees derived from second cycle of reciprocal recurrent breeding (RRS) are measured and compared to those of trees from first cycle of reciprocal recurrent breeding. Obtained results indicate that Deli x La Mé Plant material from the first cycle of RRS displays an iodine index of 55. The values of oil iodine indices of trees from the second cycle of RRS showan improvement of 2 points for trees derived from crosses using DA5D x DA3D and DA115D AF as female parents (mean iodine index = 57). The oil iodine index increases by 3 points for bunches harvested on trees derived from DA3D AF as female parent (mean iodine index = 58). Fluidity of the oil from DA115D x LM2T used as control in the comparative trials remains steady from the first to the second cycle of RRS with a mean value of 54. The significant rise in fluidity of the palm oil from the second cycle of RRS, would be essentially due to better recombinations of the genotypes of the first cycle of RRS.Keywords : Fluidity, oil, iodine index, oil Palm, Elaeis guineensis

Diurnal cycles of embolism formation and repair in petioles of grapevine (Vitis vinifera cv. Chasselas)

The impact of water deficit on stomatal conductance (gs), petiole hydraulic conductance (Kpetiole), and vulnerability to cavitation (PLC, percentage loss of hydraulic conductivity) in leaf petioles has been observed on field-grown vines (Vitis vinifera L. cv. Chasselas). Petioles were highly vulnerable to cavitation, with a 50% loss of hydraulic conductivity at a stem xylem water potential (Ψx) of –0.95 MPa, and up to 90% loss of conductivity at a Ψx of –1.5 MPa. Kpetiole described a daily cycle, decreasing during the day as water stress and evapotranspiration increased, then rising again in the early evening up to the previous morning's Kpetiole levels. In water-stressed vines, PLC increased sharply during the daytime and reached maximum values (70–90%) in the middle of the afternoon. Embolism repair occurred in petioles from the end of the day through the night. Indeed, PLC decreased in darkness in water-stressed vines. PLC variation in irrigated plants showed the same tendency, but with a smaller amplitude. The Chasselas cultivar appears to develop hydraulic segmentation, in which petiole cavitation plays an important role as a ‘hydraulic fuse’, thereby limiting leaf transpiration and the propagation of embolism and preserving the integrity of other organs (shoots and roots) during water stress. In the present study, progressive stomatal closure responded to a decrease in Kpetiole and an increase in cavitation events. Almost total closure of stomata (90%) was measured when PLC in petioles reached >90%

Visualization of lateral water transport pathways in soybean by a time of flight-secondary ion mass spectrometry cryo-system

Water movement between cells in a plant body is the basic phenomenon of plant solute transport; however, it has not been well documented due to limitations in observational techniques. This paper reports a visualization technique to observe water movement among plant cells in different tissues using a time of flight-secondary ion mass spectrometry (Tof-SIMS) cryo-system. The specific purpose of this study is to examine the route of water supply from xylem to stem tissues. The maximum resolution of Tof-SIMS imaging was 1.8 μm (defined as the three pixel step length), which allowed detection of water movement at the cellular level. Deuterium-labelled water was found in xylem vessels in the stem 2.5 min after the uptake of labelled water by soybean plants. The water moved from the xylem to the phloem, cambium, and cortex tissues within 30–60 min after water absorption. Deuterium ion counts in the phloem complex were slightly higher than those in the cortex and cambium tissue seen in enlarged images of stem cell tissue during high transpiration. However, deuterium ion counts in the phloem were lower than those in the cambium at night with no evaporative demand. These results indicate that the stem tissues do not receive water directly from the xylem, but rather from the phloem, during high evaporative demand. In contrast, xylem water would be directly supplied to the growing sink during the night without evaporative demand

Horizontal rotation signals detected by "G-Pisa" ring laser for the Mw=9.0, March 2011, Japan earthquake

We report the observation of the ground rotation induced by the Mw=9.0, 11th of March 2011, Japan earthquake. The rotation measurements have been conducted with a ring laser gyroscope operating in a vertical plane, thus detecting rotations around the horizontal axis. Comparison of ground rotations with vertical accelerations from a co-located force-balance accelerometer shows excellent ring laser coupling at periods longer than 100s. Under the plane wave assumption, we derive a theoretical relationship between horizontal rotation and vertical acceleration for Rayleigh waves. Due to the oblique mounting of the gyroscope with respect to the wave direction-of-arrival, apparent velocities derived from the acceleration / rotation rate ratio are expected to be always larger than, or equal to the true wave propagation velocity. This hypothesis is confirmed through comparison with fundamental-mode, Rayleigh wave phase velocities predicted for a standard Earth model.Comment: Accepted for publication in Journal of Seismolog

4-Arylbenzenesulfonamides as Human Carbonic Anhydrase Inhibitors (hCAIs): Synthesis by Pd Nanocatalyst-Mediated Suzuki–Miyaura Reaction, Enzyme Inhibition, and X-ray Crystallographic Studies

Benzenesulfonamides bearing various substituted (hetero)aryl rings in the para-position were prepared by palladium nanoparticle-catalyzed Suzuki–Miyaura cross-coupling reactions and evaluated as human carbonic anhydrase (hCA, EC 4.2.1.1) inhibitors against isoforms hCA I, II, IX, and XII. Most of the prepared sulfonamides showed low inhibition against hCA I isoform, whereas the other cytosolic isoenzyme, hCA II, was strongly affected. The major part of these new derivatives acted as potent inhibitors of the tumor-associated isoform hCA XII. An opposite trend was observed for phenyl, naphthyl, and various heteroaryl substituted benzenesulfonamides which displayed subnanomolar hCA IX inhibition while poorly inhibiting the other tumor-associated isoform hCA XII. The inhibition potency and influence of the partially restricted aryl–aryl bond rotation on the activity/selectivity were rationalized by means of X-ray crystallography of the adducts of hCA II with several 4-arylbenzenesulfonamides

Herbaceous angiosperms are not more vulnerable to drought-induced embolism than angiosperm trees

The water transport pipeline in herbs is assumed to be more vulnerable to drought than in trees due to the formation of frequent embolisms (gas bubbles), which could be removed by the occurrence of root pressure, especially in grasses. Here, we studied hydraulic failure in herbaceous angiosperms by measuring the pressure inducing 50% loss of hydraulic conductance (P50) in stems of 26 species, mainly European grasses (Poaceae). Our measurements show a large range in P50 from 20.5 to 27.5 MPa, which overlaps with 94% of the woody angiosperm species in a worldwide, published data set and which strongly correlates with an aridity index. Moreover, the P50 values obtained were substantially more negative than the midday water potentials for five grass species monitored throughout the entire growing season, suggesting that embolism formation and repair are not routine and mainly occur under water deficits. These results show that both herbs and trees share the ability to withstand very negative water potentials without considerable embolism formation in their xylem conduits during drought stress. In addition, structure-function trade-offs in grass stems reveal that more resistant species are more lignified, which was confirmed for herbaceous and closely related woody species of the daisy group (Asteraceae). Our findings could imply that herbs with more lignified stems will become more abundant in future grasslands under more frequent and severe droughts, potentially resulting in lower forage digestibility.

New Forests and New Forest People in Central Vietnam: The Acacia Boom

Vietnam is the country with the largest area of plantations of Australasian Acacia species (‘wattles’) in South-East Asia. Between 6 and 9% of the national land area is cultivated with tropical wattles (A. auriculiformis, A. mangium and A. × mangiiformis). From the perspective of its promoters, the wattle plantation industry in Vietnam may be seen as a success beyond expectations. We review the origins of this boom and ask what it has done to and for the coun- try’s landscape and people. The chapter combines findings and insights from an interdisciplinary research project in Thừa Thiên Huế province, north-central Vietnam. Research took place across upland and lowland wattle-growing regions, with ethnic minorities as well as the Kinh majority, and with long-term wattle growers as well as new en- trants. It drew on questionnaires, interviews and observations, as well as information from remote sensing, eco- logical surveys and hydrological assessments. We first describe how substantial areas of ‘new forest’ (short-rotation wattle plantations) were created, initially in degraded bushland, but now sometimes through clearing of highly bi- odiverse natural forest stands. These wattle plantations alter local hydrology, soils and biodiversity, and are exposed to risks including soil erosion and plant pathogens. The plantations provide wood chips and timber, supporting rev- enue, employment and a strong forestry industry. Incomes have risen appreciably for many, although unequally, and a class of successful entrepreneurs has emerged. These plantations alter the livelihoods and identities of upland ‘forest people’, historically shifting cultivators, contributing to what might be called ‘new forest people’. Ethnic mi- nority villagers are building new identities around the wattle economy and around their contracts with state forest agencies, seeing themselves increasingly as forest growers and protectors. We conclude by raising some questions regarding the social changes and issues of environmental sustainability linked to this wattle boom