Sources of resistance in durum wheat and its wild relatives to Russian wheat aphid (Hemiptea: Aphididae)

Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is a serious pest of cereals in many parts of the world, particularly in dry areas. As limited resistance sources to this pest were previously identified in durum wheat, 144 accessions of Aegilops spp. and 72 advanced durum wheat lines were evaluated for resistance to RWA in the field and in the plastic house at Tel Hadya, Syria. Ten Aegilops accessions and 14 advanced durum wheat lines showed good level of resistance to RWA. The best five lines were studied for categories of resistance, and the results showed that antibiosis, antixenosis and tolerance are involved in various combinations

Field evaluation and simulation of frost tolerance in Syrian durum wheat landraces

Forty-nine Syrian durum wheat landraces were sown in late Nov. 1989 at Tel Hadya, Syria (a low-yielding site) and 38 were sown in mid-Dec. at Homs (a high-yielding site) with or without N + P fertilizer. Jan. frosts caused less than 5% apparent foliar damage in any of the landraces. However, foliar damage by Mar. frosts averaged 23% (range 3-65%). Late frost tolerance of foliage appeared to be related to minimum winter temperatures in the regions of origin, with landraces from coastal regions showing the highest sensitivity. Fertilizer did not significantly affect foliar damage. In simulation studies based on observed foliar damage rates at Tel Hadya due to Mar. frosts, foliar damage alone did not decrease grain yield but decreased straw yield. Additional floret damage decreased grain yield and increased straw yield

Abiotic stress and molecular markers

*INRA Unité de Biochimie et Biologie Moléculaire des Céréales Montpellier (FRA) Diffusion du document : INRA Unité de Biochimie et Biologie Moléculaire des Céréales Montpellier (FRA)International audienc

Salt tolerance analysis of chickpea, faba bean and durum wheat varieties. II. Durum wheat

Seven varieties of durum wheat (Triticum turgidum), provided by ICARDA, were tested in a greenhouse experiment for their salt tolerance. Afterwards two varieties, differing in salt tolerance, were irrigated with waters of three different salinity levels in a lysimeter experiment to analyse their salt tolerance. The characteristics of the salt tolerant variety compared to the salt sensitive variety are: - a shorter growing season and earlier senescence; - a higher pre-dawn leaf water potential; - a stronger osmotic adjustment; - a better maintenance of the number of productive stems per plant. Salt tolerance of durum wheat corresponds with drought tolerance because the tolerance is caused by earlier senescence and stronger osmotic adjustment, both reducing the transpiration of the plan

Salt tolerance analysis of chickpea, faba bean and durum wheat varieties. I. Chickpea and faba bean

Two varieties of chickpea (Cicer arietinum L.) and faba bean (Vicia faba), differing in drought tolerance according to the classification of the International Center for Agronomic Research in Dry Areas (ICARDA), were irrigated with waters of three different salinity levels in a lysimeter experiment to analyse their salt tolerance. The drought-sensitive varieties are more salt tolerant than the drought-tolerant varieties. Under saline conditions, the drought-sensitive varieties show a much higher yield up to a salinity threshold, corresponding with an electrical conductivity (ECe) between 2.5 and 3 dS/m for chickpea and between 5.5 and 6 dS/m for faba bean. The drought-sensitive varieties are able to improve or maintain the water-use efficiency when irrigated with saline water. This ability can be ascribed to • the larger biomass production owing to the later senescence, which allows a better utilization of the irrigation water; • the late flowering of chickpea

Salt tolerance classification of winter cereals varieties according to grain yield performance and water use efficiency

Encyclopedia on Water resources development and management in arid and semi-arid regions of the Arab world, Vol. 8, Abu Zeid, M., Hamdy, A. (Eds.) Irrigation management with nonconventional waters (saline water, reused drainage-water, waste-water) require the identification of varieties which are adapted to saline conditions.The study aims to identify the varieties which combine high yield with the efficiency in using irrigation waters of different qualities.Durum wheat, barley and winter wheat showed an ascendant curvilinear relationship between grain yield and water use efficiency.The durum wheat varieties showed large differences in grain yield that increased at increasing salinity.Barley also showed large differences between the varieties, even more pronounced than durum wheat but not increasing with salinity.Among the bread wheat varieties only one variety was less suitable under saline conditions.The durum wheat varieties (Cham.1 and Belikh.2) and the barley varieties (California Mariout) and Melusine/A) present a combination of high yield and high water use efficiency in a saline environment, whereas the bread wheat variety (Johara.14) is less suitable under saline conditions than the other varieties.The varietal selection combining high yield and high water use efficiency constitutes an important point with respect to managing irrigation with saline waters

Salt tolerance classification of winter cereal varieties according to grain yield performance and water use efficiency

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