The relationships between leaf senescence, carbon isotope discrimination and yield performance were examined in durum wheat (
Desf.), in the high plains of Setif, eastern Algeria. Ten CIMMYT high-yielding cultivars were grown during two cropping seasons characterized by low rainfall (217 and 162 mm, respectively), freezing temperatures at heading stage and terminal heat stress. Senescence was assessed using numerical image analysis (NIA). Carbon isotope discrimination was analyzed in flag leaves at anthesis and grain at maturity. Senescence was significantly negatively correlated to grain yield in season 1, but not in season 2. There was no relationship between Δ and grain yield in both seasons. The absence of association between Δ and grain yield is likely to be due to a strong contribution of pre-anthesis assimilates to yield together with a sink limitation of yield.
Authors:J. Bányai, É. Láng, Z. Bognár, C. Kuti, T. SpitkÓ, L. Láng, and Z. Bedő
The effect of irrigation water on the yield and on individual yield components was examined for 19 durum wheat varieties by continually recording weather data and carrying out measurements on the moisture content, temperature, electrical conductivity and tension of the soil. Dry (rain-fed) and irrigated treatments were included in the experiment, which was carried out in the framework of the EU FP7-244374 DROPS project.During the rainless spring of 2011 the soil moisture content of the non-irrigated area dropped to 21–22 vol% and the effect of drought stress was still felt at harvest. The quantity of irrigation water applied during the growing season ensured normal conditions for generative development and a significant difference could be detected between the yield components in the two treatments. The thousand-kernel weight of the varieties was identical in the dry and irrigated plots, but in response to irrigation there was an increase in the number of grains per ear and the grain weight, and an improvement in fertilisation, resulting in higher yields.
Authors:Laura Ercoli, Alessandro Masoni, Marco Mariotti, and Iduna Arduini
Soil gravel content affects many soil physical properties, i.e. bulk density, porosity, water infiltration and storage, as well as crop yield. Little is known regarding the influence of soil gravel content on grain yield of durum wheat (
Desf.). In this paper the accumulation of dry matter during the vegetative and reproductive periods and the contribution of pre-anthesis assimilates to grain yield have been evaluated in two durum wheat varieties grown on soils with 0, 10, 20, and 30% gravel content. The two varieties showed similar behaviour and more soil gravel decreased plant biomass both at anthesis and at maturity. Soil gravel content greatly reduced grain yield and dry weight of all plant parts both at anthesis and maturity. Post-anthesis dry matter accumulation was 16% lower in plants grown on 30% gravel soil and dry matter remobilization was 53% lower, compared to plants grown in gravel-free soil. The differences in growth rate were attributed to the restriction of the volume of soil available for root growth.
Authors:A. Masoni, L. Ercoli, M. Mariotti, and S. Pampana
Soil gravel content affects many soil physical properties, as well as crop yield. Little is known regarding the influence of soil gravel content on growth and nutrient uptake of durum wheat (
Desf.). The accumulation of nitrogen and phosphorous during the vegetative and reproductive periods and the contribution of pre-anthesis assimilates to grain N and P content have been evaluated in two durum wheat varieties grown on soils with 0, 10, 20 and 30% gravel content. The two varieties showed similar behaviour and the increase of soil gravel decreased plant biomass during the entire biological cycle. Nitrogen and P concentration of all plant parts was not affected by soil gravel content, while N and P content was greatly reduced, owing to the effect on dry matter yield. Post-anthesis accumulation and remobilization of N and P were greatly reduced: the decrease from gravel-free soil to 30% gravel content was about 41 kg N ha
and 4 kg P ha
for the former and 14 kg N ha
and 2 kg P ha
for the latter. The differences in growth rate were attributed to differences in development of the root system due to the restricted soil volume.
The effects of arbuscular mycorrhizal fungi (AMF) and salt stress on growth and nutrient acquisition in two durum wheat (Triticum durum Desf.) cultivars exhibiting differences in salt tolerance were investigated. The plants were grown in a sterilized, low P (silty clay) soil-sand mix. Three salt levels were created by adding NaCl solution to the soil through irrigation water, resulting in saturation extract (ECe) values of 1.2 (control), 4.1 (medium) and 6.7 dS m –1 (high salt stress), respectively. Mycorrhizal colonization occurred whether the soil was salt stressed or non-stressed and in both cultivars, but the extent of AMF colonization was higher in the control than under saline soil conditions. The salt-tolerant cultivar Petra had higher mycorrhizal colonization than the salt-sensitive cultivar Hourani-27. The shoot dry matter (DM) yield was higher in mycorrhizal than in non-mycorrhizal plants of both cultivars. Petra had higher shoot DM but not higher root DM than Hourani-27 plants. The enhancement in shoot DM due to AMF inoculation was 22 and 21% in the control, 31 and 58% at medium, and 18 and 60% at high salinity level for Petra and Hourani-27, respectively. For both cultivars, the contents of P, K, Zn, Cu and Fe were higher in mycorrhizal than in non-mycorrhizal plants under control and medium saline soil conditions. Shoot Na concentrations were lower in mycorrhizal than in non-mycorrhizal plants grown under saline conditions. The enhancement in P, K, Zn, Cu and Fe acquisition due to AMF inoculation was more pronounced in Hourani-27 than in Petra under saline soil conditions. The results suggest that Hourani-27 tends to benefit from AMF colonization more than Petra under saline soil conditions, despite the fact that Petra roots were highly colonized with the AM fungus. It appears that Hourani-27 is more dependent on AMF symbiosis than Petra.
Durum wheat (
Desf.) is the main cereal crop in Italy, mostly cultivated in Southern and Central regions. Improving grain yield has been the primary objective of most national breeding programs until the end of the’ 70s. The objective of this study was to evaluate durum wheat yield stability improvements achieved in Italy over twenty years through the national breeding programs. Data from 10 coordinated field trials carried out over two 3-year periods (1977–79 and 1996–98) were considered. Analysis of the mean yield, linear regression coefficients (
), coefficients of variability (CV), coefficients of determination (
) and deviations from the regression (
d) allowed us to identify, for each period considered, remarkable differences among different cultivars in terms of yield and yield stability. The stability analysis clearly identified, during 1977–79, two different subgroups of genotypes. The first (
<1) included cultivars registered in the National Durum Wheat collection before 1974 (Cappelli, Capeiti 8, Trinakria. Appulo, Isa 1), having high adaptability to low-input environments. In contrast, the second subgroup (
>1) included semidwarf cultivars such as Valnova, Valgerardo, Creso and Valfiora, highly sensitive to environmental variability and pronounced responsiveness to high-input environments. In 1996–1998 yield stability became a primary target. Therefore the national breeding programs promoted comparative trials over-time and over-space. All cultivars selected in those years had
values close to 1 and their mean yield was significantly higher compared to the 1977–79 cultivars. As a result, the most recent cultivars possess both high adaptability traits (typical of those tall cultivars selected in arid and semiarid regions before the 70s) and high yield potential, a trait associated with
alleles (Creso and “Val” cultivars).
Authors:A. Mekliche, F. Dahlia, and L. Hanifi-Mekliche
( Triticum durum Desf.) cultivées en Algérie. (Evaluation of the genetic progress of some varieties of durumwheat ( TriticumdurumDesf.) cultivated in Algeria). Actes du premier symposium international sur la filière blé: enjeux et stratégies . ITGC
Almansouri, M., Kinet, J. M., Lutts, S. (1999): Compared effects of sudden and progressive impositions of salt stress in three durumwheat ( TriticumdurumDesf.) cultivars. J. Plant Physiol. , 154 , 743-752.
Compared effects of