Development Of Durum Wheat Research Articles

Modelling the growth, development and yield of Triticum durum Desf under the changes of climatic conditions in north-eastern Europe

How agricultural ecosystems adapt to climate change is one of the most important issues facing agronomists at the turn of the century. Understanding agricultural ecosystem responses requires assessing the relative shift in climatic constraints on crop production at regional scales such as the temperate zone. In this work we propose an approach to modeling the growth, development and yield of Triticum durum Desf. under the climatic conditions of north-eastern Poland. The model implements 13 non-measurable parameters, including climate conditions, agronomic factors, physiological processes, biophysical parameters, yield components and biological yield (latent variables), which are described by 33 measurable predictors as well as grain and straw yield (manifest variables). The agronomic factors latent variable was correlated with nitrogen fertilization and sowing density, and biological yield was correlated with grain yield and straw yield. An analysis of the model parameters revealed that a one unit increase in agronomic factors increased biological yield by 0.575. In turn, biological yield was most effectively determined by climate conditions (score of 60–62) and biophysical parameters (score of 60–67) in the 2nd node detectable stage and at the end of heading. The modeled configuration of latent and manifest variables was responsible for less than 70% of potential biological yield, which indicates that the growth and development of durum wheat in north-eastern Europe can be further optimized to achieve high and stable yields. The proposed model accounts for local climate conditions and physiological processes in plants, and it can be implemented to optimize agronomic practices in the cultivation of durum wheat and, consequently, to expand the area under T. durum to regions with a temperate climate.

Effect of Animal ByProducts Fertilization on Durum Wheat in Mediterranean Conditions: Preliminary Results.

This study aims to evaluate the effects of new-BioFertilizing Amendments (BFAs) deriving from fast organic matter decomposition of Animal ByProducts (ABPs) in comparison with ordinary soil organic amendments (compost), mineral N-fertilizers and no fertilization, on durum wheat development and production in a field trial under Mediterranean conditions. Results showed taller plants with heavier spikes and greater vigor in plots fertilized with BFAs when compared to no fertilization and N-fertilization, respectively. Likewise, BFAs fertilization resulted in higher protein content, gluten content, protein yields and higher values of yellow index with respect to no fertilization and N-fertilization. In contrast, lower values for test weight in correspondence of BFAs fertilization as well as no statistically significant differences on grain yield and gluten index were found. These preliminary results suggest that replacing N-fertilization with BFAs can be effective to ensure crop quality and yield stability in Mediterranean conditions.

Preceding crop and weed management history affect denitrification and denitrifier community structure throughout the development of durum wheat

Aside from negative impacts on crop yield, the role of weeds in agricultural systems, particularly with respect to below ground function, is not well understood. In this study, we utilised a mesocosm approach with soils collected from a long-term rotation study to compare legacy effects of previous flax (Linum usitatissimum L.) or canola (Brassica napus L.) and different levels of weediness established over a decade by different herbicide use patterns. Despite few significant differences in initial soil chemical properties, the impact of level of weediness superseded that of the preceding crop and altered the growth of durum wheat (Triticum durum L.) during early development and the temporal dynamics of denitrification and the nirK denitrifier communities. The impact of the presence of durum plants in the mesocosm experiment was relatively small, however, the presence of durum plants did modify the legacy effects of preceding crop and weediness on the denitrifier community. Differences in denitrifier community structure were due to differential presence/absence and differential abundance of multiple T-RFs. To our knowledge, this is the first study to investigate the effects of long-term weed management strategies on denitrification. Our results indicate that weediness contributes to priming effects and unexplained variation associated with these soil processes and that weed management history should be taken into consideration when determining soil function and soil microbial community dynamics in agricultural systems.

Effect of nitrogen on uptake, remobilization and partitioning of zinc and iron throughout the development of durum wheat

Deficiencies of zinc (Zn) and iron (Fe) are global nutritional problems and caused most often by their limited dietary intake. Increasing Zn and Fe concentrations of staple food crops such as wheat is therefore an important global challenge. This study investigated the effects of varied nitrogen (N) and Zn supply on the total uptake, remobilization and partitioning of Zn, Fe and N in durum wheat throughout its ontogenesis. Plants were grown under greenhouse conditions with high or low supply of N and Zn, and harvested at 8 different developmental stages for analysis of Zn, Fe and N in leaves, stems, husks and grains. The results obtained showed that the Zn and Fe uptake per plant was enhanced up to 4-fold by high N supply while the increases in plant growth by high N supply were much less. When both the Zn and N supplies were high, approximately 50% of grain Zn and 80% of grain Fe were provided by post-anthesis shoot uptake, indicating that the contribution of remobilization to grain accumulation was higher for Zn than for Fe. At the high N and Zn application, about 60% of Zn, but only 40% of Fe initially stored in vegetative parts were retranslocated to grains, and nearly 80% of total shoot Zn and 60% of total shoot Fe were harvested with grains. All these values were significantly lower at the low N treatment. Results indicate that N nutrition is a critical factor in both the acquisition and grain allocation of Zn and Fe in wheat.

Microsatellite markers flanking a stem solidness gene on chromosome 3BL in durum wheat

Sawfly (Cephus cinctus Norton) is a major insect pest of wheat (Triticum spp.). The development of durum wheat (Triticum turgidum L. var durum) with stem solidness for resistance to sawfly is a strategy to minimize loss from this insect. This study was undertaken to identify a DNA marker linked to stem solidness and sawfly cutting in durum wheat for use in marker-assisted selection. A set of 151 doubled haploid lines developed from the cross of Kyle*2/Biodur sel. (solid stemmed) and Kofa (hollow stemmed) were evaluated for stem solidness and sawfly cutting. Microsatelite primers that generated polymorphisms between the parental genotypes were tested on the whole population, and primers that followed a 1:1 ratio of parental bands were used in linkage analysis with least squares mean stem solidness scores. Three microsatellite markers, Xgwm247, Xgwm181 and Xgwm114 located on chromosome 3BL, were shown to be associated with the stem solidness locus and with sawfly cutting. The Xgwm114 marker was located on one side of the stem solidness locus with Xgwm247 and Xgwm181 on the opposing side. Recombinant inbred line populations G9580B-FE1C/AC Navigator and Golden Ball/DT379//STD65 segregating for the stem solidness trait confirmed the association between the markers and the stem solidness gene. The Golden Ball/DT379//STD65 population was also tested with the Xwmc632 microsatellite marker, which showed a polymorphism associated with stem solidness. The results also indicated the stem solidness trait was controlled by a single locus in both doubled haploid and recombinant inbred line populations. The markers should be useful in breeding programs for the identification and selection of stem solidness.

The Effect of Elevated CO2 and Drought on the Vegetative Growth and Development of Durum Wheat (Triticum durum Desf.) Cultivars

Three Syrian registered cultivars of durum wheat (Cham 1, 3 and 5) were grown in controlled environments under ambient (400 ppmv) and elevated (1000 ppmv) CO2 at two levels of water availability (well irrigated and water stressed). All cultivars responded in a similar manner to both the CO2 and the water stress. Carbon dioxide elevation raised biomass production at ear emergence by approximately 62% in well irrigated treatments. Water stress severely reduced biomass production (by 38%) but elevated CO2 was able to induce a significant yield response in water stressed treatments. Growth analysis demonstrated that biomass improvements were a result of improved tillering and denser leaves and stems rather than LAI which was unaffected by CO2but depressed by water stress. Nitrogen content of leaves were unaffected by elevated CO2 but ear and stem N% was significantly improved in contrast to previous reports. These results indicate that higher atmospheric levels of CO2 would give a benefit in durum wheat even in situations where crops are severely water stressed.

Development of durum wheat and triticale cultivars as affected by thermo-photoperiodic conditions

The understanding of the interaction between thermo-photoperiodic conditions and the genetic control of anthesis date is fundamental in explaining the environmental adaptation of durum wheat and triticale cultivars. The development of 8 durum wheat (Triticum turgidum L. var. durum) and 2 triticale (×Triticosecale Wittmack) cultivars was studied at 3 sowing dates (September, November, and March) by observations on apex development, number and rate of leaf appearance, spike fertility, and number and length of elongated internodes. Variation in anthesis date was mostly explained by the total number of leaves, which ranged between 8.3 and 15, and hence by the duration of the phase of leaf primordium production. Total leaf number also affected the length ofthe subsequent phase until flag leaf appearance. The phyllochron was influenced by both sowing date and genotype, and was minimum in the March sowing (87 degree-days). The genotypic variability in phyllochron was due either to the variations in leaf number or to genotypic intrinsic differences. Time to terminal spikelet stage was related to the number of spikelets per spike and to the number of elongated internodes, although stem length depended more on internode length than on internode number. The number of spikelets per spike was associated with leaf number, but their relationship was affected by the thermal conditions during spikelet primordium initiation. No differences were observed between wheat and triticale cultivars, apart from the number of spikelets per spike.