Application of the appropriate N fertilizer rate for wheat production is needed to improve and sustain productivity. Different methods have been developed over time to estimate these needs. The objective of this work was to evaluate the relationship basal N rate at planting — NDVI (normalized difference vegetative index) by means of a spline regression to estimate further N needs of spring wheat. Experiments were established in two planting systems; permanent beds and conventional in solid stands. Three flat N rates (25, 50, and 75 kg N ha
, and 30, 60 and 90 kg Nha
for permanent beds and conventional planting, respectively) plus an unfertilized check plot were applied according to three N timing treatments (whole rate at planting or end of tillering, and split at planting and at the end of tillering). Before the application of N treatments at the end of tillering, plots were divided into two halves to apply variable N rates according to the first segment of the spline model. Results indicated that parameter estimates from the spline regression vary within each planting system. However, variable N rates estimated for each year and location were lower than flat N rates. In spite of those differential fertilizer rates, grain yield resulting for the application of variable N rates were similar to flat N rates. Pooled data analysis suggests that NDVI readings greater than 0.56 and 0.65 for permanent beds and conventional planting, respectively, the application of N fertilizer at the end of tillering can be excluded as grain yield will not be modified.
Authors:L.V. Shchukina, T.A. Pshenichnikova, E.K. Khlestkina, S. Misheva, T. Kartseva, A. Abugalieva, and A. Börner
Bread wheat is the primary bread crop in the majority of countries in the world. The most important product that is manufactured from its grain and flour is yeast bread. In order to obtain an excellent bread, grain with high physical properties is needed for flour and dough. The Russian spring wheat cultivar Saratovskaya 29 is characterized by its exclusively high physical properties of flour and dough. The purpose of this work was to identify the chromosomes carrying the main loci for these traits in Saratovskaya 29 and to map them using recombinant substitution lines genotyped with molecular markers. A set of inter-varietal substitution lines Saratovskaya 29 (Yanetzkis Probat) was used to identify the “critical” chromosomes. The donor of individual chromosomes is a spring cultivar with average dough strength and tenacity. Substitution of 1D and 4D*7A chromosomes in the genetic background of Saratovskaya 29 resulted in a significant decrease in the physical properties of the dough. Such a deterioration in the case of 1D chromosome might be related to the variability of gluten protein composition. With the help of recombinant substitution double haploid lines obtained from a Saratovskaya 29 (Yanetzkis Probat 4D*7A) substitution line the region on the 4D chromosome was revealed in the strong-flour cultivar Saratovskaya 29, with the microsatellite locus Xgwm0165 to be associated with the unique physical properties of flour and dough. The detected locus is not related to the composition gluten proteins. These locus may be recommended to breeders for the selection of strong-flour cultivars. Additionally, a QTL associated with vitreousness of grain was mapped in the short arm of chromosome 7A.
Altenbach, S. B., DuPont, F., Kothari, K., Chan, R., Johnson, E., Lieu, D. (2003): Temperature, water and fertilizer influence the timing of key events during grain development in a US springwheat.
. 2001: Technological quality of a transgenic Australian springwheat variety under Central European conditions. pp. 261-264. In: Wootton, M., Batey, I. L., Wrigley, C. W.(eds.), Cereals 2000, Proceedings of the 11 th ICC Cereal and Bread Congress and of
Authors:Marc Lemmens, Andrea Koutnik, Barbara Steiner, Hermann Buerstmayr, Franz Berthiller, Rainer Schuhmacher, Frank Maier, and Wilhelm Schäfer
., Steiner, B., Stierschneider, M., Ruckenbauer, P. 2002. Molecular mapping of QTLs for Fusarium head blight resistance in springwheat I: resistance to fungal spread (type II resistance). Theor. Appl. Genet.