Grain number and grain yield distribution along the spike remain stable despite breeding for high yield in winter wheat

• Published in: PloS one Vol. 13; no. 10; p. e0205452
• Main Authors: Philipp, Norman, Weichert, Heiko, Bohra, Utkarsh, Weschke, Winfriede, Schulthess, Albert Wilhelm, Weber, Hans
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 10.10.2018; Public Library of Science (PLoS)
• Subjects: Agricultural production; Architecture; Autophagy; Barley; Biology; Biology and Life Sciences; Comparative analysis; Crop yield; Crop yields; Edible Grain - genetics; Edible Grain - growth & development; Genetic aspects; Genetic resources; Genetic Variation; Genetics; Genotype; Grain; Grain size; Mathematical analysis; Medicine and Health Sciences; Models, Theoretical; People and Places; Plant Breeding; Population; Population genetics; Quantitative Trait Loci; Seasons; Selection, Genetic; Triticum - genetics; Triticum - growth & development; Triticum aestivum; Weight; Wheat; Winter wheat; Europe; Germany
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0205452

Two winter wheat (Triticum aestivum L.) populations, i.e. 180 genetic resources and 210 elite varieties, were compared in a field trial to analyse how grain number and grain yield distribution along the spike changed during the breeding process and how this associates to yield-related traits. Elites showed in average 38% more yield compared to resources. This breeding improvement mainly derived from an increase in grains and yield per spike in addition to grains and yield per spikelet. These increments corresponded to 19, 23, 21 and 25%, respectively. Not much gain in thousand grain weight (4%) was observed in elites as compared to resources. The number of spikelets per spike was not, or even negatively, correlated with most traits, except of grains per spike, which suggests that this trait was not favoured during breeding. The grain number and grain yield distributions along the spike (GDAS and GYDAS) were measured and compared by using a novel mathematical tool. GDAS and GYDAS measure the deviation of a spike of interest from the architecture of a model spike with even grain and yield distribution along all spikelets, respectively. Both traits were positively correlated. Elites showed in average only a 1% improvement in GDAS and GYDAS values compared to resources. This comparison revealed that breeding increased grain number and yield uniformly along the spike without changing relative yield input of individual spikelets, thereby, maintaining the general spike architecture.