Improvement in Brazilian wheat breeding: changes in developmental phases and ecophysiological traits

• Published in: Euphytica 2018-03, Vol.214 (3), p.1-12, Article 56
• Main Authors: Beche, Eduardo, da Silva, Cristiano Lemes, Todeschini, Matheus Henrique, Milioli, Anderson Simionato, Benin, Giovani, Marchese, Jose Abramo
• Format: Article
• Language: English
• Subjects: Biomedical and Life Sciences; Biotechnology; Crop yield; Crop yields; Cultivars; Ecology; Emergence; Environmental conditions; Fertility; Flowering; Life Sciences; Phases; Physiology; Plant breeding; Plant Genetics and Genomics; Plant Pathology; Plant Physiology; Plant Sciences; Triticum; Wheat
• ISSN: 0014-2336; 1573-5060
• DOI: 10.1007/s10681-018-2134-2

Understanding the processes responsible for genetic progress in grain yield and relating them to the growth and developmental phases of the wheat plant are essential for improving yield potential. This study aimed to evaluate the duration of developmental phases and eco-physiological traits associated to grain yield in Brazilian wheat cultivars released in different decades. Wheat cultivars released from 1940 to 2009 were evaluated during 2010 and 2011 in Pato Branco, Paraná, Brazil. The length of the following periods was compared: sowing-emergence (SW-EM), emergence-double ridge (EM-DR), double ridge-terminal spikelet (DR-TS), terminal spikelet-anthesis (TS-ANT), anthesis-physiological maturity (ANT-PM), sowing-anthesis (SW-ANT) and sowing-physiological maturity (SW-PM). Yield components were also measured. Breeding has reduced the days until anthesis by 14.2%, while it has extended the grain-filling period by 7.6%, compared to the first cultivars released in the country, thereby contributing to a significant increase in 1000-grain weight (12.4 and 9.0% in 2010 and 2011, respectively). The TS-ANT phase was the only phase prior to anthesis exhibiting an extension from old to modern cultivars; this phase increased 1.56 °Cd syear −1 . Spike fertility index (SFI) showed increases of 37.8 and 23.8% in 2010 and 2011, respectively. Shortening of the time to flowering, shifting of critical phases of wheat development to better environmental conditions (i.e., TS-ANT phase), and selection for shorter cultivars have been directly responsible for the increase in spike dry weight at anthesis (SDWa) and SFI [i.e., grain number (GN)].