Year-end Sale % OFF 
Abstract
An experiment was conducted to verify how the grain yield and associated photosynthesis characteristics of wheat respond to seeding rate with cultivar replacement. Seven wheat cultivars released from 1940 to 2004 that were once widely grown on the Loess Plateau were grown in field experiments during the 2011-2012 growing season at the Changwu experiment station in China using three seeding rates (100, 250, and 350 seeds m-2), using a randomized complete block with a split-plot design and three blocks. The grain yield increased linearly with cultivar development in all seeding rate treatments, with annual genetic gains ranging from 0.65% to 1.29%. The cultivars released after the 1980s were less sensitive to seeding rate and had better population regulation. The improvements in the harvest index and thousand grain weights of the modern cultivars were significantly and positively correlated with the grain yield. The photosynthetic rate of the flag leaf and the leaf area index at anthesis consistently increased with cultivar replacement, contributing more to the thousand-grain weight and resulting in grain yield increases. Diffuse non-interceptance at anthesis resulted in opposite, stable trends with time. One reason to adapt modern cultivars for modern cultivation is their lower sensitivity to seeding rate. Thus, larger sinks for the grains and the optimization of plant types for light interception should be given greater consideration in dryland wheat breeding on the Loess Plateau.
Highlights
Wheat (Triticum aestivum L.) grain yields have doubled in the last century (Richards, 2000), with the development of genetic resources accounting for more than 40% of this increase (Brancourt-Hulmel et al, 2003)
Genetic progress regarding the grain yield, agronomic traits and photosynthetic traits of wheat has been studied in many countries (e.g., in the UK (Austin et al, 1980), Mexico (Fischer and Edmeades, 2010), Canada (McCaig and DePauw, 1995), Argentina (Maydup et al, 2012), Australia (Potgieter et al, 2016), and China (Tian et al, 2011; Zheng et al, 2011)
These studies suggest that cultivar replacement has increased the leaf area index and the net photosynthetic rate (Fischer and Edmeades, 2010; Tian et al, 2011), which are correlated with greater grain weights and harvest index (HI) values and result in genetic yield improvements (Austin et al, 1980; Perry and D’Antuono, 1989)
Summary
Wheat (Triticum aestivum L.) grain yields have doubled in the last century (Richards, 2000), with the development of genetic resources accounting for more than 40% of this increase (Brancourt-Hulmel et al, 2003). Genetic progress regarding the grain yield, agronomic traits and photosynthetic traits of wheat has been studied in many countries (e.g., in the UK (Austin et al, 1980), Mexico (Fischer and Edmeades, 2010), Canada (McCaig and DePauw, 1995), Argentina (Maydup et al, 2012), Australia (Potgieter et al, 2016), and China (Tian et al, 2011; Zheng et al, 2011) These studies suggest that cultivar replacement has increased the leaf area index and the net photosynthetic rate (per-unit leaf area) (Fischer and Edmeades, 2010; Tian et al, 2011), which are correlated with greater grain weights and harvest index (HI) values and result in genetic yield improvements (Austin et al, 1980; Perry and D’Antuono, 1989). Verifying the evolution of agronomic traits and the physiological basis of grain yields will assist breeders and agronomists in developing new wheat cultivars with stable and high yields.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
