Wheat cultivars at different decades vary widely in grain-filling characteristics in Shaanxi Province, China

Abstract

Eight cultivars of dry-land wheat (Triticum aestivum L.) historically planted in Shaanxi Province, China, were grown in plots with irrigation and drought treatments during the growing seasons of 2011-2014, so as to characterize the differences in the rate and duration of the grain-filling stage among cultivars. The experimental results showed no obvious change among cultivars with respect to the duration of the grain-filling stage and no significant correlation between duration and grain weight. The filling rates of all three phases (lag, linear, and mature periods) showed significant differences among cultivars and had a greater effect on the grain weight than the duration of the filling stage, even though drought decreased the filling rate in the linear and mature periods. A lower filling rate led to a lighter grain weight in inferior grains than in superior grains. For the superior and inferior grains in the central spikelets, modern cultivars possess faster filling rates, especially in the lag and linear periods, whereas for the whole spike, no significant trend with cultivar replacement was observed. Faster filling rates with stable filling durations will be beneficial in obtaining additional yield increases.Abbreviations: FRa, filling rate, average; FD, filling duration; FR1, filling rate in 1st period (lag period); FD1, filling duration in 1st period (lag period); FR2, filling rate in 2nd period (linger period); FD2, filling duration in 2nd period (linear period); FR3, filling rate in 3rd period (mature period); FD3, filling duration in 3rd period (mature period).