科研之友
微信
新浪微博
Facebook
分享链接
摘要
The objective of this study was to clarify the effect of reducing nitrogen application on the formation of an inferior spikelet and the yield formation of tartary buckwheat. Four nitrogen treatments, 225 kg/hm2 (N1), 135 kg/hm2 (N2), 45 kg/hm2 (N3), and 0 kg/hm2 (N4, CK) were established with Jinqiao2 (JQ2), a tartary buckwheat variety, as the experimental organism. The effects on grain filling dynamics of superior and inferior spikelets, root morphology and physiology, chlorophyll content and nitrogen metabolism-related enzyme activity in leaves, agronomic characteristics, and yield of tartary buckwheat were studied. The time to reach the maximum grain filling rate (Tmax.G) was the shortest for the N2 treatment, while the initial growth power (R0), maximum grain filling rate (Gmax), and average grain filling rate (Gmean) were the highest. The A value (final growth value), R0, Gmax, and Gmean of the superior spikelet were higher than those of the inferior spikelet, whereas its N values (shape parameter) and Tmax.G were lower. The middle filling stage made the largest contribution to grain weight, followed by the later filling stage, and the smallest contribution was in the early filling stage. With decreased nitrogen application, the total root length, root surface area, root volume, root average diameter, and root activity of JQ2 showed a tendency to first increase and then decrease; in addition, the chlorophyll content, and the activity of glutamine synthase (GS), glutamate dehydrogenase (GDH), glutamic acid synthetase (GOGAT), and nitrate reductase (NR) in leaves first increased and then decreased. The chlorophyll content and activity of nitrogen metabolism enzyme activity of the superior spikelet were higher than those of the inferior spikelet. The agronomic traits and yield from N2 treatment were higher than those from the other three treatments. Appropriate reduction of nitrogen application can delay the senescence of tartary buckwheat, promote the filling of superior and inferior spikelets, increase nitrogen metabolic enzyme activity and increase grain weight and final yield, thus achieving the goal of combining fertilizer and high yield.
- 单位
