施氮量对不同株叶型小麦旗叶光合及籽粒灌浆特性的影响

Effects of Nitrogen Application Rate on Flag Leaf Photosynthesis and Grain Filling Characteristics of Wheat with Different Leaf Types

【目的】探究不同株叶型小麦对四川盆地光照环境的适应性及施氮量的调控效应。【方法】试验采用二因素裂区设计,以小叶直立叶型小麦川麦88和大叶披垂叶型小麦蜀麦830为主区,以两个氮处理(150、200 kg/hm^(2))为裂区,探究不同处理下小麦叶片光合特性、籽粒灌浆特性和产量。【结果】品种之间旗叶叶面积、叶绿素含量、灌浆速率、单株成穗数以及粒叶比差异显著。川麦88旗叶叶绿素含量和净光合速率高,粒叶比高,单株成穗率高,源库协调性好,但旗叶易早衰;蜀麦830旗叶面积大,籽粒灌浆速率高,千粒重高,单穗重高,个体优势显著,但穗容量不足;两品种产量差异不显著;增加施氮量均可促进旗叶面积、叶绿素含量、净光合速率和产量提高,显著延长籽粒灌浆持续时间,对于大穗大叶的蜀麦830尤为显著。【结论】两种株叶型小麦各有优缺点,小叶直立叶型川麦88对四川盆地光照环境适应性良好,通过提高净光合速率、延缓旗叶衰退提高光合生产力,以高成穗率与粒叶比提升群体质量获得高产,大叶披垂叶型蜀麦830则通过增加光合面积提高灌浆速率来增加穗重。增加施氮量可以有效改善小麦旗叶的光合性能,弥补株叶型的不足,同时显著延长籽粒灌浆持续时间,促进籽粒干物质积累。

[Objective] The adaptability of wheat with different plant leaf types to light environment in Sichuan basin and the regulation effect of nitrogen application rate.[Method] The two-factor split plot design was used in the experiment.The wheat Chuanmai 88(CM88) with small leaf erect leaf and Shumai830(SM830) with large leaf drape leaf were used as the main plots,and two nitrogen treatments(150 and 200 kg/hm^(2)) were used as the split plots to explore the photosynthetic characteristics, grain filling characteristics and yield of wheat under different treatments.[Result] There were significant differences in flag leaf area, chlorophyll content, filling rate, spike number per plant and grain-leaf ratio among varieties.The flag leaf chlorophyll content and net photosynthetic rate of Chuanmai 88 were high,the grainleaf ratio and spike rate per plant were high, and the source-reservoir coordination was good,but the flag leaf was prone to premature senescence;the flag leaf area of Shumai 830 was large, the grain filling rate,1 000-grain weight and single panicle weight were high,and the individual advantages were obvious,but the panicle capacity was insufficient.There was no significant difference in yield between the two varieties;increasing nitrogen application rate can promote flag leaf area, chlorophyll content, net photosynthetic rate and yield,significantly prolong grain filling duration,especially for Shumai 830 with large panicle and large leaf.[Conclusion] The two plant-leaf types of wheat had their own advantages and disadvantages.Chuanmai 88 with small leaf erect leaf had good adaptability to light environment in Sichuan basin.It improved photosynthetic productivity by increasing net photo synthetic rate and delaying flag leaf recession, and achieved high yield by improving population quality with high spike rate and grain-leaf ratio.Shumai 830 with large leaf drape leaf increased spike weight by increasing photosynthetic area and increasing grain filling rate.Increasing nitrogen application rate can effectively improve the photo synthetic performance of flag leaf, compensate for the deficiency of plant leaf type, and significantly prolong grain filling duration and promote grain dry matter accumulation.