摘要：

为了明确冬小麦春季限灌1水条件下的最佳灌溉时期,降低限水灌溉对冬小麦群个体质量的不利影响,选用多穗型冬小麦品种藁优2018为材料,设置5个灌溉时期处理,分别在春2叶、春3叶、春4叶、春5叶和春6叶(旗叶)露尖时灌溉(T2~T6),以全生育期不灌水处理作对照(W0),研究不同叶龄期灌水对冬小麦开花后各叶层叶面积指数(LAI)、叶绿素相对含量(SPAD)、群体光合速率、干物质积累转运及产量的影响。结果表明,在春季仅灌1水的条件下,与春2叶—春4叶龄灌水相比,推迟至春5叶—春6叶龄灌溉可显著延缓小麦开花后冠层总叶面积指数的衰退,花后0~10 d,20~30 d的LAI衰退速率分别降低58.93%,14.37%。其中,在花后0~10 d主要表现为晚灌水处理倒3叶、倒4叶和倒5叶的LAI和SPAD衰退速率显著下降,在花后20~30 d主要表现为旗叶和倒2叶的衰退速率显著下降。T5和T6处理较早灌水处理灌浆前期、中期和后期的群体光合速率分别提高19.89%,35.86%,56.08%,花后干物质积累量和花前干物质向籽粒的转运量都有所增加,最终籽粒产量和收获指数分别提高9.73%,18.64%。综上,在本试验年度春季限灌1水的条件下,春5叶或春6叶露尖时灌溉有利于延缓叶片衰退,提高群体光合生产能力和籽粒产量。

关键词: 冬小麦, 灌溉时期, 叶面积指数, 群体光合速率, 干物质积累转运

Abstract:

In order to determine the optimal irrigation period of winter wheat under the condition of limited irrigation in spring and reduce the adverse effects of water restriction on the individual and population quality of wheat,five irrigation treatments,that irrigation at the 2nd,3rd,4th,5th and 6th spring leaf occurring stage(T2—T6)respective,were set.No irrigation treatment(W0)in the whole growth season was set as control.The Gaoyou 2018,a multi-panicle winter wheat variety was used.The effects of irrigation period on leaf area index(LAI)and SPAD of each leaf layer,canopy apparent photosynthetic rate after anthesis, dry matter accumulation and transportation, and yield were studied.The results showed that under the condition of only irrigation once in spring,the decay rate of canopy LAI by T5 and T6 decreased by 58.93% and 14.37% during 0—10 days and 20—30 days after anthesis,respectively,than that by irrigation at the 2nd, 3rd and 4th spring leaf occurring stage.The decay rate of LAI and SPAD of the top 3rd,4th and 5th leaf layers by T5 or T6 were lower significantly during 0—10 days after anthesis,and the decay rate of the flag leaf and top 2nd leaf layers by T5 or T6 were lower during 20—30 days after anthesis.Compared to early irrigation treatment, when irrigation was delayed to the 5th or 6th spring leaf age, the canopy apparent photosynthetic rate was increased by 19.89%,35.86% and 56.08%,respectively during the early,middle and late grain filling stage,the post-anthesis dry matter accumulation amount and the translocation amount from dry matter pre-anthesis to grains were both increased.The final grain yield and harvest index increased by 9.73% and 18.64%,respectively.In conclusion,under the condition of only irrigation once in spring of this study,irrigation at the 5th or 6th leaf age in spring was beneficial to delay leaf decay and increase population photosynthetic capacity and grain yield of wheat.

Key words: Winter wheat, Irrigation period, Leaf area index, Population photosynthetic rate, Accumulation and translocation of dry matter