低氮胁迫下油菜素内酯对小麦穗发育和产量的影响

Effects of Brassinolide on Wheat Spike Development and Yield under Low Nitrogen Stress

为明确外源油菜素内酯对低氮处理下冬小麦穗花发育形成产量的调控作用,以周麦27为试验材料,在小麦拔节后18 d叶面喷施浓度为0.1μmol/L的油菜素内酯,研究外源油菜素内酯对小麦穗部小花的发育数量、干物质重、碳氮代谢及产量的影响。结果表明,低氮处理会降低可孕育小花的结实粒数和数量,外源喷施油菜素内酯能显著降低由低氮造成的小花退化和败育,增加可孕小花成粒数。在低氮处理下喷施外源油菜素内酯后,小麦穗器官和非穗器官干物质重、可溶性糖含量等均高于低氮处理。因此,喷施外源油菜素内酯可以促进源器官的物质生产,增强糖和氮由源器官向穗库器官的分配转运能力,进而促进穗花发育,提高低氮耐受性。与低氮处理相比,喷施油菜素内酯产量增幅为41.68%,主要通过对穗粒数调控实现。该研究为小麦中低产田的抗逆栽培提供了技术支撑和理论依据。

With Zhoumai 27 as the test material,brassinolide was foliarly sprayed at a concentration of 0.1μmol/L on 18 d after wheat nodulation to clarify the regulatory effects of exogenous brassinolide on the developmental formation and yield.The effects of exogenous brassinolide on wheat spikelets,dry matter weight,carbon and nitrogen metabolism and yield were researched.Results showed that low N treatment reduce the seed-setting number and quantity of fertile florets.Spraying exogenous brassinolide could significantly reduce the florets degeneration and abortion caused by low N,enhance the number of fertile florets.The dry matter weight and soluble sugar content of wheat spike and non-spike organs were higher under the low N treatment than under the low N treatment.Thus,spraying of exogenous brassinolide could promote the material production of source organs and enhance the distribution and transfer of sugar and nitrogen source organs to spike bank organs,promote spike flower development and improve low nitrogen tolerance.Compared with the low nitrogen treatment,the increase in yield was 41.68%with the sprayed brassinolide,which was mainly achieved through the regulation of spike number.This study provided technical support and theoretical basis for stress-tolerant cultivation in low and medium yielding wheat fields.