小麦冬前次生根对生育中后期地上部发育及产量的影响

Influence of Prior-to-Winter Nodal Roots on Development of Aerial Plant Parts during Middle and Late Growing Period and Grain Yield Formation in Wheat

为明确冬前小麦单株次生根的作用,采用大田育苗盆栽移植的方式,以半冬性中熟小麦矮抗58为材料,在越冬前将育苗区单株总分蘖数为4(包括主茎)的植株根据次生根数分为3个处理:处理A(次生根数较少,次生根1~2条)、处理B(次生根数中等,次生根3~4条)和处理C(次生根数较多,次生根5条以上),研究了冬前次生根数对小麦生育中后期地上部发育、单株根系生理势及籽粒产量的影响。结果表明,本试验条件下,冬前单株次生根数较多有利于生育中后期单株蘖数、地上部干物质量和单株叶面积的提高,进而提高了植株的光合面积,促进了地上部生长和干物质积累,不同处理间存在一定的差异。其中,相对于处理A和处理B,处理C的影响相对较大。结果还表明,冬前次生根数增加有利于单株根系生理势的提高,2015-2016年蜡熟期和2016-2017年拔节期,不同处理间差异达显著水平,说明冬前次生根数对提高生育中后期植株的根系生物量、维持较高的根系活性具有一定的正效应。随着冬前次生根数增加,小麦单株穗数、结实小穗数和穗粒数也随之增加,单株产量也因此提高,其中处理C的单株穗数、结实小穗数和穗粒数比处理A分别增加了25.0%,13.4%,26.2%,产量增加了52.4%。由此可见,越冬前单株分蘖数相同条件下,小麦单株次生根数较多有利于提高籽粒产量。

In order to determine the role of prior to winter nodal roots per plant,Dwarf Resistant No.58,a semi-winter mature wheat cultivar,was used for field seeding and potted transplanting. In the nursery area before winter,the plants with four tillers （including the main stem） were divided into three groups according to the number of nodal roots. These specific grouping situations were called treatments：less nodal roots number （treatment A,nodal roots：1-2）,medium nodal roots number （treatment B,nodal roots：3-4） and more nodal roots number （treatment C,nodal roots：5 and more）. The effects of nodal roots number per plant on the development of shoots,physiological potential of the roots and yield were studied. The results showed that the increasing of the prior to winter nodal roots was beneficial to improve the total tiller number,the dry weight of the aerial parts and leaf area per plant during middle and late growth stages,which increased the photosynthetic area of the plant and promoted the aerial parts growth and the dry weight accumulation, there were certain differences between different treatments. Among them,compared with processing A and processing B,the effect of processing C was relatively large. The results also showed that the increase of prior to winter nodal roots number was beneficial to improve the physiological potential of roots,at late dough stage in 2015-2016 and jointing stage in 2016-2017,the differences between different treatments reached a significant level,which means the number of prior to winter nodal roots has positive effects on increasing root biomass and maintaining high root activity during middle and late growing period. Number of spikes,number of spikelets,seed number and grain yield increased with the increasing of prior to winter nodal roots number. Compared with treatment A,the spike number,spikelets number and seed number in treatment C increased by 25.0%,13.4%,26.2%,respectively. And the yield increased by 52.4%. So,under the condition of same tiller number per plant before winter,the more nodal roots per plant of wheat is beneficial to increase grain yield .