土壤干旱对小麦茎秆贮藏物质积累与再转运的影响

Effects of Soil Drought on Accumulation and Remobilization of Stem Reserves in Wheat

在防雨池栽条件下,以小麦旱地品种长武134(抗旱性强)和水地品种(抗旱性弱)为试材,研究干旱对不同抗旱性小麦茎秆及其组成节间花后干物质积累、转运及其对籽粒产量贡献率的影响。结果表明,干旱降低了主茎及其各组成节间干物质的积累量、主茎穗粒重积累量及其灌浆中后期的积累速率,长武134(除其它茎)降低幅度均小于陕253;干旱条件下茎秆贮藏物质的转运并未对籽粒产量产生补偿效应,干旱降低主茎穗粒重积累量与其它茎贮藏物质转运量和转运率较低有密切关系;抗旱性强的小麦品种其它茎的转运量、转运率降低幅度均大于抗旱性弱的小麦品种,从而导致其主茎贮藏物质转运对籽粒产量的贡献率显著降低。

Under rain-proof shelter culture condition, two types of winter wheat （Triticum aestivum. L）, dryland cultivar Changwu 134 （drought-resistant） and irrigated cultivar Shaan 253 （drought-sensitive）, were applied to study the effects of soil drought on post-anthesis dry matter accumulation, remobilization and contribution to grain yield of stems and their constituent internodes. The result indicated that the dry matter accumulation of main stem and constituent internodes, accumulation amount and accumulation rate of main stem spike during the middle and later grain-filling period decreased significantly as a result of soil drought, but the extent of reduction in Changwu134 （except other internodes） was much less than that of Shan253. The dry matter remobilization that accumulated at the main stem could not compensate for the loss of grain yield. However, a close relationship was found between accumulation amount of main stems pike and reserves remobilization amount as well as the remobilization rate of the other internodes under soil drought condition. The extent of reduction in dry matter remobilization amount and remobilization rate of other internodes of drought-resistant wheat were significantly higher than those of drought-sensitive wheat, which directly resulted in a significant decrease in the contribution rate to grain yield of main stem of drought-resistant wheat.