土壤水分调控对超级稻根系特征的影响

Response of Root Traits of Super-rice to Soil Moisture Regulation

【目的】探究土壤中不同含水率对超级稻节水率以及节水条件下根系生长特征的影响。【方法】采用盆栽试验,通过设置不同的土壤含水率,以占田间持水率比例进行划分:A处理(90%~100%)、B处理(80%~90%)、C处理(70%~80%)、D处理(60%~70%),并以充分灌溉为对照(CK),测算了超级稻全生育期灌溉耗水量,并测试了超级稻不同生长阶段根系相关特征指标。【结果】土壤水分调控处理比CK节水15%~30%。土壤水分调控处理能够增加超级稻根系平均直径24.67%、总根体积4.80%。在超级稻生长阶段的颖花结实期和成熟期,土壤水分调控处理组根系活力高于CK。B处理根系生长优于其他土壤水分调控处理,另外B处理超级稻平均根系干物质积累量为92.36 g。【结论】土壤水分调控处理能减少超级稻灌溉水量,促进根系发育,提高耐旱性;土壤水分为田间持水率的80%~90%时,超级稻根系生长最佳。

【Objective】The aim of this paper is to unravel how a change in soil moisture affects the water use efficiency and root traits of super-rice under water-saving irrigation methods.【Method】Pot experiments were conducted with four treatments by controlling the soil moisture at 90%-100% of the field capacity（A）, 80%-90%of the field capacity（B）, 70%-80% of the field capacity（C）, and 60%-70% of the field capacity（D）. The control（CK） was to keep the moisture at the field capacity. For each treatment, we calculated the water consumption by the crop in its whole growth season, and measured the root traits at different growth stages.【Result】Compared to CK, soil water regulation saved 15%-30% of water and increased the mean root diameter and total root volume by 4.80% and 24.67% respectively. During the spikelet filling and maturing stages, the root activity under soil moisture regulation was higher than that under CK, and the root growth under treatment B was faster than those under other treatments with the accumulated dry root matter reaching 92.36 g.【Conclusion】It can be concluded that soil water regulation can reduce the demand of the rice for water, promote root growth and increase drought tolerance. Controlling the soil moisture at 80%-90% of the field capacity appears to give the best results.