不同生育期土壤水分亏缺对双季超级稻产量及其构成的影响

摘要

We aimed to investigate the effect of soil water deficit at different growing stages on growth and yield for mation of double-cropping super indica rice by pot experiments.The result indicated that soil water deficit had significant effect on plant height of double-cropping super indica rice during the early growing period in particular the jointing-booting stage,with the largest effect on plant height.Early rice decreased by 4.53 ％ ～ 11.1％ in plant height,and the late rice 3.09％ ～ 10.04％.Plant height was declined with the soil water deficit degree,but that in late growing period had smaller effect.The leaf,ear,root weight and total dry matter accumulation of double-cropping super rice with soil water deficit at different growing period were lower than shallow water irrigation (CK),and the accumulation reduced with the soil water deficit,and root/shoot ratio varied similarly.On the other hand,soil water deficit promoted the growth of the stem and sheath to some extent and showed a compensatory etfect.The yield of the double-cropping super indica rice under the soil water deficit was lower than the CK,and it decreased with the soil water deficit.Grain yield was significantly affected by the soil water deficit,with an order of the jointing-booting stage ＞ effective tillering stage ＞ heading-florescence stage ＞ invalid tillering stage ＞ milky stage for the early rice,while that for the late rice was jointing-booting stage ＞ heading-florescence stage ＞ effective tillering stage ＞ milky stage ＞ invalid tillering stage.In addition,the effect of soil water deficit on the effective panicle number during effective tiller stage and spike number during jointing-booting stage was the greatest,mainly causing yield reduction.%通过盆栽试验研究了不同生育期土壤水分亏缺对双季稻生长发育及产量形成的影响.结果表明:双季超级稻生育前期土壤水分亏缺对株高存在较大影响,其中均以拔节孕穗期受土壤水分亏缺影响最重,早稻株高下降4.53％ ～ 11.1％,晚稻下降3.09％ ～ 10.04％,且水分亏缺程度越重,株高下降越多,而生育后期影响较小.双季超级稻不同生育期土壤水分亏缺处理的叶、穗、根及总的干物质积累量均低于浅水灌溉对照,且均表现为随土壤水分亏缺程度的加剧而积累量越少,根冠比也表现为相同规律.但土壤水分亏缺却一定程度上促进了茎鞘的发育,产生补偿作用,但作用较小.双季超级稻所有土壤水分亏缺处理的产量均低于对照浅水充分灌溉,早稻产量为对照的58.73％～99.42％,晚稻产量为对照的55.15％ ～ 96.74％.各生育期的双季稻产量均表现为随土壤水分亏缺的加剧而下降严重.双季超级稻产量受水分亏缺影响敏感程度排序:早稻为拔节孕穗期＞有效分蘖期＞抽穗开花期＞无效分蘖期＞乳熟期,晚稻为拔节孕穗期＞抽穗开花期＞有效分蘖期＞乳熟期＞无效分蘖期.水分亏缺对双季超级稻有效分蘖期的穗数和拔节孕穗期的穗粒数影响程度最大,可引起大幅减产.无效分蘖期和乳熟期受水分亏缺影响减产程度较小.