Effects of soil water deficit at different growth stages on rice growth and yield under upland conditions .1. Growth during drought
Effects of soil water deficit at different growth stages on rice growth and yield under upland conditions .1. Growth during drought
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DOI：
10.1016/0378-4290(96)00038-x
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发表时间：
1996-09-01
影响因子：
5.8
通讯作者：
Fukai, S
中科院分区：
文献类型：
--
作者：
Boonjung, H;Fukai, S
旱稻在生长过程中的任何时候都可能遭受干旱，各种生长过程对水分胁迫的反应可能取决于与作物生长阶段有关的干旱时间。在两个试验中，三个或四个生育期的水稻植株经历了23-35天的干旱，以研究茎干物质(SDM)生产及其相关过程对水分胁迫的响应。幼苗在胁迫开始时33天大，由于水分需求低，在胁迫期间保持较高的叶水势。干旱处理幼苗的辐射利用效率(即单位截获辐射的SDM产量)与灌溉对照相似，但由于截获的辐射减少了68%，SDM的产量降低了71%。幼龄植株在胁迫后即刻的水分提取速度慢于老株，而胁迫期间的总出水量与老株差异不显著。幼龄植株产生的SDM比老植株少(90vs300g m(-2))，因此水分利用效率较低(单位用水量SDM产量1.4g kg(-1)vs4.2g kg(-1))。在生长初期，根长生长对土壤水分亏缺非常敏感。当树冠截获的太阳总辐射超过总太阳辐射的60%时，较老的植物产生胁迫时，SDM产量的减少主要是由于辐射利用效率降低(1.2比2.3gMJ(-1))。植物从深层土壤中吸收水分的速度更快，叶片水势随着蒸腾水分需求量的增加而迅速下降。因此，结果表明，水稻对干旱的反应取决于冠层发育的阶段。
Upland rice can be subject to drought at any time during growth, and responses of various growth processes to water stress may depend on the timing of drought in relation to crop growth stages. In two experiments, rice plants at three or four growth stages were subjected to drought periods of 23-35 days to examine the response of shoot dry matter (SDM) production and associated processes to water stress. Young plants, 33 days old at the commencement of stress, maintained high leaf water potential during the stress period because of the low demand for water. Radiation-use efficiency (i.e. SDM production per unit intercepted radiation) of the young plants in the drought treatment was similar to that in the irrigated control, but SDM production was reduced by 71% because of 68% reduction in radiation interception. The young plants extracted water more slowly than older plants immediately after stress was imposed, whereas the total water extraction during the stress period was not significantly different from that of the older plants. The young plants produced less SDM than the older plants (90 versus 300 g m(-2)), and hence had lower water-use efficiency (i.e. SDM production per unit water used 1.4 versus 4.2 g kg(-1)). During early growth stages, root length growth was very sensitive to soil water deficit. When stress developed in the older plants with the canopy intercepting greater than about 60% of full solar radiation, reduction in SDM production was mostly due to reduced radiation-use efficiency (1.2 versus 2.3 g MJ(-1)). The plants extracted water more rapidly and from deeper soils, and leaf water potential decreased rapidly with the large demand for transpiration water. The results therefore show that rice responds to drought in a manner depending on the stage of canopy development.