Enhanced root production as a feed-forward response to soil water deficit in field-grown tomatoes
Enhanced root production as a feed-forward response to soil water deficit in field-grown tomatoes
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DOI：
10.1071/pp96079
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发表时间：
1997-01-01
期刊：
影响因子：
--
通讯作者：
Renquist, AR
中科院分区：
文献类型：
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作者：
Reid, JB;Renquist, AR
关于根作为土壤水分亏缺(SWD)“传感器”的作用的大量研究一直是在少量土壤中生长的植物进行的。我们研究了番茄加工过程中对SWD的适应性反应(Lycopsica esculentum Mill.)生长在田野里。这份简历。罐头厂行种植在根际加速器旁边，每天滴灌，除非在两个亏缺处理的开花期间保持7或14天的水分。不包括降雨。在停止灌溉的7天内，根产量大幅增加，特别是在底土中。然而，直到第9天左右，未灌溉处理和对照的黎明前和中午的叶水势才有所不同。即使到了第14天，SWD也没有影响气孔导度、蒸散量或植株干质量。在每一次亏缺处理的重新灌溉后，根系死亡率迅速增加。未灌溉地块的新根产量似乎足以维持对地上部的充足水分供应。如果是这样的话，这可能是一种比降低叶片和茎的膨胀率更有效的避免压力的方法。我们的结果似乎是第一次实际证明了根系可能扮演着这样的前馈作用。
Much research on the role of roots as 'sensors' of soil water deficits (SWD) has been with plants growing in small volumes of soil. We examined adaptive responses to SWD in processing tomatoes (Lycopersicon esculentum Mill.) growing in the field. The cv. Cannery Row was grown next to a rhizotron and trickle irrigated daily, except when water was withheld for 7 or 14 days during flowering in two deficit treatments. Rainfall was excluded.Within 7 days of withholding irrigation, there was a substantial increase in root production, particularly in the subsoil. However, predawn and midday leaf water potentials did not differ between non-irrigated and control treatments until around day 9. Even by day 14 the SWD had not affected stomatal conductances, evapotranspiration, or plant dry mass. A rapid increase in root death rate followed the reirrigation of each deficit treatment. New root production in the non-irrigated plots appeared sufficient to maintain an adequate supply of water to the shoots. If so, this could be an even more effective means of stress avoidance than reducing leaf and stem expansion rates. Our results appear to be the first practical demonstration that root systems may play such a feed-forward role.