Estación Experimental INTA Junín, I. Bousquet s/nº, Junin, 5572, Mendoza, Argentina.
J Exp Bot. 2011 Jun;62(10):3535-43. doi: 10.1093/jxb/err044. Epub 2011 Mar 7.
The aims of this work were to quantify (i) the effect of the source:sink ratio on stem water potential (SWP) and (ii) the phenotypic plasticity of SWP and its relationship to oil yield components in olive. Trees with a 3-fold variation in the source:sink ratio (crown volume/fruit number per tree) were monitored in 2007-2008 and 2008-2009 in a fully irrigated orchard in Mendoza, Argentina. The combination of rainfall, irrigation, and evaporative demand led to a steady SWP largely above -1.65 MPa in 2007-2008 and a marked seasonal decline from -1.13 MPa to -2.04 MPa in trees with a medium and low source:sink ratio in 2008-2009. Plasticity was quantified as the slope of the norm of reaction for each trait. Across seasons, trees with a high source:sink ratio had a higher SWP than their counterparts with a medium and low source:sink ratio. Plasticity of SWP was highest in olives with a low source:sink ratio (slope=1.28) and lowest for trees with a high source:sink ratio (slope=0.76). The average SWP for each source:sink ratio and season was unrelated to both the source:sink ratio and yield components. On the other hand, the plasticity of SWP was positively associated with fruit number and negatively associated with the source:sink ratio, fruit weight, and fruit oil weight. The plasticity of the SWP was unrelated to SWP per se. It is concluded that understanding the effect of the source:sink ratio on plant water relations would benefit from a dual perspective considering the trait per se and its plasticity. A dual approach would also allow for more robust plant-based indicators for irrigation.
本研究的目的是量化（i）源库比（树冠体积/每棵树的果实数）对茎水势（SWP）的影响，以及（ii）SWP 的表型可塑性及其与橄榄油产量成分的关系。在阿根廷门多萨的一个全面灌溉果园中，2007-2008 年和 2008-2009 年对源库比（树冠体积/每棵树的果实数）变化 3 倍的树木进行了监测。降雨量、灌溉和蒸发需求的组合导致 2007-2008 年 SWP 基本稳定在-1.65 MPa 以上，而在 2008-2009 年中、低源库比的树木中，SWP 呈明显季节性下降，从-1.13 MPa 降至-2.04 MPa。可塑性被量化为每个性状的反应规范斜率。在整个季节中，高源库比的树木的 SWP 高于中、低源库比的树木。低源库比橄榄的 SWP 可塑性最高（斜率=1.28），而高源库比树木的 SWP 可塑性最低（斜率=0.76）。每个源库比和季节的平均 SWP 与源库比和产量成分均无关。另一方面，SWP 的可塑性与果实数呈正相关，与源库比、果实重量和果实油重量呈负相关。SWP 的可塑性与 SWP 本身无关。综上所述，要了解源库比对植物水分关系的影响，需要从考虑性状本身及其可塑性的双重角度来考虑。双重方法还可以为更稳健的基于植物的灌溉指标提供依据。
