Elazab Abdelhalim, Molero Gemma, Serret Maria Dolores, Araus Jos Luis
Unitat de Fisiologia Vegetal, Facultat de Biologia, Universitat de Barcelona, Av. Diagonal, 647, 08028 Barcelona, Spain.
Funct Plant Biol. 2012 Jun;39(5):379-393. doi: 10.1071/FP11237.
Plant growth, root characteristics and the stable carbon (δ13C) and oxygen (δ18O) composition were studied in durum wheat. Four recombinant inbred lines with good agronomic adaptation were grown under well watered (WW) and water stress (WS) conditions until mid-grain filling in lysimeters. Gas exchange was measured in the flag leaf just before harvest and then the aerial dry matter (Aerial DM), root weight density (RWD) and root length density (RLD) and the specific root length (SRL) were evaluated and the δ13C and δ18O of the roots, the flag leaf blade and the spike were analysed. Water stress decreased stomatal conductance, plant accumulated transpiration and Aerial DM, whereas δ13C and δ18O increased. Genotypic differences were found for all gas-exchange and root traits and isotope signatures. Aerial DM was positively correlated with RLD, regardless of the water regime, whereas it was negatively correlated with δ13C and δ18O, but only under WW conditions. Moreover, RWD and RLD were negatively related to both δ13C and δ18O under the WW regime, but no clear pattern existed under WS. Our study supports the use of δ13C and δ18O as proxies for selecting root traits associated with higher growth in the absence of water stress.
在硬粒小麦中研究了植株生长、根系特征以及稳定碳（δ13C）和氧（δ18O）组成。在称重渗水器中，将四个农艺适应性良好的重组自交系在充分供水（WW）和水分胁迫（WS）条件下种植至籽粒灌浆中期。在收获前测定旗叶的气体交换，然后评估地上部干物质（地上部DM）、根重密度（RWD）、根长密度（RLD）和比根长（SRL），并分析根、旗叶叶片和穗的δ13C和δ18O。水分胁迫降低了气孔导度、植株累积蒸腾量和地上部DM，而δ13C和δ18O增加。在所有气体交换、根系性状和同位素特征方面均发现了基因型差异。无论水分状况如何，地上部DM与RLD呈正相关，而仅在WW条件下，地上部DM与δ13C和δ18O呈负相关。此外，在WW条件下，RWD和RLD与δ13C和δ18O均呈负相关，但在WS条件下没有明显的规律。我们的研究支持在没有水分胁迫的情况下，使用δ13C和δ18O作为选择与较高生长相关根系性状的指标。
