Ashe Paula, Shaterian Hamid, Akhov Leonid, Kulkarni Manoj, Selvaraj Gopalan
National Research Council of Canada, Saskatoon, SK, Canada.
Front Chem. 2017 Dec 14;5:121. doi: 10.3389/fchem.2017.00121. eCollection 2017.
In Canada, the world's top exporter of high-protein durum, varietal development over its nearly six-decade history has been driven by a quest for yield improvement without compromise on grain protein content and other quality aspects. Pelissier, a landrace selection from Algeria that was introduced into North America more than a century ago and the variety Strongfield that was released in 2004 are notable. Pelissier, known to elaborate more roots and considered as drought tolerant, has been cultivated commercially and thus deemed adapted. Strongfield has Pelissier in its pedigree, and it remains a high-acreage variety. Strongfield was found to elaborate only about half of the root biomass of Pelissier at maturity in greenhouse trials under well-watered conditions. Extended drought stress caused a significant reduction in the root biomass of both lines. However, Pelissier under drought maintained at least as much root biomass as that of Strongfield under well-watered conditions. In comparison to Pelissier, it had a superior photosynthesis rate (27.16 μmol CO m s), capacity for carboxylation (V: 132.83 μmol CO m s) and electron transport/ribulose-1,5-bisphosphate (RuBP) regeneration (J: 265.40 μmol CO m s); the corresponding values for Pelissier were 19.62 μmol CO m s, 91.87 μmol CO m s, and 163.83 μmol CO m s, respectively, under well-watered conditions. Under short-term/mild drought conditions, the carbon assimilation rate remained stable in Pelissier while it declined in Strongfield to the Pelissier level. However, Strongfield succumbed to extended drought sooner than Pelissier. Photosynthesis in Strongfield but not Pelissier was found to be sensitive to high temperature stress. These results provide encouraging prospects for further exploitation of beneficial physiological traits from Pelissier in constructing climate-resilient, agronomically favorable wheat ideotypes.
加拿大是世界上高蛋白硬质小麦的最大出口国，在其近60年的历史中，品种培育一直致力于在不降低谷物蛋白质含量和其他品质方面的前提下提高产量。佩利西埃是一个来自阿尔及利亚的地方品种，于一个多世纪前引入北美，2004年发布的品种斯特朗菲尔德也很值得注意。佩利西埃以根系发达且被认为耐旱而闻名，已进行商业化种植，因此被视为适应性良好。斯特朗菲尔德的谱系中有佩利西埃，它仍然是一个种植面积广泛的品种。在温室试验中，在水分充足的条件下，成熟时斯特朗菲尔德的根系生物量仅约为佩利西埃的一半。长期干旱胁迫导致两个品系的根系生物量显著减少。然而，干旱条件下的佩利西埃至少保持了与水分充足条件下斯特朗菲尔德相同的根系生物量。与佩利西埃相比，它具有更高的光合速率（27.16 μmol CO₂ m⁻² s⁻¹）、羧化能力（Vₛₘₐₓ：132.83 μmol CO₂ m⁻² s⁻¹）和电子传递/核酮糖-1,5-二磷酸（RuBP）再生能力（J：265.40 μmol CO₂ m⁻² s⁻¹）；在水分充足的条件下，佩利西埃的相应值分别为19.62 μmol CO₂ m⁻² s⁻¹、91.87 μmol CO₂ m⁻² s⁻¹和163.83 μmol CO₂ m⁻² s⁻¹。在短期/轻度干旱条件下，佩利西埃的碳同化率保持稳定，而斯特朗菲尔德的碳同化率下降到佩利西埃的水平。然而，斯特朗菲尔德比佩利西埃更早受到长期干旱的影响。研究发现，斯特朗菲尔德而非佩利西埃的光合作用对高温胁迫敏感。这些结果为进一步利用佩利西埃的有益生理特性构建适应气候变化、农艺性状优良的小麦理想型提供了令人鼓舞的前景。
