Herzog Max, Striker Gustavo G, Colmer Timothy D, Pedersen Ole
Freshwater Biological Laboratory, Department of Biology, University of Copenhagen, Universitetsparken 4, 3rd floor, 2100, Copenhagen, Denmark.
School of Plant Biology, Faculty of Science, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, 6009, Western Australia, Australia.
Plant Cell Environ. 2016 May;39(5):1068-86. doi: 10.1111/pce.12676. Epub 2016 Feb 7.
We review the detrimental effects of waterlogging on physiology, growth and yield of wheat. We highlight traits contributing to waterlogging tolerance and genetic diversity in wheat. Death of seminal roots and restriction of adventitious root length due to O2 deficiency result in low root:shoot ratio. Genotypes differ in seminal root anoxia tolerance, but mechanisms remain to be established; ethanol production rates do not explain anoxia tolerance. Root tip survival is short-term, and thereafter, seminal root re-growth upon re-aeration is limited. Genotypes differ in adventitious root numbers and in aerenchyma formation within these roots, resulting in varying waterlogging tolerances. Root extension is restricted by capacity for internal O2 movement to the apex. Sub-optimal O2 restricts root N uptake and translocation to the shoots, with N deficiency causing reduced shoot growth and grain yield. Although photosynthesis declines, sugars typically accumulate in shoots of waterlogged plants. Mn or Fe toxicity might occur in shoots of wheat on strongly acidic soils, but probably not more widely. Future breeding for waterlogging tolerance should focus on root internal aeration and better N-use efficiency; exploiting the genetic diversity in wheat for these and other traits should enable improvement of waterlogging tolerance.
我们综述了渍水对小麦生理、生长和产量的不利影响。我们强调了有助于小麦耐渍性和遗传多样性的性状。由于缺氧，种子根死亡和不定根长度受限导致根冠比降低。不同基因型在种子根耐缺氧性方面存在差异，但相关机制仍有待确定；乙醇产生速率并不能解释耐缺氧性。根尖存活时间较短，此后，复氧后种子根的再生长受到限制。不同基因型在不定根数量以及这些根内通气组织的形成方面存在差异，从而导致不同的耐渍性。根系延伸受到内部氧气向根尖移动能力的限制。次优氧气水平会限制根系对氮的吸收和向地上部的转运，氮素缺乏会导致地上部生长和籽粒产量降低。尽管光合作用下降，但渍水植物的地上部通常会积累糖分。在强酸性土壤上种植的小麦地上部可能会出现锰或铁中毒，但可能不会广泛发生。未来耐渍性育种应侧重于根系内部通气和更好的氮利用效率；利用小麦在这些及其他性状上的遗传多样性应能提高耐渍性。
