Cann David J, Schillinger William F, Hunt James R, Porker Kenton D, Harris Felicity A J
Department of Animal, Plant and Soil Sciences, La Trobe University, Melbourne, VIC, Australia.
Department of Crop and Soil Sciences, Washington State University, Dryland Research Station, Lind, WA, United States.
Front Plant Sci. 2020 May 27;11:568. doi: 10.3389/fpls.2020.00568. eCollection 2020.
Wheat ( L.) is the most widely-grown crop in the Mediterranean semi-arid (150-400 mm) cropping zones of both southern Australia and the inland Pacific Northwest (PNW) of the United States of America (United States). Low precipitation, low winter temperatures and heat and drought conditions during late spring and summer limit wheat yields in both regions. Due to rising temperatures, reduced autumn rainfall and increased frost risk in southern Australia since 1990, cropping conditions in these two environments have grown increasingly similar. This presents the opportunity for southern Australian growers to learn from the experiences of their PNW counterparts. Wheat cultivars with an obligate vernalization requirement (winter wheat), are an integral part of semi-arid PNW cropping systems, but in Australia are most frequently grown in cool or cold temperate cropping zones that receive high rainfall (>500 mm p.a.). It has recently been shown that early-sown winter wheat cultivars can increase water-limited potential yield in semi-arid southern Australia, in the face of decreasing autumn rainfall. Despite this research, there has to date been little breeding effort invested in winter wheat for growers in semi-arid southern Australia, and agronomic research into the management of early-sown winter wheat has only occurred in recent years. This paper explores the current and emerging environmental constraints of cropping in semi-arid southern Australia and, using the genotype × management strategies developed over 120 years of winter wheat agronomy in the PNW, highlights the potential advantages early-sown winter wheat offers growers in low-rainfall environments. The increased biomass, stable flowering time and late-summer establishment opportunities offered by winter wheat genotypes ensure they achieve higher yields in the PNW compared to later-sown spring wheat. Traits that make winter wheat advantageous in the PNW may also contribute to increased yield when grown in semi-arid southern Australia. This paper investigates which specific traits present in winter wheat genotypes give them an advantage in semi-arid cropping environments, which management practices best exploit this advantage, and what potential improvements can be made to cultivars for semi-arid southern Australia based on the history of winter wheat crop growth in the semi-arid Pacific Northwest.
小麦（L.）是澳大利亚南部和美国太平洋西北部内陆半干旱（150 - 400毫米）种植区种植最广泛的作物。降水少、冬季气温低以及春末和夏季的高温干旱条件限制了这两个地区的小麦产量。自1990年以来，由于澳大利亚南部气温上升、秋季降雨量减少以及霜冻风险增加，这两种环境下的种植条件越来越相似。这为澳大利亚南部的种植者提供了向太平洋西北部同行学习经验的机会。需要专性春化的小麦品种（冬小麦）是太平洋西北部半干旱种植系统的一个组成部分，但在澳大利亚，它们最常种植在年降雨量高（>500毫米）的凉爽或寒冷温带种植区。最近有研究表明，面对秋季降雨量减少的情况，早播冬小麦品种可以提高澳大利亚南部半干旱地区受水分限制的潜在产量。尽管有这项研究，但迄今为止，针对澳大利亚南部半干旱地区种植者的冬小麦育种工作投入很少，而且对早播冬小麦管理的农艺研究只是近年来才开展。本文探讨了澳大利亚南部半干旱地区当前和新出现的种植环境限制因素，并利用在太平洋西北部120多年冬小麦农艺学中发展起来的基因型×管理策略，强调了早播冬小麦在低降雨环境中为种植者带来的潜在优势。与晚播春小麦相比，冬小麦基因型所具有的生物量增加、开花时间稳定以及夏末种植机会等特性确保了它们在太平洋西北部能获得更高的产量。冬小麦在太平洋西北部具有优势的特性，在澳大利亚南部半干旱地区种植时也可能有助于提高产量。本文研究了冬小麦基因型中哪些特定性状使其在半干旱种植环境中具有优势，哪种管理措施能最好地利用这一优势，以及根据半干旱太平洋西北部冬小麦作物生长历史，澳大利亚南部半干旱地区的品种可以进行哪些潜在改进。
