Improving drought tolerance in maize: a view from industry
Improving drought tolerance in maize: a view from industry
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DOI：
10.1016/j.fcr.2004.07.003
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发表时间：
2004-11-08
影响因子：
5.8
通讯作者：
Schussler, JR
中科院分区：
文献类型：
--
作者：
Campos, H;Cooper, A;Schussler, JR
玉米（Zea mays L.）随着全球气候变化，随着气温上升和主要传统产区降雨分布的变化，预计干旱造成的粮食损失将增加。在过去50年中，传统作物耐旱性改良的成功形成了一个基线，新的遗传方法必须与之进行比较。在多环境试验（MET）的基础上进行选择，通过增加产量潜力和籽粒集，快速的丝绸消耗，减少贫瘠，增加了粮食产量在干旱下，虽然在较低的速度比在最佳条件下。耐旱生理学的知识已被用来解剖成一系列的关键过程的特点。这已经通过鉴定与这些相同性状相关的QTL的遗传解剖得到了补充。两者都已被用来确定合适的器官和时间特异性启动子和结构基因。表型能力没有跟上基因型知识的指数增长，大规模管理压力环境（MSE）现在被认为是进一步发展的关键。这些环境为进行大规模平行转录谱研究以及验证候选区域和基因提供了理想的环境。关键过程的遗传和作物生理模型现在被用来确认目标环境的性状价值，并提出有效的育种策略。基因与表型关系的研究表明，迄今为止发现的大多数假定的耐旱QTL可能对应用育种的效用有限，因为它们依赖于遗传背景或对环境的敏感性，加上对这些背景依赖性的生物物理基础的普遍缺乏了解。此外，在常规育种程序的多环境测试中的后代选择期间遇到的天气条件的样本可以深刻地影响育种群体中的等位基因频率和优良商业产品的胁迫耐受性。我们的结论是，虽然每株植物的籽粒增益可以通过利用本地的遗传变异之间的精英育种系，改善功能性保绿或根的分布和功能可能需要额外的遗传变异，从外部的物种。基因组工具和模式植物的使用被认为是不可或缺的工具，在这种寻求新的途径，优化玉米产量的压力。(C)2004 Elsevier B.V.保留所有权利。
Significant yield losses in maize (Zea mays L.) from drought are expected to increase with global climate change as temperatures rise and rainfall distribution changes in key traditional production areas. The success of conventional crop improvement over the past 50 years for drought tolerance forms a baseline against which new genetic methods must be compared. Selection based on performance in multi-environment trials (MET) has increased grain yield under drought through increased yield potential and kernel set, rapid silk exertion, and reduced barrenness, though at a lower rate than under optimal conditions. Knowledge of the physiology of drought tolerance has been used to dissect the trait into a series of key processes. This has been complemented by genetic dissection through the identification of QTL associated with these same traits. Both have been used to identify suitable organ- and temporal-specific promoters and structural genes. Phenotyping capacity has not kept pace with the exponential increase in genotypic knowledge, and large-scale managed stress environments (MSE) are now considered essential to further progress. These environments provide ideal settings for conducting massively parallel transcript profiling studies, and for validating candidate regions and genes. Genetic and crop physiological models of key processes are now being used to confirm the value of traits for target environments, and to suggest efficient breeding strategies. Studies of gene to phenotype relationships suggest that most putative drought tolerance QTL identified thus far are likely to have limited utility for applied breeding because of their dependency on genetic background or their sensitivity to the environment, coupled with a general lack of understanding of the biophysical bases of these context dependencies. Furthermore, the sample of weather conditions encountered during progeny selection within the multi environment testing of conventional breeding programs can profoundly affect allele frequency in breeding populations and the stress tolerance of elite commercial products. We conclude that while gains in kernels per plant can be made by exploiting native genetic variation among elite breeding lines, improvements in functional stay-green or in root distribution and function may require additional genetic variation from outside the species. Genomic tools and the use of model plants are considered indispensable tools in this search for new ways of optimizing maize yield under stress. (C) 2004 Elsevier B.V. All rights reserved.