Identification of Drought, Heat, and Combined Drought and Heat Tolerant Donors in Maize
Identification of Drought, Heat, and Combined Drought and Heat Tolerant Donors in Maize
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DOI：
10.2135/cropsci2012.09.0545
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发表时间：
2013-07-01
期刊：
影响因子：
2.3
通讯作者：
Atlin, Gary N.
中科院分区：
文献类型：
--
作者：
Cairns, Jill E.;Crossa, Jose;Atlin, Gary N.
矮玉米（Zea mays L.）玉米产量和气候变化对玉米生产的影响突出表明，需要提高东部和南部非洲的产量。气候预测表明，干旱易发地区的气温会更高。对模式物种的研究表明，对干旱和高温胁迫的耐受性在遗传上不同于对单独胁迫的耐受性，但这在玉米中尚未得到证实。在这项研究中，我们评估了300个玉米自交系与CML 539测交。在最佳条件下，生殖期干旱胁迫，高温胁迫，干旱和高温复合胁迫进行了试验。鉴定了对干旱和干旱和热胁迫组合具有高水平耐受性的品系。观察到显著的基因型X试验相互作用和非常大的图残差;因此，个体管理应力试验的重复性较低。玉米对干旱和热胁迫的耐受性在遗传上与对单个胁迫的耐受性不同，并且单独对任一胁迫的耐受性不赋予对干旱和热胁迫的耐受性。这一发现对玉米抗旱育种具有重要意义。许多当前干旱供体和广泛种植的非洲杂交种中使用的关键自交系在高温下容易受到干旱胁迫。需要将几种耐受干旱以及干旱和热胁迫组合的供体，特别是La波斯塔Sequia C7-F64-2-6-2-2和DTPYC 9-F46-1-2-1-2纳入玉米育种管道。
Low maize (Zea mays L.) yields and the impacts of climate change on maize production highlight the need to improve yields in eastern and southern Africa. Climate projections suggest higher temperatures within drought-prone areas. Research in model species suggests that tolerance to combined drought and heat stress is genetically distinct from tolerance to either stress alone, but this has not been confirmed in maize. In this study we evaluated 300 maize inbred lines testcrossed to CML539. Experiments were conducted under optimal conditions, reproductive stage drought stress, heat stress, and combined drought and heat stress. Lines with high levels of tolerance to drought and combined drought and heat stress were identified. Significant genotype x trial interaction and very large plot residuals were observed; consequently, the repeatability of individual managed stress trials was low. Tolerance to combined drought and heat stress in maize was genetically distinct from tolerance to individual stresses, and tolerance to either stress alone did not confer tolerance to combined drought and heat stress. This finding has major implications for maize drought breeding. Many current drought donors and key inbreds used in widely grown African hybrids were susceptible to drought stress at elevated temperatures. Several donors tolerant to drought and combined drought and heat stress, notably La Posta Sequia C7-F64-2-6-2-2 and DTPYC9-F46-1-2-1-2, need to be incorporated into maize breeding pipelines.