Chickpea evolution has selected for contrasting phenological mechanisms among different habitats
Chickpea evolution has selected for contrasting phenological mechanisms among different habitats
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DOI：
10.1007/s10681-011-0391-4
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发表时间：
2011-07-01
期刊：
影响因子：
1.9
通讯作者：
Malhotra, R.
中科院分区：
文献类型：
--
作者：
Berger, J. D.;Milroy, S. P.;Malhotra, R.
可以说，一年生作物最重要的适应性标准是适当的物候，最大限度地减少气候压力的影响，并在目标环境中最大限度地提高生产力。到目前为止，这已经通过在目标位置的不同基因型中进行选择来经验性地实现。这种方法可能会变得不足以应付即将到来的气候变化，因为选择是强加于结果（开花时间），而不是基本的机制（即对日照长度，环境或春化温度的反应）。与谷类植物相反，豆类植物的物候机制和环境选择压力之间的相互作用在很大程度上是未知的。本文解决了这一缺点，通过光热建模鹰嘴豆种质从世界上的主要生产地区，使用荟萃分析多环境试验位于49 A度A N到35 A度A S。种质来源对温度和日长反应性有显著影响，前者与采集地或发育地的营养生长期温度密切相关（r = 0.8）。因此，温度响应从冬季到春季播种的地中海和澳大利亚材料增加，然后到印度北部，中部和南部。种质来源也影响光温反应关系。在东地中海材料的一个强大的负相关性（r = -0.77），使温度不敏感的基因型，以补偿通过一个强大的光周期响应。显然，鹰嘴豆的进化选择了不同的物候机制在整个栖息地范围。考虑到在预期的全球变暖下，温度敏感型品种将比那些主要对光周期反应的品种相对更早开花，重要的是利用这种多样性来开发更适应未来种植环境的基因型。
Arguably the most important adaptive criterion in annual crops is appropriate phenology that minimizes exposure to climatic stresses and maximizes productivity in target environments. To date this has been achieved empirically by selecting among diverse genotypes in target locations. This approach is likely to become inadequate with pending climate change because selection is imposed on the outcome (flowering time) rather than the underlying mechanism (i.e. responses to daylength, ambient or vernalizing temperatures). In contrast to the cereals, in legumes the interaction between phenological mechanisms and environmental selection pressure is largely unknown. This paper addresses this shortcoming through photothermal modelling of chickpea germplasm from the world's key production areas using a meta-analysis of multi-environment trials located from 49A degrees A N to 35A degrees A S. Germplasm origin had significant effects on temperature and daylength responsiveness, the former strongly correlated to vegetative phase temperatures at the collection or development site (r = 0.8). Accordingly, temperature responses increase from winter- to spring-sown Mediterranean and Australian material, and then to north, central & southern India. Germplasm origin also affects the relationship between photoperiod and temperature response. In Eastern Mediterranean material a strong negative relationship (r = -0.77) enables temperature insensitive genotypes to compensate through a strong photoperiod response. Clearly, chickpea evolution has selected for different phenological mechanisms across the habitat range. Given that under the anticipated global warming temperature sensitive cultivars will flower relatively earlier than those responding largely to photoperiod, it is important to exploit this diversity in developing better-adapted genotypes for future cropping environments.