Unconscious selection drove seed enlargement in vegetable crops.
Unconscious selection drove seed enlargement in vegetable crops.
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DOI：
10.1002/evl3.6
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发表时间：
2017-06
影响因子：
5
通讯作者：
Osborne CP
中科院分区：
文献类型：
--
作者：
Kluyver TA;Jones G;Pujol B;Bennett C;Mockford EJ;Charles M;Rees M;Osborne CP
驯化谷物作物在人类栽培下从野生植物进化而来，失去了自然传播机制，变得依赖于人类，并表现出一系列其他特征的变化，包括种子大小的增加。在驯化过程中，种子增大的趋势被认为是早期农民有意选择大种子的结果。然而，就像其他一些驯化特征一样，大种子可能是通过自然选择从人类从野外采集植物的活动中进化而来的，或者是在人为的环境中种植的。或者，更大的种子可能是通过多效效应或遗传连锁而产生的，没有早期农民的预见，而是由其他器官或更大的植物的选择所驱动的。我们通过比较野生和驯化形式的蔬菜作物，将这些对种子扩大的无意识选择效应与有意选择效应区分开来。蔬菜是通过种植种子、插枝或块茎来繁殖的，但收获的是可食用的叶子、茎或根，因此种子的大小并不是产量的直接决定因素。我们发现七种蔬菜作物的地方品种的种子比它们最接近的野生亲缘品种的种子大20%到2.5倍。这些驯化效应大小完全落在谷物作物的14%至15.2倍的等效范围内，尽管驯化对谷物的总体影响明显大于蔬菜作物。通过无性繁殖的蔬菜作物的种子扩大，一定是由于植物从种子中招募并融入作物基因库时，对较大种子的自然选择，或者是通过遗传联系选择较大的植物或器官。如果类似的机制在所有物种中都起作用，那么驯化过程中的无意识选择对我们主要作物种子大小的影响可能比之前认识到的更大。
Domesticated grain crops evolved from wild plants under human cultivation, losing natural dispersal mechanisms to become dependent upon humans, and showing changes in a suite of other traits, including increasing seed size. There is tendency for seed enlargement during domestication to be viewed as the result of deliberate selection for large seeds by early farmers. However, like some other domestication traits, large seeds may have evolved through natural selection from the activities of people as they gathered plants from the wild, or brought them into cultivation in anthropogenic settings. Alternatively, larger seeds could have arisen via pleiotropic effects or genetic linkage, without foresight from early farmers, and driven by selection that acted on other organs or favored larger plants. We have separated these unconscious selection effects on seed enlargement from those of deliberate selection, by comparing the wild and domesticated forms of vegetable crops. Vegetables are propagated by planting seeds, cuttings, or tubers, but harvested for their edible leaves, stems, or roots, so that seed size is not a direct determinant of yield. We find that landrace varieties of seven vegetable crops have seeds that are 20% to 2.5‐times larger than those of their closest wild relatives. These domestication effect sizes fall completely within the equivalent range of 14% to 15.2‐times for grain crops, although domestication had a significantly larger overall effect in grain than vegetable crops. Seed enlargement in vegetable crops that are propagated vegetatively must arise from natural selection for larger seeds on the occasions when plants recruit from seed and are integrated into the crop gene pool, or via a genetic link to selection for larger plants or organs. If similar mechanisms operate across all species, then unconscious selection during domestication could have exerted stronger effects on the seed size of our staple crops than previously realized.
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影响因子：
4.2
作者：
Fuller DQ
通讯作者：
Fuller DQ
影响因子：
2.6
作者：
BRUNKEN, J;DEWET, JMJ;HARLAN, JR
通讯作者：
HARLAN, JR
影响因子：
2
作者：
HILLMAN, GC;DAVIES, MS
通讯作者：
DAVIES, MS
影响因子：
2.9
作者：
Bhatt, A. K.;Bhalla, T. C.;Upadhya, M. D.
通讯作者：
Upadhya, M. D.
影响因子：
5.4
作者：
ALDRICH, PR;DOEBLEY, J
通讯作者：
DOEBLEY, J