High-resolution mapping and functional analysis of se2.1:: A major stigma exsertion quantitative trait locus associated with the evolution from allogamy to autogamy in the genus lycopersicon
High-resolution mapping and functional analysis of se2.1:: A major stigma exsertion quantitative trait locus associated with the evolution from allogamy to autogamy in the genus lycopersicon
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DOI：
10.1534/genetics.103.022558
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发表时间：
2004-11-01
期刊：
影响因子：
3.3
通讯作者：
Tanksley, SD
中科院分区：
文献类型：
--
作者：
Chen, KY;Tanksley, SD
在许多植物物种中，柱头外露于雄蕊之上的程度是异花授粉（异花受精）的关键决定因素。番茄属的大多数种都是专性或兼性异交种，花的柱头高度外露。与此相反，栽培番茄（Lycopersicon esculentum）的花带有促进自花受精的齐平或插入的柱头。据观察，2号染色体上的一个主要QTL se2.1负责该性状的大部分表型变异，并且该位点的突变可能参与该属从异花受精到自花受精的进化。为了了解柱头外露的遗传和分子基础，我们对se2.1 QTL所在的染色体区域进行了高分辨率定位。结果表明，这是一个复合基因座，至少包含5个紧密连锁的基因，其中1个控制花柱长度，3个控制雄蕊长度，另一个控制花药开裂，花药开裂是番茄属种与其它茄科种的分类学特征。这组基因可能代表了控制交配行为的古老的共适应基因复合体的遗迹。
The degree to which stigmas are exserted above the stamen in flowers is a key determinant of cross-pollination (and hence allogamy) in many plant species. Most species in the genus Lycopersicon are obligate or facultative outcrossers and bear flowers with highly exserted stigmas. In contrast, the cultivated tomato (Lycopersicon esculentum) bears flowers with flush or inserted stigmas promoting self-fertilization. It has been observed that a major QTL, se2.1, on chromosome 2 is responsible for a large portion of phenotypic variation for this trait and that mutation(s) at this locus were likely involved in the evolution from allogamy to autogamy in this genus. To understand the genetic and molecular basis of stigma essertion, we have conducted a high-resolution mapping at the chromosome region harboring the se2.1 QTL. The results indicate that this is a compound locus, comprising at least five tightly linked genes, one controlling style length, three controlling stamen length, and the other affecting anther dehiscence, a taxonomic character used to distinguish Lycopersicon species front other solanaceous species. This cluster of genes may represent the vestiges of an ancient coadapted gene complex in controlling mating behavior.