Molecular genetic dissection of anovel unilateral incompatibility within species, which observed in self-incompatible Brassica species

自交不亲和（SI）系统通过排斥具有相同Shaplotype植株的花粉来阻止自交受精，促进异交。油菜SI系统在孢子生理上由单个位点（称为S位点）上的多个等位基因控制。在芸苔属植物花粉-柱头互作中，种间识别系统应该存在，但种间识别分子尚不清楚。在对芸苔属（Brassica rapa L.）单侧不亲和性（UI）的遗传分析过程中，我们观察到一种新的单侧不亲和性（UI），特别是当一个品种（Osome）作为雌性伴侣，而土耳其系作为花粉伴侣时。从遗传分析来看，该US位点与S位点是独立的。本研究目的是对rapa中该UI基因进行分子克隆。从更深层的遗传分析来看，花粉UI （PUI）表型由单隐性基因控制，柱头UI （SUI）表型由单显性基因控制。对于PUI基因的分离，采用F2分离群体进行AFLP分析。分离出6个连锁分子标记，分布在遗传图谱的18cM范围内。通过遗传图谱与UI表型的比较，进行QTL分析。在分析中，PUI位于E-AAC/M-CCT和E-ACG/M-GAC标记之间（5cM）。在不久的将来，我们将利用这些标记分离PUI基因。

Self-incompatibility (SI) systems prevent self-fertilization and promote out-crossing by rejecting pollen from plants with the same Shaplotype. The Brassica SI system is controlled sporophytically by multiple alleles at the single locus, termed S locus. On the pollen-stigma interaction of Brassica species, although the recognition system between species should be existed, the recognition molecules between species are unknown. In the course of genetic analysis of SI in Brassica species, we observed a novel unilateral incompatibility (UI) in Brassica rapa L. This UI was specifically observed when one cultivar (Osome) was used a female partner, and Turkish lines were used as a pollen partner. From genetic analysis, this US locus was independent to S locus. This research purpose is molecular cloning of this UI gene in B. rapa.From more deep genetic analysis, pollen UI (PUI) phenotype was controlled by a single recessive gene, and stigma UI (SUI) phenotype was controlled by a single dominant gene. For isolation of PUI gene, AFLP analysis was performed with F2 segregation population. As a result, six linking molecular markers were isolated, and were scattered within 18cM on the genetic map. From the comparison of genetic map and UI phenotype, we performed QTL analysis. In the analysis, PUI was located between E-AAC/M-CCT and E-ACG/M-GAC markers (5cM). By using these markers, we will isolate the PUI gene, near future.