Abstract:
A novel male-sterility trait was identified in a radish (Raphanus sativus L.) population. Although the size of male-sterile anthers was comparable to that of normal flowers, no pollen grain was observed during anther dehiscence. However, dissection of male-sterile anthers revealed an abundance of normal pollen grains. Analysis of segregating populations showed that a single recessive locus, designated RsMs1, conferred male sterility. Based on two radish draft genome sequences, molecular markers were developed to delimit the genomic region harboring the RsMs1. The region was narrowed down to approximately 24 kb after analyzing recombinants selected from 7511 individuals of a segregating population. Sequencing of the delimited region yielded six putative genes including four genes expressed in the floral tissue, and one gene with significant differential expression between male-fertile and male-sterile individuals of a segregating population. This differentially expressed gene was orthologous to the Arabidopsis MYB26 gene, which played a critical role in anther dehiscence. Excluding a synonymous single nucleotide polymorphism in exon3, no polymorphism involving coding and putative promoter regions was detected between alleles. A 955-bp insertion was identified 7.5 kb upstream of the recessive allele. Highly conserved motifs among four Brassicaceae species were identified around this insertion site, suggesting the presence of putative enhancer sequences. A functional marker was developed for genotyping of the RsMs1 based on the 955-bp insertion. A total of 120 PI accessions were analyzed using this marker, and 11 accessions were shown to carry the recessive rsms1 allele.
UNASSIGNED: The online version contains supplementary material available at 10.1007/s11032-021-01254-9.
摘要:
在萝卜(RaphanussativusL.)种群中发现了一种新的雄性不育性状。尽管雄性不育花药的大小与正常花的大小相当,在花药开裂期间未观察到花粉粒。然而,雄性不育花药的解剖显示出大量的正常花粉粒。对分离种群的分析表明,单个隐性基因座,指定为RsMs1,赋予雄性不育。基于两个萝卜基因组序列,分子标记被开发来界定包含RsMs1的基因组区域。在分析选自分离群体的7511个个体的重组体后,将该区域缩小至约24kb。定界区域的测序产生了六个推定的基因,包括在花组织中表达的四个基因,和一个基因在分离群体的雄性可育和雄性不育个体之间具有显着的差异表达。该差异表达基因与拟南芥MYB26基因直系同源,这在花药开裂中起了关键作用。排除外显子3中的同义单核苷酸多态性,在等位基因之间未检测到涉及编码和推定启动子区域的多态性。在隐性等位基因的上游7.5kb处鉴定出955bp的插入。在该插入位点周围发现了四种十字花科的高度保守的基序,提示推定的增强子序列的存在。基于955-bp的插入,开发了用于RsMs1基因分型的功能标记。使用该标记对总共120份PI种质进行了分析,11个种质显示携带隐性rsms1等位基因。
■在线版本包含补充材料,可在10.1007/s11032-021-01254-9获得。